Understanding the minimum clinically important difference: a review of concepts and methods

Minimal clinically important differences in pharmacological trials

The concept of a minimal clinically important difference (MCID) is well established. Here, we review the evidence base and methods used to define MCIDs as well as their strengths and limitations. Most MCIDs in chronic obstructive pulmonary disease (COPD) are empirically derived estimates applying to populations of patients. Validated MCIDs are available for many commonly used outcomes in COPD, including lung function (100 ml for trough FEV1), dyspnea (improvement of ≥ 1 unit in the Transition Dyspnea Index total score or 5 units in the University of California, San Diego Shortness of Breath Questionnaire), health status (reduction of 4 units in the St George's Respiratory Questionnaire total score), and exercise capacity (47.5 m for the incremental shuttle walking test, 45-85 s for the endurance shuttle walking test, and 46-105 s for constant-load cycling endurance tests), but there is currently no validated MCID for exacerbations. In a clinical trial setting, many factors, including study duration, withdrawal rate, baseline severity, and Hawthorne effects, can influence the measured treatment effect and determine whether it reaches the MCID. We also address recent challenges presented by clinical trials that compare active treatments and suggest that MCIDs should be used to identify the additional proportion of patients who benefit, for example, when one drug is replaced by another or when a second drug is added to a first. We propose the term "minimum worthwhile incremental advantage" to describe this parameter.

Patient global ratings of change did not adequately reflect change over time: a clinical cohort study

BACKGROUND

Global ratings of change (GROCs) are commonly used in research and clinical practice to determine which patients respond to therapy, but their validity as a criterion for change has not been firmly established. One factor related to their validity is the length of the recall period.

OBJECTIVE

The study objective was to examine the influence of the length of the recall period on the validity of a GROC for determining true change over time in the clinical setting.

DESIGN

This was a longitudinal, single-cohort observational study.

METHODS

Data from the Focus on Therapeutic Outcomes clinical database were collected for 8,955 patients reporting for physical therapy treatment of a knee disorder. Computerized adaptive testing was used to assess knee functional status (FS) at the initial and final (discharge) physical therapy visits. Each patient's GROC was obtained at discharge. Correlation and linear regression analyses of knee FS and GROC, stratified by length of time between intake and discharge, were conducted.

RESULTS

Correlations of GROC with knee FS change scores were modest even for the shortest period of recall (0-30 days) and were slightly lower for longer recall periods. Regression analyses using knee FS to predict GROC scores revealed similar findings. Correlations of GROC with intake and discharge scores indicated a strong bias toward discharge status, with little or no influence of baseline status. Standardized regression coefficients fitted the pattern expected for a valid measure of change but confirmed the strong bias toward discharge status.

LIMITATIONS

One version of the GROC administered serially in a cohort of patients seen in clinical practice was examined.

CONCLUSIONS

These results call into question the validity of GROCs for measuring change over time in routine clinical practice.

The impact of esophageal reflux-induced symptoms on quality of life after gastrectomy in patients with gastric cancer

Purpose

To evaluate the prevalence of esophageal reflux-induced symptoms after gastrectomy owing to gastric cancer and assess the relationship between esophageal reflux-induced symptoms and quality of life.

Materials and Methods

From January 2012 to May 2012, 332 patients were enrolled in this cross-sectional study. The patients had a history of curative resection for gastric cancer at least 6 months previously without recurrence, other malignancy, or ongoing chemotherapy. Esophageal reflux-induced symptoms were evaluated with the GerdQ questionnaire. The quality of life was evaluated with the European Organization for Research and Treatment QLQ-C30 and STO22 questionnaires.

Results

Of the 332 patients, 275 had undergone subtotal gastrectomy and 57 had undergone total gastrectomy. The number of GerdQ(+) patients was 58 (21.1%) after subtotal gastrectomy, and 7 (12.3%) after total gastrectomy (P=0.127). GerdQ(+) patients showed significantly worse scores compared to those for GerdQ(-) patients in nearly all functional and symptom QLQ-C30 scales, with the difference in the mean score of global health status/quality of life and diarrhea symptoms being higher than in the minimal important difference. Additionally, in the QLQ STO22, GerdQ(+) patients had significantly worse scores in every symptom scale. The GerdQ score was negatively correlated with the global quality of life score (r=-0.170, P=0.002).

Conclusions

Esophageal reflux-induced symptoms may develop at a similar rate or more frequently after subtotal gastrectomy compared to that after total gastrectomy, and decrease quality of life in gastric cancer patients. To improve quality of life after gastrectomy, new strategies are required to prevent or reduce esophageal reflux.

Criterion validity, reliability and clinical responsiveness of the CareConnections Functional Index

This study established the criterion validity, test-retest reliability and responsiveness of the CareConnections Functional Index (CCFI). The CCFI is composed of four body-region specific subscales, measuring functional ability. Reference standards included the Neck Disability Index; Modified Oswestry Disability Index; Quick Disabilities of the Arm, Shoulder and Hand and the Lower Extremity Functional Scale. One hundred subjects per body region were enrolled. Subject's rated their perceived improvement based on the 15-point Global Rating of Change questionnaire. Minimal clinically important differences (MCID) were calculated via receiver operator characteristic curve. Test-retest reliability coefficients were good to excellent. Validity correlations with the reference standard measures were acceptable (r > 0.7) for all subscales. MCID for the cervical subscale = 7 points, lumbar = 8 points, upper extremity = 16 points and lower extremity = 11 points. The results of this study support the use of the CCFI in outpatient physical therapy practice as a responsive tool with good reliability and validity. The results also indicate that future work should focus on the impact of baseline patient factors that may affect future outcome.

Identifying treatment responders and predictors of improvement after cognitive-behavioral therapy for juvenile fibromyalgia

The primary objective of this study was to estimate a clinically significant and quantifiable change in functional disability to identify treatment responders in a clinical trial of cognitive-behavioral therapy (CBT) for youth with juvenile fibromyalgia (JFM). The second objective was to examine whether baseline functional disability (Functional Disability Inventory), pain intensity, depressive symptoms (Children's Depression Inventory), coping self-efficacy (Pain Coping Questionnaire), and parental pain history predicted treatment response in disability at 6-month follow-up. Participants were 100 adolescents (11-18 years of age) with JFM enrolled in a recently published clinical trial comparing CBT to a fibromyalgia education (FE) intervention. Patients were identified as achieving a clinically significant change in disability (i.e., were considered treatment responders) if they achieved both a reliable magnitude of change (estimated as a > or = 7.8-point reduction on the FDI) using the Reliable Change Index, and a reduction in FDI disability grade based on established clinical reference points. Using this rigorous standard, 40% of patients who received CBT (20 of 50) were identified as treatment responders, compared to 28% who received FE (14 of 50). For CBT, patients with greater initial disability and higher coping efficacy were significantly more likely to achieve a clinically significant improvement in functioning. Pain intensity, depressive symptoms, and parent pain history did not significantly predict treatment response. Estimating clinically significant change for outcome measures in behavioral trials sets a high bar but is a potentially valuable approach to improve the quality of clinical trials, to enhance interpretability of treatment effects, and to challenge researchers to develop more potent and tailored interventions.

