The anchor-based minimal important change, based on receiver operating characteristic analysis or predictive modeling, may need to be adjusted for the proportion of improved patients

Estimation of minimal clinically important difference for 6-minute walking distance in patients with acute stroke using anchor-based methods and credibility instruments

BACKGROUND AND PURPOSE

Stroke impairs a patient's ability to walk. In patients with acute stroke, a 6-min walking distance (6MWD) is recommended to assess walking function. Minimal clinically important difference (MCID) is used to determine the effectiveness of rehabilitation; however, the MCID for 6MWD has not been adequately validated. This study aimed to estimate the MCID of 6MWD, a measure of walking endurance, in patients with acute stroke using anchor-based methods.

METHODS

Based on the change in 6MWD from baseline to the follow-up measurement 2 weeks later, the MCID was estimated using anchor-based methods (receiver operator operating characteristic curves, predictive and adjustment models) with a patient- and therapist-rated global rating of change scale (p-GRC, t-GRC) as external anchors. The accuracy of "meaningful change" was estimated from the area under the curve. Using MCID's credibility instruments, the credibility of each anchor was evaluated. Using the credibility instrument, high credibility was defined as satisfying 3/5 of the Core criteria and 6/9 of all criteria.

RESULTS

The analysis included 58 patients. The MCID for each anchor was 78.7-100.0 m for p-GRC, and 95.2-99.5 m for t-GRC. The p-GRC demonstrated excellent accuracy (area under the curve >0.8). With p-GRC as anchors, over 50% of patients showed improvement. The p-GRC satisfied the core criterion of 3/5 and all criteria of 6/9 on the reliability instrument. The t-GRC demonstrated low reliability and satisfied the core criterion of 2/5 and all criteria of 3/9.

DISCUSSION

Since the percentage of improved groups exceeded 50%, the adjusted model was useful in the anchor-based method. Therapists may not accurately capture patient fatigue and subjective symptoms, potentially affecting the correlation between the 6MWD change score and the t-GRC and, consequently, the reliability instrument. The p-GRC showed high accuracy and reliability; therefore, the MCID was estimated to be 78.7 m.

The minimal important change is not a universal fixed value across diagnoses when using the FAOS and FAAM in patients undergoing elective foot and ankle surgery

PURPOSE

This study aimed to calculate region and diagnosis-specific minimal important changes (MICs) of the Foot and Ankle Outcome Score (FAOS) and the Foot and Ankle Ability Measure (FAAM) in patients requiring foot and ankle surgery and to assess their variability across different foot and ankle diagnoses.

METHODS

The study used routinely collected data from patients undergoing elective foot and ankle surgery. Patients had been invited to complete the FAOS and FAAM preoperatively and at 3-6 months after surgery, along with two anchor questions encompassing change in pain and daily function. Patients were categorised according to region of pathology and subsequent diagnoses. MICs were calculated using predictive modelling (MICPRED) and receiver operating characteristic curve (MICROC) method and evaluated according to strict credibility criteria.

RESULTS

Substantial variability of the MICs between forefoot and ankle/hindfoot region was observed, as well as among specific foot and ankle diagnoses, with MICPRED and MICROC values ranging from 7.8 to 25.5 points and 9.4 to 27.8, respectively. Despite differences between MICROC and MICPRED estimates, both calculation methods exhibited largely consistent patterns of variation across subgroups, with forefoot conditions systematically showing smaller MICs than ankle/hindfoot conditions. Most MICs demonstrated high credibility; however, the majority of the MICs for the FAOS symptoms subscale and forefoot conditions exhibited insufficient or low credibility.

CONCLUSION

The MICs of the FAOS and FAAM vary across foot and ankle diagnoses in patients undergoing elective foot and ankle surgery and should not be used as a universal fixed value, but recognised as contextual parameters. This can help clinicians and researchers in more accurate interpretation of the FAOS and FAAM change scores.

LEVEL OF EVIDENCE

Level IV.

Effect of Context Specificity on Response to the Shortened WOMAC Function Scale in Patients Undergoing Total Knee Arthroplasty

OBJECTIVE

To determine, in patients undergoing total knee arthroplasty (TKA), whether increasing context specificity of selected items of the shortened version of the Western Ontario and McMaster Universities Osteoarthritis Index function (WOMAC-F) scale (ShortMAC-F) (1) enhanced the convergent validity of the ShortMAC-F with performance-based mobility measures (ii) affected mean scale score, structural validity, reliability, and interpretability.

DESIGN

Secondary analysis of randomized clinical trial data.

SETTING

A tertiary teaching hospital.

PARTICIPANTS

Patients undergoing TKA (N=114).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

The ShortMAC-F was modified by specifying the "ascending stairs" and "rising from sitting" items to enquire about difficulty in performing the tasks without reliance on compensatory strategies, whereas the modified "level walking" item enquired about difficulty in walking 400 m. Before and 12 weeks after TKA, patients completed the WOMAC-F questionnaire, modified ShortMAC-F questionnaire, knee pain scale questionnaire, sit-to-stand test, fast gait speed test, and stair climb test. Interpretability was evaluated by calculating anchor-based substantial clinical benefit estimates.

RESULTS

The modified ShortMAC-F correlated significantly more strongly than ShortMAC-F or WOMAC-F with pooled performance measures (differences in correlation values, 0.12-0.14). Increasing item context specificity of the ShortMAC-F did not influence its psychometric properties of unidimensionality (comparative fit and Tucker-Lewis indices, >0.95; root mean square error of approximation, 0.05-0.08), reliability (Cronbach's α, 0.75-0.83), correlation with pain intensity (correlation values, 0.48-0.52), and substantial clinical benefit estimates (16 percentage points); however, it resulted in lower mean score (4.5-4.8 points lower).

CONCLUSIONS

The modified ShortMAC-F showed sufficient measurement properties for clinical application, and it seemed more adept than WOMAC-F at correlating with performance-based measures in TKA.

Classification of upper-limb dysfunction severity and prediction of independence in activities of daily living after cervical spinal-cord injury

STUDY DESIGN

Prospective observational study.

OBJECTIVES

Classification of spinal-cord injury and prediction of independence in activities of daily living (ADL) based on performance evaluations such as upper-limb function have not been reported. Therefore, this study aimed to establish a severity classification and calculate cutoff values for independence in ADL using the Capabilities of Upper Extremity Test (CUE-T) for individuals with cervical spinal-cord injury (CSCI).

SETTING

A spinal-cord injury rehabilitation center in Japan.

METHODS

This study included individuals with subacute CSCI. Collected data included the CUE-T and Spinal Cord Independence Measure III (SCIM III) scores. The severity classification was used for the hierarchical cluster analysis using the CUE-T. The cutoff values of CUE-T scores for independence in ADL were calculated using an adjustment model with logistic regression analysis. The dependent variable was binary (independent/non-independent) for each SCIM III Self-care item, and the independent variable was CUE-T.

RESULTS

A total of 71 participants were included in the analysis. The severity of upper-limb dysfunction was classified into four categories using CUE-T. Significant differences in upper-limb function and ADL were observed between clusters. The cutoff values for CUE-T score for independence in ADL ranged from 37 to 91 points. All cutoff values showed good results in the internal validation, sensitivity analysis.

CONCLUSIONS

This study determined the severity of upper limb function in CSCI and the cutoff values of CUE-T scores for independence in ADL. These results may help set criteria and goals for interventions in the clinical and research fields.

SPONSORSHIP

None.

Minimal clinically important difference in 6-minute walk distance estimated by multiple methods in inpatients with subacute cardiovascular disease

BACKGROUND

Identifying the minimal clinically important difference (MCID) contributes to the ability to determine the efficacy of physiotherapy interventions and make good clinical decisions.

PURPOSE

The purpose of this study was to estimate the MCID for 6-minute walking distance (6MWD) among inpatients with subacute cardiac disease using multiple anchor-based methods.

METHODS

This study was a secondary data analysis using only data from a multicenter longitudinal observational study in which 6MWD was measured at two time points. Based on the changes in 6MWD between baseline measurement and follow-up approximately 1 week after baseline measurement, the global rating of change scales (GRCs) of patients and physiotherapists, anchor method receiver operator operating characteristic curves, predictive models, and adjusted models were used to calculate the MCID.

RESULTS

Participants comprised 35 patients. Mean (standard deviation) 6MWD was 228.9 m (121.1 m) at baseline and 270.1 m (125.0 m) at follow-up. MCID for each GRC was 27.5-35.6 m for patients and 32.5-38.6 m for physiotherapists.

CONCLUSION

The MCID in 6MWD in patients with subacute cardiovascular disease is 27.5-38.6 m. This value may be useful in determining the effectiveness of physiotherapy interventions and for decision-making.

Effect of present state bias on minimal important change estimates: a simulation study

PURPOSE

The minimal important change (MIC) in a patient-reported outcome measure is often estimated using patient-reported transition ratings as anchor. However, transition ratings are often more heavily weighted by the follow-up state than by the baseline state, a phenomenon known as "present state bias" (PSB). It is unknown if and how PSB affects the estimation of MICs using various methods.

METHODS

We simulated 3240 samples in which the true MIC was simulated as the mean of individual MICs, and PSB was created by basing transition ratings on a "weighted change", differentially weighting baseline and follow-up states. In each sample we estimated MICs based on the following methods: mean change (MC), receiver operating characteristic (ROC) analysis, predictive modeling (PM), adjusted predictive modeling (APM), longitudinal item response theory (LIRT), and longitudinal confirmatory factor analysis (LCFA). The latter two MICs were estimated with and without constraints on the transition item slope parameters (LIRT) or factor loadings (LCFA).

RESULTS

PSB did not affect MIC estimates based on MC, ROC, and PM but these methods were biased by other factors. PSB caused imprecision in the MIC estimates based on APM, LIRT and LCFA with constraints, if the degree of PSB was substantial. However, the unconstrained LIRT- and LCFA-based MICs recovered the true MIC without bias and with high precision, independent of the degree of PSB.

CONCLUSION

We recommend the unconstrained LIRT- and LCFA-based MIC methods to estimate anchor-based MICs, irrespective of the degree of PSB. The APM-method is a feasible alternative if PSB is limited.

