Patients' ratings of global perceived change during 2 years were strongly influenced by the current health status

Patient Characteristics Associated With Worsening of Neck Pain-Related Disability After Surgery for Degenerative Cervical Myelopathy: A Nationwide Study of 1508 Patients

BACKGROUND AND OBJECTIVES

Functional status, pain, and quality of life usually improve after surgery for degenerative cervical myelopathy (DCM), but a subset of patients report worsening. The objective was to define cutoff values for worsening on the Neck Disability Index (NDI) and identify prognostic factors associated with worsening of pain-related disability 12 months after DCM surgery.

METHODS

In this prognostic study based on prospectively collected data from the Norwegian Registry for Spine Surgery, the NDI was the primary outcome. Receiver operating characteristics curve analyses were used to obtain cutoff values, using the global perceived effect scale as an external anchor. Univariable and multivariable analyses were performed using mixed logistic regression to evaluate the relationship between potential prognostic factors and the NDI.

RESULTS

Among the 1508 patients undergoing surgery for myelopathy, 1248 (82.7%) were followed for either 3 or 12 months. Of these, 317 (25.4%) were classified to belong to the worsening group according to the mean NDI percentage change cutoff of 3.3. Multivariable analyses showed that smoking (odds ratio [OR] 3.4: 95% CI 1.2-9.5: P < .001), low educational level (OR 2.5: 95% CI 1.0-6.5: P < .001), and American Society of Anesthesiologists grade >II (OR 2.2: 95% CI 0.7-5.6: P = .004) were associated with worsening. Patients with more severe neck pain (OR 0.8: 95% CI 0.7-1.0: P = .003) and arm pain (OR 0.8: 95% CI 0.7-1.0; P = .007) at baseline were less likely to report worsening.

CONCLUSION

We defined a cutoff value of 3.3 for worsening after DCM surgery using the mean NDI percentage change. The independent prognostic factors associated with worsening of pain-related disability were smoking, low educational level, and American Society of Anesthesiologists grade >II. Patients with more severe neck and arm pain at baseline were less likely to report worsening at 12 months.

Responsiveness of specific and generic patient-reported outcome measures in patients with plantar fasciopathy

PURPOSE

To evaluate and compare responsiveness characteristics for the Foot Function Index revised short form (FFI-RS), RAND-12 Health Status Inventory (RAND-12), and Numeric Rating Scale (NRS), in patients with plantar fasciopathy receiving non-surgical treatment.

MATERIALS AND METHODS

This study was conducted on a sub-group of patients from an ongoing randomised controlled trial. One-hundred fifteen patients were included. The patient-reported outcome measures (PROMs) were applied at baseline and after 6 months. Responsiveness was calculated using standardised response mean and area under the receiver operating characteristic (ROC) curve. ROC curves were used to compute the minimal important change (MIC) for the outcome measures.

RESULTS

The region specific FFI-RS had best responsiveness and the NRS at rest had lowest responsiveness.

CONCLUSION

FFI-RS were marginally more responsive than the other PROMs. Responsiveness and MIC estimates should be regarded as indicative rather than fixed estimates.

Determining minimal clinically important difference estimates following surgery for degenerative conditions of the lumbar spine: analysis of the Canadian Spine Outcomes and Research Network (CSORN) registry

BACKGROUND CONTEXT

There is significant variability in minimal clinically important difference (MCID) criteria for lumbar spine surgery that suggests population and primary pathology specific thresholds may be required to help determine surgical success when using patient reported outcome measures (PROMs).

PURPOSE

The purpose of this study was to estimate MCID thresholds for 3 commonly used PROMs after surgical intervention for each of 4 common lumbar spine pathologies.

STUDY DESIGN/SETTING

Observational longitudinal study of patients from the Canadian Spine Outcomes and Research Network (CSORN) national registry.

PATIENT SAMPLE

Patients undergoing surgery from 2015 to 2018 for lumbar spinal stenosis (LSS; n = 856), degenerative spondylolisthesis (DS; n = 591), disc herniation (DH; n = 520) or degenerative disc disease (DDD n = 185) were included.

OUTCOME MEASURES

PROMs were collected presurgery and 1-year postsurgery: the Oswestry Disability Index (ODI), and back and leg Numeric Pain Rating Scales (NPRS). At 1-year, patients reported whether they were 'Much better'/'Better'/'Same'/'Worse'/'Much worse' compared to before their surgery. Responses to this item were used as the anchor in analyses to determine surgical MCIDs for benefit ('Much better'/'Better') and substantial benefit ('Much better').

METHODS

MCIDs for absolute and percentage change for each of the 3 PROMs were estimated using a receiving operating curve (ROC) approach, with maximization of Youden's index as primary criterion. Area under the curve (AUC) estimates, sensitivity, specificity and correct classification rates were determined. All analyses were conducted separately by pathology group.

RESULTS

MCIDs for ODI change ranged from -10.0 (DDD) to -16.9 (DH) for benefit, and -13.8 (LSS) to -22.0 (DS,DH) for substantial benefit. MCID for back and leg NPRS change were -2 to -3 for each group for benefit and -4.0 for substantial benefit for all groups on back NPRS. MCID estimates for percentage change varied by PROM and pathology group, ranging from -11.1% (ODI for DDD) to -50.0% (leg NPRS for DH) for benefit and from -40.0% (ODI for DDD) to -66.6% (leg NPRS for DH) for substantial benefit. Correct classification rates for all MCID thresholds ranged from 71% to 89% and were relatively lower for absolute vs percent change for those with high or low presurgical scores.

CONCLUSIONS

Our findings suggest that the use of generic MCID thresholds across pathologies in lumbar spine surgery is not recommended. For patients with relatively low or high presurgery PROM scores, MCIDs based on percentage change, rather than absolute change, appear generally preferable. These findings have applicability in clinical and research settings, and are important for future surgical prognostic work.

What are the Minimum Clinically Important Difference Values for the PROMIS and QuickDASH After Carpal Tunnel Release? A Prospective Cohort Study

BACKGROUND

To better define the clinical significance of patient-reported outcomes, the concept of a minimum clinically important difference (MCID) exists. The MCID is the minimum change that a patient will perceive as meaningful. Prior attempts to determine the MCID after carpal tunnel release are limited by methodologic concerns, including the lack of a true anchor-based MCID calculation.

QUESTIONS/PURPOSES

To address previous methodologic concerns in existing studies, as well as establish a clinically useful value for clinicians, we asked: What are the MCID values for the Patient-Reported Outcomes Measurement Information System (PROMIS) Upper Extremity (UE), PROMIS Pain Interference (PI), and the QuickDASH after carpal tunnel release?