Parents' and caregivers' perceptions of the quality of life of adolescents in the first 4 months of orthodontic treatment with a fixed appliance

OBJECTIVES

To evaluate adolescents oral health-related quality of life (OHRQoL) in the first 4 months of fixed orthodontic appliance treatment using parents and caregivers as proxies.

DESIGN

Descriptive study.

SETTING

Department of Pediatric Dentistry and Orthodontics at Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.

PARTICIPANTS

A sample of parents and caregivers of 95 adolescents undergoing orthodontic treatment with a fixed appliance.

METHODS

Participants were required to answer the Brazilian version of the Parental-Caregivers Perceptions Questionnaire (P-CPQ) before adolescent's treatment (T1) and 4 months after bonding of the fixed appliance (T2). Statistical analysis was carried out using the Wilcoxon signed rank test and the Bonferroni correction for the domains of P-CPQ.

RESULTS

Among the 95 participants, there were 73 mothers, 18 fathers and 4 were other relations. There was a statistically significant improvement in the overall score as well as in both emotional and social wellbeing subscales (P<0·001).

CONCLUSION

Parents and caregivers report an improvement on their adolescent's OHRQoL in the first 4 months of orthodontic treatment with a fixed appliance.

Minimum clinically important difference for the COPD Assessment Test: a prospective analysis

BACKGROUND

The COPD Assessment Test (CAT) is responsive to change in patients with chronic obstructive pulmonary disease (COPD). However, the minimum clinically important difference (MCID) has not been established. We aimed to identify the MCID for the CAT using anchor-based and distribution-based methods.

METHODS

We did three studies at two centres in London (UK) between April 1, 2010, and Dec 31, 2012. Study 1 assessed CAT score before and after 8 weeks of outpatient pulmonary rehabilitation in patients with COPD who were able to walk 5 m, and had no contraindication to exercise. Study 2 assessed change in CAT score at discharge and after 3 months in patients admitted to hospital for more than 24 h for acute exacerbation of COPD. Study 3 assessed change in CAT score at baseline and at 12 months in stable outpatients with COPD. We focused on identifying the minimum clinically important improvement in CAT score. The St George's Respiratory Questionnaire (SGRQ) and Chronic Respiratory Questionnaire (CRQ) were measured concurrently as anchors. We used receiver operating characteristic curves, linear regression, and distribution-based methods (half SD, SE of measurement) to estimate the MCID for the CAT; we included only patients with paired CAT scores in the analysis.

FINDINGS

In Study 1, 565 of 675 (84%) patients had paired CAT scores. The mean change in CAT score with pulmonary rehabilitation was -2·5 (95% CI -3·0 to -1·9), which correlated significantly with change in SGRQ score (r=0·32; p<0·0001) and CRQ score (r=-0·46; p<0·0001). In Study 2, of 200 patients recruited, 147 (74%) had paired CAT scores. Mean change in CAT score from hospital discharge to 3 months after discharge was -3·0 (95% CI -4·4 to -1·6), which correlated with change in SGRQ score (r=0·47; p<0·0001). In Study 3, of 200 patients recruited, 164 (82%) had paired CAT scores. Although no significant change in CAT score was identified after 12 months (mean 0·6, 95% CI -0·4 to 1·5), change in CAT score correlated significantly with change in SGRQ score (r=0·36; p<0·0001). Linear regression estimated the minimum clinically important improvement for the CAT to range between -1·2 and -2·8 with receiver operating characteristic curves consistently identifying -2 as the MCID. Distribution-based estimates for the MCID ranged from -3·3 to -3·8.

INTERPRETATION

The most reliable estimate of the minimum important difference of the CAT is 2 points. This estimate could be useful in the clinical interpretation of CAT data, particularly in response to intervention studies.

FUNDING

Medical Research Council and UK National Institute of Health Research.

The minimal clinically important difference determined using item response theory models: an attempt to solve the issue of the association with baseline score

OBJECTIVES

Determining the minimal clinically important difference (MCID) of questionnaires on an interval scale, the trait level (TL) scale, using item response theory (IRT) models could overcome its association with baseline severity. The aim of this study was to compare the sensitivity (Se), specificity (Sp), and predictive values (PVs) of the MCID determined on the score scale (MCID-Sc) or the TL scale (MCID-TL).

STUDY DESIGN AND SETTING

The MCID-Sc and MCID-TL of the MOS-SF36 general health subscale were determined for deterioration and improvement on a cohort of 1,170 patients using an anchor-based method and a partial credit model. The Se, Sp, and PV were calculated using the global rating of change (the anchor) as the gold standard test.

RESULTS

The MCID-Sc magnitude was smaller for improvement (1.58 points) than for deterioration (-7.91 points). The Se, Sp, and PV were similar for MCID-Sc and MCID-TL in both cases. However, if the MCID was defined on the score scale as a function of a range of baseline scores, its Se, Sp, and PV were consistently higher.

CONCLUSION

This study reinforces the recommendations concerning the use of an MCID-Sc defined as a function of a range of baseline scores.

Effect of alignment changes on socket reaction moments while walking in transtibial prostheses with energy storage and return feet

BACKGROUND

Energy storage and return feet are designed for active amputees. However, little is known about the socket reaction moments in transtibial prostheses with energy storage and return feet. The aim of this study was to investigate the effect of alignment changes on the socket reaction moments during gait while using the energy storage and return feet.

METHODS

A Smart Pyramid™ was used to measure the socket reaction moments in 10 subjects with transtibial prostheses while walking under 25 alignment conditions, including a nominal alignment (as defined by conventional clinical methods), as well as angle malalignments of 2°, 4° and 6° (flexion, extension, abduction, and adduction) and translation malalignments of 5mm, 10mm and 15mm (anterior, posterior, lateral, and medial) referenced from the nominal alignment. The socket reaction moments of the nominal alignment were compared with each malalignment.

FINDINGS

Both coronal and sagittal alignment changes demonstrated systematic effects on the socket reaction moments. In the sagittal plane, angle and translation alignment changes demonstrated significant differences (P<0.05) in the minimum moment, the moment at 45% of stance and the maximum moment for some comparisons. In the coronal plane, angle and translation alignment changes demonstrated significant differences (P<0.05) in the moment at 30% and 75% of stance for all comparisons.

INTERPRETATION

The alignment may have systematic effects on the socket reaction moments in transtibial prostheses with energy storage and return feet. The socket reaction moments could potentially be a useful biomechanical parameter to evaluate the alignment of the transtibial prostheses.

A Framework for Managing the Minimal Clinically Important Difference in Clinical Trials

There is a long history of discussions about what is a minimal clinically important difference (MCID) and how this term applies to clinical research. This paper deals with a practical framework for MCID and its applicability to clinical trials. A literature review on the topic confirmed the fundamental role of MCID for the clinical research, although no guide on how to best use the MCID in clinical trials was identified. We propose a framework that takes into account (1) the definition of MCID as a term when random variable is discussed, (2) a 4-level approach for classifying the MCID evidence to be considered in a clinical development program, and (3) a method of MCID evaluation, defined in a scientifically sound protocol. The proposed framework can prompt and steer stakeholders to improve the methodological sense of clinical trials based on the definition of MCID at the level of efficacy or safety, increase the quality of data derived from clinical trials and reporting of results, and allow effective planning of drug development programs.

