From: Effect of predictors on incidence rate of pregnancy among reproductive age women on antiretroviral therapy at public hospitals of Jigjiga and Harar Towns, Eastern Ethiopia: a retrospective cohort study
Cohort
Person-month
Failures
Rate
95% Conf. Interval
0–12
4060
50
0.0123
0.0094, 0.0164
12–24
2530
15
0.0059
0.0036, 0.0104
24–36
1586
4
0.0025
0.0009, 0.0090
36–48
906
3
0.0033
0.0010, 0.0162
> 48
358
0
Total
9440
72
0.0076
0.0060, 0.0098