The results of our study show that ADAP enrollment, regardless of state of residence, was associated with increased HAART utilization among clinically eligible HIV-infected women. Also, we found that HAART- and antihypertensive-indicated women enrolled in ADAP had increased, but non-significant, odds of antihypertensive medication use compared to women not enrolled in ADAP. To our knowledge, this is the first study to suggest that ADAP enrollment may increase the use of non-antiretroviral prescription drugs. Additionally, the breadth of data in this study presents a unique opportunity to assess state differences in ADAP enrollment criteria and formularies and we found that state of residence may have a lesser role in use and non-use of HAART than other factors.
Although New York had the most lenient income eligibility criteria for ADAP (below 423% FPL) compared to California and Illinois (below 400% FPL),1
women in New York did not have significantly different HAART utilization rates compared to the other states. California had the largest percentage of women enrolled (42.8%) while Illinois and New York had much lower rates at 13.7% and 10.9% respectively. This likely reflects each state’s policy towards Medicaid and ADAP co-enrollment. California allows Medi-Cal (the state’s form of Medicaid) and ADAP co-insurance while New York and Illinois mostly allow only patients without health insurance to enroll into ADAP. Therefore, while New York had the broadest financial eligibility for ADAP enrollment, differences in co-insurance criteria complicated our analysis.
Other factors including age, ethnicity, income, and alcohol use were found to be associated with HAART utilization. Non-Hispanic and Hispanic white women had higher likelihood of HAART use when compared to African-Americans. These findings are similar to many studies,5,6,7,8,9
including those done on the WIHS population,10,11,12,13
which consistently have shown that health disparities by ethnicity still exist. Other studies support our finding that increased alcohol consumption is associated with decreased likelihood of antiretroviral utilization,11
however it is unclear whether alcohol use is related to patient factors, such as non-compliance, or providers’ unwillingness to prescribe therapy. In our study there was a dose-response relationship – higher consumption was more strongly associated with non-use of HAART utilization – which leads us to believe that this is a strong predictor. Women with higher income were more likely to report HAART use. This may reflect increased access to care and ability to pay for medication.
While ADAP enrollment increased the likelihood of using HAART, its relationship with antihypertensive medication use was of borderline statistical significance (p= 0.07), due in part to the smaller sample size for this subgroup analyses. State variability was not associated with antihypertensive drug utilization even though New York’s ADAP included hypertension medications on its formulary.1
California’s ADAP does not cover hypertension medication and as a result enrollees may access these drugs using Medi-Cal. However, New York enrollees cannot have any other forms of insurance and as a result may utilize ADAP to access antihypertensive medication when they otherwise could not. Like the HAART analysis, ADAP eligibility policies regarding co-insurance complicated our study.
Although the association between ADAP enrollment and antihypertensive utilization was of borderline significance, women with Medicaid and Medicare insurance were more likely to use hypertension medication than those with private insurance. A review of data within the Women’s Health Initiative found that women insured by Medicaid had higher treatment rates and better outcomes compared to those with private insurance and only Medicare.22
The author hypothesized that differences in medication coverage and/or age distributions could explain this disparity. Therefore, other government-sponsored health and prescription insurance programs may play a larger role than ADAP in terms of antihypertensive use, even in HIV-infected women.
Similar to HAART use, women with higher incomes were more likely to use antihypertensive medication. In addition, cigarette smokers were less likely to use hypertension medications. This finding is particularly troublesome as smokers who are hypertensive are at significantly higher risk of developing cardiovascular complications.23
Studies have shown that smokers may have decreased adherence to medications24
which may explain this population’s decreased use of antihypertensive medication.
In contrast to HAART use, African-Americans were more likely to use antihypertensive medication compared to non-Hispanic whites and other ethnicities. Prior studies have reinforced our finding but also report that while African-Americans are more likely to use antihypertensive medication than non-Hispanic whites, rates of controlled hypertension are lower.25,26,27
The juxtaposition between ethnicity and HAART and antihypertensive drug use warrants further investigation into the reasons why these disparities exist. A review of HIV care in minority populations by Cargill and Stone theorized that patient satisfaction with their care, prescriber bias, and patient-physician racial discordance could be possible provider-related reasons for HIV treatment disparities.28
They also found that minorities needed more information and time to make HIV-related treatment decisions. Stigma related to HIV, which can lead to delayed seeking of treatment and even denial of infection, has also been thought to influence antiretroviral treatment use and adherence.28
These reasons highlight the need for better outreach and education to minority populations about the benefits of HAART and to destigmatize HIV as a disease.
One limitation of this study is the cross-sectional design. Thus the results represent only one point in time and we are unable to determine a temporal relationship between enrollment into ADAP and use of HAART or antihypertensive medication. However, longitudinal data exists and could be the subject of a future investigation. While longitudinal data was used to determine our study population and eligibility criteria, health outcomes, though collected by WIHS, were not included within this analysis. Therefore, we did not determine whether ADAP’s influence on HAART and antihypertensive medication use are also predictive of improved health results, such as elevated CD4+ cell counts and blood pressure control. Another limitation is that other unmeasured factors that may influence medication use, such as prescriber patterns and frequency of clinic visits, were not assessed. In addition, these results are based on HIV-infected women who were recruited from large urban centers in 3 states in the US and may not be representative of HIV-infected men or women residing in non-urban areas. Finally, our study was done with mostly self-reported data and consequently could be subject to participant bias. However, highly trained interviewers using standardized, interview-based questionnaires were used to collect the most accurate data possible.
In summary, in light of recent and proposed funding cuts for ADAP and projected increase in demand of ADAP services, we provided evidence that this program was strongly associated with better HAART medication utilization. We also found that populations that constitute the majority of ADAP enrollees, those with lower income and of African-American descent, had decreased HAART use compared to those with higher incomes and of non-African-American descent. As a result, state ADAPs should be continued in order to improve antiretroviral use in these at-risk populations. We found that state of study site was not associated with increased likelihood of HAART or antihypertensive use. However, ADAP enrollment was associated with an increased, but non-significant, likelihood of blood pressure medication utilization while Medicare and Medicaid were strongly associated with increased use. Therefore government-funded programs that provide prescription drug coverage, such as ADAP, may play a valuable role in promoting increased access and utilization of essential medications for chronic diseases for underserved HIV-infected women.