Percutaneous Stereotactic Radiofrequency Lesioning for Trigeminal Neuralgia

BACKGROUND:

The Visual Analog Scale (VAS) and the Barrow Neurological Institute Pain Scale (BNI-PS) are 2 patient-reported outcome (PRO) tools frequently used to rate pain from trigeminal neuralgia (TN). Outcomes studies often use these patient-reported outcomes to assess treatment effectiveness, but it is unknown exactly what degree of change in the numerical scores constitutes the minimum clinically important difference (MCID). MCID remains uninvestigated for percutaneous stereotactic radiofrequency lesioning (RFL), a common surgical procedure for TN.

OBJECTIVE:

To determine MCID values for the VAS and BNI-PS in patients undergoing RFL.

METHODS:

Forty-three consecutive patients with TN who underwent RFL by a single surgeon were prospectively assessed with the VAS and BNI-PS preoperatively and 3 years postoperatively. Three anchors were used to assign each patient's outcome: satisfaction, willingness to have the surgery again, and Health Transition Index. We then used 3 well-established, anchor-based methods to calculate MCID: average change, minimum detectable change, and change difference.

RESULTS:

Patients experienced substantial improvement in both VAS (9.81 vs 3.35; P &lt; .001) and BNI-PS (4.95 vs 2.44; P &lt; .001) after RFL. The 3 MCID calculation methods generated a range of MCID values for each of the PROs (VAS, 4.13-8.20; BNI-PS, 1.03-3.30). The area under the receiver-operating characteristic curve was greater for BNI-PS compared with VAS for all 3 anchors, indicating that BNI-PS is probably better suited for calculating MCID.

CONCLUSION:

RFL-specific MCID is variable on the basis of the calculation technique. With the use of the minimum detectable change calculation method with the Health Transition Index anchor, the minimum clinically important difference is 4.49 for VAS and 1.16 for BNI-PS after RFL for TN.

Usefulness of minimum clinically important difference for assessing patients with subaxial degenerative cervical spine disease: statistical versus substantial clinical benefit

BACKGROUND

The measurement of the therapeutic outcome of cervical spine surgeries commonly relies on four main patient reported outcomes (PROs): Neck Disability Index (NDI), Visual Analog Scale (VAS) for pain, and Short Form-36 (SF-36) Physical (PCS) and Mental (MCS) Component Summary. However, the clinical impact of such scores and how they could effectively measure therapeutic efficacy remains unclear. In this context, the concept of minimum clinically important difference (MCID) is developing into the standard by which to evaluate treatments, patient satisfaction and cost-effectiveness.

METHODS

Eighty-eight consecutive patients undergoing surgery for subaxial degenerative cervical spine disease were selected from a prospective blinded database. PROs (NDI, PCS, MCS and VAS) were collected preoperatively, and together with blinded Surgeon Ratings (SR) at 3 months and 6 months post-surgery. Four anchor-based approaches were used to calculate different MCIDs. Three anchors (VAS, HTI (Health Transition Item of the SF-36) and SR) were used to evaluate surgery outcome. The best clinically and statistically relevant MCID was chosen.

RESULTS

On average, all patients presented with a statistically significant improvement (p < 0.001) postoperatively for NDI (27.42 to 19.42), PCS (33.02 to 42.03), MCS (44 to 50.74) and VAS (2.85 to 1.93). The four MCID anchor-based approaches yielded a range of values for each PRO: 2.23-16.59 for PCS, 0.11-16.27 for MCS and 2.72-12.08 for NDI. When compared to the VAS and HTI anchors, the area under the ROC curve was greater for SR. This finding suggests that SR may be a more reliable anchor for MCID calculation.

CONCLUSION

The MDC (minimum detectable change) approach together with the SR anchor appears to be the most appropriate MCID method. It offers the greatest area under the ROC curve (threshold above the 95 % CI), and the choice of the anchor did not significantly affect this result. MCID values for this dataset were 5.6 for PCS, 5.12 for MCS and 2.41 for NDI.

Measuring Surgical Outcomes in Subaxial Degenerative Cervical Spine Disease Patients

BACKGROUND:

Although the concept of minimum clinically important difference (MCID) as a measurement of surgical outcome has been extensively studied, there is lack of consensus on the most valid or clinically relevant MCID calculation approach.

OBJECTIVE:

To compare the range of MCID threshold values obtained by different anchor-based and distribution-based approaches to determine the best clinically meaningful and statistically significant MCID for our studied group.

METHODS:

Eighty-eight consecutive patients undergoing surgery for subaxial degenerative cervical spine disease were analyzed from a prospective blinded database. Preoperative, 3-, and 6-month postoperative patient reported outcome (PRO) scores and blinded surgeon ratings were collected. Four calculation methods were used to calculate MCID threshold values: average change, change difference, minimum detectable change, and receiver operating characteristic (ROC) curve. Three anchors were used to evaluate meaningful improvement postsurgery: health transition item, patient overall status, and surgeon ratings.

RESULTS:

On average, all patients had a statistically significant improvement (P &lt; .001) postoperatively for neck disability index (score 27.42 preoperatively to 19.42 postoperatively), physical component of the Short Form of the Medical Outcomes Study (SF-36) (33.02–42.23), mental component of the SF-36 (44–50.74), and visual analog scale (2.85–1.93). The 4 MCID approaches yielded a range of values for each PRO: 2.23 to 16.59 for physical component of the SF-36, 0.11 to 16.27 for mental component of the SF-36, and 2.72 to 12.08 for neck disability index. In comparison with health transition item and patient overall status anchors, the area under the ROC curve was consistently greater for surgeon ratings for all 4 PROs.

CONCLUSION:

Minimum detectable change together with surgeon ratings anchor appears to be the most appropriate MCID method. Based on our findings, this combination offers the greatest area under the ROC curve (threshold above the 95% confidence interval). The choice of the anchor did not significantly affect this result.

Microvascular decompression for classic trigeminal neuralgia: determination of minimum clinically important difference in pain improvement for patient reported outcomes

BACKGROUND

Outcomes studies use patient-reported outcome (PRO) measurements to assess treatment effectiveness, but can lack direct clinical meaning. Minimum clinically important difference (MCID) calculation provides a point estimate of the critical threshold needed to achieve clinically relevant treatment effectiveness. MCID remains uninvestigated for microvascular decompression (MVD), a common surgical procedure for trigeminal neuralgia.

OBJECTIVE

We aimed to determine MCID for the most commonly used PRO measures of pain after MVD: Visual Analog Scale (VAS) and Barrow Neurological Institute Pain Scale (BNI-PS).

METHODS

Sixty consecutive patients with classic trigeminal neuralgia who decided to undergo MVD by a single surgeon were prospectively assessed with VAS and BNI-PS preoperatively and 2 years postoperatively. Three anchors were used to assign each patient's outcome. We then used 3 well-established, anchor-based methods to calculate MCID.

