History and background information
There are thousands of health status measurement instruments that are being used in research and clinical practice. Often many instruments exist for measuring one single concept. Instruments differ in their qualitative attributes, i.e. the construct that is being measured, the purpose and target population, its format, interpretability, and ease of use. Instruments also differ in their measurement properties, i.e. reliability, validity, and responsiveness. The variety in content and quality of available instruments makes it difficult to select the best instrument for a specific purpose.
Instrument selection should be based on systematic reviews in which the content and measurement properties (reliability, validity, responsiveness) of all instruments measuring a certain construct, are critically appraised and compared. In the last decade the number of systematic reviews of measurement properties has increased enormously.
An important step in systematic reviews of measurement properties is to rate the methodological quality of the included studies on measurement properties. It is important that the methodological quality of these studies is taken into account when summarizing the results of the included studies. To facilitate the assessment of the methodological quality of these studies, a standardized tool was developed. In 2005 an international steering committee was constituted with the aim to develop a consensus based checklist which contains standards for the evaluation of the methodological quality of studies on measurement properties. The focus was on Health-Related Patient-Reported Outcomes (HR-PROs). An international Delphi study was performed in which consensus was reached on standards for design requirements and appropriate statistical methods for assessing measurement properties. Based on these standards, the COSMIN checklist was developed.
It is our mission to promote, perform, support, and disseminate high quality systematic reviews of measurement instruments, to enable evidence-based instrument selection.