The COSMIN checklist for assessing the methodological quality of studies on measurement properties of health status measurement instruments: an international Delphi study

BACKGROUND: Aim of the COSMIN study (COnsensus-based Standards for the selection of health status Measurement INstruments) was to develop a consensus-based checklist to evaluate the methodological quality of studies on measurement properties. We present the COSMIN checklist and the agreement of the panel on the items of the checklist. METHODS: A four-round Delphi study was performed with international experts (psychologists, epidemiologists, statisticians and clinicians). Of the 91 invited experts, 57 agreed to participate (63%). Panel members were asked to rate their (dis)agreement with each proposal on a five-point scale. Consensus was considered to be reached when at least 67% of the panel members indicated 'agree' or 'strongly agree'. RESULTS: Consensus was reached on the inclusion of the following measurement properties: internal consistency, reliability, measurement error, content validity (including face validity), construct validity (including structural validity, hypotheses testing and cross-cultural validity), criterion validity, responsiveness, and interpretability. The latter was not considered a measurement property. The panel also reached consensus on how these properties should be assessed. CONCLUSIONS: The resulting COSMIN checklist could be useful when selecting a measurement instrument, peer-reviewing a manuscript, designing or reporting a study on measurement properties, or for educational purposes.This study was financially supported by the EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, and the Anna Foundation, Leiden, The Netherlands

Value of health-related quality of life to predict disability course in multiple sclerosis

Objective: To determine the value of health-related quality of life (HRQoL) to predict change in disability status in patients with multiple sclerosis (MS). Methods: Over a 5-year period, data were collected on HRQoL (Medical Outcomes Study Short Form-36 Health Survey) and disability status (Expanded Disability Status Scale) from a heterogeneous group of 81 Dutch-speaking patients with MS. Results: Multivariate logistic regression analysis showed that HRQoL in the domains of Physical Functioning and Role-Physical Functioning is a significant predictor of change in disability status. Conclusions: A patient's subjectively perceived health-related quality of life may not be only a clinically and psychosocially meaningful outcome per se but may also be a predictor of objective outcomes such as change in disability status over a substantial period of time