METHODS

We conducted a prospective cohort study at an urban, Midwest, multihospital, academic health system. One hundred forty-seven adult patients undergoing unilateral carpal tunnel release between September 2020 and February 2022 were identified. PROMIS UE, PI, and QuickDASH scores were collected preoperatively and 3 months postoperatively. We also collected responses to an anchor-based question: "Since your treatment, how would you rate your overall function?" (much worse, worse, slightly worse, no change, slightly improved, improved, or much improved). Patients who did not respond to the 3-month postoperative surveys were excluded. A total of 122 patients were included in the final analysis (83% response proportion [122 of 147]). The mean age was 57 years (range 23 to 87 years), and 68% were women. The MCID was calculated using both anchor-based and distribution-based methods. Although anchor-based calculations are generally considered more clinically relevant because they consider patients' perceptions of improvement, an estimation of the minimum detectable change (which represents measurement error) relies on a distribution-based calculation. We determined a range of MCID values to propose a final MCID value for all three instruments. A negative MCID value for the PROMIS PI instrument represents a decrease in pain, whereas a positive value for the PROMIS UE instrument represents an improvement in function. A negative value for the QuickDASH instrument represents an increase in function.

RESULTS

The final proposed MCID values were 6.2 (interquartile range [IQR] 5.4 to 9.0) for the PROMIS UE, -7.8 (IQR -6.1 to -8.5) for the PROMIS PI, and -18.2 (IQR -13.3 to -34.1) for the QuickDASH.

CONCLUSION

We recommend that clinicians use the following values as the MCID after carpal tunnel release: 6 for the UE, -8 for the PI, and -18 for the QuickDASH. Surgeons may find these values useful when counseling patients postoperatively regarding improvement. Future studies could examine whether a single MCID (or small range) for PROMIS instruments is applicable to a variety of conditions and interventions.

LEVEL OF EVIDENCE

Level II, therapeutic study.

Return to Work After Surgery for Cervical Radiculopathy: A Nationwide Registry-based Observational Study

STUDY DESIGN

An observational multicenter study.

SUMMARY OF BACKGROUND DATA

Return to work (RTW) is increasingly used to assess the standard, benefit, and quality of health care.

OBJECTIVE

The aim of this study was to evaluate sick leave patterns among patients undergoing surgery for cervical radiculopathy and identify predictors of successful RTW using two nationwide databases.

MATERIALS AND METHODS

Data from the Norwegian Registry for Spine Surgery (NORspine) and the Norwegian Labour and Welfare Administration were linked on an individual level. We included patients between 18 and 60 years of age registered in NORspine from June 2012 through December 2019 that were temporarily out of the labor force for medical reasons at the time of surgery. We assessed types and grades of sickness benefits before and after surgery and conducted logistic regression analyses.

RESULTS

Among 3387 patients included in the study, 851 (25.1%) received temporary benefits one year before surgery. The proportion of recipients increased steadily towards surgery. Postoperatively the medical benefit payment decreased rapidly, and half of the patients had already returned to work by four months. The rate of RTW reached a plateau at one year. By the end of the third year, 2429 patients (71.7%) had returned to work. The number of sick days, categorized as 90 or less, during the year before surgery had the most powerful association with RTW at two years (odds ratio: 4.54, 95% CI: 3.42-6.03, P <0.001). Improvement in neck-related disability was the second strongest predictor (odds ratio: 2.17, 95% CI: 1.69-2.78, P <0.001).

CONCLUSION

RTW after cervical radiculopathy surgery occurs primarily during the first year. The strongest predictor of RTW was fewer sick days before surgery. The clinical improvement after surgery had a lesser impact.

LEVEL OF EVIDENCE

2.

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.

Is the VISA-A Still Seaworthy, or Is It in Need of Maintenance?

Background

The Victorian Institute of Sport Assessment-Achilles (VISA-A) questionnaire is validated and widely used in Achilles tendinopathy. How well it can evaluate treatment outcomes is not well understood.

Purpose

To evaluate the responsiveness of the VISA-A in midportion Achilles tendinopathy and compare it with other patient-reported outcome measures.

Study Design

Cohort study (diagnosis); Level of evidence, 2.

Methods

Enrolled were 97 participants with clinically diagnosed Achilles tendinopathy (median age, 50 years [interquartile range, 18 years]; symptom duration, 10 months [interquartile range, 28.7 months). The participants underwent a baseline evaluation and completed between 1 and 6 follow-up evaluations at 8, 16, 24, 32, 40, and/or 48 weeks. Participants completed the VISA-A, the Patient Reported Outcomes Measurement Information System short form Version 2.0 (PROMIS) Physical Function and Pain Interference subscales, and the Tampa Scale for Kinesiophobia (TSK). Three thresholds were evaluated with a receiver operating characteristic analysis (minimal clinically important difference [MCID], substantial benefit [SB], and complete recovery [CR]) using an 11-point global rating of change scale as an anchor. Thresholds were evaluated on raw scores as well as changes from baseline.

Results

The VISA-A was able to detect all 3 thresholds for changes over time, with raw scores >70.5, >77.5, and >89.5 representing the MCID, SB, and CR, respectively; thresholds for changes from baseline on the VISA-A were increases of 23.5, 19.5, and 37.5 points from baseline, respectively. The PROMIS subscale raw scores had identical thresholds for SB and CR (52.45 for Physical Function and 45.6 for Pain Interference). A score <34.5 on the TSK was the threshold for SB.

Conclusion

The VISA-A was the most responsive outcome measure evaluated. Raw scores had increasingly higher thresholds for the MCID, SB, and CR, which were therefore logically consistent.

What is success of treatment? Expected outcome scores in cervical radiculopathy patients were much higher than the previously reported cut-off values for success

PURPOSE

Treatment success can be defined by asking a patient how they perceive their condition compared to prior to treatment, but it can also be defined by establishing success criteria in advance. We evaluated treatment outcome expectations in patients undergoing surgery or non-operative treatment for cervical radiculopathy.

METHODS

The first 100 consecutive patients from an ongoing randomized controlled trial (NCT03674619) comparing the effectiveness of surgical and nonsurgical treatment for cervical radiculopathy were included. Patient-reported outcome measures and expected outcome and improvement were obtained before treatment. We compared these with previously published cut-off values for success. Arm pain, neck pain and headache were measured by a numeric rating scale. Neck disability index (NDI) was used to record pain-related disability. We applied Wilcoxon signed-rank test to compare the expected outcome scores for the two treatments.

RESULTS

Patients reported mean NDI of 42.2 (95% CI 39.6-44.7) at baseline. The expected mean NDI one year after the treatment was 4 (95% CI 3.0-5.1). The expected mean reduction in NDI was 38.3 (95% CI 35.8-40.8). Calculated as a percentage change score, the patients expected a mean reduction of 91.2% (95% CI 89.2-93.2). Patient expectations were higher regarding surgical treatment for arm pain, neck pain and working ability, P < 0.001, but not for headache.

CONCLUSIONS

The expected improvement after treatment of cervical radiculopathy was much higher than the previously reported cut-off values for success. Patients with cervical radiculopathy had higher expectations to surgical treatment.

