Construct Validity Testing of the Provider Co-Management Index to Measure Shared Care in Provider Dyads

Abstract

Abstract Background Co-management encompasses the dyadic process between two health care providers. The Provider Co-Management Index (PCMI) was initially developed as a 20-item instrument across three theory-informed subscales. Objective This study aimed to establish construct validity of the PCMI with a sample of primary care providers through exploratory and confirmatory factor analyses. Methods We conducted a cross-sectional survey of primary care physicians, nurse practitioners, and physician assistants randomly selected from the IQVIA database across New York State. Mail surveys were used to acquire a minimum of 300 responses for split sample factor analyses. The first subsample (derivation sample) was used to explore factorial structure by conducting an exploratory factor analysis. A second (validation) sample was used to confirm the emerged factorial structure using confirmatory factor analysis. We performed iterative analysis and calculated good fit indices to determine the best-fit model. Results There were 333 responses included in the analysis. Cronbach's alpha was high for a 3-item per dimension scale within a one-factor model. The instrument was named PCMI–9 to indicate the shorter version length. Discussion This study established the construct validity of an instrument that scales the co-management of patients by two providers. The final instrument includes 9 items on a single factor using a 4-point, Likert-type scale. Additional research is needed to establish discriminant validity.