Adapting PROMIS physical function items for users of assistive technology.
|Title||Adapting PROMIS physical function items for users of assistive technology.|
|Publication Type||Journal Article|
|Authors||Amtmann D, Bamer AM, Cook KF, Harniss M, Johnson KL|
|Journal||Disability and Health Journal|
Introduction: The Patient Reported Outcomes Measurement Information System (PROMIS) is an NIH roadmap initiative to develop publicly available and psychometrically sound banks of items measuring patient reported outcomes. This study modified the PROMIS physical function (PF) domain bank to make it appropriate and relevant to individuals who use wheelchairs, mobility aids, and other assistive technology (AT). Method/Approach: Items were reviewed by experts and those determined not appropriate or relevant to AT users were removed or modified. Additional items were created to cover the content relevant to individuals who use mobility aids. Cognitive interviews with users of AT (N531) were conducted. Each new or adapted item was reviewed by at least 8 AT users. Based on these results, a candidate item bank was developed and administered to 600 individuals with multiple sclerosis, spinal cord injury, and arthritis. A subset of unchanged domain items was also administered to allow for calibration along the same metric as the original PF item bank. Results/Findings: The Cronbach alpha for the modified items was .986. Several items had low information and required that response categories be collapsed for analysis. DIF analyses indicated sufficient number of items without DIF for co-calibrating the current and modified items. Comparisons of test information functions for new/modified and original items indicate that the new items lowered the item banks’ floor effect. Conclusion/Recommendations: The modified bank has sound psychometric properties and allows researchers to measure individuals who use mobility aids on the same continuum as those who do not. It includes items appropriate for AT users and for assessment of people with low physical function. Computerized adaptive testing, short forms, and all items will be available to researchers via the PROMIS website.