The minimal clinically important difference of the scleroderma clinical trials consortium damage index

Objective

The Scleroderma Clinical Trials Consortium Damage Index is an index of global damage in systemic sclerosis. The objective of this study is to determine the minimal clinically important difference of the Scleroderma Clinical Trials Consortium Damage Index.

Methods

Patients in the Canadian Scleroderma Research Group registry and the Australian Scleroderma Cohort Study who completed Scleroderma Clinical Trials Consortium Damage Index scores and the SF36v2 at baseline and the first full follow-up visit were studied. To calculate the minimal clinically important difference, an anchor question came from SF36v2: "Compared to one year ago, how would you rate your health in general?." Options were: much better, somewhat better, about the same, somewhat worse and much worse. We use the "somewhat worse" or "much worse" categories to indicate those with any worsening. We used four anchor methods: receiver operating characteristic curve, change difference, regression analysis, and average change.

Results

We studied 1672 patients. Mean disease duration was 11.4 ± 10.0 years; 62.5% had diffuse cutaneous systemic sclerosis. Baseline mean Damage Index was 5.3 ± 4.2; mean change of Damage Index over 1 year was 0.9 ± 1.8 units. The calculated minimal clinically important difference values were 1 for receiver operating characteristic method, 0.625 for change difference, 0.1879 for regression analysis, and 1.37 for average change. Omitting the regression analysis method as an outlier, the mean of the other methods was 1.

Conclusion

The most appropriate minimal clinically important difference for the Scleroderma Clinical Trials Consortium Damage Index is a change of ⩾ 1.0 units in the Scleroderma Clinical Trials Consortium Damage Index as is already recognized by patients as a significant change after 1 year. This can be applied to group means as well as to individuals where an ordinal change is required.

Minimal clinically important difference in days at home up to 30 days after surgery

Patient-centred outcomes are increasingly recognised as crucial measures of healthcare quality. Days alive and at home up to 30 days after surgery (DAH₃₀ ) is a validated and readily obtainable patient-centred outcome measure that integrates much of the peri-operative patient journey. However, the minimal difference in DAH₃₀ that is clinically important to patients is unknown. We designed and administered a 28-item survey to evaluate the minimal clinically important difference in DAH₃₀ among adult patients undergoing inpatient surgery. Patients were approached pre-operatively or within 2 days postoperatively. We did not study patients undergoing day surgery or nursing home residents. Patients ranked their opinions on the importance of discharge home using a Likert scale (from 1, not important at all to 6, extremely important) and the minimum number of extra days at home that would be meaningful using this scale. We recruited 104 patients; the survey was administered pre-operatively to 45 patients and postoperatively to 59 patients. The mean (SD) age was 53.5 (16.5) years, and 51 (49%) patients were male. Patients underwent a broad range of surgery of mainly intermediate (55%) to major (33%) severity. The median minimal clinically important difference for DAH₃₀ was 3 days; this was consistent across a broad range of scenarios, including earlier discharge home, complications delaying hospital discharge and the requirement for admission to a rehabilitation unit. Discharge home earlier than anticipated and discharge home rather than to a rehabilitation facility were both rated as important (median score = 5). Empirical data on the minimal clinically important difference for DAH₃₀ may be useful to determine sample size and to guide the non-inferiority margin for future clinical trials.

Is the minimal clinically important difference (MCID) in acute pain a good measure of analgesic efficacy in regional anesthesia?

In the field of acute pain medicine research, we believe there is an unmet need to incorporate patient related outcome measures that move beyond reporting pain scores and opioid consumption. The term “minimal clinically important difference” (MCID) defines the clinical benefit of an intervention as perceived by the patient, as opposed to a mathematically determined statistically significant difference that may not necessarily be clinically significant. The present article reviews the concept of MCID in acute postoperative pain research, addresses potential pitfalls in MCID determination and questions the clinical validity of extrapolating MCID determined from chronic pain and non-surgical pain studies to the acute postoperative pain setting. We further suggest the concepts of minimal clinically important improvement, substantial clinical benefit and patient acceptable symptom state should also represent aspirational outcomes for future research in acute postoperative pain management.