RESULTS

Patients experienced significant improvement in both VAS (9.9 vs. 2.0, P < .001) and BNI-PS (5.0 vs. 1.9, P < .001) after MVD. The area under the receiver-operating characteristic curve was greater for BNI-PS than for VAS for all 3 anchors, indicating that BNI-PS is probably better suited for calculating MCID. The 3 MCID calculation methods generated a range of MCID values for each of the PROs (VAS: 1.40-8.87, BNI-PS: 0.95-3.26).

CONCLUSION

MVD-specific MCID is highly variable based on calculation technique. Some of these calculations appear to either overestimate or underestimate the patients' preoperative expectations. When the different MCID methods are averaged, the results are clinically appropriate and consistent with preoperative expectations. The average MCID for VAS is 6.25 and for BNI-PS is 2.44.

Development and use of a knowledge translation tool: the rehabilitation measures database

Clinical translation of research evidence is a challenge for rehabilitation clinicians. Publicly accessible and free, online educational resources that summarize research evidence can support implementation of research evidence into practice. Several online resources have been developed recently to overcome common knowledge translation barriers. The Rehabilitation Measures Database (RMD) is a free, web-based searchable database of standardized instruments that was designed to support knowledge translation. It helps clinicians select valid and sensitive instruments for screening patients, monitoring progress, and assessing rehabilitation outcomes. The RMD was developed using feedback from focus groups and beta-test participants. Since its launch in 2011, RMD use has grown to an average of 1851 hits per day from 168 countries. As of September 2013, 202 instrument summaries are viewable in the RMD. Most summaries are linked to copies of the instrument or to purchase instructions. A challenge in updating and expanding the RMD is securing the resources to ensure its future. Collaborative relationships with professional associations and graduate programs in the health sciences are critical in sustaining this resource.

Responsiveness of the Child Health Questionnaire-Parent Form in adolescents with non-specific chronic pain or fatigue

BACKGROUND

The Child Health Questionnaire (CHQ) is a widely used instrument for measuring health-related quality of life covering both the physical and psychosocial domain. This study examined the responsiveness of the Dutch CHQ 50-item Parent Form (PF50) in a sample of adolescents with chronic non-specific pain and/or fatigue.

METHOD

Five different methods were used to calculate the responsiveness for the physical (PhS) and psychosocial (PsS) subscale of the CHQ-50: standardized response mean (SRM), pooled effect sizes (ESs), standard error of measurement of agreement (SEMagreement ), minimal detectable change (MDC) and the area under the receiver operating characteristics (ROC) curve. For data analysis, the population was divided into two groups based on the parent's global perceived effect of treatment: a changed group (A) and an unchanged group (B).

RESULTS

The responsiveness analyses were performed including 92 adolescents (88.0% girls; mean age 16.4 years). The SRMs are 2.89 and 1.01 for the PhS and PsS, respectively. Large ESs are found for group A (PhS = 3.30; PsS = 1.16). The method used for calculating SEMagreement results in a score of PhS = 18.92 and PsS = 11.39. The MDCs of PhS and PsS are 52.45 and 31.57, respectively. The area under the ROC curve (AUC) for PhS = 0.79 and for PsS = 0.64, and the corresponding optimal cut-off points are 21.1 and 7.0.

CONCLUSION

Using the methods SRM, ES and AUC, the responsiveness of the CHQ-PF50 in adolescents with non-specific chronic pain or fatigue treated in a rehabilitation clinic is adequate for the physical scale and moderate for the psychosocial scale.

Clinically important deterioration in patients undergoing lumbar spine surgery: a choice of evaluation methods using the Oswestry Disability Index, 36-Item Short Form Health Survey, and pain scales: clinical article

OBJECT

Health-related quality of life (HRQOL) measures have become the mainstay for outcome appraisal in spine surgery. Clinically meaningful interpretation of HRQOL improvement has centered on the minimum clinically important difference (MCID). The purpose of this study was to calculate clinically important deterioration (CIDET) thresholds and determine a CIDET value for each HRQOL measure for patients undergoing lumbar fusion.

METHODS

Seven hundred twenty-two patients (248 males, 127 smokers, mean age 60.8 years) were identified with complete preoperative and 1-year postoperative HRQOLs including the Oswestry Disability Index (ODI), 36-Item Short Form Health Survey (SF-36), and numeric rating scales (0-10) for back and leg pain following primary, instrumented, posterior lumbar fusion. Anchor-based and distribution-based methods were used to calculate CIDET for each HRQOL. Anchor-based methods included change score, change difference, and receiver operating characteristic curve analysis. The Health Transition Item, an independent item of the SF-36, was used as the external anchor. Patients who responded "somewhat worse" and "much worse" were combined and compared with patients responding "about the same." Distribution-based methods were minimum detectable change and effect size.

RESULTS

Diagnoses included spondylolisthesis (n = 332), scoliosis (n = 54), instability (n = 37), disc pathology (n = 146), and stenosis (n = 153). There was a statistically significant change (p < 0.0001) for each HRQOL measure from preoperatively to 1-year postoperatively. Only 107 patients (15%) reported being "somewhat worse" (n = 81) or "much worse" (n = 26). Calculation methods yielded a range of CIDET values for ODI (0.17-9.06), SF-36 physical component summary (-0.32 to 4.43), back pain (0.02-1.50), and leg pain (0.02-1.50).

CONCLUSIONS

A threshold for clinical deterioration was difficult to identify. This may be due to the small number of patients reporting being worse after surgery and the variability across methods to determine CIDET thresholds. Overall, it appears that patients may interpret the absence of change as deterioration.

Validation of a consensus-based minimal clinically important difference (MCID) threshold using an objective functional external anchor

BACKGROUND CONTEXT

The minimal clinically important difference (MCID) is defined as the smallest change in an outcome that a patient would perceive as meaningful. The Initiative on Methods, Measurement and Assessment in Clinical Trials (IMMPACT) group proposed defining the MCID as a 30% improvement in self-reported pain or function. However, this MCID threshold has not been validated against an objective physical measure.

PURPOSE

To test the validity of the IMMPACT-based MCID threshold, using an objective physical measure as an external anchor.

STUDY DESIGN/SETTING

Prospective study of chronic disabling occupational lumbar disorder (CDOLD) patients completing a functional restoration program.

PATIENT SAMPLE

A consecutive cohort of 743 CDOLD patients.

OUTCOME MEASURES

Self-report measures of pain-related function were compared with an objective lifting measure, the progressive isoinertial lifting evaluation (PILE), obtained after treatment.

METHODS

The association between reporting 30% or greater improvement (the IMMPACT's MCID key criterion) and the PILE score after treatment was assessed.

RESULTS

A 30% or greater improvement on the self-report measures was significantly associated with improvement in physical function on the PILE task.

CONCLUSIONS

Despite extensive use of the MCID to evaluate effects of treatment in spinal disorders, this is the first empirical documentation of the validity of the IMMPACT's 30% change criterion compared with an objective physical anchor.

