Association of inpatient hospital utilization statewide with HIV care engagement patterns and socio-demographic characteristics – South Carolina, 2006-2008

Background: Inpatient hospitalization is costly. Prompt linkage to HIV primary care and strict adherence to antiretroviral therapy may reduce the need for inpatient treatment.

Methods: This is a retrospective cohort study of South Carolina HIV-infected individuals diagnosed from January 1986 to December 2005 who accessed inpatient services from January 2006 to December 2008. Suboptimal primary care engagement defined as <2 reports of a CD4+T-cell or viral load measurement to surveillance in each calendar year from January 2006 to December 2008. Multivariate logistic regression assessed differences in inpatient utilization according to HIV primary care engagement pattern by socio-demographics and health status. Negative binomial regression assessed frequency of inpatient hospitalization by degree of primary care engagement, socio-demographics, and health status. Results: Individuals hospitalized with opportunistic infections had greater risk of sub-optimal HIV primary care engagement (aOR=1.68;95%CI=1.32-2.14) but more inpatient hospitalizations (IRR=1.69;95%CI=1.58-1.82) . Medicare protected against suboptimal primary care engagement (aOR=0.53;95%CI=0.37-0.77) but was associated with more hospitalizations (IRR=1.36;95%;CI=1.22-1.53). Rurality was associated with decreased risk of suboptimal primary care engagement (aOR=0.77;95%CI=0.62-0.96) but increased risk of hospitalization (IRR=1.07;95%CI=1.00-1.16). An AIDS diagnosis <1 year post-HIV diagnosis was associated with decreased risk of suboptimal primary care engagement (aOR=0.08;95%CI=0.04-0.16) but increased number of hospitalizations (IRR=1.11;95%CI=1.00-1.23). AIDS diagnosis >1 year post-HIV diagnosis was associated with decreased risk of suboptimal care engagement (aOR=0.08;95%CI=0.05-0.15), but more hospitalizations (IRR=1.12;95%CI=1.02-1.23).

Conclusions: Disease stage, rurality and insurance status determine HIV-infected individuals' inpatient utilization in South Carolina. Strategies to improve testing, early linkage, and access to primary care may reduce inpatient hospitalization.