Validating the Adult Primary Care Assessment Tool

Journal of Family Practice, Feb, 2001 by Leiyu Shi, Barbara Starfield, Jiahong Xu

* BACKGROUND This paper reports on the validation of the Consumer/Client Primary Care Assessment Tool--Adult Edition (PCAT-AE). Specifically, we assessed the congruence between the theoretically derived measures and the empirical results in terms of the underlying structure of the principal primary care domains within a diverse sample of populations, including members of Health Maintenance Organizations (HMOs) and users of Community Health Centers (CHCs).

* METHODS The study participants were randomly selected from an HMO group (n=35) and a low-income group (n=540) in South Carolina. They were surveyed regarding the provision of primary care. Reliability, validity, and scaling analyses were conducted to assess and validate the 9 scales representing core primary care subdomains and 3 derivative domains: first contact--accessibility, first contact--utilization (first contact domain), longitudinality--interpersonal relationships (longitudinality domain), coordination of services (coordination domain), comprehensiveness --services available, comprehensiveness services received (comprehensiveness domain), family-centeredness, community orientation, and cultural competence (derivative domains).

* RESULTS The results indicate that the hypothesized scales for primary care have substantial reliability and validity, and extracted factors explained 88.1% of the total variance in the item scores. All of the 5 scaling assumptions (item-convergent validity, item-discriminant validity, equal item variance, equal item-scale correlation, and score reliability) were met, suggesting that these items may be used to represent the prunary care scales and the scoring of these items may be summed without standardization or weighting.

Separate factor analyses were performed with the 2 groups. The results were largely comparable in terms of the factors that emerged as significant, indicating the generalizability of the tool to both vulnerable and middle-income populations. The only major differences are that the CHC subpopulation analysis yielded an additional significant factor: cultural competence. In contrast, the HMO subpopulation analysis yielded an additional significant factor: family-centeredness. Thus, when using PCAT-AE on vulnerable populations, questions measuring cultural competence should be retained.

* CONCLUSIONS Understanding primary care as multidimensional is consistent with the Institute of Medicines's conceptualization of primary care and more precisely captures the quality of primary care. Psychometric assessment supported the integrity and general adequacy of the PCAT-AE for assessing the characteristics and quality of primary care for adults. The PCAT-AE can be used as a quality measurement tool to assess the adequacy of the primary care experience rendered under different health care systems or settings, and for patients with different sociodemographic attributes. It can also be used with other outcomes to assess the effect of policy interventions and systems changes on the delivery of critical aspects of primary care.

* KEYWORDS Primary health care; healthcare quality, access, and evaluation; public policy. (J Fam Pract 2001; 51:161)

EDITOR'S NOTE

This is a groundbreaking health services research study, and we are also breaking new ground at JFP by publishing it in a different way. An expanded, structured abstract is presented above to assure that all readers of JFP are aware of this important new work.- The full article, with extensive tables that would be difficult to present in print, can be found online at our new freely accessible, full-text Web site (http://www.jfponline.com). Please take this opportunity to join me online and let me know what you think of this new approach to publishing medical research.

* Submitted, revised, October 2, 2000.

From the Department of Health Policy and Management, The Johns Hopkins School of Public Health and Hygiene,. Baltimore, Maryland (L.S., B.S.), and the Department of Biostatistics and Epidemiology, University of South Carolina, Columbia (J.X.). All requests for reprints should be sent to Leiyu Shi, DrPH, MBA, Department of Health Policy and Management, The Johns Hopkins School of Public Health and Hygiene, 624 North Broadway/Room 409, Baltimore MD 21205-1996.