Clinimetrics corner: a closer look at the minimal clinically important difference (MCID)

Minimal clinically important difference (MCID) scores are commonly used by clinicians when determining patient response to treatment and to guide clinical decision-making during the course of treatment. For research purposes, the MCID score is often used in sample size calculations for adequate powering of a study to minimize the false-positives (type 1 errors) and the false-negatives (type 2 errors). For clinicians and researchers alike, it is critical that the MCID score is a valid and stable measure. A low MCID value may result in overestimating the positive effects of treatment, whereas a high MCID value may incorrectly classify patients as failing to respond to treatment when in fact the treatment was beneficial. The wide range of methodologies for calculating the MCID score results in varied outcomes, which leads to difficulties with interpretation and application. This clinimetrics corner outlines key factors influencing MCID estimates and discusses limitations with the use of the MCID in both clinical and research practice settings.

Validity and clinimetric properties of the Spinal Alignment and Range of Motion Measure in children with cerebral palsy

AIM

The aim of this study was to assess the validity, responsiveness, and clinimetric properties of the Spinal Alignment and Range of Motion Measure (SAROMM) in children with cerebral palsy (CP).

METHOD

Sixty-two children with CP (40 males, 22 females) with a median age of 3 years and 11 months (range 1-6y) and their caregivers participated in this study. Among the children, 56 had spastic CP while six had non-spastic CP; 53 had bilateral CP, while nine had unilateral limb involvement. Thirty-three children were classified as Gross Motor Function Classification System (GMFCS) levels I to III and 23 as levels IV or V. Fifty-six children (90%) received regular rehabilitation by means of regular physical or occupational therapy (50% once or twice per week and 40% more than two times per week) and six children (10%) received irregular rehabilitation (less than once a week). Construct validity was determined by assessing the strength of the correlation between the spinal alignment SAROMM (SAROMM-SA), the range of motion SAROMM (SAROMM-ROM), and the total SAROMM (SAROMM-total), and construct measures, including the 66-item Gross Motor Function Measure (GMFM-66) and Functional Independence Measures for Children (WeeFIM), at baseline and at 6-months follow-up. Responsiveness was examined using effect size. Minimal detectable change (MDC) at the 90% confidence level (MDC90) and minimal clinically important difference (MCID) were analysed.

RESULTS

The SAROMM with the GMFM-66 and WeeFIM had fair to good construct validity. The effect size values of all SAROMM scales were 0.24 to 0.48. The MDC90 values and MCID range were 1.43 and 0.47 to 1.67 for the SAROMM-SA, 3.12 and 3.68 to 4.07 for the SAROMM-ROM, and 3.22 and 4.53 to 4.62 for the SAROMM-total.

INTERPRETATION

The clinimetric properties of the SAROMM allow clinicians to determine whether a change in SAROMM score represents a clinically meaningful change.

The use of the Patient-Specific Functional Scale to measure rehabilitative progress in a physiotherapy setting

OBJECTIVE

The Patient-Specific Functional Scale (PSFS) and the Numeric Pain Rating Scale (NPRS) are two measures which the Accident Compensation Corporation (ACC) of New Zealand have made compulsory for physiotherapists to record at a patients initial visit and discharge. Therefore, it is important to assess clinicians' compliance to this reporting requirement, and whether research results regarding effectiveness of these measures are transferable to the clinic.

METHOD

A retrospective observational study that assessed compliance in recording these measures, and analyzed the changes in scores seen across 11 physiotherapy practices in New Zealand over a 12-month period.

RESULTS

Overall compliance rates of 51·8% [95% confidence interval (CI): 50·7-52·9] for PSFS and 51·9% (95% CI: 50·7-53·0) for NPRS were reported. These figures increase to 85·3% (95% CI: 82·0-88·6) PSFS; and 85·1% (95% CI: 81·7-88·4) NPRS, when a full discharge for the patient was made. Mean change in PSFS scores were 5·1 (95% CI: 5·0-5·1) points representing an 85·2% (95% CI: 84·1-86·3) change in total score.

DISCUSSION

The study has shown that when patients complete a prescribed course of rehabilitation, clinicians show good compliance in recording PSFS and NPRS. Change in PSFS score is, on average, above the minimal clinically important difference shown in previous studies.

Ventral fusion versus dorsal fusion: determining the optimal treatment for cervical spondylotic myelopathy

Cervical spondylotic myelopathy (CSM) often can be surgically treated by either ventral or dorsal decompression and fusion. However, there is a lack of high-level evidence on the relative advantages and disadvantages for these treatments of CSM. The authors' goal was to provide a comprehensive review of the relative benefits of ventral versus dorsal fusion in terms of quality of life (QOL) outcomes, complications, and costs. They reviewed 7 studies on CSM published between 2003 and 2013 and summarized the findings for each category. Both procedures have been shown to lead to statistically significant improvement in clinical outcomes for patients. Ventral fusion surgery has been shown to yield better QOL outcomes than dorsal fusion surgery. Complication rates for ventral fusion surgery range from 11% to 13.6%, whereas those for dorsal fusion surgery range from 16.4% to 19%. Larger randomized controlled trials are needed, with particular emphasis on QOL and minimum clinically important differences.

Adult Degenerative Scoliosis Surgical Outcomes: A Systematic Review and Meta-analysis

INTRODUCTION

There is increasing awareness of adult degenerative or de novo scoliosis, and its surgical treatment when indicated can be challenging and resource intense. Surgical randomized controlled trials are rare, and observational studies pose limitations because of the heterogeneity of surgical practices, techniques, and patient populations. Pooled analysis of current literature may identify effective treatment strategies and guide future efforts at prospective clinical research. This study aimed to synthesize existing data on the outcomes of surgical intervention for adult degenerative scoliosis.

METHODS

PubMed, Medline, Cochrane, and Web of Science databases were searched using key words and were limited to the English language. Spine surgeons reviewed abstracts and evaluated whether they contained surgically treated cohorts of adults (more than 18 years of age) with degenerative scoliosis. Full-text articles were reviewed in detail and data were abstracted. All meta-analyses were conducted using random effects models and heterogeneity was estimated with I². Random-effects meta-regression models were used to investigate the association of treatment effects with baseline levels of each outcome.

RESULTS

Of 482 articles, 24 (n = 805) met inclusion criteria Available outcomes included Cobb angle correction, coronal and sagittal balance, visual analog scale for pain (VAS), and Oswestry Disability Index. Despite significant heterogeneity among studies, random-effects meta-analysis showed significant improvements in Cobb angle (-11.1°; 95% confidence interval [CI], -13.86° to -8.40°), coronal balance (7.674 mm; 95% CI, -10.5 to -4.9), VAS (-3.24; 95% CI, -4.5 to -1.98), and Oswestry Disability Index (-27.18%; 95% CI, -34.22 to -20.15) postoperative treatment (p < .001). Meta-regression models showed that preoperative values for Cobb angle, coronal balance, and VAS were significantly associated with surgical treatment effect (p < .05). Changes in sagittal balance did not reach statistical significance although only 6 articles were included.

CONCLUSIONS

Exhaustive literature review yielded 24 studies reporting preoperative and postoperative data regarding the surgical treatment of adult degenerative scoliosis. No randomized clinical trials (RCTs) were identified. Despite heterogeneity, a limited meta-analysis showed significant improvement in Cobb angle, coronal balance, and VAS after surgical treatment of adult degenerative scoliosis.

