The Clinical Significance Consensus Meeting Group. Estimating clinically significant differences in quality of life outcomes
University of Hamburg, Hamburg, Hamburg, Germany Quality of Life Research
(Impact Factor: 2.49).
04/2005; 14(2):285-95. DOI: 10.1007/s11136-004-0705-2
This report extracts important considerations for determining and applying clinically significant differences in quality of life (QOL) measures from six published articles written by 30 international experts, in the field of QOL assessment and evaluation. The original six articles were presented at the Symposium on Clinical Significance of Quality of Life Measures in Cancer Patients at the Mayo Clinic in April 2002 and subsequently were published in Mayo Clinic Proceedings.
Specific examples and formulas are given for anchor-based methods, as well as distribution-based methods that correspond to known or relevant anchors to determine important differences in QOL measures. Important prerequisites for clinical significance associated with instrument selection, responsiveness, and the reporting of QOL trial results are provided. We also discuss estimating the number needed to treat (NNT) relative to clinically significant thresholds. Finally, we provide a rationale for applying group-derived standards to individual assessments.
While no single method for determining clinical significance is unilaterally endorsed, the investigation and full reporting of multiple methods for establishing clinically significant change levels for a QOL measure, and greater direct involvement of clinicians in clinical significance studies are strongly encouraged.
Available from: Peter G Robinson
- " . Furthermore , it is important to note that the trials were powered to detect changes in Schiff scores , as the primary out - come , rather than DHEQ . The clinical significance consensus group commented that evaluations of PROs , particularly QoL in clinical trials and the assessment of clinically significant thresholds for change are complex ( Wyrwich et al . 2005 ) . Indeed , strategies to determine change have not kept pace with the explosion in QoL measures in medi - cine and dentistry . Whilst we used several analytic strategies , DHEQ , like all such measures should be con - stantly reviewed , incorporating new data and psychometric techniques as they emerge . We used both anchor - based ( i"
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ABSTRACT: To validate the Dentine Hypersensitivity Experience Questionnaire in terms of responsiveness to change and to determine the minimally important difference (MID).
The study was a secondary analysisof data from three randomised controlled trials with 311 participants. Three aspects of responsiveness were examined: change within individuals, differences between people who improved, stayed the same or worsened using an external referent, and change due to treatment. Responsiveness to treatments of differing efficacywas assessed in trials with negative and active controls.
The measureshowed excellent internal reliability, test-retest reliability and criterion validity. The measure was highly responsive to change within individuals (Cohen's effect sizes: 0.28, 0.56, 0.86) showing decreases in the total score (i.e. improvement in OHrQoL) across all trials. The effect sizes in participants whose self-reported QoL'improved' were large (0.73 - 1.31).DHEQ detected a treatment effect in one of two negative control trials (effect size: 0.47). DHEQ scores were similar in the test and control groups in the active control trial. The minimally important differencerange wasbetween 22 and 39 points.
The measure is longitudinally reliable, valid and responsive and can discriminate between treatments of different efficacy. This article is protected by copyright. All rights reserved.
Available from: Jøran Hjelmesæth
- "There are different approaches to addressing this. Here we have chosen the effect size (ES) to grade the efficiency of surgical versus nonsurgical treatment [22,23]. "
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ABSTRACT: There is little robust evidence relating to changes in health related quality of life (HRQL) in morbidly obese patients following a multidisciplinary non-surgical weight loss program or laparoscopic Roux-en-Y Gastric Bypass (RYGB). The aim of the present study was to describe and compare changes in five dimensions of HRQL in morbidly obese subjects. In addition, we wanted to assess the clinical relevance of the changes in HRQL between and within these two groups after one year. We hypothesized that RYGB would be associated with larger improvements in HRQL than a part residential intensive lifestyle-intervention program (ILI) with morbidly obese subjects.
A total of 139 morbidly obese patients chose treatment with RYGB (n=76) or ILI (n=63). The ILI comprised four stays (seven weeks) at a specialized rehabilitation center over one year. The daily schedule was divided between physical activity, psychosocially-oriented interventions, and motivational approaches. No special diet or weight-loss drugs were prescribed. The participants completed three HRQL-questionnaires before treatment and 1 year thereafter. Both linear regression and ANCOVA were used to analyze differences between weight loss and treatment for five dimensions of HRQL (physical, mental, emotional, symptoms and symptom distress) controlling for baseline HRQL, age, age of onset of obesity, BMI, and physical activity. Clinical relevance was assessed by effect size (ES) where ES<.49 was considered small, between .50-.79 as moderate, and ES>.80 as large.
The adjusted between group mean difference (95% CI) was 8.6 (4.6,12.6) points (ES=.83) for the physical dimension, 5.4 (1.5–9.3) points (ES=.50) for the mental dimension, 25.2 (15.0–35.4) points (ES=1.06) for the emotional dimension, 8.7 (1.8–15.4) points (ES=.37) for the measured symptom distress, and 2.5 for (.6,4.5) fewer symptoms (ES=.56), all in favor of RYGB. Within-group changes in HRQOL in the RYGB group were large for all dimensions of HRQL. Within the ILI group, changes in the emotional dimension, symptom reduction and symptom distress were moderate. Linear regression analyses of weight loss on HRQL change showed a standardized beta-coefficient of –.430 (p<.001) on the physical dimension, –.288 (p=.004) on the mental dimension, –.432 (p<.001) on the emotional dimension, .287 (p=.008) on number of symptoms, and .274 (p=.009) on reduction of symptom pressure.
Morbidly obese participants undergoing RYGB and ILI had improved HRQL after 1 year. The weaker response of ILI on HRQL, compared to RYGB, may be explained by the difference in weight loss following the two treatments.
Clinical Trials.gov number NCT00273104
Available from: Michael Mackenzie
- "There are a number of widely accepted assessments of the clinical significance of change in an intervention, using both anchor-based (i.e., clinical) and distribution-based (i.e., statistical) assessments  . Anchor-based approaches are methods that relate change to an external event, rating, or condition, while distribution-based methods link clinical significance to a statistical parameter of group or individual data . Examination of the yoga and cancer intervention literature reveals minimal reporting of anchor-based metrics. "
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ABSTRACT: Limited research suggests yoga may be a viable gentle physical activity option with a variety of health-related quality of life, psychosocial and symptom management benefits. The purpose of this review was to determine the clinical significance of patient-reported outcomes from yoga interventions conducted with cancer survivors. A total of 25 published yoga intervention studies for cancer survivors from 2004-2011 had patient-reported outcomes, including quality of life, psychosocial or symptom measures. Thirteen of these studies met the necessary criteria to assess clinical significance. Clinical significance for each of the outcomes of interest was examined based on 1 standard error of the measurement, 0.5 standard deviation, and relative comparative effect sizes and their respective confidence intervals. This review describes in detail these patient-reported outcomes, how they were obtained, their relative clinical significance and implications for both clinical and research settings. Overall, clinically significant changes in patient-reported outcomes suggest that yoga interventions hold promise for improving cancer survivors' well-being. This research overview provides new directions for examining how clinical significance can provide a unique context for describing changes in patient-reported outcomes from yoga interventions. Researchers are encouraged to employ indices of clinical significance in the interpretation and discussion of results from yoga studies.
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