pneumonia prophylaxis has become a standard quality-of-care measure for persons with advanced HIV disease. The number of HIV-related features offered by clinics serving as the usual source of care for our study cohort was a stronger predictor than either clinic AIDS care experience or specialty of PCP prophylaxis and PCP as the initial AIDS diagnosis. Several of these HIV-focused features resemble interventions used by multifaceted cancer prevention programs.26
Receipt of various cancer prevention services has shown greater improvement when both providers and patients receive reminders and educational materials.27
An initial HIV-evaluation protocol may serve the same purpose as chart-based cancer prevention reminders.7,8,9,27–30
Widely observed deficiencies in HIV care knowledge 31, 32
are likely to be improved by appointing a director of HIV care, holding multidisciplinary HIV conferences, and having clinic providers prepared to manage PCP without consultants.
Physician–HIV patient continuity of care was also positively associated with PCP prophylaxis. In general populations, increased continuity of care improves patient clinical outcomes and satisfaction.33
Increased continuity of care helps the physician keep abreast of the patient's changing clinical status and allows initiation of prophylactic therapy in a timely fashion. In our study, continuity of care was assessed only by clinic directors' ratings, but half rated continuity as low or moderate, indicating an effort to be self-critical.
Offering aerosolized pentamidine on-site was related to greater PCP prophylaxis rates. This service probably improves PCP prevention by promoting patient convenience and access to therapy, but it resulted in greater use of this less effective form of prophylaxis. However, our study largely preceded evidence that alternatives such as trimethoprim-sulfamethoxazole are more effective.34, 35
Case management was associated with greater odds of PCP prophylaxis and, in other chronically ill populations, improved delivery of preventive health care.36
Case managers work to improve access to care and other services and may also help patients comply with HIV-related care including medication use. Unfortunately, we did not know the case manager's location or the content of his or her interactions with patients. A survey of 175 AIDS case managers found that those based in hospitals had more clinical training and experience with drug-using populations than those in the community.37
Further research should study case managers' preparation and types of counseling and assistance.
We acknowledge that we are only able to examine associations. Therefore, the clinic characteristics in our analysis may be markers for clinics with other unmeasured features that may actually be responsible for the observed benefits. In addition, we cannot evaluate specific physician characteristics associated with PCP quality of care.
Only 44% of our cohort received prophylaxis, slightly higher than the 40% rate observed for patients with CD4 counts less than 200/μL when they first visited a clinical trial center in a similar time frame as our study.12
Reassuringly, the odds of prophylaxis in our cohort increased significantly over time so that current rates are likely to be higher. As reported by others,38
the rate of PCP has declined less impressively in the 1990s.
Drug users of both genders were more likely to develop PCP than male non–drug users. Fortunately, we observed a marked trend toward greater prophylaxis use by female drug users by the last year of our study. However, female non–drug users and male drug users still lagged behind in their use of prophylaxis in our last study year. Older age was a significant predictor of greater prophylaxis use but was not associated with PCP. We could not examine the association of race-ethnicity with these two outcomes, but other researchers have reported that African Americans have lower adjusted odds of PCP prophylaxis than whites.11
Access to care and prescribing habits of providers have been postulated as contributing to this finding.11
We also could not assess patient compliance and toxicity. Drug toxicity, either real or theoretical, may explain the lower use of prophylaxis by persons with comorbidities such as hypertension or diabetes.
Several other limitations of this study should be acknowledged. We focused on clinic and not on private group or individual practitioner care. Although clinics are the most common source of longitudinal ambulatory care for persons with AIDS in the United States,22, 39
the quality of HIV care in private offices is also important to investigate. Other research suggests that private practitioners may adopt standard elements of HIV care more slowly.40
We studied only patients with a usual source of care, but those without a usual source of care are even less likely to receive PCP prophylaxis.11
In addition, we did not examine patients in managed care arrangements.
Our experience measure is based on a count of Medicaid-enrolled persons with AIDS followed in study clinics adjusted for the proportion of all persons with AIDS in the clinic who are covered by Medicaid. As the median proportion reported by study clinic directors was 85%, AIDS patients in study clinics were predominantly enrolled in Medicaid. In other analyses, we observed longer survival for Medicaid-enrolled women with AIDS treated in clinics with greater experience, measured using a similar approach from claims and interview data.41
The lack of an association of experience with PCP prevention is unexpected but may be due to the possibility that patients in highly experienced clinics may not develop AIDS-defining conditions (needed to be included in our cohort) due to appropriate prophylaxis or antiretroviral therapy.
In support of the completeness of our identification of primary PCP cases, however, PCP was the initial AIDS diagnosis for 40% of reported New York State AIDS cases versus 38% of our study population (Jones J, New York State Department of Health, personal communication). Theoretically, some in our study cohort might not have needed prophylaxis, but this group is most likely small because CD4 T-lymphocyte counts are generally well below 200/μL when AIDS-related conditions occur,42
and other indications for prophylaxis such as oral candidiasis often precede an AIDS diagnosis.5
Our cohort had been diagnosed with HIV infection more than 2 months before their first AIDS diagnosis, giving their providers sufficient time to start prophylaxis. The generalizability of our data to other HIV populations or demographic groups is not known. However, New York State is an epicenter of the HIV epidemic in the United States,43
and Medicaid is the most common payer for AIDS care nationally.
In recent years, the New York State Department of Health has taken a proactive stance in regard to HIV care and mandated that many of these HIV-focused features be provided by clinics that receive enhanced payments under fee-for-service arrangements for HIV-infected Medicaid enrollees.44
Efforts are under way to move New York State Medicaid enrollees with HIV infection into managed care settings that offer the special expertise and HIV-focused features needed to ensure quality care. Our data support such efforts to concentrate HIV care in settings that have the support and expertise needed to manage this complex population.