Development and validation of an HIV risk scorecard model

Abstract

This research paper covers the development of an HIV risk scorecard using SAS Enterprise MinerTM. The HIV risk scorecard was developed using the 2007 South African annual antenatal HIV and syphilis seroprevalence data. Antenatal data contains various demographic characteristics for each pregnant woman, such as pregnant woman's age, male sexual partner's age, race, level of education, gravidity, parity, HIV and syphilis status. The purpose of this research was to use a scorecard to rank the effects of the demographic characteristics on influencing an individual's risk of acquiring an HIV infection, not the probability of being sick. The project encompassed the selection of the data sample, classing, selection of demographic characteristics, fitting of a regression model, generation of weights-of-evidence (WOE), calculation of information values (IVs), creation and validation of an HIV risk scorecard. The educational level and syphilis status of the pregnant women produced information values below 0.05 and were rejected from inclusion in the final HIV risk scorecard. Based on their respective information values, the following four demographic characteristics of the pregnant women were found to be of medium predictive strength and thus included in the final HIV risk scorecard; age, age of male sexual partner, gravidity and parity. The age of the pregnant woman had the highest information value and Gini coefficient. The HIV risk scorecard showed that the risk of contracting an HIV infection increased gradually up to the age of 30 years for females and 34 years old for their male sexual partners. Thereafter, the risk decreased gradually towards the age of 45.