Improved survival from diagnosis of AIDS in adult cases in the United Kingdom and bias due to reporting delays.

OBJECTIVE: To measure developments in survival patterns among United Kingdom adult AIDS cases. DESIGN: A follow-up survey of cases reported voluntarily to the national surveillance schemes was undertaken to obtain up-to-date information on vital status. METHODS: All reporting clinicians who had a current AIDS patient not known to have died whose AIDS-defining illness was diagnosed before the end of September 1990 were contacted. A total of 3984 cases were included in the analysis. RESULTS: An extra third of deaths other than those reported through routine channels were ascertained by follow-up. Median survival for patients diagnosed before and after the end of 1986 increased from 15 to 18 months for men who had sex with men presenting with Kaposi's sarcoma, from 10 to 19 months for other men who had sex with men and from 7 to 16 months for all others. Improvement in survival was greatest in the first 3 months. One-third of patients have been surviving 2 years or more. Factors observed with independent effects on improved survival are recent diagnosis, younger age and larger cumulative AIDS case load of reporting centre. HIV encephalopathy and other central nervous system symptoms may be associated with poorer survival. CONCLUSIONS: Survival patterns have been changing and generally improving. Average survival for very recent cohorts tends to be underestimated because longer survival has been observed in patients for whom there is a longer delay between AIDS diagnosis and report to the Communicable Disease Surveillance Centre. Information on mortality is improved by active follow-up.

United Kingdom AIDS survival in adults.

OBJECTIVE: To examine the impact of age, year and region of AIDS diagnosis on early (up to 12 months) and late survival of AIDS patients in different exposure categories; to describe the hazard pattern from 12 months after AIDS diagnosis. PATIENTS: A total of 4577 UK adult AIDS diagnoses to the end of 1991 in men who have sex with men, 273 AIDS cases in injecting drug users, 411 AIDS patients infected by blood products, and 535 other adult AIDS cases, mainly ascribed to heterosexual transmission. Deaths have been recorded for 4739 of these 5796 AIDS patients. RESULTS: The influence of calendar year and region of AIDS diagnosis on survival were short-term, for the most part operative only within the first year of follow-up. The monthly death-rate was roughly constant from 12 to 48 months post-AIDS [pooled estimate, 0.055 with 95% confidence interval (CI), 0.053-0.057] but was more than halved for 4-year survivors (pooled estimate, 0.022; 95% CI, 0.017-0.027). About 7% of AIDS cases diagnosed in 1990-1991 survive for at least 48 months. Survival after AIDS diagnosis shortens with advancing age at AIDS diagnosis: the relative hazard per decade of age (1.35; 95% CI, 1.29-1.41 in the first year after AIDS) is significantly greater (P < 0.001) in the first year after AIDS diagnosis than from 12 to 48 months (1.19; 95% CI, 1.13-1.25 in the second epoch). CONCLUSIONS: The influence of covariates, including age, is strongest in the first year of follow-up after AIDS diagnosis. Monthly death-rate is roughly constant at 0.055 from 12 to 48 months post-AIDS and at 0.022 thereafter.

Survival of adults with AIDS in the United Kingdom.

Accurate estimates of expected survival times and survival rates of AIDS patients are important both for estimating the prognosis of individuals and for monitoring the progress of the HIV/AIDS epidemic as new treatments are introduced. They are also needed for projecting future numbers of AIDS cases. Data on reported AIDS cases held at the PHLS AIDS Centre at the Communicable Disease Surveillance Centre and the Scottish Centre for Infection and Environmental Health confirmed the time, age, and reporting delay effects identified in earlier analyses of the United Kingdom AIDS database. The duration of survival after AIDS is diagnosed has improved since the epidemic began--median survival was 10.6 months in cases diagnosed before 1987 and has been at least 18.4 months in cases diagnosed each year since then. People who are diagnosed younger live longer--median survival fell from 21.6 months at age 15 to 29 to 12.6 months at age 45 or over. Delay in reporting AIDS cases adversely affects survival estimates for cases reported in recent years. Survival was longer in cases reported over a year after diagnosis of AIDS--23.7 months compared with 16.9 months in those reported less than a year after diagnosis. The experience of the hospital, measured by its cumulative AIDS caseload, was an important factor in the survival of men who have sex with men presenting with Kaposi's sarcoma alone or 'other' diagnoses--survival was shorter for cases reported from smaller centres. Men who have sex with men with Pneumocystis carinii pneumonia alone or other opportunistic infections alone who were known to be HIV positive before being diagnosed with AIDS had a shorter survival after being diagnosed than those who were unaware of their HIV infection. This supports the hypothesis that treatment for HIV infection and prophylaxis may extend the period before AIDS develops but reduce the period between developing AIDS and dying.