Comparison of Multilevel Anterior Cervical Discectomy and Fusion Performed in an Inpatient Versus Outpatient Setting

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To evaluate differences in patient factors, procedural factors, early outcomes and safety in mutlilevel anterior cervical discectomy and fusion (ACDF) in the inpatient versus outpatient setting.

METHODS

Patient demographics, operative factors, and outcomes of multilevel ACDF performed in an inpatient and outpatient setting were compared using Fisher's exact test for categorical and Student's t test for continuous variables.

RESULTS

Fifty-seven patients had surgery on an outpatient and 46 on an inpatient basis. Inpatients were older (56.7 vs 52.2 years, P = .012) and had a higher ASA (American Society of Anesthesiologists) class (P = .002). Sixty percent of 2-level cases were outpatient surgeries, compared with 35% of 3-level cases (P = .042). Outpatients had shorter operative times (71.26 vs 83.59 minutes, P < .0001) and shorter lengths of stay (8.51 vs 35.76 hours, P < .0001), lower blood loss (33.04 vs 45.87 mL, P = .003), and fewer in-hospital complications (5.3% vs 37.0%, P < .0001). Outpatients had better early outcomes in terms of 6-week Neck Disability Index (NDI) (27.97 vs 37.59, P = .014), visual analogue scale (VAS) neck (2.92 vs 4.02, P = .044), and Short Form-12 Physical Health Score (SF-12 PHS) (35.66 vs 30.79, P = .008). However, these differences did not persist at 6 months.

CONCLUSIONS

The results of our study suggest that multilevel ACDF can be performed safely in the outpatient setting without an increased risk of complications compared with the inpatient setting in an appropriately selected patient. Specifically, patients' age, ASA class, and number of levels being fused should be taken into consideration. At our institution, ASA class 3, body mass index >40 kg/m², age >80 years, intubation time >2.5 hours, or not having a responsible adult with the patient warrant inpatient admission. Importantly, the setting of the surgery does not affect patient-reported outcomes.

Comparison of Best Versus Worst Clinical Outcomes for Adult Cervical Deformity Surgery

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

Factors that predict outcomes for adult cervical spine deformity (ACSD) have not been well defined. To compare ACSD patients with best versus worst outcomes.

METHODS

This study was based on a prospective, multicenter observational ACSD cohort. Best versus worst outcomes were compared based on Neck Disability Index (NDI), Neck Pain Numeric Rating Scale (NP-NRS), and modified Japanese Orthopaedic Association (mJOA) scores.

RESULTS

Of 111 patients, 80 (72%) had minimum 1-year follow-up. For NDI, compared with best outcome patients (n = 28), worst outcome patients (n = 32) were more likely to have had a major complication (P = .004) and to have undergone a posterior-only procedure (P = .039), had greater Charlson Comorbidity Index (P = .009), and had worse postoperative C7-S1 sagittal vertical axis (SVA; P = .027). For NP-NRS, compared with best outcome patients (n = 26), worst outcome patients (n = 18) were younger (P = .045), had worse baseline NP-NRS (P = .034), and were more likely to have had a minor complication (P = .030). For the mJOA, compared with best outcome patients (n = 16), worst outcome patients (n = 18) were more likely to have had a major complication (P = .007) and to have a better baseline mJOA (P = .030). Multivariate models for NDI included posterior-only surgery (P = .006), major complication (P = .002), and postoperative C7-S1 SVA (P = .012); models for NP-NRS included baseline NP-NRS (P = .009), age (P = .017), and posterior-only surgery (P = .038); and models for mJOA included major complication (P = .008).

CONCLUSIONS

Factors distinguishing best and worst ACSD surgery outcomes included patient, surgical, and radiographic factors. These findings suggest areas that may warrant greater awareness to optimize patient counseling and outcomes.

Quality of Life in Patients Undergoing Spine Surgery: Systematic Review and Meta-Analysis

STUDY DESIGN

Meta-analysis.

