Table 4.

NNS and NNT to detect a TB suspect, active TB or TB-HIV case using active case finding, Kampala, 2008–2009^*

Study population	Total n	NNS (95%CI)†	NNT (95%CI)‡
All participants enrolled	5102
Chronic cough (⩾2 weeks)	199	26 (23–30)	NA
Previously undetected active TB (smear- and/or culture-positive)	39	131 (96–179)	5 (5.3–4.7)
Previously undetected active TB (smear only)	30	170 (123–256)	7 (7.1–6.3)
TB-HIV-negative	26	196 (145–323)	8 (7.2–8.3)
TB-HIV co-infected	13	393 (222–667)	15 (14–17)
Undetected HIV-positive in those with chronic cough	25	NA	8 (7.4–8.6)

^*The risk subgroup constitutes the denominators for NNS or NNT, and numerators are either overall population or those with chronic cough.

^†Numerator for NNS = 5102; the rest of the numbers in the column with totals constitute the denominators.

^‡Numerator for NNT = 199; the rest of the numbers in the column with totals below chronic cough constitute the denominators.

NNS = number needed to screen; NNT = number needed to test; TB = tuberculosis; HIV = human immunodeficiency virus; NA = not available.