Statistical methods for short-term projections of AIDS incidence

Area of Science:

• Epidemiology
• Biostatistics

Background:

• Accurate short-term projections of Acquired Immunodeficiency Syndrome (AIDS) incidence are crucial for effective healthcare resource allocation.
• The back-calculation method is a key technique for estimating past infection rates based on current AIDS diagnoses.

Purpose of the Study:

• To present and evaluate the back-calculation method for short-term AIDS incidence projections.
• To propose a method for estimating reporting delays and incorporate new infections into projections.
• To apply these methods to project AIDS incidence in the United States.

Main Methods:

• Utilized back-calculation from AIDS incidence data and the incubation period distribution to estimate past infections.
• Developed a computationally efficient method for estimating AIDS case reporting delays.
• Incorporated an approach to account for new infections in short-term projections.

Main Results:

• The reporting delay distribution for AIDS cases in the U.S. was found to vary geographically.
• Projected cumulative AIDS incidence in the U.S. by the end of 1992 was 287,100 (no new infections after July 1, 1987) or 330,600 (constant infection rate).
• These projections did not include effects of revised AIDS surveillance definitions or underreporting.

Conclusions:

• The back-calculation method, when applied with accurate data and reliable incubation period estimates, provides valuable short-term AIDS incidence projections.
• Accurate estimation of reporting delays is essential for robust back-calculation.
• Further refinements are needed to account for evolving surveillance criteria and reporting completeness.