Table 1.

Baseline characteristics of cases (n = 92) and controls (n = 184)^a

Characteristics	Cases n (%)	Controls n (%)	Cases v. controls p value
Age group (years)
18–30	23 (25)	46 (25)	0.887
31–45	26 (28.2)	52 (28.2)	0.887
46–60	18 (19.5)	36 (19.5)	0.862
61–75	19 (20.6)	38 (20.6)	0.887
76–90	6 (6.5)	12 (6.5)	0.791
Mean age (years)	49.9 ± 19.0	48.12 ± 18.5	0.455
Gender
Male	72 (78.2)	144 (78.2)	0.887
Female	20 (21.7)	40 (21.7)	0.887
Area of residence
Rural	69 (75.0)	117 (63.5)	0.076
Urban	23 (25.0)	67 (36.4)	0.076
Socio-economic status
Highb	1 (1)	1 (0.5)	1
Middlec	42 (45.6)	88 (47.8)	0.823
Lowd	49 (53.2)	95 (51.6)	0.887
Overcrowding at homee	34 (36.9)	61 (33.1)	0.624
High risk occupation	3 (3.2)	2 (1.0)	0.337
Smokers
Total	67 (72.8)	68 (36.9)	<0.0001
Male	50 (54.3)	52 (28.2)	1
Female	17 (18.4)	16 (8.6)	1
Mean age for starting smoking (years)	17.3 ± 4.4	19.7 ± 7	0.002
Type of smoking
Cigarette	29 (31.5)	7 (3.8)	<0.0001
Beedi	38 (41.3)	61 (33.1)	<0.0001
Number of cigarettes/beedis smoked per day	14.2 ± 6.6	10.61 ± 4.39	0.0001
Duration of smoking (years)	27.9 ± 14.6	30.56 ± 11.9	0.106
Smoking pack years	19.46 ± 12.62	16.01 ± 9.52	0.011
Regular alcohol use	44 (47.8)	60 (32.6)	0.019
History of contact with TB patient	14 (15.2)	4 (2.1)	<0.0001
Past history of TB	10 (10.8)	1 (0.5)	<0.0001
Family history of TB	12 (13.0)	3 (1.6)	0.0002
Underweightf	19 (20.6)	12 (6.5)	0.0009

TPE, tuberculous pleural effusion; TB, tuberculosis.

^aData are number (%) of patients or mean ± s.d.

^bAnnual family income >Rs. 850 000 (1 Pound Sterling = 92.90 Indian Rupees).

^cAnnual family income Rs. 50 000–850 000.

^dAnnual family income <Rs. 50 000.

^eExpressed as the number of persons per room exceeding the accepted standards of 2 persons in 1 room, 3 in 2 rooms, 5 in 3 rooms, 7 in 4 rooms and 10 persons in 5 rooms (an additional 2 for each further room).

^fBody mass index <18.5 kg/m².