Talk:Measurement websites
From RiCkyPedia
Content validity
Content validity is "the extent to which a measure samples a representative range of the content under study. In interpreting content validity, questions regarding item sufficiency and patient population should be addressed carefully. For example, the range of items needed to assess physical functioning in arthritic patients may be too gross for application to many coronary heart disease samples. Also, one or two aspects of depression, such as somatic complaints, domainate some self-report depression questionnaires. A clear idea of what aspects of a concept are to be measured is essential in assessing content validity. Content validity evaluations tend to be fairly subjective, but ideally include systematic comparison of a measure with existing standards, well-accepted theoretical definitions, expert opinions, and interviews with individuals for whom the measure is targeted. Often in the development of a new scale a content map is created and items are constructed to cover the dimensions of interest."
Patrick et al. (Value in Health, 2007, vol. 10) set forth some stringent requirements for documenting content validity including each of the following:
+ Chronology of all item development activities
+ Protocols for qualitative interviews, focus groups, cognitive interviews and other research used to identify concepts, generate items, or revise an existing instrument, including training of interviewers
+ Development of response options, modes of administration and scoring
+ Size, characteristics, location, and (if requested) transcripts of each qualitative interview and focus group
+ Documentation on how saturation was achieved (i.e. no new information was obtained from additional qualitative interviews or focus groups)
+ Description of any pilot test, including cognitive interviewing, cognitive interview transcripts (if requested)
+ Versions of the instrument at various milestones of development
+ Item tracking table that list the source of each item in the final instrument, and how it changed during development
+ A summary statement of qualitative research in support of content validity of the PRO instrument
ISPOR has a task force working on content validity for labeling claims: http://www.ispor.org/taskforces/ISPORContentValidityWS2008_DraftMR.pdf http://www.ispor.org/taskforces/RothmanISPOR3rdplenaryfinal.pdf
