Objective. To examine the associations between comorbid mental illness and length of hospital stays (LOS) among Medicaid beneficiaries with AIDS.
Data Source and Collection/Study Setting. Merged 1992–1998 Medicaid claims and AIDS surveillance data obtained from the State of New Jersey for adults with ≥1 inpatient stay after an AIDS diagnosis from 1992 to 1996.
Study Design. Observational study of 6,247 AIDS patients with 24,975 inpatient visits. Severe mental illness (SMI) and other less severe mental illness (OMI) diagnoses at visits were ascertained from ICD–9 Codes. About 4 percent of visits had an SMI diagnosis; 5 percent had an OMI diagnosis; 43 percent did not have a mental illness diagnosis, but were patients who had been identified as having an SMI or OMI history; and 48 percent were from patients with no identified history of mental illness.
Principal Findings. The overall mean hospital LOS was 12.7 days. After adjusting for measures of HIV disease severity and health care access in multivariate models, patients presenting with primary and secondary severe mental illness (SMI) diagnoses had ∼32 percent and ∼11 percent longer LOS, respectively, than did similar patients without a mental illness history (p<0.001 for each). But in these adjusted models of length of stay: (1) diagnosis of OMI was not related to LOS, and (2) in the absence of a mental illness diagnosed at the visit, an identified history of either SMI or OMI was also not related to LOS. In adjusted models of time to readmission for a new visit, current diagnosis of SMI or OMI and in the absences of a current diagnosis, history of SMI or OMI all tended to be associated with quicker readmission.
Conclusions. This study finds greater (adjusted) LOS for AIDS patients diagnosed with severe mental illness (but not for those diagnosed with less severe mental comorbidity) at a visit. The effect of acute severe mental illness on hospitalization time may be comparable to that of an acute AIDS opportunistic illness. While previous research raises concerns that mental illness increases LOS by interfering with treatment of HIV conditions, the associations here may simply indicate that extra time is needed to treat severe mental illnesses or arrange for discharge of afflicted patients.