TY - JOUR
T1 - Methods for projecting course of acquired immunodeficiency syndrome epidemic
AU - Gail, Mitchell H.
AU - Brookmeyer, Ron
N1 - Funding Information:
"Received June 13, 1988; accepted June 23, 1988. 2R. Brookmeyer was supported in part by Public Health Service grant CA-48723 from the National Cancer Institute, National Institutes of Health, Department of Health and Human Services. 3Epidemiologic Methods Section, Biostatistics Branch, Epidemiology and Biostatistics Program, Division of Cancer Etiology, National Cancer Institute, Executive Plaza North, Rm. 403, National Institutes of Health, Bethesda, MD 20892. •"Department of Biostatistics, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, MD. 'We thank Jennifer Donaldson and Anne Damiano for technical assistance in preparation of this paper.
PY - 1988/8/17
Y1 - 1988/8/17
N2 - Three methods for projecting the short-term course of the acquired immunodeficiency syndrome (AIDS) epidemic are discussed: (a) empirical extrapolation, (b) the method of "back calculation," and (c) projections based on compartmental models. Extrapolation, which requires only data on AIDS incidence, is based on an assumed functional form and on the supposition that previous trends will continue. The method of back calculation incorporates both information on previous AIDS incidence and knowledge about the incubation period distribution. These calculations provide some evidence of how many infections occurred during previous time intervals. Although this information is not precise, particularly for the recent past, it is sufficient to produce stable short-term projections. Compartmental models can be used to project future prevalence of infection as well as future AIDS incidence. However, such projections are very dependent on assumptions about initial numbers of individuals infected, rates of transmission, changes in high-risk behaviors over time, and assumptions about transmission among subpopulations with differing transmission rates and initial prevalence of infection. Thus, compartmental models offer insights into the trends in an epidemic but do not currently provide a practical tool for obtaining quantitative projections. We present projections for various risk groups based on the method of back calculation and discuss the use of additional epidemiologic data to obtain accurate projections a decade in advance. [J Natl Cancer Inst 1988; 80: 900-911]
AB - Three methods for projecting the short-term course of the acquired immunodeficiency syndrome (AIDS) epidemic are discussed: (a) empirical extrapolation, (b) the method of "back calculation," and (c) projections based on compartmental models. Extrapolation, which requires only data on AIDS incidence, is based on an assumed functional form and on the supposition that previous trends will continue. The method of back calculation incorporates both information on previous AIDS incidence and knowledge about the incubation period distribution. These calculations provide some evidence of how many infections occurred during previous time intervals. Although this information is not precise, particularly for the recent past, it is sufficient to produce stable short-term projections. Compartmental models can be used to project future prevalence of infection as well as future AIDS incidence. However, such projections are very dependent on assumptions about initial numbers of individuals infected, rates of transmission, changes in high-risk behaviors over time, and assumptions about transmission among subpopulations with differing transmission rates and initial prevalence of infection. Thus, compartmental models offer insights into the trends in an epidemic but do not currently provide a practical tool for obtaining quantitative projections. We present projections for various risk groups based on the method of back calculation and discuss the use of additional epidemiologic data to obtain accurate projections a decade in advance. [J Natl Cancer Inst 1988; 80: 900-911]
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U2 - 10.1093/jnci/80.12.900
DO - 10.1093/jnci/80.12.900
M3 - Review article
C2 - 3294425
AN - SCOPUS:0023720298
SN - 0027-8874
VL - 80
SP - 900
EP - 911
JO - Journal of the National Cancer Institute
JF - Journal of the National Cancer Institute
IS - 12
ER -