Changes in AIDS-defining illnesses in a London Clinic, 1987-1998.
OBJECTIVE
To describe the incidence of AIDS-defining illnesses within a single large clinic setting, to describe temporal changes over a 10-year period in the overall incidence and of individual AIDS-defining illnesses and to investigate the impact of HIV treatment regimen on the incidence of AIDS-defining illnesses.


METHODS
A person-years analysis was used to determine the incidence of AIDS-defining illnesses according to calendar year and stratification by CD4 lymphocyte count and treatment regimen in 1806 patients from the Royal Free Centre for HIV Medicine with at least one CD4 lymphocyte count and follow-up visit.


RESULTS
Prior to 1992, the incidence of all AIDS-defining illnesses was 27.4/100 person-years of follow-up (PYFU; 95% confidence interval [CI], 22.8-32.0) and during 1997 this incidence had dropped to 6.9/100 PYFU (95% CI, 4.7-9.1; p < .0001, test for trend). The decline in incidence over time occurred in esophageal candidiasis, cytomegalovirus disease (including retinitis), Kaposi's sarcoma, lymphoma, wasting syndrome, and Pneumocystis carinii pneumonia (p < .05, test for trend), but there was no evidence of a decline in AIDS dementia or in Mycobacterium avium complex. In 1997, among patients with CD4 lymphocyte counts of < or =200 cells/mm3, the incidence rates for any AIDS-defining illness was 51.1/100 PYFU for patients taking no therapy (95% CI, 27.9-85.7), 34.5 among patients on monotherapy (95% CI, 4.2-124.6), 13.2 among patients taking dual combination therapy (95% CI, 3.6-33.8) and 6.1 among patients taking triple therapy or more complex regimens (95% CI, 0.7-22.0; p < .0001, test for trend).


CONCLUSIONS
There was a considerable decline in AIDS-defining illnesses during 1996 and 1997, coinciding with the rapid development of new antiretroviral treatments and combinations of treatment. Further follow-up of large observational cohorts is essential to monitor the incidence of diagnoses less common than we were able to consider, such as tuberculosis, cryptosporidiosis, and cryptococcosis, and also to investigate whether the incidence of disease continues to fall, or whether it starts to rise again, as toxicities, compliance, drug resistance, and long-term side effects begin to appear.
Mocroft
A
A
Department of Primary Care and Population Sciences, Royal Free Centre for HIV Medicine, Royal Free and University College Medical School, University College London, England. amanda@rfhsm.ac.uk
Sabin
C A
CA
Youle
M
M
Madge
S
S
Tyrer
M
M
Devereux
H
H
Deayton
J
J
Dykhoff
A
A
Lipman
M C
MC
Phillips
A N
AN
Johnson
M A
MA
D015526:AIDS Dementia Complex / Q000453:epidemiology; D017088:AIDS-Related Opportunistic Infections / Q000453:epidemiology*; D000163:Acquired Immunodeficiency Syndrome / Q000150:complications* / Q000188:drug therapy / Q000453:epidemiology* / Q000635:transmission; D000293:Adolescent; D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D018791:CD4 Lymphocyte Count; D002180:Candidiasis, Oral / Q000453:epidemiology; D016001:Confidence Intervals; D003586:Cytomegalovirus Infections / Q000453:epidemiology; D004359:Drug Therapy, Combination; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008131:London / Q000453:epidemiology; D016483:Lymphoma, AIDS-Related / Q000453:epidemiology; D008297:Male; D015270:Mycobacterium avium-intracellulare Infection / Q000453:epidemiology; D010044:Outpatient Clinics, Hospital / Q000706:statistics & numerical data; D011020:Pneumonia, Pneumocystis / Q000453:epidemiology; D012514:Sarcoma, Kaposi / Q000453:epidemiology*; D019282:Wasting Syndrome / Q000453:epidemiology
D019380:Anti-HIV Agents