Primary care delivery is associated with greater physician experience and improved survival among persons with AIDS

Abstract

Objective: It has been shown that greater physician experience in the care of persons with AIDS prolongs survival, but how more experienced primary care physicians achieve better outcomes is not known.

Design/setting/patients: Retrospective cohort study of HIV-infected patients enrolled in a large staff-model health maintenance organization from 1990 through 1999.

Measurements: Adjusted odds of medical service delivery and adjusted hazard ratio of death by physician experience level (least, moderate, most) and service utilization.

Main results: Primary care delivery by physicians with greater AIDS experience was associated with improved survival. After controlling for disease severity, patients cared for by the most experienced physicians were twice as likely to receive a primary care visit in a given month compared with patients of the least and moderately experienced physicians (P <.01). Patients of the least experienced physicians received the lowest level of outpatient pharmacy and laboratory services (P <.001) and were half as likely to have a specialty care visit compared with patients of the most and moderately experienced physicians (P <.05). Patients who received infrequent primary care visits by the least experienced physicians were 15.3 times more likely to die than patients of the most experienced physicians (P =.02). There was a significant increase in primary care services delivered to the population of HIV-infected patients receiving care in 1999, when highly active antiretroviral therapy (HAART) was in general use, compared with the time period prior to the introduction of HAART.

Conclusions: Primary care delivery by physicians with greater HIV experience contributes to improved patient outcomes.

FIGURE 1

Classification of primary care utilization by disease severity and visit frequency. (A) Classification of disease severity at time of the diagnosis of AIDS. Patients were categorized into 4 levels of disease severity (low, moderate, high, and very high) at time of the diagnosis of AIDS based on CD4 cell count level and severity of AIDS-defining illness. The 4 categories of disease severity were associated with distinct levels of risk. Patients classified with very high, high, and moderate disease severity had a relative risk of death of 9.1, 2.9, (P < .0001), and 1.6 (P < .07), respectively, compared with patients with low disease severity. (B) Classification of primary care utilization by disease severity. We assumed that patients with very high disease severity would receive at least 1 primary care visit a month, while patients with low disease severity would have at least 1 visit every 2 months. This corresponded to the lower quintile of average monthly visits within each disease severity category and was classified as infrequent primary care.

FIGURE 2

Adjusted odds ratio of primary care, specialty care, and no outpatient or inpatient care in a month according to physician experience level.