Measuring surgical outcomes in cervical spondylotic myelopathy patients undergoing anterior cervical discectomy and fusion: assessment of minimum clinically important difference

Object

The concept of minimum clinically important difference (MCID) has been used to measure the threshold by which the effect of a specific treatment can be considered clinically meaningful. MCID has previously been studied in surgical patients, however few studies have assessed its role in spinal surgery. The goal of this study was to assess the role of MCID in patients undergoing anterior cervical discectomy and fusion (ACDF) for cervical spondylotic myelopathy (CSM).

Methods

Data was collected on 30 patients who underwent ACDF for CSM between 2007 and 2012. Preoperative and 1-year postoperative Neck Disability Index (NDI), Visual-Analog Scale (VAS), and Short Form-36 (SF-36) Physical (PCS) and Mental (MCS) Component Summary PRO scores were collected. Five distribution- and anchor-based approaches were used to calculate MCID threshold values average change, change difference, receiver operating characteristic curve (ROC), minimum detectable change (MDC) and standard error of measurement (SEM). The Health Transition Item of the SF-36 (HTI) was used as an external anchor.

Results

Patients had a significant improvement in all mean physical PRO scores postoperatively (p<0.01) NDI (29.24 to 14.82), VAS (5.06 to 1.72), and PCS (36.98 to 44.22). The five MCID approaches yielded a range of values for each PRO: 2.00–8.78 for PCS, 2.06–5.73 for MCS, 4.83–13.39 for NDI, and 0.36–3.11 for VAS. PCS was the most representative PRO measure, presenting the greatest area under the ROC curve (0.94). MDC values were not affected by the choice of anchor and their threshold of improvement was statistically greater than the chance of error from unimproved patients.

Conclusion

SF-36 PCS was the most representative PRO measure. MDC appears to be the most appropriate MCID method. When MDC was applied together with HTI anchor, the MCID thresholds were: 13.39 for NDI, 3.11 for VAS, 5.56 for PCS and 5.73 for MCS.

Comprehensive Assessment of 1-Year Outcomes and Determination of Minimum Clinically Important Difference in Pain, Disability, and Quality of Life After Suboccipital Decompression for Chiari Malformation I in Adults

BACKGROUND:

To date, there has been no study to comprehensively assess the effectiveness of suboccipital craniectomy (SOC) for Chiari malformation I (CMI) using validated patient-reported outcome measures.

OBJECTIVE:

To determine the effectiveness and minimum clinically important difference thresholds of SOC for the treatment of adult patients with CMI using patient-reported outcome metrics.

METHODS:

Fifty patients undergoing first-time SOC and C1 laminectomy for CMI at a single institution were followed up for 1 year. Baseline and 1-year postoperative pain, disability, quality of life, patient satisfaction, and return to work were assessed. Minimum clinically important difference thresholds were calculated with 2 anchors: the Health Transition Index and North American Spine Society satisfaction questionnaire.

RESULTS:

The severity of headaches improved in 37 patients (74%). Improvement in syrinx size was seen in 12 patients (63%) and myelopathy in 12 patients (60%). All patient-reported outcomes showed significant improvement 1 year postoperatively (P &lt; .05). Of the 38 patients (76%) employed preoperatively, 29 (76%) returned to work postoperatively at a median time of 6 weeks (interquartile range, 4-12 weeks). Minimum clinically important difference thresholds after SOC for CMI were 4.4 points for numeric rating scale for headache, 0.7 points for numeric rating scale for neck pain, 13.8 percentage points for Headache Disability Index, 14.2 percentage points for Neck Disability Index, 7.0 points for Short Form-12 Physical Component Summary, 6.1 points for Short Form-12 Mental Component Summary, 4.5 points for Zung depression, 1.7 points for modified Japanese Orthopaedic Association, and 0.34 quality-adjusted life-years for Euro-Qol-5D.

CONCLUSION:

Surgical management of CMI in adults via SOC provides significant and sustained improvement in pain, disability, general health, and quality of life as assessed by patient-reported outcomes. This patient-centered assessment suggests that suboccipital decompression for CMI in adults is an effective treatment strategy.

Treatment outcome in adults with chronic fatigue syndrome: a prospective study in England based on the CFS/ME National Outcomes Database

BACKGROUND

Chronic fatigue syndrome (CFS) is relatively common and disabling. Over 8000 patients attend adult services each year, yet little is known about the outcome of patients attending NHS services.

AIM

Investigate the outcome of patients with CFS and what factors predict outcome.

DESIGN

Longitudinal patient cohort.

METHODS

We used data from six CFS/ME (myalgic encephalomyelitis) specialist services to measure changes in fatigue (Chalder Fatigue Scale), physical function (SF-36), anxiety and depression (Hospital Anxiety and Depression Scale) and pain (visual analogue pain rating scale) between clinical assessment and 8-20 months of follow-up. We used multivariable linear regression to investigate baseline factors associated with outcomes at follow-up.

RESULTS

Baseline data obtained at clinical assessment were available for 1643 patients, of whom 834 (51%) had complete follow-up data. There were improvements in fatigue [mean difference from assessment to outcome: -6.8; 95% confidence interval (CI) -7.4 to -6.2; P < 0.001]; physical function (4.4; 95% CI 3.0-5.8; P < 0.001), anxiety (-0.6; 95% CI -0.9 to -0.3; P < 0.001), depression (-1.6; 95% CI -1.9 to -1.4; P < 0.001) and pain (-5.3; 95% CI -7.0 to -3.6; P < 0.001). Worse fatigue, physical function and pain at clinical assessment predicted a worse outcome for fatigue at follow-up. Older age, increased pain and physical function at assessment were associated with poorer physical function at follow-up.

CONCLUSION

Patients who attend NHS specialist CFS/ME services can expect similar improvements in fatigue, anxiety and depression to participants receiving cognitive behavioural therapy and graded exercise therapy in a recent trial, but are likely to experience less improvement in physical function. Outcomes were predicted by fatigue, disability and pain at assessment.

When does a difference make a difference? Interpretation of number needed to treat, number needed to harm, and likelihood to be helped or harmed

Although great effort is made in clinical trials to demonstrate statistical superiority of one intervention vs. another, insufficient attention is paid regarding the clinical relevance or clinical significance of the observed outcomes. Effect sizes are not always reported. Available absolute effect size measures include Cohen's d, area under the curve, success rate difference, attributable risk and number needed to treat (NNT). Of all of these measures, NNT is arguably the most clinically intuitive and helps relate effect size difference back to real-world concerns of clinical practice. This commentary reviews the formula for NNT, and proposes acceptable values for NNT and its analogue, number needed to harm (NNH), using examples from the medical literature. The concept of likelihood to be helped or harmed (LHH), calculated as the ratio of NNH to NNT, is used to illustrate trade-offs between benefits and harms. Additional considerations in interpreting NNT are discussed, including the importance of defining acceptable response, adverse outcomes of interest, the effect of time, and the importance of individual baseline characteristics.

