SURVIVAL AFTER DIAGNOSIS OF AIDS - A PROSPECTIVE OBSERVATIONAL STUDY OF 2625 PATIENTS

Objective: To estimate median survival and changes in survival in pati ents diagnosed as having AIDS. Design: Prospective observational study . Setting: Clinics in two large London hospitals. Subjects: 2625 patie nts with AIDS seen between 1982 and July 1995. Main outcome measures: Survival, estimated using lifetable analyses, and factors associated w ith survival, identified from Cox proportional hazards models. Results : Median survival (20 months) was longer than previous estimates. The CD4 lymphocyte count at or before initial AIDS defining illness decrea sed significantly over time from 90 x 10(6)/l during 1987 or earlier t o 40x10(6)/l during 1994 and 1995 (P < 0.0001). In the first three mon ths after diagnosis, patients in whom AIDS was diagnosed after 1987 ha d a much lower risk of death (relative risk 0.44, 95% confidence inter val 0.22 to 0.86; P=0.0.017) than patients diagnosed before 1987. When the diagnosis was based on oesophageal candidiasis or Kaposi's sarcom a, patients had a lower risk of death than when the diagnosis was base d on Pneumocystis carinii pneumonia (0.21 (0.07 to 0.59), P=0.0030 and 0.37 (0.16 to 0.83), P=0.016). Three months after AIDS diagnosis, the risk of death was similar in patients whose diagnosis was made after and before 1987 (1.02 (0.79 to 1.31), P=0.91). There were no differenc es in survival between patients diagnosed during 1958-90, 1991-3, or 1 994-5. Conclusions:In later years, patients were much more likely to s urvive their initial illness, but long term survival has remained poor . The decrease in CD4 lymphocyte count at AIDS diagnosis indicates tha t patients are being diagnosed as having AIDS at ever more advanced st ages of immunodeficiency.