This study provides the most recent estimates of the cost of treating HIV infection, using data from a large sample of patients from multiple provider sites. HIV-infected individuals in this cohort reported high utilization of inpatient and outpatient care and antiretroviral medications, resulting in high costs of HIV care at all CD4 strata. Overall costs of care increased as patients became more immunosuppressed. A substantial proportion of costs was attributable to antiretroviral medication. In patients with severe immunosuppression, inpatient services were the most expensive cost category.
The cost of HAART has been previously estimated to exceed $10,000 per year.[12
] Our ARV medication cost estimate, across CD4 categories, was $10,315 (95% CI: 10,183, 10,448, n=14,691). However, the mean includes people who were not taking antiretroviral medications. Among those with nonzero ARV costs, the mean was $13,251 (95% CI: 13,124, 13,378). Thus, our overall estimate of annual ART costs is consistent with prior estimates, despite the fact that some prior estimates were implicitly based on average wholesale prices, which we discounted by 23%. On the other hand, our analyses are based on prescribed medications, not actual purchases; to the extent that patients did not purchase all the medications prescribed for them, our estimates would overstate costs.
Mean ARV costs were lower for patients with CD4 counts ≤ 50 cells/mm3 than for those with CD4 counts between 51 and 200 cells/mm3. In the former CD4 category, 78% had some ARV medications prescribed, versus 86% in the latter CD4 category. People with severe immunosuppression may have extensive resistance, with few available HAART options, or may not be able to tolerate these medications.
Antiretroviral medication costs remained substantial for patients with CD4 counts > 350 cells/mm3. Presumably, the higher ARV costs in the higher CD4 strata in this study, compared to the 1998 estimates, are due to the effectiveness of maintenance HAART in increasing the CD4 count.
Our overall per-person annual cost estimate ($19,912) is slightly higher than the overall mean of $18,300 in 1998 obtained in HCSUS [1
]. Estimated HIV care costs from HCSUS ranged from $28,128 for those with CD4 counts less than 50 cells/mm3
, to $16,332 for those with CD4 counts between 50 and 200 cells/mm3
, and $6,384 for those with CD4 counts over 500 cells/mm3
] Adjusted to 2006 dollars, these figures are $33,987, $19,734, and $7,714, respectively. The first estimate is broadly similar to current results, but the last two are lower than current estimates. Differences in antiretroviral regimens between 1998 and 2006 may contribute to differences between the current estimates and those derived from HCSUS. In HCSUS, the proportion of costs due to medications was under 20% for all CD4 strata, except for those with CD4> 500 cells/mm3
. In contrast, the proportion of costs due to medications was greater in the current analyses.
Based on data from 635 patients in one clinic in Alabama in 2001, Chen et al. estimated a mean total cost of $18,640 per patient per year, ranging from $36,532 for those with CD4 counts ≤ 50 cells/mm3
to $13,885 for those with CD4 counts ≥350 cells/mm3
] Our estimates were higher in all CD4 strata. Inpatient expenditure estimates were considerably higher in our study (e.g., $19,658 versus $8,353 in Chen et al. for inpatient care for those with CD4 count ≤ 50 cell/mm3
). Our results point to variation in average expenditures from site to site, which highlights the importance of basing estimates on data from multiple sites.
In all CD4 strata, some of the costs are likely due to treatment of non-HIV comorbidities. Rates of hospitalizations for liver-related complications, comorbid psychiatric disease, and substance abuse disorders have increased in HIV-infected populations [28
]. It is likely that costs will continue to increase in the next decade due to non-HIV-related complications, including age-related conditions such as cardiovascular disease, cerebrovascular disease, and malignancies [34
]. The higher costs for persons in older age groups in this study may arise from their having more comorbid conditions.
The cost estimates in this study do not include expenditures for other services, such as treatment for alcohol or substance abuse, mental health care (beyond the costs of psychotropic medications), and non-reimbursable costs for services provided by case managers, adherence counselors, nutritionists, expanded access nurses, and other social service providers. It is clear that the costs of treating HIV infection are high, and the costs of caring for persons with HIV are higher still. Yet, improved efforts are needed to link those who have tested positive into care as quickly as possible to improve long term clinical outcomes.
Although our study is one of the most comprehensive assessments of health care costs among HIV-infected patients in the United States, our sample is not nationally representative and may not generalize to all HIV patients. However, the sites from which patients were sampled do encompass a broad geographic distribution, and multi-site studies afford greater generalizeability than single-site studies. The sites in the HIVRN were all highly experienced in the treatment of HIV; results may differ for patients at sites with less provider experience with HIV or smaller caseloads of HIV patients. It is possible that patients received medical care from multiple providers, and data from one provider might not capture all services used. Provider staff believed that most of their patients received all their HIV care at their site, and we removed from the analysis data from 5 sites where staff were less sure that this was the case. Nevertheless, our cost estimates are lower bounds to the extent that patients received services from multiple providers.
In conclusion, the annual per-person costs of care for HIV-infected patients in the United States are high. It is misleading to focus on a single number as representing “the” cost of treating HIV infection. Costs estimates varied greatly, depending on severity of illness. Within each CD4 stratum, confidence intervals for total costs could cover a range of $600 to $6,000. Such variation should be considered in resource allocation decisions. ARV regimens containing “boosted” protease inhibitors are now increasingly prevalent and may also be more costly. Given the potential increases in costs of therapeutic agents, toxicities and comorbidities due to HAART, and aging-related comorbidities, it is likely that the aggregate costs of HIV care will continue to increase for the foreseeable future.