Managed care for AIDS patients: is bigger better?

CONTEXT: Medicaid provides funds for the majority of AIDS-related health care services in the United States. In an effort to stabilize steeply rising Medicaid costs, managed care programs are replacing traditional fee-for-service Medicaid services.
OBJECTIVE: To assess the impact of patient volume on the quality of care received by AIDS patients within a state's Medicaid managed care system.
DESIGN: Cohort study of AIDS patients who were enrolled in Medicaid at any time from July 1997 through December 1998. Patient charts were reviewed and abstracted. Additional information on the AIDS patients' mode of exposure, date of AIDS diagnosis, and vital status were obtained from the state's HIV/AIDS surveillance database. PATIENTS AND
SETTING: All known AIDS patients enrolled in the Maryland Medicaid managed care program were eligible. A total of 1052 of 1585 patient records were reviewed and analyzed. MAIN OUTCOME MEASURES: CD4 and viral load tests; preventive health care including screening for sexually transmitted infections; placement of tuberculin purified protein derivative (PPDs); hepatitis B and C screening; vaccination for hepatitis B; vaccination for pneumococcal pneumonia; Papanicolaou test screening; medication utilization including receipt of antiretroviral therapy and prophylaxis against Pneumocystis carinii pneumonia; case management services; and mortality.
RESULTS: Health care quality indicators were examined by comparing the performance of clinical sites that saw a low volume of Medicaid AIDS patients per site (1-15 patients), a medium volume (16-100 patients), and a high volume (101-500 patients). High-volume sites performed better on virtually all quality indicators. There were few differences in performance between low- and medium-volume sites. High-volume sites experienced a greater number of patient deaths; this was true after adjusting for potential confounders such as age, use of antiretrovirals, time since AIDS diagnosis, appropriate laboratory monitoring, and hospitalizations.
CONCLUSIONS: Variations in quality of care for AIDS patients were observed in a statewide managed care system. These variations existed despite provisions to ensure quality care such as an enhanced payment system for managed care organizations providing services for AIDS. High-volume sites were more likely to adhere to Public Health Service guidelines and may offer the best opportunity to provide high-quality AIDS care.