Patient-Rated Wrist Evaluation Threshold for Successful Open Surgery of the Triangular Fibrocartilage Complex

Purpose  To determine thresholds in patient-reported outcome measures at baseline in patients electing to undergo triangular fibrocartilage complex (TFCC) surgery to select patients with clinically improved outcomes. Methods  The study cohort comprised consecutive patients who underwent open TFCC repair between December 2011 and December 2018 in various clinics in the Netherlands. All patients were asked to complete the patient-rated wrist evaluation (PRWE) questionnaire at baseline as well as at 12 months postoperatively. The minimal clinically important difference (MCID) for the PRWE was calculated to be 24 using an anchor-based method. We compared patient, disease, and surgical characteristics between patients who did and did not reach the MCID. The t -tests and chi-square tests were undertaken to test differences between outcomes and satisfaction in patients who did or did not reach the MCID. Results  Patients (34%) who did not reach MCID had a longer history of complaints. The chances of reaching the MCID for patients with a low PRWE score at baseline were slim. Of patients with a PRWE score <34 at baseline, only 14% reached the MCID, whereas in patients with a PRWE score of ≥34, 69% reached the MCID. Conclusion  A PRWE total score at baseline <34 is a strong signal to reconsider open surgery of the TFCC because the chance of reaching a clinically meaningful outcome is slim. Level of Evidence  II. Type of Study  Therapeutic.

Minimal important change in the Berg Balance Scale in older women with vertebral compression fractures: A retrospective multicenter study

BACKGROUND

Vertebral compression fractures, which are commonly associated with older age and osteoporotic fractures, have an increased risk of re-fracture. Therefore, improving balance is important to prevent falls. The minimal important change (MIC) has been recommended for interpreting clinically meaningful changes in rating scales. The MIC of the Berg Balance Scale (BBS) for use in older women with vertebral compression fractures has not been established.

OBJECTIVE

To identify the MIC of the BBS that can be used in older women with vertebral compression fractures using predictive modeling methods and the receiver-operating characteristic (ROC)-based method.

DESIGN

A retrospective longitudinal multicenter study.

PATIENTS

Sixty older women (mean age ± standard deviation: 84.1 ± 7.0 years) with vertebral compression fractures who were unable to ambulate independently on a level surface.

METHODS

A change of one point in the Functional Ambulation Category (FAC) was used as an anchor to calculate the MIC of the BBS based on the change between admission and discharge. We calculated the MIC for the women whose FAC score improved by ≥1 point. We used three anchor-based methods to examine the MIC: the ROC-based method (MICROC), the predictive modeling method (MICpred), and the MICpred-based method adjusted by the rate of improvement and reliability of transition (MICadj).

RESULTS

Thirty-nine women comprised the "important change" group based on their FAC score improvement. In this group, the MICROC (95% confidence interval [CI]) value of the BBS was 10.0 points (5.5-15.5), with an area under the curve of 0.71. The MICpred (95% CI) value was 9.7 (8.1-11.0), and the MICadj (95% CI) was 7.0 (5.5-8.5) points.

CONCLUSION

For women with vertebral compression fractures who are unable to ambulate independently, a 7.0-point improvement in the BBS score may be a useful indicator for reducing the amount of assistance required for walking.

The minimal important change (MIC) and minimal clinically important difference (MCID) of the patient and observer scar assessment scale (POSAS) 2.0

BACKGROUND

The Patient and Observer Scar Assessment Scale (POSAS) is frequently used to assess scar quality after burns. It is important to be aware of the minimal important change (MIC) and the minimal clinically important difference (MCID) to establish if a POSAS score represents a clinically relevant change or difference. The aim of this study is to explore the MIC and MCID of POSAS version 2.0.

METHODS

This prospective study included 127 patients with deep dermal burns that underwent split thickness skin grafting with a mean age of 44 years (range 0 - 87) and total body surface area burned of 10 % (range 0.5 - 55). POSAS data was obtained for one burn scar area at three, six, and 12 months after split skin grafting. At the second and third visits, patients rated the degree of clinical change in scar quality in comparison to the previous visit. At 12 months, they completed the POSAS for a second burn scar area and rated the degree of clinical difference between the two scar areas. Two anchor-based methods were used to determine the MIC and MCID.

RESULTS

MIC values of the patient POSAS ranged from - 0.59 to - 0.29 between three and six months and from - 0.75 to - 0.38 between six and 12 months follow-up. Both had a poor discriminatory value. MCID values ranged from - 0.39 and - 0.08, with a better discriminatory value.

CONCLUSION

Results suggest that patients consider minor differences (less than 0.75 on the 1-10 scale) in POSAS scores as clinically important scar quality changes. MCID values can be used to evaluate the effects of burn treatment and perform sample-size calculations.

Measurement Properties of the Oxford Shoulder Score and Minimal Clinically Important Changes After Primary Total Shoulder Replacement Surgery

OBJECTIVE

We evaluated the measurement properties of the Oxford Shoulder Score (OSS) and estimated the minimal clinically important change (MCIC) in patients undergoing primary total shoulder replacement in Australia.

METHODS

Deidentified data from the Australian Orthopaedic Association National Joint Replacement Registry were used for this analysis. Pre- and 6-month postoperative OSS scores were used, with the 5-level EuroQoL quality of life instrument and shoulder pain scores used as comparators. Floor and ceiling effects, internal consistency reliability, construct validity, and responsiveness to change were evaluated using standard psychometric methods. Mean change and predictive modeling approaches (with and without adjustment for the proportion of improved patients) were used to calculate MCIC thresholds, with patient-perceived improvement after surgery as the anchor.

RESULTS

Preoperative OSS data were available for 1,117 patients (59% female; 90% aged ≥60 years) undergoing primary total shoulder replacement. No floor or ceiling effects were observed pre- or postoperatively. The OSS showed high internal consistency reliability (Cronbach alpha >0.89), good construct validity, and high responsiveness to change (effect size 1.88). The MCIC derived from the mean change method was 6.50 points (95% confidence interval [95% CI] 4.41-8.61). The predictive modeling approach produced an MCIC estimate of 8.42 points (95% CI 5.68-12.23) after adjustment.

CONCLUSION

The OSS has good measurement properties to capture pain and function outcomes after shoulder replacement procedures and is highly responsive to change. Based on robust methods, an increase in OSS scores of at least eight points can be considered as meaningful improvement after surgery from the patient's perspective.

The construct validity, responsiveness, reliability and interpretability of the Recap of atopic eczema questionnaire (RECAP) in children

BACKGROUND

The Recap of atopic eczema questionnaire (RECAP) was developed to measure eczema control in patients with atopic dermatitis (AD). The measurement properties of RECAP have not yet been validated in caregivers of children with AD.

OBJECTIVES

To assess the construct validity, responsiveness, reliability and interpretability of the Dutch proxy version of RECAP.

METHODS

A prospective validation study was conducted in children (aged < 12 years) with AD and their caregivers (in a Dutch tertiary hospital). At three timepoints (T0 = baseline; T1 = after 1-7 days; T2 = after 4-8 weeks) RECAP and multiple reference instruments were completed by caregivers of child patients. Single- and change-score validity (responsiveness) were tested with a priori hypotheses on correlations with reference instruments. Intraclass correlation coefficients (ICCagreement) and standard error of agreement (SEMagreement) were reported. Bands for perceived eczema control were proposed. The smallest detectable change (SDC) and minimally important change (MIC) were determined. Two anchor-based methods based on receiver operating characteristic curve (ROC) and predictive modelling were used to determine the MIC.

RESULTS

A total of 231 children with AD and their caregivers participated. Of our a priori hypotheses for single-score and change-score validity, 77% and 80% were confirmed, respectively. A stronger correlation than hypothesized was found for all rejected hypotheses.Excellent reliability was found (ICCagreement = 0.94, 95% confidence interval 0.90-0.96). The SEMagreement was 1.9 points. The final banding was 0-1 (completely controlled), 2-7 (mostly controlled), 8-12 (moderately controlled), 13-18 (a little controlled) and 19-28 (not at all controlled). A cutoff point of ≥ 8 was selected to identify children whose AD is not under control. The SDC was 5.3 and the MIC values were 1.5 and 3.6 for the ROC and predictive modelling approaches, respectively. No floor or ceiling effects were observed.

CONCLUSIONS

The proxy version of RECAP is a valid, reliable and responsive measurement instrument for measuring eczema control in children with AD. An improvement of ≥ 6 points can be regarded as a real and important change in children with AD.

Patient acceptable symptom state and treatment failure threshold values for work productivity and activity Impairment and EQ-5D-5L in osteoarthritis

OBJECTIVE

To estimate patient acceptable symptom state (PASS) and treatment failure (TF) threshold values for Work Productivity and Activity Impairment (WPAI) measure and EQ-5D-5L among people with hip or knee osteoarthritis (OA) 3 and 12 months following participation in a digital self-management intervention (Joint Academy®).

METHODS

Among the participants, we computed work and activity impairments scores (both 0-100, with a higher value reflecting higher impairment) and the Swedish hypothetical- (range: - 0.314 to 1) and experience-based (range: 0.243-0.976) EQ-5D-5L index scores (a higher score indicates better health status) at 3- (n = 14,607) and 12-month (n = 2707) follow-ups. Threshold values for PASS and TF were calculated using anchor-based adjusted predictive modeling. We also explored the baseline dependency of threshold values according to pain severity at baseline.

RESULTS

Around 42.0% and 48.3% of the participants rated their current state as acceptable, while 4.2% and 2.8% considered the treatment had failed at 3 and 12 months, respectively. The 3-month PASS/TF thresholds were 16/29 (work impairment), 26/50 (activity impairment), 0.92/0.77 (hypothetical EQ-5D-5L), and 0.87/0.77 (the experience-based EQ-5D-5L). The thresholds at 12 months were generally comparable to those estimated at 3 months. There were baseline dependencies in PASS/TF thresholds with participants with more severe baseline pain considering poorer (more severe) level of WPAI/EQ-5D-5L as satisfactory.

CONCLUSION

PASS and TF threshold values for WPAI and EQ-5D-5L might be useful for meaningful interpretation of these measures among people with OA. The observed baseline dependency of estimated thresholds limits their generalizability and values should be applied with great caution in other settings/populations.

Anchor-based minimal important difference values are often sensitive to the distribution of the change score

PURPOSE

Anchor-based studies are today the most popular approach to determine a minimal important difference value for an outcome variable. However, a variety of construction methods for such values do exist. This constitutes a challenge to the field. In order to distinguish between more or less adequate construction methods, meaningful minimal requirements can be helpful. For example, minimal important difference values should not reflect the intervention(s) the patients are exposed to in the study used for construction, as they should later allow to compare interventions. This requires that they are not sensitive to the distribution of the change score observed. This study aims at investigating to which degree established construction methods fulfil this minimal requirement.

METHODS

Six constructions methods were considered, covering very popular and recently suggested methods. The sensitivity of MID values to the distribution of the change score was investigated in a simulation study for these six construction methods.