Interpreting patient reports of perceived change during treatment for depression: Findings from the Veterans Outcome Assessment survey

This study addressed ongoing questions about the meaning of patients' perceptions of change during treatment. The study used data from the Veterans Outcome Assessment survey for patients with a depressive disorder, without mental health comorbidities, treated in Department of Veterans Affairs general mental health clinics (n = 694). Perceived changes in problems/symptoms, other domains, and the quality of communication with providers were evaluated with items from the Experience of Care & Health Outcomes (ECHO) survey. Depressive symptoms were measured with the Patient Health Questionnaire-9 (PHQ-9). Linear regression models evaluated associations of perceived change at 3-months post-baseline with observed change in PHQ-9 scores, scores on other patient-reported outcome measures (PROMs), and ratings of communication with providers. Patients' reports of their clinical condition at follow-up together with ratings of communication accounted for approximately one-third of the variance in patients' perceptions of change. Adding change-scores based on baseline and follow-up scores on the PHQ-9 and other PROMs did not improve model fit. The findings suggest that patient reports of perceived change during treatment reflect their current clinical state and their experience of care more closely than actual changes in the PHQ-9 or other PROMs.

Adaptation of the Patient Benefit Assessment Scale for Hospitalised Older Patients: development, reliability and validity of the P-BAS picture version

Background

The Patient Benefit Assessment Scale for Hospitalised Older Patients (P-BAS HOP) is a tool developed to both identify the priorities of the individual patient and to measure the outcomes relevant to him/her, resulting in a Patient Benefit Index (PBI), indicating how much benefit the patient had experienced from the hospitalisation. The reliability and the validity of the P-BAS HOP appeared to be not yet satisfactory and therefore the aims of this study were to adapt the P-BAS HOP and transform it into a picture version, resulting in the P-BAS-P, and to evaluate its feasibility, reliability, validity, responsiveness and interpretability.

Methods

Process of instrument development and evaluation performed among hospitalised older patients including pilot tests using Three-Step Test-Interviews (TSTI), test-retest reliability on baseline and follow-up, comparing the PBI with Intraclass Correlation Coefficient (ICC), and hypothesis testing to evaluate the construct validity. Responsiveness of individual P-BAS-P scores and the PBI with two different weighing schemes were evaluated using anchor questions. Interpretability of the PBI was evaluated with the visual anchor-based minimal important change (MIC) distribution method and computation of smallest detectable change (SDC) based on ICC.

Results

Fourteen hospitalised older patients participated in TSTIs at baseline and 13 at follow-up after discharge. After several adaptations, the P-BAS-P appeared feasible with good interviewer’s instructions. The pictures were considered relevant and helpful by the participants. Reliability was tested with 41 participants at baseline and 50 at follow-up. ICC between PBI₁ and PBI₂ of baseline test and retest was 0.76, respectively 0.73. At follow-up 0.86, respectively 0.85.

For the construct validity, tested in 169 participants, hypotheses regarding importance of goals were confirmed. Regarding status of goals, only the follow-up status was confirmed, baseline and change were not. The responsiveness of the individual scores and PBI were weak, resulting in poor interpretability with many misclassifications. The SDC was larger than the MIC.

Conclusions

The P-BAS-P appeared to be a feasible instrument, but there were methodological barriers for the evaluation of the reliability, validity, and responsiveness. We therefore recommend further research into the P-BAS-P.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02708-7.

Minimum Clinically Important Difference: A Metric That Matters in the Age of Patient-Reported Outcomes

➤

As the Patient-Reported Outcomes Measurement Information System (PROMIS) is increasingly utilized in orthopaedic research and clinical practice, there is not a consensus regarding the minimum clinically important difference (MCID) calculation.

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The varied MCID calculation methods can lead to a range of possible values, which limits the translatability of research efforts.

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The completion rate and follow-up period also influence MCID values and should be reported alongside study results.

Single item self-rated general health: SF-36 based observations from 16,910 spine surgery procedures

PURPOSE

In spine surgery single item patient-reported outcome assessment has been used for many years. Items 1 and 2 of SF-36 are used for assessment of general health. We used these items to explore single item, self-rated, general health assessment after spine surgery.

METHODS

Patients operated for lumbar disc herniation or lumbar spinal stenosis between 2007 and 2017, were recruited from the national Swedish spine register. A total of 16,910 procedures were eligible for analysis. The responsiveness of the SF-36 general health assessment items to surgical treatment was evaluated with the standardized response mean (SRM). Improvement in self-rated general health was used to dichotomize SF-36 profiles and EQ VAS distributions.

RESULTS

For disc herniation, 5852 (83%) patients reported improvement in general health 1 year after surgery. For spinal stenosis, the corresponding numbers were 6,482 (66%). The additional improvement after year 1 was small. The responsiveness of the SF-36 item 2 (the health transition item) to surgical treatment of disc herniation or spinal stenosis was substantial. There was a clear association between improvement in SF-36 item 2 and improvements in all domains of SF-36.

CONCLUSIONS

Surgery for disc herniation or spinal stenosis improve patients' perception of general health 1 year after surgery. The improvement in general health after year 1 is limited. The SF-36 item 2 is a responsive measure of self-rated general health that may be used for dichotomization of SF-36 and EQ VAS data when evaluating surgical outcome in spine surgery.

Criteria for failure and worsening after surgery for lumbar spinal stenosis: a prospective national spine registry observational study

BACKGROUND CONTEXT

Criteria for success after surgical treatment of lumbar spinal stenosis (LSS) have been defined previously; however, there are no clear criteria for failure and worsening after surgery as assessed by patient-reported outcome measures (PROMs).

PURPOSE

We aimed to quantify changes in standard PROMs that most accurately identified failure and worsening after surgery for LSS.

STUDY DESIGN /SETTING

Retrospective analysis of prospective national spine registry data with 12-months follow-up.

PATIENT SAMPLE

We analyzed 10,822 patients aged 50 years and older operated in Norway during a decade, and 8,258 (76%) responded 12 months after surgery.

OUTCOME MEASURES (PROMS)

We calculated final scores, absolute changes, and percentage changes for Oswestry Disability Index (ODI), Numeric Rating Scale (NRS) for back and leg pain (0-10), and EuroQol-5D (EQ-5D). These 12 PROM derivates were compared to the Global Perceived Effect (GPE), a 7-point Likert scale.

METHODS

We used ODI, NRS back and leg pain, and EQ-5D 12 months after surgery to identify patients with failure (no effect) and worsening (clinical deterioration). The corresponding GPE at 12-months was graded as failure (GPE=4-7) and worsening (GPE=6-7) and used as an external criterion. To quantify the most accurate cut-off values corresponding to failure and worsening, we calculated areas under the curves (AUCs) of receiver operating characteristics (ROC) curves for the respective PROM derivates.

