The outcome and cost of alcohol and drug treatment in an HMO: Day hospitalversus traditional outpatient regimens

Objective. To compare outcome and cost-effectiveness of the two primary add iction treatment options, day hospitals (DH) and traditional outpatient pro grams (OP) in a managed care organization, in a population large enough to examine patient subgroups. Data Sources. Interviews with new admissions to a large HMO's chemical depe ndency program in Sacramento, California between April 1994 and April 1996, with follow-up interviews eight months later. Computerized utilization and cost data were collected from 1993 to 1997. Study Design. Design was a randomized control trial of adult patients enter ing the HMO's alcohol and drug treatment program (N = 668). To examine the generalizability of findings as well as self-selection factors, we also stu died patients presenting during the same period who were unable or unwillin g to be randomized (N = 405). Baseline interviews characterized type of sub stance use, addiction severity, psychiatric status, and motivation. Follow- up interviews were conducted at eight months following intake. Breathanalys is and urinalysis were conducted. Program costs were calculated. Data Collection. Interview data were merged with computerized utilization a nd cost data. Principal Findings. Among randomized subjects, both study arms showed signi ficant improvement in all drug and alcohol measures. There were no differen ces overall in outcomes between DH and OF, but DH subjects with midlevel ps ychiatric severity had significantly better outcomes, particularly in regar d to alcohol abstinence (OR = 2.4; 95% CI = 1.2, 4.9). The average treatmen t costs were $1,640 and $895 for DH and OP programs, respectively. In the m idlevel psychiatric severity group, the cost of obtaining an additional per son abstinent from alcohol in the DH cohort was approximately $5,464. Among the 405 self-selected subjects, DH was related to abstinence (OR = 2.1; 95 % CI = 1.3, 3.5). Conclusions. Although significant benefits of the DH program were not found in the randomized study, DH treatment was associated with better outcomes in the self-selected group. However, for subjects with mid-level psychiatri c severity in both the randomized and self-selected samples, the DH program produced higher rates of abstention and was more cost-effective. Self-sele ction in studies that randomize patients to services requiring very differe nt levels of commitment may be important in interpreting findings for clini cal practice.