Clinimetric properties of the Assessment of Preschool Children's Participation in children with cerebral palsy

This study examines the criterion-related validity and clinimetric properties of the Assessment of Preschool Children's Participation (APCP) for children with cerebral palsy (CP). Eighty-two children with CP (age range, two to five years and 11 months) and their caregivers participated in this study. The APCP consists of diversity and intensity scores in the areas of play (PA), skill development (SD), active physical recreation (AP), social activities (SA), and total areas. Tests were administered at baseline and at six-month follow-up. Concurrent and predictive validities were identified by assessing the strength of correlations between APCP scores and criterion-related measures--the 66-item Gross Motor Function Measure (GMFM-66) and Functional Independence Measure for Children (WeeFIM). Responsiveness was measured by standardized response mean (SRM). Minimal detectable change (MDC) at the 95% confidence level (MDC95) and minimal clinically important difference (MCID) were analyzed. The APCP with GMFM-66 and WeeFIM had fair to excellent concurrent validity (r=0.39-0.85) and predictive validity (r=0.46-0.82). The SRM values of the APCP diversity and intensity scales in all areas were 0.8-1.3. The MDC95 and MCID ranges for all areas (i.e., PA, SD, AP, SA, and total areas) were 0.1-0.7 and 0.4-1.2 points for intensity scores, respectively, and 4-17% and 10-19% for diversity scores, respectively. Therefore, the APCP scale was markedly responsive to change. Clinicians and researchers can use these clinimetric APCP data to determine whether a change score represents a "true" or clinically meaningful effect at post-treatment and follow-up.

Different minimally important clinical difference (MCID) scores lead to different clinical prediction rules for the Oswestry disability index for the same sample of patients

BACKGROUND

Minimal clinically important difference (MCID) scores for outcome measures are frequently used evidence-based guides to gage meaningful changes. There are numerous outcome instruments used for analyzing pain, disability, and dysfunction of the low back; perhaps the most common of these is the Oswestry disability index (ODI). A single agreed-upon MCID score for the ODI has yet to be established. What is also unknown is whether selected baseline variables will be universal predictors regardless of the MCID used for a particular outcome measure.

OBJECTIVE

To explore the relationship between predictive models and the MCID cutpoint on the ODI.

SETTING

Data were collected from 16 outpatient physical therapy clinics in 10 states.

DESIGN

Secondary database analysis using backward stepwise deletion logistic regression of data from a randomized controlled trial (RCT) to create prognostic clinical prediction rules (CPR).

PARTICIPANTS AND INTERVENTIONS

One hundred and forty-nine patients with low back pain (LBP) were enrolled in the RCT. All were treated with manual therapy, with a majority also receiving spine-strengthening exercises.

RESULTS

The resultant predictive models were dependent upon the MCID used and baseline sample characteristics. All CPR were statistically significant (P < 001). All six MCID cutpoints used resulted in completely different significant predictor variables with no predictor significant across all models.

LIMITATIONS

The primary limitations include sub-optimal sample size and study design.

CONCLUSIONS

There is extreme variability among predictive models created using different MCIDs on the ODI within the same patient population. Our findings highlight the instability of predictive modeling, as these models are significantly affected by population baseline characteristics along with the MCID used. Clinicians must be aware of the fragility of CPR prior to applying each in clinical practice.

Predictors of Oswestry Disability Index worsening after lumbar fusion

The authors identified patients with an increase in their Oswestry Disability Index (ODI) score after lumbar spine fusion to evaluate whether this is a plausible definition of deterioration and to determine whether any common patient characteristics exist.A total of 1054 patients who underwent lumbar spinal fusion and had 2-year follow-up data, including the Short Form 36, the ODI, and numeric rating scales for back and leg pain, were identified. Patients with worsening ODI were compared with the remaining cohort. Twenty-eight patients had an absolute increase (worse) in ODI at 1 year postoperatively. Participants with worsening ODI scores included 13 men and 15 women with an average age of 43.3 years; 15 (54%) were smokers. Common medical comorbidities included obesity and hypertension. Complications occurred in 5 (18%) patients and included wound infection, dural tear, and nerve root injury. Pseudarthrosis was common (n=8; 28%). Twenty-one patients required an additional intervention, including epidural injections, fusion revision, and cervical spine surgery.It is important to have a clear definition of deterioration to better provide informed consent or choice of treatment. Only 28 (2.6%) patients were identified as having an increase in ODI score at 2-year follow-up.

The minimal clinically important difference after simple decompression for ulnar neuropathy at the elbow

PURPOSE

Establishing minimally clinically important difference (MCID) for patient-reported outcomes questionnaires is an important component of outcomes research to understand treatment effectiveness from the patient's perspective. For patients with ulnar neuropathy at the elbow (UNE), these assessments are vital to examine how much change in the questionnaire scores equate to patient satisfaction.

METHODS

We calculated the change in scores of Michigan Hand Outcomes Questionnaire (MHQ), Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire, and Carpal Tunnel Questionnaire (CTQ) from preoperative to 3, 6, and 12 months after ulnar nerve simple decompression procedure. We used the anchor-based approach of receiver operating characteristic curves to determine the MCID.

RESULTS

On average, MCID of 10, 12, and 7 points were identified for pain, function, and activities of daily living domains of the MHQ. Similarly, DASH, CTQ-symptom severity scale, and CTQ-function severity scale had an average MCID of 7, 0.7, and 0.3, points respectively. At the 3, 6, and 12 months' time points, an MCID of 9, 8, and 13 points for pain; 12, 12, and 12 points for function; and 6, 8, and 6 points for activities of daily living domains of the MHQ were identified; similarly an MCID of 8, 7, and 7 points for DASH; 0.4, 0.7, and 0.7 points for CTQ-symptom severity scale; and 0.3, 0.3, and 0.4 points for CTQ-function severity scale were established.

CONCLUSIONS

The smaller MCIDs of MHQ, DASH, and even smaller MCIDs of CTQ found in our study indicate that a small change in the scores identified satisfied patients. Simple decompression surgery for UNE produced patient satisfaction with only a small change in their questionnaire scores. The implications of this finding are that simple decompression surgery for UNE is a highly effective procedure and that the outcomes questionnaires used are highly responsive, which minimizes sample size requirements for future research studies relating to UNE.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic II.

Can we define success criteria for lumbar disc surgery? : estimates for a substantial amount of improvement in core outcome measures

BACKGROUND AND PURPOSE

A successful outcome after lumbar discectomy indicates a substantial improvement. To use the cutoffs for minimal clinically important difference (MCID) as success criteria has a large potential bias, simply because it is difficult to classify patients who report that they are "moderately improved". We propose that the criteria for success should be defined by those who report that they are "completely recovered" or "much better".

METHODS

A cohort of 692 patients were operated for lumbar disc herniation and followed for one year in the Norwegian Registry for Spine Surgery. The global perceived scale of change was used as an external criterion, and success was defined as those who reported that they were "completely recovered" or "much better". Criteria for success for each of (1) the Oswestry disability index (ODI; score range 0-100 where 0 = no disability), (2) the numerical pain scale (NRS; range 0-10 where 0 = no pain) for back and leg pain, and (3) the Euroqol (EQ-5D; -0.6 to 1 where 1 = perfect health) were estimated by defining the optimal cutoff point on receiver operating characteristic curves.