RESULTS

Mean (95% CI) age was 68.3 (68.1 - 68.5) years, and 52% were females. There were 1,683 (20%) failures, and 476 (6%) patients were worse after surgery. The mean (95% CI) pre- and postoperative ODIs were 39.8 (39.5 - 40.2) and 23.7 (23.3 - 24.1), respectively. At 12 months, the mean difference (95% CI) in ODI was 16.1 (15.7 - 16.4), and the mean (95% CI) percentage improvement 38.8% (37.8 - 38.8). The PROM derivates identified failure and worsening accurately (AUC>0.80), except for the absolute change in EQ-5D. The ODI derivates were most accurate to identify both failure and worsening. We found that less than 20% improvement in ODI most accurately identified failure (AUC=0.89 [95% CI: 0.88 to 0.90]), and an ODI final score of 39 points or more most accurately identified worsening (AUC =0.91 [95% CI: 0.90 - 0.92]).

CONCLUSIONS

In this national register study, ODI derivates were most accurate to identify both failure and worsening after surgery for degenerative lumbar spinal stenosis. We recommend use of ODI percentage change and ODI final score for further studies of failure and worsening in elective spine surgery.

Evaluation of occupational therapy-led advanced practice hand therapy clinics for patients on surgical outpatient waiting lists at eight Australian public hospitals

STUDY DESIGN

This is a prospective cohort study.

INTRODUCTION

Evidence is emerging that advanced practice hand therapy clinics improve patient outcomes.

PURPOSE OF THE STUDY

The aim of this study was to evaluate an advanced practice hand therapy model of care for patients with chronic hand conditions on surgical outpatient waiting lists at eight Australian public hospitals.

METHODS

Nonurgent and semiurgent patients were screened and treated, as required, by an advanced practice hand therapist and then discharged from the surgical outpatient waiting list as appropriate. Outcomes included patient safety, impact on the waiting list, patient satisfaction, and patients' perception of change as measured by Global Rating of Change (GROC). The GROC score was also compared across diagnoses. The relationship between the waiting time and need for surgical review during hand therapy treatment was also assessed. As appropriate, T-tests and analysis of variance were used for statistical analyses.

RESULTS

A total of 37.2% of patients who commenced hand therapy were removed or discharged from the surgical outpatient waiting lists. Of the subset of patients who completed hand therapy (n = 1116), 28.4% were discharged without requiring surgical follow-up. A further 7.53% requested return to the waiting list despite discharge being recommended. The model of care was safe, and patient satisfaction was above 90%. The mean GROC score was +2.09 (±3.58) but varied across diagnoses with trigger finger or trigger thumb showing the greatest improvement (+4.21 ± 2.92, P < .01). Patients who did not require surgical consultation during hand therapy had a shorter wait time for their initial hand therapy appointment (P < .001).

CONCLUSIONS

The advanced practice hand therapy model of care was safe and effective in reducing hospital surgical outpatient waiting lists. Patients reported high satisfaction.

Responsiveness of five shoulder outcome measures at follow-ups from 3 to 24 months

Background

To assess responsiveness of five outcome measures at four different follow-ups in patients with SLAP II lesions of the shoulder.

Methods

119 patients with symptoms and signs, MRI arthrography and arthroscopic findings were included. The Western Ontario Shoulder Instability Index (WOSI), Oxford Instability Shoulder Score (OISS), EuroQol (EQ-5D3L), Rowe Score and Constant-Murley Score (CMS) were assessed at baseline, 3, 6, 12 and 24 months. The analysis contains both anchor-based and distribution-based methods, and hypothesis testing.

Results

Confidence intervals for ROC cut-off values, representing MID, for OISS, CMS and EQ-5D3L crossed zero at 3 months. Cut-off values were stable between 6- and 24-months follow-up. At 24-months ROC cut-off values (95% CI) were: Rowe 18 (13 to 24); WOSI 331 (289 to 442); OISS 9 (5 to 14); CMS 11 (9 to 15) and EQ-5D3L 0.123 (0.035 to 0.222). MID_95%limit estimates were substantially higher than ROC cut-off values and MID_MEAN at all follow-ups for all instruments. The reliable change proportion (RCP) values in the improved group were highest for WOSI and the Rowe Score (ranging from 68 to 87%) and significantly lower for CMS. EQ-5D3L had the lowest values (13 to 16%). We found a moderate correlation between mean change scores of the outcome measures and the anchor, except for the EQ-5D3L.

Conclusions

In patients with SLAP II-lesions the patient reported OISS and WOSI and the clinical Rowe score had best responsiveness. Our results suggest that 3 months follow-up is too early for outcome evaluation.

Estimates of the mean difference in orthopaedic randomized trials: obligatory yet obscure

Background

Randomized controlled trials in orthopaedics are powered to mainly find large effect sizes. A possible discrepancy between the estimated and the real mean difference is a challenge for statistical inference based on p-values. We explored the justifications of the mean difference estimates used in power calculations. The assessment of distribution of observations in the primary outcome and the possibility of ceiling effects were also assessed.

Methods

Systematic review of the randomized controlled trials with power calculations in eight clinical orthopaedic journals published between 2016 and 2019. Trials with one continuous primary outcome and 1:1 allocation were eligible. Rationales and references for the mean difference estimate were recorded from the Methods sections. The possibility of ceiling effect was addressed by the assessment of the weighted mean and standard deviation of the primary outcome and its elaboration in the Discussion section of each RCT where available.

Results

264 trials were included in this study. Of these, 108 (41 %) trials provided some rationale or reference for the mean difference estimate. The most common rationales or references for the estimate of mean difference were minimal clinical important difference (16 %), observational studies on the same subject (8 %) and the ‘clinical relevance’ of the authors (6 %). In a third of the trials, the weighted mean plus 1 standard deviation of the primary outcome reached over the best value in the patient-reported outcome measure scale, indicating the possibility of ceiling effect in the outcome.

Conclusions

The chosen mean difference estimates in power calculations are rarely properly justified in orthopaedic trials. In general, trials with a patient-reported outcome measure as the primary outcome do not assess or report the possibility of the ceiling effect in the primary outcome or elaborate further in the Discussion section.

Construct Validity and Responsiveness of the University of Wisconsin Running Injury and Recovery Index

OBJECTIVES

The University of Wisconsin Running Injury and Recovery Index (UWRI) is the first running-specific patient-reported outcome measure (PROM). The UWRI evaluates the key elements runners use to self-assess running ability during recovery. This study evaluated the construct-related validity and responsiveness of the UWRI as an evaluative PROM of running ability following running-related injury (RRI).

DESIGN

Prospective longitudinal study.

METHODS

Runners seeking care from a physical therapist for an RRI (n = 396) completed PROMs at baseline and 12 weeks later. Change in UWRI score was validated against the global rating of change (GROC), Veterans RAND 12-Item Health Survey (VR-12) change, and change in body region- specific PROMs. Responsiveness was evaluated using anchor-based and distribution-based techniques.