OBJECTIVE

Despite the increasing importance of tracking clinical outcomes using valid patient-reported outcome measures, most providers do not routinely obtain baseline preoperative health-related quality of life (HRQoL) data in patients undergoing spine surgery, precluding objective outcomes analysis in individual practices. We conducted a meta-analysis of pre- and postoperative HRQoL data obtained from the most commonly published instruments to use as reference values.

METHODS

We searched PubMed, EMBASE, and an institutional registry for studies reporting EQ-5D, SF-6D, and Short Form-36 Physical Component Summary scores in patients undergoing surgery for degenerative cervical and lumbar spinal conditions published between 2000 and 2014. Observational data was pooled meta-analytically using an inverse variance-weighted, random-effects model, and statistical comparisons were performed.

RESULTS

Ninety-nine articles were included in the final analysis. Baseline HRQoL scores varied by diagnosis for each of the 3 instruments. On average, postoperative HRQoL scores significantly improved following surgical intervention for each diagnosis using each instrument. There were statistically significant differences in baseline utility values between the EQ-5D and SF-6D instruments for all lumbar diagnoses.

CONCLUSIONS

The pooled HRQoL values presented in this study may be used by practitioners who would otherwise be precluded from quantifying their surgical outcomes due to a lack of baseline data. The results highlight differences in HRQoL between different degenerative spinal diagnoses, as well as the discrepancy between 2 common utility-based instruments. These findings emphasize the need to be cognizant of the specific instruments used when comparing the results of outcome studies.

Measuring acute postoperative pain using the visual analog scale: the minimal clinically important difference and patient acceptable symptom state

Background

The 100 mm visual analog scale (VAS) score is widely used to measure pain intensity after surgery. Despite this widespread use, it is unclear what constitutes the minimal clinically important difference (MCID); that is, what minimal change in score would indicate a meaningful change in a patient's pain status.

Methods

We enrolled a sequential, unselected cohort of patients recovering from surgery and used a VAS to quantify pain intensity. We compared changes in the VAS with a global rating-of-change questionnaire using an anchor-based method and three distribution-based methods (0.3 sd , standard error of the measurement, and 5% range). We then averaged the change estimates to determine the MCID for the pain VAS. The patient acceptable symptom state (PASS) was defined as the 25th centile of the VAS corresponding to a positive patient response to having made a good recovery from surgery.

Results

We enrolled 224 patients at the first postoperative visit, and 219 of these were available for a second interview. The VAS scores improved significantly between the first two interviews. Triangulation of distribution and anchor-based methods resulted in an MCID of 9.9 for the pain VAS, and a PASS of 33.

Conclusions

Analgesic interventions that provide a change of 10 for the 100 mm pain VAS signify a clinically important improvement or deterioration, and a VAS of 33 or less signifies acceptable pain control (i.e. a responder), after surgery.

Patient-Reported Outcome Measures in Neurosurgery: A Review of the Current Literature

BACKGROUND

Patient-reported outcome measures (PROMs) play an important role in the evaluation of health outcomes, quality of life, and satisfaction, and have been successfully utilized in many areas of clinical medicine and surgical practice. The prevalence of PROMs in neurosurgery is not known.

OBJECTIVE

To review the PROMs that have been utilized in the published neurosurgery literature to date.

METHODS

Articles were searched in MEDLINE, EMBASE, HMIC Health Management Information Consortium, PsycARTICLES, and PsycINFO using search terms related to neurosurgery and PROMs, published from 1806 to August 2016. A total of 268 articles were identified that were stratified by the inclusion and exclusion criteria leading to a total of 137 articles. Twenty-six PROMs, involving both adult and pediatric populations, were identified.

RESULTS

A large number of generic and disease-specific PROMs are used in the neurosurgical literature. Generic PROMs are usually nonspecific measures of health status. Disease-specific PROMs may not address issues relevant to neurosurgical procedures. There are very few neurosurgery-specific PROMs that take into account the impact of a neurosurgical procedure on a specific condition.