RESULTS

Five out of six construction methods turned out to yield MID values which are sensitive to the distribution of the change score to a degree that questions their usefulness. Insensitivity can be obtained by using construction methods based solely on an estimate of the conditional distribution of the anchor variable given the change score.

CONCLUSION

In future the computation of MID values should be based on construction methods avoiding sensitivity to the distribution of the change score.

Responsiveness and minimal important changes of the OARSI core set of performance-based measures in patients with knee osteoarthritis following physiotherapy intervention

PURPOSE

The Osteoarthritis Research Society International has recommended a core set of performance-based tests of physical function for use in knee osteoarthritis (OA) patients. The core set includes 30-second chair stand test (30-s CST), 4 × 10 m fast-paced walk test (40-m FPWT), and a stair climb test. This study aimed to evaluate responsiveness and minimal important changes (MICs) of these performance-based measures in knee OA patients following physiotherapy.

METHODS

Sixty patients with knee OA, undergoing 4-week physiotherapy performed 30-s CST, 40-m FPWT, and 4-step stair climb test (4-step SCT) at pre- and post-intervention. Patients also completed the 7-point global rating scale as an external anchor at post-intervention. Responsiveness was evaluated using receiver operating characteristics curve and correlation analysis.

RESULTS

All three performance-based measures of physical function showed area under the curve > 0.70. Correlation analysis showed relationship of 30-s CST, 40-m FPWT, and 4-Step SCT with the external anchor fell within moderate to good range (Spearman = 0.43-0.63). Furthermore, MIC values reflecting improvement for 30-s CST, 40-m FPWT, and 4-Step SCT were 2.5, 0.21, and 3.21, respectively.

CONCLUSION

Our findings demonstrated all three performance-based measures have good responsiveness to measure improvement in physical functions of knee OA patients following physiotherapy. The MIC reflecting improvement can help clinicians and researchers to make a decision based on the clinical significance of improvements in patients' functional status.

Minimal important change thresholds change over time after knee and hip arthroplasty

OBJECTIVES

The minimal important change (MIC) reflects what patients, on average, consider the smallest improvement in a score that is important to them. MIC thresholds may vary across patient populations, interventions used, posttreatment time points and derivation methods. We determine and compare MIC thresholds for the Oxford Knee Score and Oxford Hip Score (OKS/OHS) at 3 months postoperatively to 12- and 24-month thresholds in patients undergoing knee or hip arthroplasty.

STUDY DESIGN AND SETTING

This cohort study used data from patients undergoing total knee arthroplasty (TKA), unicompartmental knee arthroplasty (UKA), or total hip arthroplasty (THA) at a public hospital between February 2016 and February 2023. At 3, 12, and 24 months postoperatively, patients responded to the OKS/OHS and a 7-point anchor question determining experienced changes in knee or hip pain and functional limitations. We used the adjusted predictive modeling method that accounts for the proportion improved and the reliability of the anchor question to determine MIC thresholds and their mean differences between time points.

RESULTS

Complete data were obtained from 695/957 (73%), 1179/1703 (69%), and 1080/1607 (67%) patients undergoing TKA, 474/610 (78%), 438/603 (73%), and 355/507 (70%) patients undergoing UKA, and 965/1315 (73%), 978/1409 (69%), and 1059/1536 (69%) patients undergoing THA at 3, 12, and 24 months, respectively. The median age ranged from 68 to 70 years and 55% to 60% were females. The proportions improved ranged between 83% and 95%. The OKS/OHS MIC thresholds were 0.1, 4.2, and 5.1 for TKA, 1.8, 5.6, and 3.4 for UKA, and 1.3, 6.1, and 6.0 for THA at 3, 12, and 24 months postoperatively, respectively. The reliability ranged between 0.64 and 0.82, and the MIC values increased between three and 12 months but not between 12 and 24 months.

CONCLUSION

Any absence of deterioration in pain and function is considered important at 3 months after knee or hip arthroplasty. Increasing thresholds over time suggest patients raise their standards for what constitutes a minimal important improvement over the first postoperative year. Besides improving our understanding of patients' views on postoperative outcomes, these clinical thresholds may aid in interpreting registry-based treatment outcome evaluations.

Ingelsrud L, Roos EM, Silbernagel KG, Snyder-Mackler L, Risberg MA. Patient Acceptable Symptom State Thresholds for IKDC-SKF and KOOS at the 10-Year Follow-up After Anterior Cruciate Ligament Injury: A Study From the Delaware-Oslo ACL Cohort

Background

Clinicians need thresholds for the Patient Acceptable Symptom State (PASS) and Treatment Failure to interpret group-based patient-reported outcome measures after anterior cruciate ligament (ACL) injury. Validated thresholds that are crucial for accurately discerning patient symptom state and facilitating effective interpretation have not been determined for long-term follow-up after ACL injury.

Purpose

To calculate and validate thresholds for PASS and Treatment Failure for the International Knee Documentation Committee Subjective Knee Form (IKDC-SKF) and the Knee injury and Osteoarthritis Outcome Score (KOOS) subscales at the 10-year follow-up after ACL injury.

Study Design

Cohort study; Level of evidence, 3.

Methods

A total of 163 participants with unilateral ACL injury (treated with reconstruction or rehabilitation alone) from the Delaware-Oslo ACL Cohort were included. Thresholds for PASS were calculated for IKDC-SKF and KOOS subscales using anchor-based predictive modeling and receiver operating characteristic (ROC) analysis. Too few participants had self-reported Treatment Failure to calculate thresholds for that outcome. Nonparametric bootstrapping was used to derive 95% CIs. The criterion validity of the predictive modeling and ROC-derived thresholds were assessed by comparing actual patient-reported PASS outcome with the calculated PASS outcome for each method of calculation and calculating their positive and negative predictive values with respect to the anchor questions.

Results

A total of 127 (78%) participants reported satisfactory symptom state. Predictive modeling PASS thresholds (95% CIs) were 76.2 points (72.1-79.4 points) for IKDC-SKF, 85.4 points (80.9-89.2 points) for KOOS Pain, 76.5 points (67.8-84.7 points) for KOOS Symptoms, 93.8 points (90.1-96.9 points) for KOOS activities of daily living, 71.6 points (63.4-77.7 points) for KOOS Sports, and 59.0 points (53.7-63.9 points) for KOOS quality of life (QoL). Predictive modeling thresholds classified 81% to 93% of the participants as having satisfactory symptom state, whereas ROC-derived thresholds classified >50% as unsatisfied. The thresholds for IKDC-SKF, KOOS Sports, and KOOS QoL resulted in the most accurate percentages of PASS among all identified thresholds and therefore demonstrate the highest validity.

Conclusion

Predictive modeling provided valid PASS thresholds for IKDC-SKF and KOOS at the 10-year follow-up after ACL injury. The thresholds for IKDC-SKF, KOOS Sports, and KOOS QoL should be used when determining satisfactory outcomes. ROC-derived thresholds result in substantial misclassification rates of the participants who reported satisfactory symptom state.

Pooled Minimal Clinically Important Differences of the Mini-Balance Evaluation Systems Test in Patients With Early Subacute Stroke: A Multicenter Prospective Observational Study

OBJECTIVE

Balance problems are common in patients with stroke, and the Mini-Balance Evaluation Systems Test (Mini-BESTest) is a reliable and valid assessment tool for measuring balance function. Determining the minimal clinically important difference (MCID) is crucial for assessing treatment effectiveness. This study aimed to determine the MCID of the Mini-BESTest in patients with early subacute stroke.

METHODS

In this prospective multicenter study, 53 patients with early subacute stroke undergoing rehabilitation in inpatient units were included. The mean age of the patients was 72.6 (SD = 12.2) years. The Mini-BESTest, which consists of 14 items assessing various aspects of balance function, including anticipatory postural adjustments, postural responses, sensory orientation, and dynamic gait, was used as the assessment tool. The global rating of change (GRC) scales completed by the participants and physical therapists were used as external anchors to calculate the MCID. The GRC scale measured subjective improvement in balance function, ranging from -3 (very significantly worse) to +3 (very significantly better), with a GRC score of ≥+2 considered as meaningful improvement. Four methods were used to calculate the MCID: mean of participants with GRC of 2, receiver operating characteristic-based method, predictive modeling method, and adjustment of the predictive modeling method based on the rate of improvement. From the MCID values obtained using these methods, a single pooled MCID value was calculated.

RESULTS

The MCID values for the Mini-BESTest obtained through the 4 methods ranged from 3.2 to 4.5 points when using the physical therapist's GRC score as the anchor but could not be calculated using the participant's GRC score. The pooled MCID value for the Mini-BESTest was 3.8 (95% CI = 2.9-5.0).

CONCLUSIONS

The Mini-BESTest MCID obtained in this study is valuable for identifying improvements in balance function among patients with early subacute stroke.

IMPACT

Determination of the MCID is valuable for evaluating treatment effectiveness. The study findings provide clinicians with practical values that can assist in interpreting Mini-BESTest results and assessing treatment effectiveness.

30 years with the Knee injury and Osteoarthritis Outcome Score (KOOS)

This narrative review describes the development and use of patient-reported outcomes over 30 years, focusing on the Knee injury and Osteoarthritis Outcome Score (KOOS). KOOS is a five-subscale patient-reported instrument intended for use from the time of knee injury to the development of osteoarthritis. Numerous studies have confirmed that the psychometric properties of the KOOS and its short-form KOOS-12 are acceptable. More recent research has focused on the use and interpretation of KOOS scores in clinical trials using thresholds, such as minimal important differences, patient-acceptable symptom states, and treatment failure. As an indication of KOOS's popularity, the total 3854 PubMed results for KOOS have increased exponentially since the first KOOS paper was published 25 years ago and now seem to have plateaued at around 650 annually. The selected articles are not based on a systematic search, but on the author's own publications, reading, and literature search that grew organically from that.

Estimating anchor-based minimal important change using longitudinal confirmatory factor analysis

PURPOSE

The minimal important change (MIC) is defined as the smallest within-individual change in a patient-reported outcome measure (PROM) that patients on average perceive as important. We describe a method to estimate this value based on longitudinal confirmatory factor analysis (LCFA). The method is evaluated and compared with a recently published method based on longitudinal item response theory (LIRT) in simulated and real data. We also examined the effect of sample size on bias and precision of the estimate.

METHODS

We simulated 108 samples with various characteristics in which the true MIC was simulated as the mean of individual MICs, and estimated MICs based on LCFA and LIRT. Additionally, both MICs were estimated in existing PROMIS Pain Behavior data from 909 patients. In another set of 3888 simulated samples with sample sizes of 125, 250, 500, and 1000, we estimated LCFA-based MICs.