RESULTS

Change in UWRI score (mean ± SD, 7.7 ± 8.9 points) was correlated with the GROC (r = 0.67), as well as with changes in the VR-12 Physical Component Summary (PCS) (r = 0.54) and Mental Component Summary (MCS) (r = 0.31). Change in UWRI score was correlated with changes in the Foot and Ankle Ability Measure sports subscale (r = 0.75), the 12-item International Hip Outcome Tool (r = 0.75), and the Anterior Knee Pain Scale (r = 0.48), but not with the Oswestry Disability Index Version 2.0 (r = 0.05). Change in UWRI score was significantly different in runners reporting significant improvement (12.2 ± 5.9 points), slight improvement (7.1 ± 6.6 points), no change (0.0 ± 9.1 points), and worsening (-14.6 ± 7.4 points) on the GROC anchor-based responsiveness assessment. The UWRI minimal important change and minimal clinically important difference were 5 and 8 points, respectively.

CONCLUSION

The UWRI is a valid clinical tool for evaluating running ability following RRI; it demonstrated longitudinal validity (GROC), convergent validity (PCS and body region- specific PROMs), divergent validity (MCS), and responsiveness to changes in patient-perceived running ability. J Orthop Sports Phys Ther 2020;50(12):702-710. Epub 28 Oct 2020. doi:10.2519/jospt.2020.9698.

Minimal important change in physical function in trauma patients: a study using the short musculoskeletal function assessment

Purpose

The Short Musculoskeletal Function Assessment (SMFA) questionnaire can be used to evaluate physical functioning in patients with traumatic injuries. It is not known what change in score reflects a meaningful change to patients. The aim was to determine minimal important change (MIC) values of the subscales (0–100) of the Dutch SMFA-NL in a sample of patients with a broad range of injuries.

Methods

Patients between 18 and 65 years of age completed the SMFA-NL and the Global Rating of Effect (GRE) questions at 6-week and 12-month post-injury. Anchor-based MIC values were calculated using univariable logistic regression analyses.

Results

A total of 225 patients were included (response rate 67%). The MIC value of the Upper Extremity Dysfunction (UED) subscale was 8 points, with a misclassification rate of 43%. The Lower Extremity Dysfunction subscale MIC value was 14 points, with a misclassification rate of 29%. The MIC value of the Problems with Daily Activities subscale was 25 points, with a misclassification rate of 33%. The MIC value of the Mental and Emotional Problems (MEP) subscale was 7 points, with a misclassification rate 37%.

Conclusion

MIC values of the SMFA-NL were determined. The MIC values aid interpreting whether a change in physical functioning can be considered clinically important. Due to the considerable rates of misclassification, the MIC values of the UED and MEP subscales should be used with caution.

Can a Successful Outcome After Surgery for Lumbar Disc Herniation Be Defined by the Oswestry Disability Index Raw Score?

STUDY DESIGN

Prospective multicenter cohort study.

OBJECTIVE

To investigate (1) the discriminative ability and cutoff estimates for success 12 months after surgery for lumbar disc herniation on the Oswestry Disability Index (ODI) raw score compared with a change and a percentage change score and (2) to what extent these clinical outcomes depend on the baseline disability.

METHODS

A total of 6840 patients operated for lumbar disc herniation from the Norwegian Registry for Spine Surgery (NORspine) were included. In receiver operating characteristic (ROC) curve analyses, a global perceived effect (GPE) scale (1-7) was used an external anchor. Success was defined as categories 1-2, "completely recovered" and "much better." Cutoffs for success for subgroups with different preoperative disability were also estimated.

RESULTS

When defining success after surgery for lumbar disc herniation, the accuracy (sensitivity, specificity, area under the curve, 95% CI) for the ODI raw score (0.83, 0.87, 0.930, 0.924-0.937) was comparable to the ODI percentage change score (0.85, 0.85, 0.925, 0.918-0.931), and higher than the ODI change score (0.79, 0.73, 0.838, 0.830-0.852). The cutoff for success was highly dependent on the amount of baseline disability (low-high), with cutoffs ranging from 13 to 28 for the ODI raw score and 39% to 66% for ODI percentage change. The ODI change score (points) was not as accurate.

CONCLUSION

The 12-month ODI raw score, like the ODI percentage change score, can define a successful outcome with excellent accuracy. Adjustment for the baseline ODI score should be performed when comparing outcomes across groups, and one should consider using cutoffs according to preoperative disability (low, medium, high ODI scores).

Reliability and Responsiveness of the Observable Movement Quality Scale for Children with Mild to Moderate Motor Impairments

AIM

The Observable Movement Quality (OMQ) scale measures generic movement quality and is used alongside standardized age-adequate motor performance tests. The scale consists of 15 items, each focusing on a different aspect; together, the entire construct of movement quality is assessed. This study aimed to determine interrater and intrarater reliability, and responsiveness of the OMQ scale.

METHODS

A prospective intervention study with pre-post design in pediatric physical therapy practices. For interrater reliability, 3 physical therapists observed video-recorded motor assessments of 30 children with mild to moderate motor impairments -aged 4 to 12 years-using the OMQ scale. One therapist scored baseline assessment a second time for intrarater reliability, and to calculate smallest detectable change (SDC). Responsiveness (n = 28) was tested by comparing outcomes before and after intervention.

RESULTS

Interrater reliability was moderate to good (ICC_2,1: 0.79); intrarater reliability was high (ICC_2,1: 0.97). Responsiveness results revealed an SDC of 2.4 and a minimal important change of 2.5; indicating sufficient validity in differentiating groups of children showing improved versus unchanged movement quality.

CONCLUSION

The OMQ scale is reliable and responsive to change when used to assess movement quality in clinical practice for children with mild to moderate motor impairments, aged 4-12 year.

New insight to the characteristics and clinical course of clusters of patients with imaging confirmed disc-related sciatica

BACKGROUND

Referral to secondary care is common for a considerable proportion of patients with persistent sciatica symptoms. It is unclear if information from clinical assessment can further identify distinct subgroups of disc-related sciatica, with perhaps different clinical courses.

AIMS

This study aims to identify and describe clusters of imaging confirmed disc-related sciatica patients using latent class analysis, and compare their clinical course.

METHODS

The study population were 466 patients with disc-related sciatica. Variables from clinical assessment were included in the analysis. Characteristics of the identified clusters were described and their clinical course over 2 years was compared.

RESULTS

A four-cluster solution was optimal. Cluster 1 (n = 110) had mild back and leg pain; cluster 2 (n = 59) had moderate back and leg pain; cluster 3 (n = 158) had mild back pain and severe leg pain; cluster 4 (n = 139) had severe back and leg pain. Patients in cluster 4 had the most severe profile in terms of disability, distress and comorbidity and the lowest reported global change and the smallest proportion of patients with a successful outcome at 2 years. Of the 135 patients who underwent surgery, 42% and 41% were in clusters 3 and 4, respectively.

