Abstract
OBJECTIVE: To link the Activity Measure for Post-Acute Care (AM-PAC) Applied Cognition to the Patient-Reported Outcomes Measurement Information System (PROMIS) Cognitive Function, allowing for a common metric across scales. DESIGN: Cross-sectional survey study. SETTING: Outpatient rehabilitation clinics. PARTICIPANTS: Consecutive sample of 500 participants (N=500) aged ≥18 years presenting for outpatient therapy (physical, occupation, speech). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: AM-PAC Medicare and Generic Cognition short forms and PROMIS Cognitive Function items representing the PROMIS Cognitive Function item bank. RESULTS: The calibration of 25 AM-PAC cognition items with 11 fixed PROMIS cognitive function item parameters using item-response theory indicated that items were measuring the same underlying construct (cognition). Both scales measured a wide range of functioning. The AM-PAC Generic Cognitive assessment showed more reliability with lower levels of cognition, whereas the PROMIS Cognitive Function full-item bank was more reliable across a larger distribution of scores. Data were appropriate for a fixed-anchor item response theory-based crosswalk and AM-PAC Cognition raw scores were mapped onto the PROMIS metric. CONCLUSIONS: The crosswalk developed in this study allows for converting scores from the AM-PAC Applied Cognition to the PROMIS Cognitive Function scale.