From: Effect of isoniazid preventive therapy on tuberculosis incidence and associated risk factors among HIV infected adults in Tanzania: a retrospective cohort study
IPT status
Number of TB cases
Total person-years (TPYrs)
Incidence rate (per 100pyrs)
IRR (95% CI)
Never on IPT
2845
96,845
2.94
1.0
Ever on IPT
279
18,081
1.54
0.52 (0.46–0.59)
Total
3124
114,926
2.7