RESULTS

The MIC was equally well recovered with the LCFA-method as using the LIRT-method, but the LCFA analyses were more than 50 times faster. In the Pain Behavior data (with higher scores indicating more pain behavior), an LCFA-based MIC for improvement was estimated to be 2.85 points (on a simple sum scale ranging 14-42), whereas the LIRT-based MIC was estimated to be 2.60. The sample size simulations showed that smaller sample sizes decreased the precision of the LCFA-based MIC and increased the risk of model non-convergence.

CONCLUSION

The MIC can accurately be estimated using LCFA, but sample sizes need to be preferably greater than 125.

Responsiveness and minimal important change of the Family Reported Outcome Measure (FROM-16)

BACKGROUND

The FROM-16 is a generic family quality of life (QoL) instrument that measures the QoL impact of patients' disease on their family members/partners. The study aimed to assess the responsiveness of FROM-16 to change and determine Minimal Important Change (MIC).

METHODS

Responsiveness and MIC for FROM-16 were assessed prospectively with patients and their family members recruited from outpatient departments of the University Hospital Wales and University Hospital Llandough, Cardiff, United Kingdom. Patients completed the EQ-5D-3L and a global severity question (GSQ) online at baseline and at 3-month follow-up. Family members completed FROM-16 at baseline and a Global Rating of Change (GRC) in addition to FROM-16 at follow-up. Responsiveness was assessed using the distribution-based (effect size-ES, standardized response mean -SRM) and anchor-based (area under the receiver operating characteristics curve ROC-AUC) approaches and by testing hypotheses on expected correlation strength between FROM-16 change score and patient assessment tools (GSQ and EQ-5D). Cohen's criteria were used for assessing ES. The AUC ≥ 0.7 was considered a good measure of responsiveness. MIC was calculated using anchor-based (ROC analysis and adjusted predictive modelling) and distribution methods based on standard deviation (SD) and standard error of the measurement (SEM).

RESULTS

Eighty-three patients with 15 different health conditions and their relatives completed baseline and follow-up questionnaires and were included in the responsiveness analysis. The mean FROM-16 change over 3 months = 1.43 (SD = 4.98). The mean patient EQ-5D change over 3 months = -0.059 (SD = 0.14). The responsiveness analysis showed that the FROM-16 was responsive to change (ES = 0.2, SRM = 0.3; p < 0.01). The ES and SRM of FROM-16 change score ranged from small (ES = 0.2; SRM = 0.3) for the distribution-based method to large (ES = 0.8, SRM = 0.85) for anchor-based methods. The AUC value was above 0.7, indicating good responsiveness. There was a significant positive correlation between the FROM-16 change scores and the patient's disease severity change scores (p < 0.001). The MIC analysis was based on data from 100 family members of 100 patients. The MIC value of 4 was suggested for FROM-16.

CONCLUSIONS

The results of this study confirm the longitudinal validity of FROM-16 which refers to the degree to which an instrument is able to measure change in the construct to be measured. The results yield a MIC value of 4 for FROM-16. These psychometric attributes of the FROM-16 instrument are useful in both clinical research as well as clinical practice.

Machine Learning Models for Predicting Disability and Pain Following Lumbar Disc Herniation Surgery

Importance

Lumber disc herniation surgery can reduce pain and disability. However, a sizable minority of individuals experience minimal benefit, necessitating the development of accurate prediction models.

Objective

To develop and validate prediction models for disability and pain 12 months after lumbar disc herniation surgery.

Design, Setting, and Participants

A prospective, multicenter, registry-based prognostic study was conducted on a cohort of individuals undergoing lumbar disc herniation surgery from January 1, 2007, to May 31, 2021. Patients in the Norwegian Registry for Spine Surgery from all public and private hospitals in Norway performing spine surgery were included. Data analysis was performed from January to June 2023.

Exposures

Microdiscectomy or open discectomy.

Main Outcomes and Measures

Treatment success at 12 months, defined as improvement in Oswestry Disability Index (ODI) of 22 points or more; Numeric Rating Scale (NRS) back pain improvement of 2 or more points, and NRS leg pain improvement of 4 or more points. Machine learning models were trained for model development and internal-external cross-validation applied over geographic regions to validate the models. Model performance was assessed through discrimination (C statistic) and calibration (slope and intercept).

Results

Analysis included 22 707 surgical cases (21 161 patients) (ODI model) (mean [SD] age, 47.0 [14.0] years; 12 952 [57.0%] males). Treatment nonsuccess was experienced by 33% (ODI), 27% (NRS back pain), and 31% (NRS leg pain) of the patients. In internal-external cross-validation, the selected machine learning models showed consistent discrimination and calibration across all 5 regions. The C statistic ranged from 0.81 to 0.84 (pooled random-effects meta-analysis estimate, 0.82; 95% CI, 0.81-0.84) for the ODI model. Calibration slopes (point estimates, 0.94-1.03; pooled estimate, 0.99; 95% CI, 0.93-1.06) and calibration intercepts (point estimates, -0.05 to 0.11; pooled estimate, 0.01; 95% CI, -0.07 to 0.10) were also consistent across regions. For NRS back pain, the C statistic ranged from 0.75 to 0.80 (pooled estimate, 0.77; 95% CI, 0.75-0.79); for NRS leg pain, the C statistic ranged from 0.74 to 0.77 (pooled estimate, 0.75; 95% CI, 0.74-0.76). Only minor heterogeneity was found in calibration slopes and intercepts.

Conclusion

The findings of this study suggest that the models developed can inform patients and clinicians about individual prognosis and aid in surgical decision-making.

Construct validity, responsiveness, and interpretability of the Utrecht Scale for Evaluation of Rehabilitation (USER) in patients admitted to inpatient geriatric rehabilitation

OBJECTIVE

The Utrecht Scale for Evaluation of Rehabilitation is a multi-domain measurement with good content validity, structural validity and reliability for measuring physical functioning (mobility, selfcare) and cognitive functioning in geriatric rehabilitation. We aimed to determine the construct validity of both Utrecht Scale for Evaluation of Rehabilitation scales and the responsiveness and interpretability of the scale for physical functioning in geriatric rehabilitation.

DESIGN

Prospective follow-up study embedded in routine care.

SETTING

Four care organisations in The Netherlands.

SUBJECTS

Patients admitted for inpatient geriatric rehabilitation (2021-2022).

MAIN MEASURES

Data collection included the Utrecht Scale for Evaluation of Rehabilitation, Mini-Mental State Examination, Barthel index, and a global rating scale anchor on recovery. Hypothesis testing was used to determine construct validity and responsiveness. For interpretability, minimal important change and floor and ceiling effects were determined.

RESULTS

The mean age of participants (n = 211) was 77 (SD 10.4). Their mean length of stay was 38.6 days (SD 26.3), and 81% returned home. The Utrecht Scale for Evaluation of Rehabilitation showed adequate construct validity, as all three hypotheses were confirmed for both scales. The Utrecht Scale for Evaluation of Rehabilitation-physical function scale showed adequate responsiveness, with all five hypotheses confirmed. The mean change for physical function (scale range 0-70) was 15.5 points (SD 17.1). The minimal important change for Utrecht Scale for Evaluation of Rehabilitation-physical function was 14.5 points difference for improvement. This scale showed no floor (2%) and ceiling effects (14%) at admission and discharge.

CONCLUSIONS

The Utrecht Scale for Evaluation of Rehabilitation showed to be effective for evaluating physical functioning during geriatric rehabilitation as well as screening cognitive functioning. In total, 14.5 points difference has been established as a minimal important change for physical functioning.

Reliability, Measurement Error, Responsiveness, and Minimal Important Change of the Patient-Specific Functional Scale 2.0 for Patients With Nonspecific Neck Pain

OBJECTIVE

The Patient-Specific Functional Scale (PSFS) is a patient-reported outcome measure used to assess functional limitations. Recently, the PSFS 2.0 was proposed; this instrument includes an inverse numeric rating scale and an additional list of activities that patients can choose. The aim of this study was to assess the test-retest reliability, measurement error, responsiveness, and minimal important change of the PSFS 2.0 when used by patients with nonspecific neck pain.

METHODS

Patients with nonspecific neck pain completed a numeric rating scale, the PSFS 2.0, and the Neck Disability Index at baseline and again after 12 weeks. The Global Perceived Effect (GPE) was also collected at 12 weeks and used as an anchor. Test-retest measurement was assessed by completion of a second PSFS 2.0 after 1 week. Measurement error was calculated using a Bland-Altman plot. The receiver operating characteristic method with the anchor (GPE) functions as the reference standard was used for calculating the minimal important change.

RESULTS

One hundred patients were included, with 5 lost at follow-up. No floor and ceiling effects were reported. In the test-retest analysis, the mean difference was 0.15 (4.70 at first test and 4.50 at second test). The ICC (mixed models) was 0.95, indicating high agreement (95% CI = 0.92-0.97). For measurement error, the upper and lower limits of agreement were 0.95 and -1.25 points, respectively, with a smallest detectable change of 1.10. The minimal important change was determined to be 2.67 points. The PSFS 2.0 showed satisfactory responsiveness, with an area under the curve of 0.82 (95% CI = 0.70-0.93). There were substantial to high correlations between the change scores of the PSFS 2.0 and the Neck Disability Index and GPE (0.60 and 0.52, respectively; P < .001).

CONCLUSION

The PSFS 2.0 is a reliable and responsive patient-reported outcome measure for use by patients with neck pain.

Minimal important change and difference in health outcome: An overview of approaches, concepts, and methods

OBJECTIVE

To provide an overview of approaches, concepts, and methods used to define and assess minimal important change and difference in health outcome.

METHOD

A narrative review of the literature, guided by a conceptual framework.

RESULTS

We distinguish between (i) interpretation of health outcome in individuals versus groups, (ii) change within individuals or groups versus difference between change within individuals or groups; and (iii) the responder approach (based on the proportion of patients that obtain a defined response) versus the group average approach (based on the average amount of change in a group). We review approaches, concepts, and methods.

CONCLUSION

By bringing together and juxtaposing various approaches, concepts, and methods, we set a precursory step in the direction of consensus building in the field concerned with defining and assessing minimal important change and difference in health outcome. We emphasize the need for conceptual clarification and terminological standardization. We argue that assessing minimal importance of change and difference in health outcome is essentially a value judgment involving a range of considerations and perspectives.

Cost-effectiveness of a second opinion program on spine surgeries: an economic analysis

BACKGROUND

In this study we proposed a new strategy to measure cost-effectiveness of second opinion program on spine surgery, using as measure of effectiveness the minimal important change (MIC) in the quality of life reported by patients, including the satisfaction questionnaire regarding the treatment and direct medical costs.

