Table 4.

Subgroup analysis for the association between body mass index (BMI) and risks of tuberculosis (TB) in the cohort in Yunnan, 2013–2015

Covariates	BMI groups	Person-years	Number of cases	Incidence rate	aHR	P value
			n	(95% CI)	(95% CI)
Sex*
Male	Underweight	1408.3	5	355 (115.3 to 828.6)	1.69 (0.59 to 4.82)	0.33
	Normal	12 370.7	17	137.4 (80.1 to 220.0)	Ref
	Overweight	7452.7	4	53.7 (14.6 to 137.4)	0.44 (0.15 to 1.31)	0.14
Female	Underweight	2056.5	1	48.6 (1.2 to 270.9)	0.38 (0.05 to 2.93)	0.35
	Normal	15 011.2	14	93.3 (51.0 to 156.5)	Ref
	Overweight	6274.9	2	31.9 (3.9 to 115.1)	0.22 (0.05 to 0.97)	0.05
Age (years)†
<65	Underweight	2981.1	2	67.1 (8.1 to 242.3)	1.79 (0.37 to 8.65)	0.47
	Normal	24 229.7	9	37.1 (17.0 to 70.5)	Ref
	Overweight	12 016.6	2	16.6 (2.0 to 60.1)	0.42 (0.09 to 2.00)	0.28
≥65	Underweight	483.7	4	827 (225.3 to 2117.6)	1.2 (0.41 to 3.54)	0.74
	Normal	3152.3	22	697.9 (437.4 to 1056.7)	Ref
	Overweight	1711	4	233.8 (63.7 to 598.6)	0.36 (0.12 to 1.00)	0.05

*Adjusted with covariates: age, ethnicity, marital status, previously treated TB, smoking status, alcohol use; all variables were adjusted as categorical variables.

†Adjusted with covariates: sex, ethnicity, marital status, previously treated TB, smoking status, alcohol use; all variables were adjusted as categorical variables.

aHR, adjusted HR.