We examined quality measures that could be assessed by a medical record review. All but 1 (nondetectable viral load) of these measures are process measures. Our findings may have differed if we could have assessed mortality rates, hospitalization rates, appropriate management of opportunistic infections, changes in health status, medication adherence, or patient reports about or ratings of care (30). Similarly, our findings might have differed if we had measured the performance of more complex HIV-related care decisions (such as managing treatment failure) or had assessed other types of quality in these patients (such as appropriate care of depression, diabetes, hypertension, or hyperlipidemia). Four care processes that we assessed (purified protein derivative testing, hepatitis C screening, Pap smears, and influenza vaccinations) are simple for anyone with basic clinical training to implement, and the remaining 4 care processes (HAART, viral load control, P. carinii prophylaxis, and visit frequency) are the subject of detailed clinical practice guidelines (31 - 32). Nonetheless, we found similar results across all 8 quality measures. Finally, we studied patients receiving care in clinics that have CARE Act Title III funding, and we cannot know whether our findings are generalizable to other settings. Sites that receive this funding, however, disproportionately care for patients with low incomes and complex social problems. We therefore expect that NPs and PAs would have less, not more, difficulty caring for more advantaged populations.