Conducting a secondary data analysis to estimate the incidence of congenital syphilis in South Africa, 2010 - 2016.

Analysis of existing health data is often used as a cost-effective and time-efficient means to provide evidence to inform important public health decisions. However, the accuracy of the resultant decisions largely depends on the quality of the accessible data, and how the data are processed, analyzed, interpreted and reported. This case study, based on an actual secondary data analysis that was conducted by a trainee of the South African Field Epidemiology Training Programme during April 2017, was designed to provide a classroom simulation of practical considerations that should be taken into account when planning an analysis of a secondary dataset. The case study is ideally suited to reinforce principles already covered in lectures or in background reading assignments.