https://research.vu.nl/ws/files/2901670/267479.pdf

Quality criteria were proposed for measurement properties of health status questionnaires

Background A number of studies have computed the minimally important difference (MID) for health-related quality of life instruments. Objective To determine whether there is consistency in the magnitude of MID estimates from different instruments. Methods We conducted a systematic review of the literature to identify studies that computed an MID and contained sufficient information to compute an effect size (ES). Thirty-eight studies fulfilled the criteria, resulting in 62 ESs. Results For all but 6 studies, the MID estimates were close to one half a SD (mean = 0.495, SD = 0.155). There was no consistent relationship with factors such as disease-specific or generic instrument or the number of response options. Negative changes were not associated with larger ESs. Population-based estimation procedures and brief follow-up were associated with smaller ESs, and acute conditions with larger ESs. An explanation for this consistency is that research in psychology has shown that the limit of people's ability to discriminate over a wide range of tasks is approximately 1 part in 7, which is very close to half a SD. Conclusion In most circumstances, the threshold of discrimination for changes in health-related quality of life for chronic diseases appears to be approximately half a SD.

Interpretation of changes in health-related quality of life the remarkable universality of half a standard deviation

We have developed a 12-item questionnaire for patients having a total knee replacement (TKR). We made a prospective study of 117 patients before operation and at follow-up six months later, asking them to complete the new questionnaire and the form SF36. Some also filled in the Stanford Health Assessment Questionnaire (HAQ). An orthopaedic surgeon completed the American Knee Society (AKS) clinical score. The single score derived from the new questionnaire had high internal consistency, and its reproducibility, examined by test-retest reliability, was found to be satisfactory. Its validity was established by obtaining significant correlations in the expected direction with the AKS scores and the relevant parts of the SF36 and HAQ. Sensitivity to change was assessed by analysing the differences between the preoperative scores and those at follow-up. We also compared change in scores with the patients' retrospective judgement of change in their condition. The effect size for the new questionnaire compared favourably with those for the relevant parts of the SF36. The change scores for the new knee questionnaire were significantly greater (p < 0.0001) for patients who reported the most improvement in their condition. The new questionnaire provides a measure of outcome for TKR that is short, practical, reliable, valid and sensitive to clinically important changes over time.

Questionnaire on the perceptions of patients about total hip replacement

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140673607604577.pdf

The operation of the century: total hip replacement

OBJECTIVES: To estimate the magnitude of small meaningful and substantial individual change in physical performance measures and evaluate their responsiveness.

DESIGN: Secondary data analyses using distribution- and anchor-based methods to determine meaningful change.

SETTING: Secondary analysis of data from an observational study and clinical trials of community-dwelling older people and subacute stroke survivors.

PARTICIPANTS: Older adults with mobility disabilities in a strength training trial (n=100), subacute stroke survivors in an intervention trial (n=100), and a prospective cohort of community-dwelling older people (n=492).

MEASUREMENTS: Gait speed, Short Physical Performance Battery (SPPB), 6-minute-walk distance (6MWD), and self-reported mobility.

RESULTS: Most small meaningful change estimates ranged from 0.04 to 0.06 m/s for gait speed, 0.27 to 0.55 points for SPPB, and 19 to 22 m for 6MWD. Most substantial change estimates ranged from 0.08 to 0.14 m/s for gait speed, 0.99 to 1.34 points for SPPB, and 47 to 49 m for 6MWD. Based on responsiveness indices, per-group sample sizes for clinical trials ranged from 13 to 42 for substantial change and 71 to 161 for small meaningful change.

CONCLUSION: Best initial estimates of small meaningful change are near 0.05 m/s for gait speed, 0.5 points for SPPB, and 20 m for 6MWD and of substantial change are near 0.10 m/s for gait speed, 1.0 point for SPPB, and 50 m for 6MWD. For clinical use, substantial change in these measures and small change in gait speed and 6MWD, but not SPPB, are detectable. For research use, these measures yield feasible sample sizes for detecting meaningful change.

Meaningful Change and Responsiveness in Common Physical Performance Measures in Older Adults

Background: The purpose of this study was to develop a short, reliable, and valid measure of physical function and symptoms related to upper-limb musculoskeletal disorders by shortening the full, thirty-item DASH (Disabilities of the Arm, Shoulder and Hand) Outcome Measure.

Methods: Three item-reduction techniques were used on the cross-sectional field-testing data derived from a study of 407 patients with various upper-limb conditions. These techniques were the concept-retention method, the equidiscriminative item-total correlation, and the item response theory (Rasch modeling). Three eleven-item scales were created. Data from a longitudinal cohort study in which the DASH questionnaire was administered to 200 patients with shoulder and wrist/hand disorders were then used to assess the reliability (Cronbach alpha and test-retest reliability) and validity (cross-sectional and longitudinal construct) of the three scales. Results were compared with those derived with the full DASH.

Results: The three versions were comparable with regard to their measurement properties. All had a Cronbach alpha of ≥0.92 and an intraclass correlation coefficient of ≥0.94. Evidence of construct validity was established (r ≥ 0.64 with single-item indices of pain and function). The concept-retention method, the most subjective of the approaches to item reduction, ranked highest in terms of its similarity to the original DASH.

Conclusions: The concept-retention version is named the QuickDASH. It contains eleven items and is similar with regard to scores and properties to the full DASH. A comparison of item-reduction approaches suggested that the retention of clinically sensible and important content produced a comparable, if not slightly better, instrument than did more statistically driven approaches.

Clinical Relevance: The QuickDASH is a more efficient version of the DASH outcome measure that appears to retain its measurement properties.

Development of the QuickDASH: comparison of three item-reduction approaches.

A comparison of different indices of responsiveness

A taxonomy for responsiveness.

A comparative contrast of clinimetric and psychometric methods for constructing indexes and rating scales.

We aimed to assess individual differences in complaints in patients just before total hip replacement (THR) and the importance attached to the relief of each of them. In a pilot study, using open-ended interviews, we identified 16 main complaints, four of which (night pain, unequal leg length and discomfort during sexual and recreational activities) were not included in any of the six hip-rating scales in general use. Each of the 16 complaints was then assessed in 72 patients and rated for severity and the relative importance of relief. From this we calculated a severity-importance rating for each complaint and a patient-specific score for all complaints. The 72 patients had a mean age of 64 years (17 to 92) and 51% were men. The most important reasons for wanting a THR were day pain and walking difficulty, but the complaints mentioned above and not included in standard hip scores were also important. Greater attention to the individual requirements of patients might improve evaluation of the outcome of orthopaedic treatments.

James G. Wright

Papers

Development of the QuickDASH: comparison of three item-reduction approaches.

A comparison of different indices of responsiveness

A taxonomy for responsiveness.

A comparative contrast of clinimetric and psychometric methods for constructing indexes and rating scales.

Ask patients what they want. Evaluation of individual complaints before total hip replacement.