METHODS

Retrospective analysis of patients with prior indication for spine surgery included in a second opinion program during May 2011 to May 2019. Treatment costs and outcomes were compared considering each patients' recommended treatment before and after the second opinion. Costs were measured under the perspective of the hospital, including hospital stay, surgical room, physician and staff fees and other costs related to hospitalization when surgery was performed and physiotherapy or injection costs when a conservative treatment was recommended. Reoperation costs were also included. For comparison analysis, we used data based on our clinical practice, using data from patients who underwent the same type of surgical procedure as recommended by the first referral. The measure of effectiveness was the percentage of patients who achieved the MIC in quality of life measured by the EQ-5D-3 L 2 years after starting treatment. An incremental cost-effectiveness ratio (ICER) was calculated.

RESULTS

Based upon the assessment of 1,088 patients that completed the entire second opinion process, conservative management was recommended for 662 (60.8%) patients; 49 (4.5%) were recommended to injection and 377 (34.7%) to surgery. Complex spine surgery, as arthrodesis, was recommended by second opinion in only 3.7% of cases. The program resulted in financial savings of -$6,705 per patient associated with appropriate treatment indication, with an incremental effectiveness of 0.077 patients achieving MIC when compared to the first referral, resulting in an ICER of $-87,066 per additional patient achieving the MIC, ranging between $-273,016 and $-41,832.

CONCLUSION

After 2 years of treatment, the second opinion program demonstrated the potential for cost-offsets associated with improved quality of life.

Verification of the minimal clinically important difference of the Capabilities of Upper Extremity Test in patients with subacute spinal cord injury

CONTEXT

The number of patients with cervical spinal cord injury (CSCI) is increasing, and the Capabilities of Upper Extremity Test (CUE-T) is recommended for introduction in clinical trials. We calculated the minimal clinically important difference (MCID) of the CUE-T using an adjustment model with an interval of 1 month.

DESIGN

This was a prospective study.

SETTING

This study was conducted with participants from the Chiba Rehabilitation Center in Japan.

PARTICIPANTS

The participants were patients with subacute CSCI.

INTERVENTIONS

The CUE-T and spinal cord independence measure (SCIM) III were performed twice within an interval of 1 month.

OUTCOME MEASURES

The MCID was calculated using an adjustment model based on logistic regression analysis. The participants were classified into an improvement group and a non-improvement group based on the amount of change in the two evaluations using the 10-point SCIM III MCID as an anchor.

RESULTS

There were 52 participants (56.8 ± 13.5 years old, 45 men/7 women) with complete or incomplete CSCI: 18 in the improvement group and 34 in the non-improvement group. A significant regression equation was obtained when calculating the MCID, and the total, hand, and side scores were 7.7, 2.0, and 3.7 points, respectively.

CONCLUSION

The calculated MCID of the CUE-T in this study was 7.7 points. The results of this study provide useful criteria for implementation in clinical trials. Future studies should use patient-reported outcomes, a more recommended anchor, and calculate the MCID using methods such as the patient's condition.

Validity, reliability, responsiveness and interpretability of the Recap of atopic eczema (RECAP) questionnaire

BACKGROUND

Limited research has been conducted on the measurement properties of the Recap of atopic eczema (RECAP) questionnaire, particularly in relation to interpretability.

OBJECTIVES

To investigate the validity, reliability, responsiveness and interpretability of the Dutch RECAP in adults with atopic dermatitis (AD).

METHODS

We conducted a prospective study in a Dutch tertiary hospital, recruiting adults with AD between June 2021 and December 2022. Patients completed the RECAP questionnaire, reference instruments and anchor questions at the following three timepoints: baseline, after 1-3 days and after 4-12 weeks. Hypotheses testing was used to investigate single-score validity and change-score validity (responsiveness). To assess reliability, both standard error of measurement (SEMagreement) and intraclass correlation coefficient (ICCagreement) were reported. To assess the interpretability of single scores, bands for eczema control were proposed. To investigate the interpretability of change scores, both smallest detectable change (SDC) and minimally important change (MIC) scores were determined. To estimate the MIC scores, four different anchor-based methods were employed: the mean change method, 95% limit cut-off point, receiver operating characteristic curve and predictive modelling.

RESULTS

In total, 200 participants were included (57.5% male sex, mean age 38.5 years). Of the a priori hypotheses, 82% (single-score validity) and 59% (responsiveness) were confirmed. Known-group analyses showed differences in the RECAP scores between patient groups based on disease severity and impairment of the quality of life. The SEMagreement was 1.17 points and the ICCagreement was 0.988. The final banding was as follows: 0-1 (completely controlled); 2-5 (mostly controlled); 6-11 (moderately controlled); 12-19 (a little controlled); 20-28 (not at all controlled). Moreover, a single cut-off point of ≥ 6 was determined to identify patients whose AD is not under control. The SDC was 3.2 points, and the MIC value from the predictive modelling was 3.9 points. Neither floor nor ceiling effects were observed.

CONCLUSIONS

The RECAP has good single-score validity, moderate responsiveness and excellent reliability. This study fills a gap in the interpretability of the RECAP. Our results indicate a threshold of ≥ 6 points to identify patients whose AD is 'not under control', while an improvement of ≥ 4 points represents a clinically important change. Given its endorsement by the Harmonising Outcome Measures for Eczema initiatives, the results of this study support the integration of RECAP into both routine clinical practice and research settings.

From numbers to meaningful change: Minimal important change by using PROMIS in a cohort of fracture patients

INTRODUCTION

use of the Patient-Reported Outcomes measurement Information System (PROMIS®) is slowly increasing in patients with a fracture. Yet, minimal important change of PROMIS in patients with fractures has been addressed in a very limited number of studies. As the minimal important change (MIC) is important to interpret PROMIS-scores, the goal is to estimate the MIC for PROMIS physical function (PF), PROMIS pain interference (PI) and PROMIS ability to participate in social roles and activities (APSRA) in patients with a fracture. Secondly, the smallest detectable change was determined.

MATERIALS AND METHODS

A longitudinal cohort study on patients ≥ 18 years receiving surgical or non-surgical care for fractures was conducted. Patients completed PROMIS PF V1.1, PROMIS PI V1.1 and PROMIS APSRA V2.0. For follow-up, patients completed three additional anchor questions evaluating patient-reported improvement on a seven point rating scale. The predictive modeling method was used to estimate the MIC value of all three PROMIS questionnaires.

RESULTS

Hundred patients with a mean age of 55.4 ± 12.6 years were included of which sixty (60%) were female. Seventy-two (72%) patients were recovering from a surgical procedure. PROMIS-CAT T-scores of all PROMIS measures showed significant correlations with their anchor questions. The predictive modeling method showed a MIC value of +2.4 (n = 98) for PROMIS PF, -2.9 (n = 96) for PROMIS PI and +3.2 (n = 91) for PROMIS APSRA.

CONCLUSION

By using the anchor based predictive modeling method, PROMIS MIC-values for improvement of respectively +2.4 points on a T-score metric for PROMIS-PF, -2.9 for PROMIS-PI and +3.2 for PROMIS APSRA give the impression of being meaningful to patients. These values can be used in clinical practice for managing patient expectations; to inform on treatment results; and to assess if patients experience significant change. This in order to encourage patient centered care.

Responsiveness and Minimal Important Change of the Arabic Disabilities of the Arm, Shoulder and Hand (DASH) in Patients with Upper Extremity Musculoskeletal Disorders

The aim of this study was to examine the responsiveness of the Arabic Disabilities of the Arm, Shoulder and Hand (DASH) and to quantify its minimal important change (MIC) for improvement. People with upper extremity musculoskeletal problems who were receiving physical therapy were evaluated at baseline and again during a follow-up appointment, with a median time frame of 7 days between the two testing sessions (range of 6 to 72 days). The participants completed the Arabic DASH, Global Assessment of Function (GAF), Numeric Pain Rating Scale (NPRS) and Global Rating of Change Scale (GRC). The responsiveness of the Arabic DASH was assessed by examining the pre-specified hypotheses. The MIC for improvement was determined using the receiver operating characteristic method (MICROC) and the predictive modeling method (MICpred). As hypothesized, a change in the Arabic DASH demonstrated a significant positive correlation with changes in the GAF (r = 0.69), NPRS (r = 0.68) and GRC (r = 0.73). Consistent with our hypotheses, the DASH change scores could be used to differentiate between participants who improved and those who did not improve (area under the receiver operating characteristic curve = 0.87), and they showed a large magnitude of change (effect size = 1.53, standardized response mean = 1.42) in patients who improved. All the hypotheses specified a priori were supported by the results. The Arabic DASH MICROC and MICpred were estimated to be 14.22 and 14.85. The interaction between the DASH change and baseline score was not a significant predictor of status (improved vs. not improved) (p = 0.75), indicating that the DASH MIC was not baseline-dependent. The Arabic DASH demonstrated sufficient responsiveness, supporting the idea that the Arabic DASH is capable of detecting changes in upper extremity function over time. The value of the Arabic DASH MIC was similar when estimated using the predictive modeling and ROC methods, and the MIC was not dependent on baseline status.

Estimating cutpoints of gait speed and sit-to-stand test values for self-reported mobility limitations in a cohort of community-dwelling older adults from Singapore: comparing receiver operating characteristic (ROC) analysis with adjusted predictive modelling

OBJECTIVES

Clinical interpretability of the gait speed and 5-times sit-to-stand (5-STS) tests is commonly established by comparing older adults with and without self-reported mobility limitations (SRML) on gait speed and 5-STS performance, and estimating clinical cutpoints for SRML using the receiver operating characteristics (ROC) method. Accumulating evidence, however, suggests that the adjusted predictive modeling (APM) method may be more appropriate to estimate these interpretational cutpoints. Thus, we aimed to compare, in community-dwelling older adults, gait speed and 5-STS cutpoints estimated using the ROC and APM methods.

DESIGN

Cross-sectional study.

SETTING AND PARTICIPANTS

This study analyzed data from 955 community-dwelling independently walking older adults (73%women) aged ≥60 years (mean, 68; range, 60-88).

METHODS

Participants completed the 10-metre gait speed and 5-STS tests. Participants were classified as having SRML if they responded "Yes" to either of the 2 questions regarding walking and stair climbing difficulty. Cutpoints for SRML and its component questions were estimated using ROC analysis with Youden criterion and the APM method.