CONCLUSIONS

Using a strict diagnosis of sciatica, this work identified four clusters of patients primarily differentiated by back and leg pain severity. Patients with severe back and leg pain had the most severe profile at baseline and follow-up irrespective of intervention. This simple classification system may be useful when considering prognosis and management with sciatica patients.

SIGNIFICANCE

Using data from a large observational prospective study, this work identifies four distinct clusters of patients with imaging confirmed disc-related sciatica. This classification could be used when considering prognosis and management with sciatica patients at their initial consultation.

Up-regulation of circulating microRNA-17 is associated with lumbar radicular pain following disc herniation

Background

Previous studies suggest that regulatory microRNAs (miRs) may modulate neuro-inflammatory processes. The purpose of the present study was to examine the role of miR-17 following intervertebral disc herniation.

Methods

In a cohort of 97 patients with leg pain and disc herniation verified on MRI, we investigated the association between circulating miR-17 and leg pain intensity. A rat model was used to examine possible changes in miR-17 expression in nucleus pulposus (NP) associated with leak of NP tissue out of the herniated disc. The functional role of miR-17 was addressed by transfection of miR-17 into THP-1 cells (human monocyte cell line).

Results

An association between the level of miR-17 in serum and the intensity of lumbar radicular pain was shown. Up-regulation of miR-17 in the rat NP tissue when applied onto spinal nerve roots and increased release of TNF following transfection of miR-17 into THP-1 cells were also observed. Hence, our data suggest that miR-17 may be involved in the pathophysiology underlying lumbar radicular pain after disc herniation.

Conclusions

We conclude that miR-17 may be associated with the intensity of lumbar radicular pain after disc herniation, possibly through a TNF-driven pro-inflammatory mechanism.

Electronic supplementary material

The online version of this article (10.1186/s13075-019-1967-y) contains supplementary material, which is available to authorized users.

Truthfulness in patient-reported outcomes: factors affecting patients' responses and impact on data quality

The use of patient-reported outcome (PRO) measures in research and clinical care has expanded dramatically, reflective of an increasing recognition of patient-centeredness as an important aspect of high-quality health care. Given this rapid expansion, ensuring that data collected using PRO measures is of high quality is crucial for their continued successful application. Because of the subjective nature of the outcomes assessed, there are many factors that may influence patients' responses and thus challenge the overall quality of the data. In this review, we discuss the multiple factors that may affect patients' responses on PRO measures. These factors may arise during instrument development and administration or secondary to patient-level response behaviors. We further examine the relevant literature to delineate how these factors may impact data quality and review methods for accounting for these factors. Consideration of such factors is critical to ensuring data collected truthfully reflects patients' evaluations and provides accurate conclusions.

Follow-up score, change score or percentage change score for determining clinical important outcome following surgery? An observational study from the Norwegian registry for Spine surgery evaluating patient reported outcome measures in lumbar spinal stenosis and lumbar degenerative spondylolisthesis

Background

Assessment of outcomes for spinal surgeries is challenging, and an ideal measurement that reflects all aspects of importance for the patients does not exist. Oswestry Disability Index (ODI), EuroQol (EQ-5D) and Numeric Rating Scales (NRS) for leg pain and for back pain are commonly used patients reported outcome measurements (PROMs). Reporting the proportion of individuals with an outcome of clinical importance is recommended. Knowledge of the ability of PROMs to identify clearly improved patients is essential. The purpose of this study was to search cut-off criteria for PROMs that best reflect an improvement considered by the patients to be of clinical importance.

Methods

The Global Perceived Effect scale was utilized to evaluate a clinically important outcome 12 months after surgery. The cut-offs for the PROMs that most accurately distinguish those who reported ‘completely recovered’ or ‘much improved’ from those who reported ‘slightly improved’, unchanged’, ‘slightly worse’, ‘much worse’, or ‘worse than ever’ were estimated. For each PROM, we evaluated three candidate response parameters: the (raw) follow-up score, the (numerical) change score, and the percentage change score.

Results

We analysed 3859 patients with Lumbar Spinal Stenosis [(LSS); mean age 66; female gender 50%] and 617 patients with Lumbar Degenerative Spondylolisthesis [(LDS); mean age 67; 72% female gender]. The accuracy of identifying ‘completely recovered’ and ‘much better’ patients was generally high, but lower for EQ-5D than for the other PROMs. For all PROMs the accuracy was lower for the change score than for the follow-up score and the percentage change score, especially among patients with low and high PROM scores at baseline.

The optimal threshold for a clinically important outcome was ≤24 for ODI, ≥0.69 for EQ-5D, ≤3 for NRS leg pain, and ≤ 4 for NRS back pain, and, for the percentage change score, ≥30% for ODI, ≥40% for NRS leg pain, and ≥ 33% for NRS back pain. The estimated cut-offs were similar for LSS and for LDS.

Conclusion

For estimating a ‘success’ rate assessed by a PROM, we recommend using the follow-up score or the percentage change score. These scores reflected a clinically important outcome better than the change score.

Assessing health status over time: impact of recall period and anchor question on the minimal clinically important difference of copd health status tools

Background

The Minimal Clinically Important Difference (MCID) assesses what change on a measurement tool can be considered minimal clinically relevant. Although the recall period can influence questionnaire scores, it is unclear if it influences the MCID. This study is the first to examine longitudinally the impact of the recall period of an anchor question and its design on the MCID of COPD health status tools using the COPD Assessment Test (CAT), Clinical COPD Questionnaire (CCQ) and the St. George’s Respiratory Questionnaire (SGRQ).

Methods

Moderate to very severe COPD patients without respiratory co-morbidities were recruited during 3-week Pulmonary Rehabilitation (PR). CAT, CCQ and SGRQ were completed at baseline, discharge, 3, 6, 9 and 12 months. A 15-point Global Rating of Change scale (GRC) was completed at each follow-up. A five-point GRC was used as second anchor at 12 months. Mean change scores of a subset of patients indicating a minimal improvement on each of the anchor questions were considered the MCID. The MCID estimates over different time periods were compared with one another by evaluating the degree of overlap of Confidence Intervals (CI) adjusted for dependency.

Results

In total 451 patients were included (57.9 ± 6.6 years, 65% male, 50/39/11% GOLD II/III/IV), of which 309 completed follow-up. Baseline health status scores were 20.2 ± 7.3 (CAT), 2.9 ± 1.2 (CCQ) and 50.7 ± 17.3 (SGRQ). MCID estimates for improvement ranged − 3.1 to − 1.4 for CAT, − 0.6 to − 0.3 for CCQ, and − 10.3 to − 7.6 for SGRQ. Absolute higher – though not significant – MCIDs were observed for CAT and CCQ directly after PR. Significantly absolute lower MCID estimates were observed for CAT (difference − 1.4: CI -2.3 to − 0.5) and CCQ (difference − 0.2: CI -0.3 to −0.1) using a five-point GRC.

