Does Isoniazid Preventive Therapy Provide Better Treatment Outcomes in HIV-Infected Individuals in Northern Ethiopia? A Retrospective Cohort Study

Table 2

Incidence of tuberculosis among patients living with HIV/AIDS taking IPT and ART versus ART alone in Northern Ethiopia, 2009–2017.

Disease/exposure		Exposure to IPT		Total	value
		No (on ART only)	Yes (IPT and ART)
Development of tuberculosis	No	970 (78.1%)	593 (95.5%)	1563 (83.9%)	<0.0001
	Yes	272 (21.9%)	28 (4.5%)	300 (16.1%)
	Total	1242 (100.0%)	621 (100.0%)	1863 (100.0%)	<0.0001
Incidence rate of TB (per 100,000 persons-years)		3160	620

On average, the time to development of TB incidence post-IP exposure was 926 days (two and half years). The incidence rate of TB (per 100,000 PYs) was 620 (incidence rate difference = −2250; 95% CI: −3000 to −2110; value < 0.0001) for the exposed groups and 3160 (incidence rate ratio = 2340; 95% CI: 1530 to 3470) for the unexposed groups (Table 2). The KM analysis for the incidence of TB illustrated that unexposed patients had more chance of developing TB than exposed patients () (Figure 2).