Development of a chlamydia infection model for evaluating costs and outcomes of health interventions

Introduction: Chlamydia is a very common bacterial sexual transmitted infection (STI) among young adults. High numbers of asymptomatic cases hamper a timely treatment start, whereas the treatment itself is efficient and cheap. Proactive screening can decrease this mismatch. There are many models which are able to evaluate and simulate different screening options.Most of them though are based on old or insufficient data, are not accessible for everybody, or are not designed in a user-friendly way. Aim: We want to determine the feasibility of developing an easy-to-use chlamydia infection model, which can be easily updated to reflect changes in medical knowledge.Methods: Starting with a literature review, we have set up a chlamydia infection model. This model was refined with the help of STI experts. The model was implemented by using the programming language Java (version 1.6). We validated the model using internal and external validation methods. Results: The implementation of the model allows users to edit all parameters. The model consists of two separate sub-models. One sub-model simulates health effects of chlamydia for individuals, including the different outcomes in males and females. The other sub-model tracks the spreading of chlamydia within the computed cohort and regards heterosexual as well as homosexual partnerships. Both sub-models are independent of each other and therefore easily exchangeable. The overall model can be kept up to date by either updating single parameters of the model or exchanging a sub-model. The model can be operated by graphical user interfaces to enable non-health economists and non-modelling experts to work with this disease model. Discussion: We showed the feasibility of implementing an easy-to-use chlamydia model. This study can be regarded as a step towards more user-friendly decision support tools in health economics to assist decision makers in medicine.