CONCLUSION

PROMs that currently feature in the neurosurgical literature may not address the specific outcomes relevant to neurosurgical practice. There is an emergent need for generic and disease-specific PROMs to be validated in neurosurgical patients and neurosurgery-specific PROMs developed to address unmet needs of patients undergoing neurosurgical procedures.

Validation of Patient-Reported Outcomes Measurement Information System (PROMIS) computerized adaptive tests in cervical spine surgery

OBJECTIVE The Patient-Reported Outcomes Measurement Information System (PROMIS), which is funded by the National Institutes of Health, is a set of adaptive, responsive assessment tools that measures patient-reported health status. PROMIS measures have not been validated for surgical patients with cervical spine disorders. The objective of this project is to evaluate the validity (e.g., convergent validity, known-groups validity, responsiveness to change) of PROMIS computer adaptive tests (CATs) for pain behavior, pain interference, and physical function in patients undergoing cervical spine surgery. METHODS The legacy outcome measures Neck Disability Index (NDI) and SF-12 were used as comparisons with PROMIS measures. PROMIS CATs, NDI-10, and SF-12 measures were administered prospectively to 59 consecutive tertiary hospital patients who were treated surgically for degenerative cervical spine disorders. A subscore of NDI-5 was calculated from NDI-10 by eliminating the lifting, headaches, pain intensity, reading, and driving sections and multiplying the final score by 4. Assessments were administered preoperatively (baseline) and postoperatively at 6 weeks and 3 months. Patients presenting for revision surgery, tumor, infection, or trauma were excluded. Participants completed the measures in Assessment Center, an online data collection tool accessed by using a secure login and password on a tablet computer. Subgroup analysis was also performed based on a primary diagnosis of either cervical radiculopathy or cervical myelopathy. RESULTS Convergent validity for PROMIS CATs was supported with multiple statistically significant correlations with the existing legacy measures, NDI and SF-12, at baseline. Furthermore, PROMIS CATs demonstrated known-group validity and identified clinically significant improvements in all measures after surgical intervention. In the cervical radiculopathy and myelopathic cohorts, the PROMIS measures demonstrated similar responsiveness to the SF-12 and NDI scores in the patients who self-identified as having postoperative clinical improvement. PROMIS CATs required a mean total of 3.2 minutes for PROMIS pain behavior (mean ± SD 0.9 ± 0.5 minutes), pain interference (1.2 ± 1.9 minutes), and physical function (1.1 ± 1.4 minutes) and compared favorably with 3.4 minutes for NDI and 4.1 minutes for SF-12. CONCLUSIONS This study verifies that PROMIS CATs demonstrate convergent and known-groups validity and comparable responsiveness to change as existing legacy measures. The PROMIS measures required less time for completion than legacy measures. The validity and efficiency of the PROMIS measures in surgical patients with cervical spine disorders suggest an improvement over legacy measures and an opportunity for incorporation into clinical practice.

Two-Year Results of the Prospective Spine Treatment Outcomes Study: Analysis of Postoperative Clinical Outcomes Between Patients with and without a History of Previous Cervical Spine Surgery

OBJECTIVE

History of previous cervical spine surgery is a frequently cited cause of worse outcomes after cervical spine surgery. The purpose of this study was to determine any differences in clinical outcomes after cervical spine surgery between patients with and without a history of previous cervical spine surgery.

METHODS

A multicenter prospective database was reviewed retrospectively to identify patients with cervical spondylosis undergoing surgery with a minimum 2-year follow-up. Patients were divided into 2 groups: patients with (W) or without (WO) previous history of cervical spine surgery. Statistical analyses of Health-Related Quality of Life scores were analyzed with statistical software to fit linear mixed models for continuous longitudinal outcome.

RESULTS

A total of 1286 patients (377 W, 909 WO) met criteria for inclusion. Overall, patients in both groups experienced an improvement in their Health-Related Quality of Life scores. However, patients in the W group had significantly decreased improvement compared with WO patients in the Neck Disability Index score and the following SF-36 domain scores: Role Physical, Bodily Pain, General Health, Vitality, Social Functioning, Health Transition, and Physical Component Summary at all time points (P < 0.05). There was no statistically significant difference between the W and WO groups in operative time, estimated blood loss, length of stay, or complications (P > 0.05).

