Responsiveness, construct and criterion validity of the Personal Care-Participation Assessment and Resource Tool (PC-PART)

Background: The Personal Care-Participation Assessment and Resource Tool (PC-PART) was designed to measure participation restrictions in activities of daily living required for community life. Rasch analysis has confirmed that the PC-PART contains two unidimensional scales providing interval-level measurement: the Self Care and Domestic Life scales. This study investigated validity and responsiveness of these PC-PART scales using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) approach.

Methods:
Thirteen hypotheses about Self Care and Domestic Life scale scores were established prior to conducting the analyses. Data from a prospective randomized controlled trial of additional (weekend) inpatient rehabilitation in Melbourne, Australia, were used. The 996 participants had a mean (SD) age of 74 (13) years and were admitted with orthopaedic (n = 581), neurological (n = 203) or other disabling impairments (n = 212). Self Care and Domestic Life scores were compared to functional independence (FIM), comorbidity (Charlson Comorbidity Index), whether activities of daily living goals were met, and discharge destination.

Results: Low to moderate correlations between FIM and PC-PART scales’ scores supported hypotheses that the PC-PART measures a different construct from functional independence: Self Care r s -0.52(95 % CI -.46 to -.57) and Domestic Life r s -0.32(95 % CI -.25 to -.38). The scales had low to moderate discriminative ability for discharge destination, with the area under the curve for Self Care, 0.70 (95 % CI 0.62-0.78), and Domestic Life, 0.72 (95 % CI 0.64-0.80). The discharge to community living cut-off scores for Self Care: 5.50 (sensitivity .83, specificity .53) and Domestic Life: 7.50 (sensitivity .75, specificity .60), represented patients having no participation restrictions. Change scores from admission to discharge demonstrated larger effect sizes for the Self Care (1.67) and Domestic Life (1.50) scales than for the FIM (1.10), supporting hypotheses about responsiveness. Ten of the 13 hypotheses were supported.

Conclusions: This study provided evidence supporting construct validity, criterion validity and responsiveness of the PC-PART Self Care and Domestic Life scales for inpatient rehabilitation. Clinicians, managers and researchers who wish to measure the patterns and extent of people’s participation restrictions in activities of daily living and the associated burden of care, before and/or after intervention, can be somewhat confident about the PC-PART’s validity and responsiveness for this purpose.

Trial registration: Data used in this research were gathered during a registered randomized controlled trial: Australian and New Zealand Clinical Trials Registry ACTRN12609000973213.