RESULTS

The proportions of participants with self-reported walking difficulty, self-reported stair climbing difficulty, and SRML were 10%, 19%, and 22%, respectively. Gait speed and 5-STS time were moderately correlated with each other (r=-0.56) and with the self-reported measures (absolute r-values, 0.39-0.44). ROC-based gait speed cutpoints were 0.14 to 0.16 m/s greater than APM-based cutpoints (P < 0.05) whilst ROC-based 5-STS time cutpoints were 0.8 to 3.3 s lower than APM-based cutpoints (P < 0.05 for walking difficulty). Compared with ROC-based cutpoints, APM-based cutptoints were more precise and they varied monotonically with self-reported walking difficulty, self-reported stair climbing difficulty, and SRML.

CONCLUSIONS AND IMPLICATIONS

In a sample of 955 older adults, our findings of precise and biologically plausible gait speed and 5-STS cutpoints for SRML estimated using the APM method indicate that this promising method could potentially complement or even replace traditional ROC methods.

Interpretation threshold values for patient-reported outcomes in patients participating in a digitally delivered first-line treatment program for hip or knee osteoarthritis

Objective

Establish proportions of patients reporting important improvement, acceptable symptoms and treatment failure and define interpretation threshold values for pain, patient-reported function and quality-of-life after participating in digital first-line treatment including education and exercise for hip and knee osteoarthritis (OA).

Methods

Observational study. Responses to the pain Numeric Rating Scale (NRS, 0-10 best to worst), Knee injury and Osteoarthritis Outcome Score 12 (KOOS-12) and Hip disability and Osteoarthritis Outcome Score 12 (HOOS-12, both 0-100 worst to best) were obtained for 4383 (2987) and 2041 (1264) participants with knee (hip) OA at 3 and 12 months post intervention. Threshold values for Minimal Important Change (MIC), Patient Acceptable Symptom State (PASS) and Treatment Failure (TF) were estimated using anchor-based predictive modeling.

Results

70-85% reported an important improvement in pain, function and quality of life after 3 and 12 months follow-up. 42% (3 months) and 51% (12 months) considered their current state as satisfactory, whereas 2-4% considered treatment failed. MIC values were -1 (NRS) and 0-4 (KOOS/HOOS-12) across follow-ups and joint affected. PASS threshold value for NRS was 3, and 53-73 for the KOOS/HOOS-12 subscales Corresponding values for TF were 5 (NRS) and 34-55 (KOOS/HOOS-12). Patients with more severe pain at baseline had higher MIC scores and accepted poorer outcomes at follow-ups.

Conclusion

Threshold estimates aid in the interpretation of outcomes after first-line OA interventions assessed with NRS Pain and KOOS/HOOS-12. Baseline pain severity is important to consider when interpreting threshold values after first-line interventions in these patients.

The anchor design of anchor-based method to determine the minimal clinically important difference: a systematic review

BACKGROUND

Positive results for clinical outcomes should be not only statistically significant, but also clinically significant. The minimum clinically important difference (MCID) is used to define the minimum threshold of clinical significance. The anchor-based method is a classical method for ascertaining MCID. This study aimed to summarise the design of the anchors of the anchor-based method by reviewing the existing research and providing references and suggestions.

METHOD

This study was mainly based on literature research. We performed a systematic search using Web of Science, PubMed, CNKI, Wanfang, and VIP databases. Two reviewers independently screened titles and abstracts to identify relevant articles. Data were extracted from eligible articles using a predefined data collection form. Discrepancies were resolved by discussion and the involvement of a third reviewer.

RESULT

Three hundred and forty articles were retained for final analysis. For the design of anchors, Subjective anchors (99.12%) were the most common type of anchor used, mainly the Patient's rating of change or patient satisfaction (66.47%) and related scale health status evaluation items or scores (39.41%). Almost half of the studies (48.53%) did not assess the correlation test between the anchor and the research indicator or scale. The cut-off values and grouping were usually based on the choice of the anchor types. In addition, due to the large number of included studies, this study selected the most calculated SF-36 (28 articles) for an in-depth analysis. The results showed that the overall design of the anchor and the cut-off value were the same as above. The statistical methods used were mostly traditional (mean change, ROC). The MCID thresholds of these studies had a wide range (SF-36 PCS: 2-17.4, SF-36 MCS: 1.46-10.28), and different anchors or statistical methods lead to different results.

CONCLUSION

It is of great importance to select several types of anchors and to use more reliable statistical methods to calculate the MCID. It is suggested that the order of selection of anchors should be: objective anchors > anchors with established MCID in subjective anchors (specific scale > generic scale) > ranked anchors in subjective anchors. The selection of internal anchors should be avoided, and anchors should be evaluated by a correlation test.

Minimal important difference, patient acceptable symptom state and longitudinal validity of oxford elbow score and the quickDASH in patients with tennis elbow

BACKGROUND

The Oxford Elbow Score (OES) and the short version of Disabilities of Arms, Shoulder and Hand (QuickDASH) are common patient-reported outcomes for people with elbow problems. Our primary objective was to define thresholds for the Minimal Important Difference (MID) and Patient-Acceptable Symptom State (PASS) for the OES and QuickDASH. The secondary aim was to compare the longitudinal validity of these outcome measures.

METHODS

We recruited 97 patients with clinically-diagnosed tennis elbow for a prospective observational cohort study in a pragmatic clinical setting. Fifty-five participants received no specific intervention, 14 underwent surgery (11 as primary treatment and 4 during follow-up), and 28 received either botulinum toxin injection or platelet rich plasma injection. We collected OES (0 to 100, higher is better) and QuickDASH (0 to 100, higher is worse), and global rating of change (as an external transition anchor question) at six weeks, three months, six months and 12 months. We defined MID and PASS values using three approaches. To assess the longitudinal validity of the measures, we calculated the Spearman's correlation coefficient between the change in the outcome scores and external transition anchor question, and the Area Under the Curve (AUC) from a receiver operating characteristics (ROC) analysis. To assess signal-to-noise ratio, we calculated standardized response means.

RESULTS

Depending on the method, MID values ranged from 16 to 21 for OES Pain; 10 to 17 for OES Function; 14 to 28 for OES Social-psychological; 14 to 20 for OES Total score, and - 7 to -9 for QuickDASH. Patient-Acceptable Symptom State (PASS) cut offs were 74 to 84 for OES Pain; 88 to 91 for OES Function; 75 to 78 with OES Social-psychological; 80 to 81 with OES Total score and 19 to 23 with Quick-DASH. OES had stronger correlations with the anchor items, and AUC values suggested superior discrimination (between improved and not improved) compared with QuickDASH. OES also had superior signal-to-noise ratio compared with QuickDASH.

CONCLUSION

The study provides MID and PASS values for OES and QuickDASH. Due to better longitudinal validity, OES may be a better choice for clinical trials.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02425982 (first registered April 24, 2015).

Face Name Associative Memory Exam and biomarker status in the ARMADA study: Advancing reliable measurement in Alzheimer's disease and cognitive aging

The Face Name Associative Memory Exam (FNAME) was introduced into the NIH Toolbox as part of the ARMADA study and establishes normative data for diverse participants, ages 64 to 85+, and proposes cutoff scores between biomarker positive versus negative (+/-) groups. The FNAME was administered to 257 participants across the clinical spectrum with 122 having amyloid biomarkers. Linear regression explored the association between demographics and FNAME and between amyloid (+/-) groups. Receiver operating characteristic curves (ROC) identified performance thresholds that best discriminated between biomarker (+/-) individuals. Lower FNAME scores occurred in males, older ages, Black/African Americans, Hispanics, and biomarker-positive participants. ROC analyses demonstrated acceptable accuracy (0.73 to 0.77) but only when combined with clinical status. The diagnostic discrimination of amyloid positivity was acceptable but not excellent, suggesting the FNAME may be a better screening indicator of clinical status rather than amyloid deposition in cognitively normal individuals. Normative data are provided.

Measurement Properties of the Patient-Specific Functional Scale in Rehabilitation for Patients With Stroke: A Prospective Observational Study

OBJECTIVE

This study investigated the validity, reliability, responsiveness, and interpretability of the Patient-Specific Functional Scale (PSFS) in subacute stroke rehabilitation to determine its suitability to measure patient-identified rehabilitation goals.

METHODS

A prospective observational study was designed according to the checklist from Consensus-Based Standards for Selecting Health Measurement Instruments. Seventy-one patients diagnosed with stroke were recruited in the subacute phase from a rehabilitation unit in Norway. The International Classification of Functioning, Disability and Health was used to assess the content validity. Assessment of construct validity was based on hypotheses for correlation of the PSFS and comparator measurements. We assessed reliability by calculating the Intraclass Correlation Coefficient (ICC) (3.1) and the standard error of measurement. The assessment of responsiveness was based on hypotheses for the correlation of change scores between the PSFS and the comparator measurements. A receiver operating characteristic analysis was conducted to assess responsiveness. The smallest detectable change and minimal important change were calculated.

RESULTS

Eighty percent of the PSFS items were classified as activities and participation in the International Classification of Functioning, Disability and Health, indicating satisfactory content validity. The reliability was satisfactory with an ICC of 0.81 (95% CI = 0.69-0.89). The standard error of measurement was 0.70 point, and the smallest detectable change was 1.94 points. Five of 7 hypotheses were confirmed for construct validity, and 5 of 6 were confirmed for responsiveness, indicating moderate construct validity and high responsiveness. Assessing responsiveness with a criterion approach resulted in an area under the curve of 0.74. A ceiling effect was identified for 25% of the participants 3 months after discharge. The minimal important change was estimated to be 1.58 points.

CONCLUSION

This study demonstrates satisfactory measurement properties for the PSFS in individuals undergoing inpatient stroke rehabilitation.

IMPACT

This study supports the use of the PSFS to document and monitor patient-identified rehabilitation goals in patients receiving subacute stroke rehabilitation when applied using a shared decision approach.

Responsiveness and minimal important change of seven PROMIS computerized adaptive tests (CAT) in patients with advanced chronic kidney disease

BACKGROUND

The Patient-Reported Outcomes Measurement Information System (PROMIS®) has the potential to harmonize the measurement of health-related quality of life (HRQL) across medical conditions. We evaluated responsiveness and minimal important change (MIC) of seven Dutch-Flemish PROMIS computerized adaptive tests (CAT) in Dutch patients with advanced chronic kidney disease (CKD).

METHODS

CKD patients (eGFR < 30 ml/min.1.73m²) completed at baseline and after 6 months seven PROMIS CATs (assessing physical function, pain interference, fatigue, sleep disturbance, anxiety, depression, and ability to participate in social roles and activities), Short Form Health Survey 12 (SF-12), PROMIS Pain Intensity single item, Dialysis Symptom Index (DSI), and Global Rating Scales (GRS) of change. Responsiveness was assessed by testing predefined hypotheses about expected correlations among measures, area under the ROC Curve, and effect sizes. MIC was determined with predictive modelling.