Conclusions

The recall period of a 15-point anchor question seemed to have limited impact on the MCID for improvement of CAT, CCQ and SGRQ during PR; although a 3-week MCID estimate directly after PR might lead to absolute higher values. However, the design of the anchor question was likely to influence the MCID of CAT and CCQ.

Trial registration

RIMTCORE trial #DRKS00004609 and #12107 (Ethik-Kommission der Bayerischen Landesärztekammer).

Electronic supplementary material

The online version of this article (10.1186/s12955-018-0950-7) contains supplementary material, which is available to authorized users.

Testing the construct validity of a health transition question using vignette-guided patient ratings of health

Background

A single-item transition question is often used to assess improvement or worsening in health, but its validity has not been tested extensively. The purpose of this study was to test the construct validity of a transition question by relating it to qualitative changes in patient’s self-rating of health guided by clinical vignettes.

Methods

We studied 169 patients with active rheumatoid arthritis (RA) before and after treatment escalation. At both assessments, patients scored their current health on a rating scale after first rating three vignettes describing mild, moderate, or severe RA. We classified patients into one of these three RA categories using a nearest-neighbor match. We then related the change in these self-rated categories between visits to responses to a transition question on visit 2.

Results

Sixty patients improved their RA vignette category after treatment, 86 remained in the same vignette category, and 23 worsened categories. On the transition question, 101 patients reported improvement, 48 reported no change, and 20 reported worsening, representing a modest association with changes in RA vignette categories (polychoric correlation r = 0.19). The association was stronger if patients who were in the mild RA category at both visits were also classified as improved if their self-rating changed from below to above their mild vignette rating (r = 0.23) and when incorporating the importance of changes on the transition question (r = 0.26).

Conclusion

Changes in health states, guided by clinical vignettes, support the construct validity of the transition question.

The Pelvic Girdle Questionnaire: Responsiveness and Minimal Important Change in Women With Pregnancy-Related Pelvic Girdle Pain, Low Back Pain, or Both

BACKGROUND

The Pelvic Girdle Questionnaire (PGQ) is a condition-specific measure for women with pelvic girdle pain (PGP). The PGQ includes items relating to activity/participation and bodily symptoms and has reliability, validity, and feasibility for use in research and clinical practice.

OBJECTIVE

The purposes of this study were to examine the responsiveness of the PGQ, to determine the minimal important change (MIC) for the PGQ, and to compare the PGQ with other outcome measures.

DESIGN

This study used a prospective cohort design.

METHODS

A total of 801 women responded to a booklet of questionnaires in the last trimester of their pregnancy and within 3 months post partum. Responsiveness analyses followed recommendations from the Consensus-Based Standards for the Selection of Health Measurement Instruments (COSMIN) checklist. The responsiveness of the PGQ was tested by examining correlations between the change scores of the total PGQ and the other patient-reported outcome measures.

RESULTS

A total of 606 women (76%) reported PGP, low back pain, or both. Of these women, 441 (73%) responded to the follow-up questionnaire post partum. The PGQ (both subscale and total scores) discriminated most accurately between participants who improved and those who did not improve, with an area under the receiver operator characteristic curve of 72%. The MIC values indicated that a change score smaller than 25 for the total score and activity subscale score and a change score of 20 for the symptom subscale score should be regarded as insignificant. Baseline PGQ scores had a large impact on the MIC estimates for the absolute change scores but not on the relative percentage change scores. Five of 6 hypotheses were supported (83%).

LIMITATIONS

The type of anchor and definition of important change used might be weaknesses in women whose status is changing from pregnant to post partum.

CONCLUSIONS

The PGQ showed acceptable responsiveness in women with PGP, low back pain, or both.

The value of patient global assessment in lumbar spine surgery: an evaluation based on more than 90,000 patients

PURPOSE

There are two, principally different ways to obtain patient opinions regarding the outcome of spine surgery: using prospective multi-item questionnaires preoperatively and at follow-up, and using a retrospective single-item question at follow-up-both methods have distinct advantages and limitations. The purpose of the study was to explore the utility of using the simple transition question global assessment, GA, ("How is your back/leg pain today as compared to before the surgery?") as an overall patient-reported outcome measure (PROM) based on the large real-life database in the Swedish spine registry (Swespine).

METHODS

The correlation between GA and the score-changes and the final scores at 1 year of follow-up for the PROMs VAS, ODI, and EQ-5D was examined. The correlations between GA and item-specific domains within the ODI, EQ-5D and SF-36 as well as the discriminative ability of PROMs with GA as reference criterion were also analysed. The cohort consisted of 94,132 patients registered in Swespine who were surgically treated for disc herniation, spinal stenosis or degenerative disc disease.

RESULTS

The correlation coefficients for GA vs. the score-changes were lower than for GA vs final scores. For VAS they ranged for the different diagnosis groups from 0.33 to 0.61 and from 0.50 to 0.79, respectively. For ODI, the corresponding values ranged from 0.43 to 0.65 and 0.63 to 0.76; for the EQ-5D from 0.32 to 0.45 and 0.54 to 0.71. Further, GA showed a somewhat stronger correlation to pain-specific PROMs than to quality-of-life PROMs.

CONCLUSIONS

The single-item outcome measure global assessment (GA) appears to be a feasible overall patient-reported outcome measure (PROM) and a useful reference for interpreting the scores of patient-reported outcome measures.

Criteria for failure and worsening after surgery for lumbar disc herniation: a multicenter observational study based on data from the Norwegian Registry for Spine Surgery

PURPOSE

In clinical decision-making, it is crucial to discuss the probability of adverse outcomes with the patient. A large proportion of the outcomes are difficult to classify as either failure or success. Consequently, cutoff values in patient-reported outcome measures (PROMs) for "failure" and "worsening" are likely to be different from those of "non-success". The aim of this study was to identify dichotomous cutoffs for failure and worsening, 12 months after surgical treatment for lumbar disc herniation, in a large registry cohort.

METHODS

A total of 6840 patients with lumbar disc herniation were operated and followed for 12 months, according to the standard protocol of the Norwegian Registry for Spine Surgery (NORspine). Patients reporting to be unchanged or worse on the Global Perceived Effectiveness (GPE) scale at 12-month follow-up were classified as "failure", and those considering themselves "worse" or "worse than ever" after surgery were classified as "worsening". These two dichotomous outcomes were used as anchors in analyses of receiver operating characteristics (ROC) to define cutoffs for failure and worsening on commonly used PROMs, namely, the Oswestry Disability Index (ODI), the EuroQuol 5D (EQ-5D), and Numerical Rating Scales (NRS) for back pain and leg pain.

