Force of tuberculosis infection among adolescents in a high HIV and TB prevalence community: a cross-sectional observation study

Table 4 Predicted prevalence, ARTI and force of infection by age in study cohort

Age	Number of participants	Predicted Prevalence* (95% CI)	ARTI**	Force of infection ^Φ
5	1	0.22 (0.17 - 0.27)	4.85
6	36	0.24 (0.19 - 0.29)	4.47	2.93
7	84	0.26 (0.22 - 0.30)	4.21	3.15
8	112	0.28 (0.24 - 0.32)	4.06	3.39
9	92	0.31 (0.27 - 0.34)	3.96	3.81
10	71	0.33 (0.29 - 0.36)	3.91	3.96
11	59	0.35 (0.32 - 0.39)	3.89	4.28
12	107	0.38 (0.35 - 0.41)	3.91	4.47
13	135	0.41 (0.38 - 0.43)	3.93	5.03
14	116	0.43 (0.41 - 0.46)	3.97	5.11
15	84	0.46 (0.44 - 0.49)	4.04	5.58
16	106	0.49 (0.46 - 0.52)	4.10	5.70
17	154	0.52 (0.48 - 0.55)	4.18	6.05
18	112	0.54 (0.51 - 0.58)	4.27	6.44
19	101	0.57 (0.53 - 0.61)	4.36	6.63
20	46	0.60 (0.55 - 0.64)	4.45	7.11
21	21	0.62 (0.58 - 0.67)	4.55	7.37
22	14	0.65 (0.60 - 0.70)	4.66	7.34

* Predictive logistic regression model: logit{P(Age)} = -1.82+0.111 age.
** The ARTI calculations are based on the mean age for the age category+0.5 years, as described in the methods section.
^Φ Force of infection = annual change in prevalence/(1-prevalence)

ISSN: 1471-2334