RESULTS

207 patients were included; 186 (90%) completed the follow-up. Most results were in accordance with expectations (70-91% of hypotheses confirmed), with some exceptions for PROMIS Anxiety and Ability to Participate (60% and 42% of hypotheses confirmed, respectively). For PROMIS Anxiety and Depression correlations with the GRS were too low (0.04 and 0.20, respectively) to calculate a MIC. MIC values, representing minimal important deterioration, ranged from 0.4 to 2.5 T-score points for the other domains.

CONCLUSION

We found sufficient responsiveness of PROMIS CATs Physical Function, Fatigue, Sleep Disturbance, and Depression. The results for PROMIS CATs Pain Interference were almost sufficient, but some results for Anxiety and Ability to Participate in Social Roles and Activities were not as expected. Reported MIC values should be interpreted with caution because most patients did not change.

Responsiveness and Minimal Important Change of the PROMIS Pain Interference Item Bank in Patients Presented in Musculoskeletal Practice

We evaluated the responsiveness of the Patient Reported Outcome Information System Pain Interference item bank in patients with musculoskeletal pain by testing predefined hypotheses about the relationship between the change scores on the item bank, change scores on legacy instruments and Global Ratings of Change (GRoC), and we estimated Minimal Important Change (MIC). Patients answered the full Dutch-Flemish V1.1 item bank. From the responses we derived scores for the standard 8-item short form (SF8a) and a CAT-score was simulated. Correlations between the change scores on the item bank, GRoC and legacy instruments were calculated, together with Effect Sizes, Standardized Response Means, and Area Under the Curve. GRoC were used as an anchor for estimating the MIC with (adjusted) predictive modeling. Of 1,677 patients answering baseline questionnaires 960 completed follow-up questionnaires at 3 months. The item bank correlated moderately high with the GRoC (Spearman's rho 0.63) and with the legacy instruments (Pearson's R ranging from .45 to .68). It showed a high ES (.97) and Standardized Response Means (.71), and could distinguish well between improved and not improved patients based on the GRoC (Area Under the Curve .77). Comparable results were found for the derived SF8a and CAT-scores. The MIC was estimated to be 3.2 (CI 2.6-3.7) T-score points. PERSPECTIVE: Our study supports the responsiveness of the PROMIS-PI item bank in patients with musculoskeletal complaints. Almost all predefined hypotheses were met (94%). The PROMIS-PI item bank correlated well with several legacy instruments which supports generic use of the item bank. MIC for PROMIS-PI was estimated to be 3.2 T-score points.

Measurement properties of PROMIS short forms for pain and function in patients receiving knee arthroplasty

BACKGROUND

While there are a few studies on measurement properties of PROMIS short forms for pain and function in patients with knee osteoarthritis, nothing is known about the measurement properties in patients with knee arthroplasty. Therefore, this study examined the measurement properties of the German Patient-Reported Outcomes Measurement Information System (PROMIS) short forms for pain intensity (PAIN), pain interference (PI) and physical function (PF) in knee arthroplasty patients.

METHODS

Short forms were collected from consecutive patients of our clinic's knee arthroplasty registry before and 12 months post-surgery. Oxford Knee Score (OKS) was the reference measure. A subsample completed the short forms twice to test reliability. Construct validity and responsiveness were assessed using scale-specific hypothesis testing. For reliability, Cronbach's alpha, intraclass correlation coefficients, and agreement using standard error of measurement (SEM_agr) were used. Agreement was used to determine standardised effect sizes and smallest detectable changes (SDC90). Individual-level minimal important change (MIC) was calculated using a method of adjusted prediction.

RESULTS

Of 213 eligible patients, 155 received questionnaires, 143 returned baseline questionnaires and 119, 12-month questionnaires. Correlations of short forms with OKS were large (│r│ ≥ 0.7) with slightly lower values for PAIN, and specifically for men. Cronbach's alpha values were ≥ 0.84 and intraclass correlation coefficients ≥ 0.90. SEM_agr were around 3.5 for PAIN and PI and 1.7 for PF. SDC90 were around 8 for PAIN and PI and 4 for PF. Follow-up showed a relevant ceiling effect for PF. Correlations with OKS change scores of around 0.5 to 0.6 were moderate. Adjusted MICs were 7.2 for PAIN, 3.5 for PI and 5.7 for PF.

CONCLUSION

Our results partly support the use of the investigated short forms for knee arthroplasty patients. The ability of PF to differentiate between patients with high perceived recovery is limited. Therefore, the advantages and disadvantages should be strongly considered within the context of the intended use.

Estimating meaningful thresholds for multi-item questionnaires using item response theory

PURPOSE

Meaningful thresholds are needed to interpret patient-reported outcome measure (PROM) results. This paper introduces a new method, based on item response theory (IRT), to estimate such thresholds. The performance of the method is examined in simulated datasets and two real datasets, and compared with other methods.

METHODS

The IRT method involves fitting an IRT model to the PROM items and an anchor item indicating the criterion state of interest. The difficulty parameter of the anchor item represents the meaningful threshold on the latent trait. The latent threshold is then linked to the corresponding expected PROM score. We simulated 4500 item response datasets to a 10-item PROM, and an anchor item. The datasets varied with respect to the mean and standard deviation of the latent trait, and the reliability of the anchor item. The real datasets consisted of a depression scale with a clinical depression diagnosis as anchor variable and a pain scale with a patient acceptable symptom state (PASS) question as anchor variable.

RESULTS

The new IRT method recovered the true thresholds accurately across the simulated datasets. The other methods, except one, produced biased threshold estimates if the state prevalence was smaller or greater than 0.5. The adjusted predictive modeling method matched the new IRT method (also in the real datasets) but showed some residual bias if the prevalence was smaller than 0.3 or greater than 0.7.

CONCLUSIONS

The new IRT method perfectly recovers meaningful (interpretational) thresholds for multi-item questionnaires, provided that the data satisfy the assumptions for IRT analysis.

The challenges inherent with anchor-based approaches to the interpretation of important change in clinical outcome assessments

PURPOSE

Anchor-based methods are group-level approaches used to derive clinical outcome assessment (COA) interpretation thresholds of meaningful within-patient change over time for understanding impacts of disease and treatment. The methods explore the associations between change in the targeted concept of the COA measure and the concept measured by the external anchor(s), typically a global rating, chosen as easier to interpret than the COA measure. While they are valued for providing plausible interpretation thresholds, group-level anchor-based methods pose a number of inherent theoretical and methodological conundrums for interpreting individual-level change.

METHODS

This investigation provides a critical appraisal of anchor-based methods for COA interpretation thresholds and details key biases in anchor-based methods that directly influences the magnitude of the interpretation threshold.

RESULTS

Five important research issues inherent with the use of anchor-based methods deserve attention: (1) global estimates of change are consistently biased toward the present state; (2) the use of static current state global measures, while not subject to artifacts of recall, may exacerbate the problem of estimating clinically meaningful change; (3) the specific anchor assessment response(s) that identify the meaningful change group usually involves an arbitrary judgment; (4) the calculated interpretation thresholds are sensitive to the proportion of patients who have improved; and (5) examination of anchor-based regression methods reveals that the correlation between the COA change scores and the anchor has a direct linear relationship to the magnitude of the interpretation threshold derived using an anchor-based approach; stronger correlations yielding larger interpretation thresholds.

CONCLUSIONS

While anchor-based methods are recognized for their utility in deriving interpretation thresholds for COAs, attention to the biases associated with estimation of the threshold using these methods is needed to progress in the development of standard-setting methodologies for COAs.

Comparison of anchor-based methods for estimating thresholds of meaningful within-patient change using simulated PROMIS PF 20a data under various joint distribution characteristic conditions

PURPOSE

To compare the performance of anchor-based methods for estimating thresholds of meaningful within-patient change (i.e., individual change) of clinical outcome assessments in conditions reflecting data characteristics of small- to medium-sized clinical trials.

METHODS

Datasets were generated from the joint distributions of the PROMIS PF 20a T-score changes and a seven-point global change anchor measure. The 108 simulation conditions (1000 replications per condition) included combinations of three marginal distributions of T-score changes, three improvement percentages in the anchor measure, four levels of responsiveness correlations, and three sample sizes. Threshold estimation methods included mean change, median change, ROC curve, predictive modeling, half SD, and SEM. Relative bias, precision, accuracy, and measurement significance of the estimates were evaluated based on comparison with true thresholds and IRT-based individual reliable changes of PROMIS scores. Quantile regression models were applied to select and interpret effects of simulation conditions on estimation bias.

RESULTS

When PROMIS T-score changes were distributed normally, the predictive modeling method performed best with 50% or more responders identified by the anchor; the mean and median methods were preferred with 30% responders. For skewed distributions, the median method and ROC method gained more advantages. Among the evaluated study conditions, the improvement percentage condition had the most obvious effects on estimation bias.

CONCLUSION

To establish accurate and precise thresholds, clinical researchers are recommended to prioritize study designs with at least 50% anchor-defined responders and strongly responsive target endpoints with highly reliable scoring calibration and to select optimal anchor-based methods given the data characteristics.

Minimal important difference and patient acceptable symptom state for common outcome instruments in patients with a closed humeral shaft fracture - analysis of the FISH randomised clinical trial data

Background

Two common ways of assessing the clinical relevance of treatment outcomes are the minimal important difference (MID) and the patient acceptable symptom state (PASS). The former represents the smallest change in the given outcome that makes people feel better, while the latter is the symptom level at which patients feel well.

Methods

We recruited 124 patients with a humeral shaft fracture to a randomised controlled trial comparing surgery to nonsurgical care. Outcome instruments included the Disabilities of Arm, Shoulder, and Hand (DASH) score, the Constant-Murley score, and two numerical rating scales (NRS) for pain (at rest and on activities). A reduction in DASH and pain scores, and increase in the Constant-Murley score represents improvement. We used four methods (receiver operating characteristic [ROC] curve, the mean difference of change, the mean change, and predictive modelling methods) to determine the MID, and two methods (the ROC and 75th percentile) for the PASS. As an anchor for the analyses, we assessed patients’ satisfaction regarding the injured arm using a 7-item Likert-scale.

Results

The change in the anchor question was strongly correlated with the change in DASH, moderately correlated with the change of the Constant-Murley score and pain on activities, and poorly correlated with the change in pain at rest (Spearman’s rho 0.51, -0.40, 0.36, and 0.15, respectively).

Depending on the method, the MID estimates for DASH ranged from -6.7 to -11.2, pain on activities from -0.5 to -1.3, and the Constant-Murley score from 6.3 to 13.5.

