A Bayesian approach to uncertainty analysis of sexually transmitted infection models
- 1 November 2009
- journal article
- research article
- Published by BMJ in Sexually Transmitted Infections
- Vol. 86 (3), 169-174
- https://doi.org/10.1136/sti.2009.037341
Abstract
Objectives To propose a Bayesian approach to uncertainty analysis of sexually transmitted infection (STI) models, which can be used to quantify uncertainty in model assessments of policy options, estimate regional STI prevalence from sentinel surveillance data and make inferences about STI transmission and natural history parameters. Methods Prior distributions are specified to represent uncertainty regarding STI parameters. A likelihood function is defined using a hierarchical approach that takes account of variation between study populations, variation in diagnostic accuracy as well as random binomial variation. The method is illustrated using a model of syphilis, gonorrhoea, chlamydial infection and trichomoniasis in South Africa. Results Model estimates of STI prevalence are in good agreement with observations. Out-of-sample projections and cross-validations also show that the model is reasonably well calibrated. Model predictions of the impact of interventions are subject to significant uncertainty: the predicted reductions in the prevalence of syphilis by 2020, as a result of doubling the rate of health seeking, increasing the proportion of private practitioners using syndromic management protocols and screening all pregnant women for syphilis, are 43% (95% CI 3% to 77%), 9% (95% CI 1% to 19%) and 6% (95% CI 4% to 7%), respectively. Conclusions This study extends uncertainty analysis techniques for fitted HIV/AIDS models to models that are fitted to other STI prevalence data. There is significant uncertainty regarding the relative effectiveness of different STI control strategies. The proposed technique is reasonable for estimating uncertainty in past STI prevalence levels and for projections of future STI prevalence.Keywords
This publication has 31 references indexed in Scilit:
- Sexual behaviour patterns in South Africa and their association with the spread of HIV: insights from a mathematical modelDemographic Research, 2009
- Treating Curable Sexually Transmitted Infections to Prevent HIV in AfricaJAIDS Journal of Acquired Immune Deficiency Syndromes, 2008
- China’s Syphilis Epidemic: A Systematic Review of Seroprevalence StudiesSexually Transmitted Diseases, 2006
- Improved plausibility bounds about the 2005 HIV and AIDS estimatesSexually Transmitted Infections, 2006
- Changes in the Etiology of Sexually Transmitted Diseases in Botswana between 1993 and 2002: Implications for the Clinical Management of Genital Ulcer DiseaseClinical Infectious Diseases, 2005
- Sentinel surveillance of sexually transmitted infections in South Africa: a reviewSexually Transmitted Infections, 2005
- Investigating ethnic inequalities in the incidence of sexually transmitted infections: mathematical modelling studySexually Transmitted Infections, 2004
- The impact of HIV epidemic phases on the effectiveness of core group interventions: insights from mathematical modelsSexually Transmitted Infections, 2002
- Epidemiology and Control of Curable Sexually Transmitted DiseasesSexually Transmitted Diseases, 2000
- Bayesian Statistics without Tears: A Sampling-Resampling PerspectiveThe American Statistician, 1992