RESULTS

"Failure" after 12 months for each PROM, as an insufficient improvement from baseline, was (sensitivity and specificity): ODI change <13 (0.82, 0.82), ODI% change <33% (0.86, 0.86), ODI final raw score >25 (0.89, 0.81), NRS back-pain change <1.5 (0.74, 0.86), NRS back-pain % change <24 (0.85, 0.81), NRS back-pain final raw score >5.5 (0.81, 0.87), NRS leg-pain change <1.5 (0.81, 0.76), NRS leg-pain % change <39 (0.86, 0.81), NRS leg-pain final raw score >4.5 (0.91, 0.85), EQ-5D change <0.10 (0.76, 0.83), and EQ-5D final raw score >0.63 (0.81, 0.85). Both a final raw score >48 for the ODI and an NRS >7.5 were indicators for "worsening" after 12 months, with acceptable accuracy.

CONCLUSION

The criteria with the highest accuracy for defining failure and worsening after surgery for lumbar disc herniation were an ODI percentage change score <33% for failure and a 12-month ODI raw score >48. These cutoffs can facilitate shared decision-making among doctors and patients, and improve quality assessment and comparison of clinical outcomes across surgical units. In addition to clinically relevant improvements, we propose that rates of failure and worsening should be included in reporting from clinical trials.

Differential Characterization of Two Kinds of Stem Cells Isolated from Rabbit Nucleus Pulposus and Annulus Fibrosus

Objective. Nucleus pulposus (NP) and annulus fibrosus (AF) are two main components of intervertebral disc (IVD). We aimed to figure out whether NP and AF also contain stem cells and whether these stem cells share common properties with chondrocytes and/or fibroblasts in their phenotypes or whether they are completely different types of cells with different characteristics. Design. The disk cells were isolated from AF and NP tissues of the same lumbar spine of the rabbits. The properties of these disk cells were characterized by their morphology, population doubling time (PDT), stem cell marker expression, and multidifferentiation potential using tissue culture techniques, immunocytochemistry, and RT-PCR. Results. Both disk cells formed colonies in culture and expressed stem cell markers, nucleostemin, Oct-4, SSEA-4, and Stro-1, at early passages. However, after 5 passages, AFSCs became elongated and NPSCs appeared senescent. Conclusion. This study indicated that IVD contains stem cells and the characteristics of AFSCs and NPSCs are intrinsically different. The findings of this study may provide basic scientific data for understanding the properties of IVD cells and the mechanisms of lower back pain.

Responsiveness and Minimal Important Change of the Pain Self-Efficacy Questionnaire and Short Forms in Patients With Chronic Low Back Pain

The Pain Self-Efficacy Questionnaire (PSEQ) is a valid and reliable patient-reported instrument used to assess pain self-efficacy in patients with chronic low back pain (CLBP). Recently, the 2-item (PSEQ-2) and the 4-item (PSEQ-4) short versions were developed showing satisfactory measurement properties in mixed populations with chronic pain. The aim of this study was to examine responsiveness and minimal important change (MIC) of PSEQ, PSEQ-2, and PSEQ-4 in patients with CLBP. We used a sample of 104 patients undergoing multimodal physical therapy designed to partly change pain self-efficacy beliefs. Responsiveness was assessed by testing 16 a priori formulated hypotheses regarding effect sizes, areas under the curve, and correlations with changes in other instruments measuring other constructs. The MIC was calculated using an external anchor specific for pain self-efficacy and the receiver operator characteristic (ROC) method. The PSEQ and the PSEQ-4 met all hypotheses, whereas the PSEQ-2 met all but 1. The MICs were 5.5 for the PSEQ (9% of the scale range) and 1.5 for PSEQ-2 (13% scale range) and PSEQ-4 (6% scale range). MIC values were different for patients with low or high baseline values for all 3 instruments. The PSEQ and its short versions are adequately responsive instruments in patients with CLBP.

PERSPECTIVE

This study suggests that the PSEQ and its short versions are responsive measures of pain self-efficacy in patients with CLBP, adding to previous literature on their validity and reliability. Considering their similar responsiveness, the 4-item PSEQ could replace the original 10-item version in busy clinical or research settings.

Perceived 10-year change in respiratory health: reliability and predictive ability

OBJECTIVE

To investigate the usefulness of a self-reported respiratory health transition question over 10 years through reliability, ability to capture long-term asthma trajectory and predictive ability.

SETTINGS

In two 20-year cohorts (Asthma-E3N, n = 16,371, 61-88 years; EGEA, n = 1254, 27-82 years), perceived 10-year change in respiratory health ("Overall, in the last 10 years, do you think that your bronchial or respiratory health has changed?" if yes: "Has it improved/deteriorated?") was studied in relation with change in respiratory medication dispensation and lung function, with change in asthma status measured over the same period of time, and with subsequent asthma-related outcomes.

RESULTS

Perceived deterioration (14% in Asthma-E3N) was associated with increased dispensations of respiratory medications over time (from 17% with >2 dispensations in 2004 to 26% in 2010). Report of perceived deterioration (13% in EGEA) was related to a lung function decline steeper by 9.3 mL/year as compared to perceived improvement. In both cohorts, change (improvement or deterioration) was more often perceived by participants with than without asthma (>45% vs <20%) and was dominant among participants with persistent current asthma (77%). Perceived deterioration was related to poorer asthma control 7 years later and to higher use of oral corticosteroids in the following 18 months.

CONCLUSION

The proposed simple self-reported respiratory health transition question over 10 years allows predicting part of the long-term trajectory of asthma.

Individual patient monitoring in daily clinical practice: a critical evaluation of minimal important change

PURPOSE

In daily practice, physicians translate knowledge from clinical trials to practice, to improve health in individual patients. To help interpret meaningful change on disease outcome measures, the concept of minimal important change (MIC) was conceived. The objective of this study was to investigate whether MIC values are suited for individual patient monitoring.

METHODS

Three main elements of the MIC concept were evaluated: (1) MIC values for improvement and deterioration were determined, and the amount of misclassification present in quantifying minimal change was analyzed. (2) Discordance between change categories (improved, unchanged, deteriorated), defined by the MIC values, and patients' satisfaction with their health was inspected. (3) Discordance between change categories, defined by MIC values, and patients' willingness to alter therapy was inspected.

RESULTS

MIC value analysis was based on 469 patients with RA seen in daily practice. The chance of falsely classifying health change of an individual patient was high (false-positive range 19-30 % and false-negative range 43-72 %). Of patients classified as improved, 24 % were not satisfied with their health and 69 % were not willing to change therapy. Of patients classified as deteriorated, 54 % were satisfied with their health and 57 % were not willing to change therapy.

CONCLUSIONS

The misclassification in the quantification of change and high proportions of discordance between change categories defined by MIC cutoff values and patients' satisfaction and willingness to alter therapy indicate that MIC values as such are not suited for individual patient monitoring.