The ROC method provided reliable estimates for DASH (-6.7 points, Area Under Curve [AUC] 0.77), the Constant-Murley Score (7.6 points, AUC 0.71), and pain on activities (-0.5 points, AUC 0.68).

The PASS estimates were 14 and 10 for DASH, 2.5 and 2 for pain on activities, and 68 and 74 for the Constant-Murley score with the ROC and 75th percentile methods, respectively.

Conclusion

Our study provides credible estimates for the MID and PASS values of DASH, pain on activities and the Constant-Murley score, but not for pain at rest. The suggested cut-offs can be used in future studies and for assessing treatment success in patients with humeral shaft fracture.

Trial registration

ClinicalTrials.gov NCT01719887, first registration 01/11/2012.

Minimal important change was on the lower spectrum of previous estimates and responsiveness was sufficient for core outcomes in chronic low back pain

OBJECTIVES

The objective of this study was to estimate the minimal important change (MIC) and responsiveness of core patient reported outcome measures for chronic low back pain (LBP) and Modic changes.

STUDY DESIGN AND SETTING

In the Antibiotics in Modic changes (AIM) trial we measured disability (RMDQ, ODI), LBP intensity (NRS) and health-related quality of life (EQ5D) electronically at baseline, three- and 12-month follow-up. MICs were estimated using Receiver Operating Curve (ROC) curve and Predictive modeling analyses against the global perceived effect. Credibility of the estimates was assessed by a standardized set of criteria. Responsiveness was assessed by a construct and criterion approach according to COSMIN guidelines.

RESULTS

The MIC estimates of RMDQ, ODI and NRS scores varied between a 15-40% reduction, depending on including "slightly improved" in the definition of MIC or not. The MIC estimates for EQ5D were lower. The credibility of the estimates was moderate. For responsiveness, five out of six hypotheses were confirmed and AUC was >0.7 for all PROMs.

CONCLUSION

When evaluated in a clinical trial of patients with chronic LBP and Modic changes, MIC thresholds for all PROMs were on the lower spectrum of previous estimates, varying depending on the definition of MIC. Responsiveness was sufficient.

Clinically important change on the Unified Dyskinesia Rating Scale among patients with Parkinson's disease experiencing dyskinesia

Background

The Unified Dyskinesia Rating Scale (UDysRS) evaluates dyskinesia in patients with Parkinson's disease (PD). A minimal clinically important change (MCIC)—the smallest change in a treatment outcome that a patient considers important—remains undefined for the UDysRS.

Objective

To utilize pivotal amantadine delayed-release/extended-release (DR/ER) trial data to derive MCICs for the UDysRS total score in patients with PD experiencing dyskinesia.

Methods

Pivotal trials included PD patients with ≥1 h daily ON time with troublesome dyskinesia and baseline scores ≥2 on the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part IV, item 4.2. Patients randomized to amantadine DR/ER or placebo completed two consecutive 24-h diaries before each clinic visit and were evaluated during ON time with dyskinesia using the UDysRS, MDS-UPDRS, and Clinician Global Impression of Change (CGI-C). The UDysRS changes from baseline to week 12 were anchored to corresponding changes in MDS-UPDRS item 4.2 scores. A minimal clinically important improvement in the CGI-C and diary-reported ON time with troublesome dyskinesia (≥0.5 h) were supportive anchors. Receiver operating characteristic curves determined the UDysRS change values optimizing sensitivity and specificity to at least minimal improvement on each anchor.

Results

The analyses included 196 patients. Week 12 UDysRS total score reduction of ≥8 points corresponded to at least minimal MDS-UPDRS item 4.2 improvement. UDysRS reduction of ≥9 points corresponded to decreased ON time with troublesome dyskinesia of ≥0.5 h per patient diaries, and UDysRS reduction of ≥10 points corresponded to at least minimal improvement on the CGI-C.

Conclusion

Anchored to the MDS-UPDRS Part IV, item 4.2, an 8-point reduction in the UDysRS total score can be considered an MCIC for PD patients with dyskinesia.

Meaningful thresholds for patient-reported outcomes following interventions for anterior cruciate ligament tear or traumatic meniscus injury: a systematic review for the OPTIKNEE consensus

OBJECTIVE

We synthesised and assessed credibility (ie, trustworthiness) of thresholds that define meaningful scores for patient-reported outcome measures (PROMs) following interventions for anterior cruciate ligament (ACL) tear or traumatic meniscus injury.

DESIGN

Systematic review, narrative synthesis.

DATA SOURCES

We searched five databases, handsearched references of included studies and tracked citations.

ELIGIBILITY

Included studies investigated: individuals with ACL tear or meniscus injury; mean age <35 years; and PROM thresholds calculated using any method to define a minimal important change (MIC) or a meaningful post-treatment score (Patient Acceptable Symptom State (PASS) or Treatment Failure).

RESULTS

We included 18 studies (15 ACL, 3 meniscus). Three different methods were used to calculate anchor-based MICs across 9 PROMs, PASS thresholds across 4 PROMs and treatment failure for 1 PROM. Credibility was rated 'high' for only one study-an MIC of 18 for the Knee injury and Osteoarthritis Outcome Score Quality-of-life (KOOS-QOL) subscale (using the MID Credibility Assessment Tool). Where multiple thresholds were calculated among 'low' credibility thresholds in ACL studies, MICs converged to within a 10-point range for KOOS-Symptoms (-1.2 to 5.4) and function in daily living (activities of daily living, ADL 0.5-8.1) subscales, and the International Knee Documentation Committee Subjective Knee Form (7.1-16.2). Other PROM thresholds differed up to 30 points. PASS thresholds converged to within a 10-point range in KOOS-ADL for ACL tears (92.3-100), and KOOS-Symptoms (73-78) and KOOS-QOL (53-57) in meniscus injuries.

CONCLUSION

Meaningful PROM thresholds were highly susceptible to study heterogeneity. While PROM thresholds can aid interpretability in research and clinical practice, they should be cautiously interpreted.

Likely change indexes improve estimates of individual change on patient-reported outcomes

PURPOSE

Individual change on a patient-reported outcome (PRO) measure can be assessed by statistical significance and meaningfulness to patients. We explored the relationship between these two criteria by varying the confidence levels of the coefficient of repeatability (CR) on the Patient-Reported Outcomes Measurement Information System (R) Physical Function (PF) 10a (PF10a) measure.

METHODS

In a sample of 1129 adult cancer patients, we estimated individual-change thresholds on the PF10a from baseline to 6 weeks later with the CR at 50%, 68%, and 95% confidence. We also assessed agreement with group- and individual-level thresholds from anchor-based methods [mean change and receiver operating characteristic (ROC) curve] using a PF-specific patient global impression of change (PGIC).

RESULTS

CRs at 50%, 68%, and 95% confidence were 3, 4, and 7 raw score points, respectively. The ROC- and mean-change-based thresholds for deterioration were -4 and -6; for improvement they were both 2. Kappas for agreement between anchor-based thresholds and CRs for deterioration ranged between κ = 0.65 and 1.00, while for improvement, they ranged between 0.35 and 0.83. Agreement between the PGIC and all CRs always fell below "good" (κ < 0.40) for deterioration (0.30-0.33) and were lower for improvement (0.16-0.28).

CONCLUSIONS

In comparison to the CR at 95% confidence, CRs at 50% and 68% confidence (considered likely change indexes) have the advantage of maximizing the proportion of patients appropriately classified as changed according to statistical significance and meaningfulness.

Establishing thresholds for meaningful within-individual change using longitudinal item response theory

Purpose

Thresholds for meaningful within-individual change (MWIC) are useful for interpreting patient-reported outcome measures (PROM). Transition ratings (TR) have been recommended as anchors to establish MWIC. Traditional statistical methods for analyzing MWIC such as mean change analysis, receiver operating characteristic (ROC) analysis, and predictive modeling ignore problems of floor/ceiling effects and measurement error in the PROM scores and the TR item. We present a novel approach to MWIC estimation for multi-item scales using longitudinal item response theory (LIRT).

Methods

A Graded Response LIRT model for baseline and follow-up PROM data was expanded to include a TR item measuring latent change. The LIRT threshold parameter for the TR established the MWIC threshold on the latent metric, from which the observed PROM score MWIC threshold was estimated. We compared the LIRT approach and traditional methods using an example data set with baseline and three follow-up assessments differing by magnitude of score improvement, variance of score improvement, and baseline-follow-up score correlation.

Results

The LIRT model provided good fit to the data. LIRT estimates of observed PROM MWIC varied between 3 and 4 points score improvement. In contrast, results from traditional methods varied from 2 to 10 points—strongly associated with proportion of self-rated improvement. Best agreement between methods was seen when approximately 50% rated their health as improved.

Conclusion

Results from traditional analyses of anchor-based MWIC are impacted by study conditions. LIRT constitutes a promising and more robust analytic approach to identifying thresholds for MWIC.

Interpretation threshold values for the Oxford Knee Score in patients undergoing unicompartmental knee arthroplasty

BACKGROUND AND PURPOSE

Developing meaningful thresholds for the Oxford Knee Score (OKS) advances its clinical use. We determined the minimal important change (MIC), patient acceptable symptom state (PASS), and treatment failure (TF) values as meaningful thresholds for the OKS at 3-, 12-, and 24-month follow-up in patients undergoing unicompartmental knee arthroplasty (UKA).

PATIENTS AND METHODS

This is a cohort study with data from patients undergoing UKA collected at a hospital in Denmark between February 2016 and September 2021. The OKS was completed preoperatively and at 3, 12, and 24 months postoperatively. Interpretation threshold values were calculated with the anchor-based adjusted predictive modeling method. Non-parametric bootstrapping was used to derive 95% confidence intervals (CI).

RESULTS

Complete 3-, 12-, and 24-month postoperative data was obtained for 331 of 423 (78%), 340 of 479 (71%), and 235 of 338 (70%) patients, median age of 68-69 years (58-59% females). Adjusted OKS MIC values were 4.7 (CI 3.3-6.0), 7.1 (CI 5.2-8.6), and 5.4 (CI 3.4- 7.3), adjusted OKS PASS values were 28.9 (CI 27.6-30.3), 32.7 (CI 31.5-33.9), and 31.3 (CI 29.1-33.3), and adjusted OKS TF values were 24.4 (CI 20.7-27.4), 29.3 (CI 27.3-31.1), and 28.5 (CI 26.0-30.5) at 3, 12, and 24 months postoperatively, respectively. All values statistically significantly increased from 3 to 12 months but not from 12 to 24 months.

INTERPRETATION

The UKA-specific measurement properties and clinical thresholds for the OKS can improve the interpretation of UKA outcome and assist quality assessment in institutional and national registries.