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Comprehensive & Cost Effective Laboratory Monitoring of HIV/AIDS: an African Role Model
Published on: October 31, 2010
A competing risks analysis of presenting AIDS diagnoses trends
R E Fusaro1, P Bacchetti, N P Jewell
1Division of Biostatistics and School of Optometry, University of California, Berkeley 94720-7380, USA.
Biometrics
|March 1, 1996
Summary
The proportion of Kaposi's sarcoma (KS) diagnoses among gay men with AIDS has decreased over time. This study suggests shorter incubation periods for KS, rather than cofactors, explain these observed trends.
Area of Science:
- Epidemiology
- Statistics in Medicine
- Public Health
Background:
- Temporal trends in AIDS diagnoses among gay men show a declining proportion of Kaposi's sarcoma (KS).
- Hypotheses for this decline include cofactor requirements or shorter KS incubation periods.
Purpose of the Study:
- To investigate if a shorter incubation period for Kaposi's sarcoma (KS) can explain the observed decline in its proportion among AIDS diagnoses.
- To analyze temporal trends in AIDS diagnoses within a competing risks framework.
Main Methods:
- Nonparametric estimation of cause-specific hazard functions using doubly-censored data.
- Application of the Expectation-Maximization (EM) algorithm with roughness penalized likelihood maximization.
- Analysis of data from the San Francisco City Clinic Cohort.
Main Results:
- Estimated cause-specific hazard functions indicate significant differences in diagnosis trends.
- These differences in hazard functions substantially account for the observed decline in Kaposi's sarcoma (KS) diagnoses over time.
Conclusions:
- Differences in underlying cause-specific hazard functions, potentially related to incubation periods, are a major factor in the declining trend of Kaposi's sarcoma (KS) as an initial AIDS diagnosis.
- The competing risks framework provides a valuable approach for understanding temporal trends in disease diagnoses.
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