Research potentials and pitfalls in the use of an HIV clinical database: Chelsea and Westminster Hospital

This article summarizes the various problems and pitfalls in using clinical databases for epidemiologic research, with particular reference to an HIV clinical database. The combined population of HIV-infected individuals attending the Chelsea and Westminster Hospital, the Charing Cross Hospital, and the Victoria Clinic in London is the largest cohort of HIV-positive individuals in the U.K. A computerized database was developed in the mid-1980s and was adapted into a clinically oriented observational database for approximately 6,653 HIV-1-positive registered patients from three hospital-based clinics within the Riverside Health Authority in London, U.K.: Chelsea and Westminster Hospital Clinic (n = 5,000); Charing Cross Hospital (n = 500); and the Victoria Clinic (n = 500). The majority (83%) of HIV-infected patients registered at these sites are homosexual or bisexual men. Of 2,078 patients seen within the last 6 months, 22% an asymptomatic and 33% have AIDS; 30% have a CD4 cell count of less than 100 cells/mm(3) and 17% have a CD4 cell count of greater than 500 cells/mm(3). Dates of seroconversion are known for approximately 285 patients. For each patient, information on demographic characteristics, clinical symptoms, and HIV-related diagnoses, outpatient pharmacy prescriptions, day care treatments and procedures, and enrollment into clinical trials is routinely collected at outpatient clinic visits and entered into the database. Inpatient diagnoses and treatments were integrated into the database in September 1995. Unused serum samples from routine AIDS antibody or antigen testing are stored in a local specimen repository. The main purpose of the HIV database is to provide a multipurpose resource for use by physicians, researchers, and managers for administration, clinical care, and research. The specific functions of the database are the following: to enhance patient management by providing access to a clinical summary sheet detailing up-to-date information; to serve as a research tool for clinical and epidemiologic research; to aid in the identification of patients eligible for planned or ongoing clinical trials; to provide a facility for local and regional AIDS surveillance and reporting; and to provide a facility for administration and resource management of HIV services. The major limitations of this database in the conduct of clinical research have been losses to follow-up and incomplete information about clinical outcomes, because physicians have failed to update the clinical information.