RESULTS

The cutoff values for success for the mean change scores were 20 (ODI), 2.5 (NRS back), 3.5 (NRS leg), and 0.30 (EQ-5D). According to the cutoff estimates, the proportions of successful outcomes were 66% for the ODI and 67% for the NRS leg pain scale.

INTERPRETATION

The sensitivity/specificity values for the ODI and leg pain were acceptable, whereas they were very low for the EQ-5D. The cutoffs for success can be used as benchmarks when comparing data from different surgical units.

Finnish Degenerative Meniscal Lesion Study (FIDELITY): a protocol for a randomised, placebo surgery controlled trial on the efficacy of arthroscopic partial meniscectomy for patients with degenerative meniscus injury with a novel 'RCT within-a-cohort' study design

INTRODUCTION

Arthroscopic partial meniscectomy (APM) to treat degenerative meniscus injury is the most common orthopaedic procedure. However, valid evidence of the efficacy of APM is lacking. Controlling for the placebo effect of any medical intervention is important, but seems particularly pertinent for the assessment of APM, as the symptoms commonly attributed to a degenerative meniscal injury (medial joint line symptoms and perceived disability) are subjective and display considerable fluctuation, and accordingly difficult to gauge objectively.

METHODS AND ANALYSIS

A multicentre, parallel randomised, placebo surgery controlled trial is being carried out to assess the efficacy of APM for patients from 35 to 65 years of age with a degenerative meniscus injury. Patients with degenerative medial meniscus tear and medial joint line symptoms, without clinical or radiographic osteoarthritis of the index knee, were enrolled and then randomly assigned (1 : 1) to either APM or diagnostic arthroscopy (placebo surgery). Patients are followed up for 12 months. According to the prior power calculation, 140 patients were randomised. The two randomised patient groups will be compared at 12 months with intention-to-treat analysis. To safeguard against bias, patients, healthcare providers, data collectors, data analysts, outcome adjudicators and the researchers interpreting the findings will be blind to the patients' interventions (APM/placebo). Primary outcomes are Lysholm knee score (a generic knee instrument), knee pain (using a numerical rating scale), and WOMET score (a disease-specific, health-related quality of life index). The secondary outcome is 15D (a generic quality of life instrument). Further, in one of the five centres recruiting patients for the randomised controlled trial (RCT), all patients scheduled for knee arthroscopy due to a degenerative meniscus injury are prospectively followed up using the same protocol as in the RCT to provide an external validation cohort. In this article, we present and discuss our study design, focusing particularly on the internal and external validity of our trial and the ethics of carrying out a placebo surgery controlled trial.

ETHICS AND DISSEMINATION

The protocol has been approved by the institutional review board of the Pirkanmaa Hospital District and the trial has been duly registered at ClinicalTrials.gov. The findings of this study will be disseminated widely through peer-reviewed publications and conference presentations.

TRIAL REGISTRATION

ClinicalTrials.gov, number NCT00549172.

The minimal clinically important difference of six-minute walk in Asian older adults

BACKGROUND

Rehabilitation interventions promote functional recovery among frail older adults and little is known about the clinical significance of physical outcome measure changes. The purpose of our study is to examine the minimal clinically important difference (MCID) for the 6-minute walk distance (6MWD) among frail Asian older adults.

METHODS

Data from the "Evaluation of the Frails' Fall Efficacy by Comparing Treatments" study were analyzed. Distribution-based and anchor-based methods were used to estimate the MCID of the 6MWD. Participants who completed the trial rated their perceived change of overall health on the Global Rating of Change (GROC) scale. The receiver operating characteristic curve (ROC) was used to analyze the sensitivity and specificity of the cut-off values of 6MWD (in meters) for GROC rating of "a little bit better" (+2), based on feedback from participants.

RESULTS

The mean (SD) change in 6MWD was 37.3(46.2) m among those who perceived a change (GROC ≥ 2), while those who did not was 9.3(18.2) m post-intervention (P = 0.011). From the anchor-based method, the MCID value for the 6MWD was 17.8 m (sensitivity 56.7% and specificity 83.3%) while distribution-based method estimated 12.9 m.

CONCLUSION

The MCID estimate for 6MWD was 17.8 m in the moderately frail Asian older adults with a fear of falling. The results will aid the clinicians in goal setting for this patient population.

Unilateral stance strategies of athletes with ACL deficiency

Aberrant movement strategies are characteristic of ACL-deficient athletes with recurrent knee instability (noncopers), and may instigate premature or accelerate joint degradation. Biomechanical evaluation of kinematic changes over time may elucidate noncopers' responses to neuromuscular intervention and ACL reconstruction (ACLR). Forty noncopers were randomized into a perturbation group or a strength training only group. We evaluated the effects of perturbation training, and then gender on knee angle and tibial position during a unilateral standing task before and after ACLR. No statistically significant interactions were found. Before surgery, the strength training only group demonstrated knee angle asymmetry, but 6 months after ACLR, both groups presented with similar knee flexion between limbs. Aberrant and asymmetrical tibial position was found only in females following injury and ACLR. Neither treatment group showed distinct unilateral standing strategies following intervention; however, males and female noncopers appear to respond uniquely to physical therapy and surgery.

Effects of craniosacral therapy as adjunct to standard treatment for pelvic girdle pain in pregnant women: a multicenter, single blind, randomized controlled trial

OBJECTIVE

Pelvic girdle pain (PGP) is a disabling condition affecting 30% of pregnant women. The aim of this study was to investigate the efficacy of craniosacral therapy as an adjunct to standard treatment compared with standard treatment alone for PGP during pregnancy.

DESIGN

Randomized, multicenter, single blind, controlled trial.

SETTING

University hospital, a private clinic and 26 maternity care centers in Gothenburg, Sweden.

POPULATION

A total of 123 pregnant women with PGP.

METHODS

Participants were randomly assigned to standard treatment (control group, n = 60) or standard treatment plus craniosacral therapy (intervention group, n = 63).

MAIN OUTCOME MEASURES

PRIMARY OUTCOME MEASURES

pain intensity (visual analog scale 0-100 mm) and sick leave.

SECONDARY OUTCOMES

function (Oswestry Disability Index), health-related quality of life (European Quality of Life measure), unpleasantness of pain (visual analog scale), and assessment of the severity of PGP by an independent examiner.

RESULTS

Between-group differences for morning pain, symptom-free women and function in the last treatment week were in favor of the intervention group. Visual analog scale median was 27 mm (95% confidence interval 24.6-35.9) vs. 35 mm (95% confidence interval 33.5-45.7) (p = 0.017) and the function disability index was 40 (range 34-46) vs. 48 (range 40-56) (p = 0.016).

CONCLUSIONS

Lower morning pain intensity and less deteriorated function was seen after craniosacral therapy in conjunction with standard treatment compared with standard treatment alone, but no effects regarding evening pain and sick-leave. Treatment effects were small and clinically questionable and conclusions should be drawn carefully. Further studies are warranted before recommending craniosacral therapy for PGP.