Changing use of hospital services and costs at a London AIDS referral centre, 1983-1989.

OBJECTIVE: To describe the use of hospital-based services and associated costs over time for HIV-infected individuals by disease stage and year of treatment.
METHODS: Data on service use were abstracted from inpatient and outpatient case-notes of 459 HIV-infected patients (121 asymptomatic and 338 AIDS patients) treated at St Mary's Hospital, London between 1983 and 1989. Cost estimates were derived from a survey of the 37 departments involved with HIV-related care. The number and type of admissions and outpatient visits, referral and discharge venues, number and type of tests and procedures performed, drugs prescribed and associated costs for the study period were the outcome measures used.
RESULTS: Most patients were homosexual men. At the time of first HIV-related visit, 80.7% lived in London. Most day cases and planned admissions were organized through the outpatient clinic; 31% of emergency admissions were initiated by patients themselves. For people with AIDS the number of day case admissions increased while planned admissions decreased. There was a marked reduction in the duration of inpatient stays, especially for AIDS patients. Costs associated with inpatient care decreased concomitantly. The number of outpatient visits for patients with symptomatic disease increased, resulting in increased outpatient expenditure. Asymptomatic patients had fewer inpatient tests, while outpatient tests did not change over time; costs followed similar patterns. Mean inpatient and outpatient drug-days prescribed did not change nor did average inpatient drug-costs although outpatient drug-costs increased. Inpatient tests performed on symptomatic non-AIDS patients decreased, while mean outpatient tests increased; average costs followed similar patterns. Inpatient drug-days prescribed and costs remained the same, while outpatient drug-days and average drug-costs increased during the study period. For AIDS patients, the number of inpatient tests performed and their average costs decreased but outpatient tests performed increased, though their average costs remained the same. Mean inpatient drug-days prescribed and average drug-costs decreased, while number of outpatient drug-days prescribed and average drug-costs increased markedly over time. For each disease category, expenditure on admissions and related tests decreased over time, while expenditure on outpatient visits and drug-costs increased.
CONCLUSIONS: The shift from an inpatient- to an outpatient-based service has resulted in fewer patients being investigated and treated in hospital and more as outpatients. This has resulted in a reduction of inpatient-related costs, while outpatient-related costs have increased. The overall contribution of drug-costs to the total cost has increased greatly over time. With the anticipated advent of new antiviral compounds, the importance of ascertaining their effectiveness as well as their efficacy will become crucial.