Hospitalization risk following initiation of highly active antiretroviral therapy

Abstract

Objectives: While highly active antiretroviral therapy (HAART) decreases long-term morbidity and mortality, its short-term effect on hospitalization rates is unknown. The primary objective of this study was to determine hospitalization rates over time in the year after HAART initiation for virological responders and nonresponders.

Methods: Hospitalizations among 1327 HAART-naïve subjects in an urban HIV clinic in 1997-2007 were examined before and after HAART initiation. Hospitalization rates were stratified by virological responders (> or =1 log(10) decrease in HIV-1 RNA within 6 months after HAART initiation) and nonresponders. Causes were determined through International Classification of Diseases, 9th Revision (ICD-9) codes and chart review. Multivariate negative binomial regression was used to assess factors associated with hospitalization.

Results: During the first 45 days after HAART initiation, the hospitalization rate of responders was similar to their pre-HAART baseline rate [75.1 vs. 78.8/100 person-years (PY)] and to the hospitalization rate of nonresponders during the first 45 days (79.4/100 PY). The hospitalization rate of responders fell significantly between 45 and 90 days after HAART initiation and reached a plateau at approximately 45/100 PY from 91 to 365 days after HAART initiation. Significant decreases were seen in hospitalizations for opportunistic and nonopportunistic infections.

Conclusions: The first substantial clinical benefit from HAART may be realized by 90 days after HAART initiation; providers should keep close vigilance at least until this time.

Fig. 1

Hospitalization rates for virological responders and nonresponders prior to and over the first year following highly active antiretroviral therapy (HAART) initiation. *Indicates P < 0.05 for the relative rate (RR) vs. days 1–45 for responders; ^†indicates P < 0.05 for the RR for responders vs. nonresponders within the time period. ‘Prior’ is 180 days preceding HAART initiation. n, number of persons observed within each time period. PY, person-years.

Fig. 2

Hospitalization rates for the top seven diagnostic categories prior to and over the first year following highly active antiretroviral therapy (HAART) initiation. (a) Virological responders. *Indicates P < 0.05 for the relative rate (RR) vs. days 1–45; hatched areas indicate the portion of AIDS-defining illnesses (ADIs) attributed to immune reconstitution inflammatory syndromes. (b) Nonresponders. ^#Indicates P between 0.05 and 0.15 for the RR vs. days 1–45; ^†indicates P < 0.05 for the RR vs. the 180 days prior to HAART initiation, which was used as the referent for cardiovascular admissions among nonresponders as there were no admissions for this group during days 1–45. Inf, infection; Psych, psychiatric; GI, gastrointestinal; CV, cardiovascular; End/Met, endocrine, nutritional, metabolic or immune.