CONCLUSIONS

Patients with a history of previous cervical spine surgery had inferior improvement in quality of life outcome scores. Patients with a history of previous surgical intervention who elect to undergo subsequent surgeries should be appropriately counseled about expected results.

Minimal Clinically Important Difference for Three Quality of Recovery Scales

Background

Several quality of recovery (QoR) health status scales have been developed to quantify the patient’s experience after anesthesia and surgery, but to date, it is unclear what constitutes the minimal clinically important difference (MCID). That is, what minimal change in score would indicate a meaningful change in a patient’s health status?

Methods

The authors enrolled a sequential, unselected cohort of patients recovering from surgery and used three QoR scales (the 9-item QoR score, the 15-item QoR-15, and the 40-item QoR-40) to quantify a patient’s recovery after surgery and anesthesia. The authors compared changes in patient QoR scores with a global rating of change questionnaire using an anchor-based method and three distribution-based methods (0.3 SD, standard error of the measurement, and 5% range). The authors then averaged the change estimates to determine the MCID for each QoR scale.

Results

The authors enrolled 204 patients at the first postoperative visit, and 199 were available for a second interview; a further 24 patients were available at the third interview. The QoR scores improved significantly between the first two interviews. Triangulation of distribution- and anchor-based methods results in an MCID of 0.92, 8.0, and 6.3 for the QoR score, QoR-15, and QoR-40, respectively.

Conclusion

Perioperative interventions that result in a change of 0.9 for the QoR score, 8.0 for the QoR-15, or 6.3 for the QoR-40 signify a clinically important improvement or deterioration.

Proportion of Expectations Fulfilled: A New Method to Report Patient-centered Outcomes of Spine Surgery

STUDY DESIGN

Prospective lumbar and cervical surgery cohorts.

OBJECTIVE

Compare fulfillment of expectations with traditional global outcomes and provide evidence for its validity.

SUMMARY OF BACKGROUND DATA

New lumbar and cervical spine surgery Expectations Surveys can be used to measure fulfillment of expectations and their performance should be compared with existing outcomes.

METHODS

Three hundred thirty-six lumbar and 133 cervical spine surgery patients preoperatively completed valid 20-item Expectations Surveys measuring symptoms, function, and psychological well-being. Approximately 2 years postoperatively patients rated how much improvement they received for each item. The proportion of expectations fulfilled was compared with traditional outcomes, including global satisfaction and change in standard spine questionnaires, with correlation coefficients (r) and areas under receiver operator characteristic curves (AUC).

RESULTS

Ninety percent of lumbar patients had some expectations fulfilled (24% had all expectations fulfilled completely or exceeded). The mean proportion of expectations fulfilled was 0.66 and was associated with satisfaction (r = 0.73 (95% CI 0.68-0.78); AUC = 0.92 (95% CI 0.89-0.95) (P < 0.0001)). Based on the association with satisfaction, a clinically important proportion of expectations fulfilled for lumbar surgery is approximately 0.60 (sensitivity 0.90, specificity 0.79).Ninety-one percent of cervical patients had some expectations fulfilled (31% had all expectations fulfilled completely or exceeded). The mean proportion of expectations fulfilled was 0.78 and was associated with satisfaction (r = 0.62 (95% CI 0.50-0.72); AUC = 0.92 (95% CI 0.87-0.97) (P < 0.0001)). Based on the association with satisfaction, a clinically important proportion of expectations fulfilled for cervical surgery is approximately 0.62 (sensitivity 0.91, specificity 0.80).

CONCLUSION

The proportion of expectations fulfilled is a new patient-centered outcome that measures results of spine surgery. Unique features of this novel outcome are that it requires prospectively acquired pre- and postoperative data, provides details about in what ways patients believe surgery did and did not meet goals, and offers surgeons opportunities to address unfilled expectations directly.

LEVEL OF EVIDENCE

1.