Fig. 3

Scatterplot displaying all reported relationship age pairings and associated incident HIV infections for men and women. (Bottom panel) smoothed incidence rates of HIV by reported age pairings for men and women. Greater than expected incidence – compared to the mean incidence with no age-pair effect – is depicted within the red-dashed upper 99% credible bounds, generated by iterating the smoothed model under the null hypothesis of no age-pair effect.