Mental illness and length of inpatient stay for Medicaid recipients with AIDS

Health Services Research, Oct, 2004 by Donald R. Hoover, Usha Sambamoorthi, James T. Walkup, Stephen Crystal

Other Patient Characteristics. Demographic characteristics (i.e., gender, race, county of residence), HIV exposure category, and date of HIV diagnosis were obtained from surveillance data. Race/ethnicity was characterized as non-Latino white, African American, and Latino. In multivariate analyses, non-Latino white was the reference category. Age at Diagnosis was categorized as: 18-29 years, 30-39 years, 40-49 years, and > 50 (reference category). Year of Diagnosis of HIV infection was categorized as 1995-1996, 1993-1994, 1990-1992, and before 1990 (reference category). Persons living in the Highest HIV Prevalence counties, those nearest to New York City and Philadelphia, were compared to persons living elsewhere in New Jersey. Risk Group was based on information on injection drug use history from the AIDS Registry with patients classified as either IDU, non-IDU, or "Missing." Some participants in Medicaid were eligible for Medicare. Dual Medicare coverage (yes/no) was assessed from claim type recorded in paid Medicaid claims data. Some New Jersey Medicaid recipients are enrolled in ACCAP, an HIV-specific Medicaid home and community-based care waiver program, that offers case management and other services. Participation in the ACCAP was determined from procedure codes in Medicaid claims for waivered services. As an indicator of HAART therapy, from National Drug Codes recorded in pharmacy claims, we identified the use of Protease Inhibitor/Non-Nucleoside Reverse Transcriptase Inhibitor (PUNNRTI) and the first date that an individual Used a Pl or NNRT1. This was an intent-to-treat variable; patients were considered to be on PI/NNRTI for all visits after the initiation date.

Analytic Procedures

Both univariate (one predictor) and multivariate (all predictors) linear models for LOS and TR were fit using patient-visits as the observations. Since repeated visits from the same persons were used, we applied robust covariance methods (Diggle, Liang, and Zeger 1994) to account for correlations between repeated measures from the same patients with SUDAAN (Shah, Barnwell, and Bieler 1996). Due to skewed distributions (for the adjusted and unadjusted analyses of Table 2), LOS and TR were log (base e) transformed to improve symmetry and other statistical properties. Exponentiated values of differences in logs (which can be roughly interpreted as ratios) are reported. Some problems may exist from the censoring of very long patient stays and readmissions by the date of analysis, December 1998. While the technical issues are complicated, we believe the impact is minor as most patients had numerous (i.e., ~ 4) admissions and the study covered six years.

RESULTS

Of the 6,247 patients (data not tabled), 62 percent were male; 59 percent were African American, 18 percent Latino, and 23 percent non-Latino white. Half (50 percent) were aged 30-49 years at diagnosis of HIV. The IDU was the largest HIV risk group (63 percent). Seventy percent of the study cohort lived in high HIV prevalence urban areas (near New York City or Philadelphia) at time of initial HIV diagnosis. A minority (26 percent) was enrolled in the ACCAP waiver program, and 29 percent received Medicare after diagnosis of AIDS. Thirty-two percent were alive as of December 1998. About 14 percent (868) were identified as having severe mental illness; 334 with schizophrenia, 96 with bipolar disorder (but not schizophrenia), and 438 with major depressive disorder (but not schizophrenia or bipolar disorder); 1,682 (27 percent) of other patients had identified admissions for less severe mental illnesses (OMI).