Implications of Generalists' Slow Adoption of Zidovudine in Clinical Practice

BACKGROUND: The lag time for adoption of new acquired immunodeficiency syndrome (AIDS) therapies into the clinical practices of different types of ambulatory care providers can be estimated from patient use of zidovudine therapy during the first few years after approval by the Food and Drug Administration. METHODS: We analyzed receipt of zidovudine therapy from April 1987 through March 1990 by 3643 patients with a diagnosis of AIDS. The study group was continuously enrolled in the New York State Medicaid program for at least 6 months after diagnosis. For each patient, the dominant providers of ambulatory care, receipt of zidovudine therapy, and consultation with a human immunodeficiency virus-AIDS specialist within 6 months after diagnosis were determined from Medicaid claims. AIDS specialists included physicians or clinics specializing in infectious disease or hematology/oncology or specific clinics within designated AIDS centers. RESULTS: In 1987, 55% of those who had an AIDS specialist as their dominant care provider received zidovudine therapy, compared with only 36% of patients with a primary care clinic as their dominant care provider. It was not until 1990, 3 years after approval by the Food and Drug Administration, that the percentage of patients receiving zidovudine therapy (77% to 78%) was comparable for patients of primary care clinics and AIDS specialists. In logistic regression analysis, zidovudine use did not differ between patients of AIDS specialists and patients with other types of dominant providers when the latter group had consulted with an AIDS specialist (adjusted odds ratio, 1.38; 95% confidence interval, 0.99 to 1.95). CONCLUSIONS: In our AIDS study population, there was at least a 3-year lag before patients of primary care clinics received zidovudine therapy at the same rate as patients of AIDS specialists. Conditions such as AIDS with rapid changes in treatment options may require a close relationship between generalists and specialists to increase access to new therapies.