Table 1.

Description of the sample, according to the study variables. Salvador, Bahia, Brazil, 2009 (n 1019)

Variable	n	%*	95 %CI
Per capita monthly income, shown as tertiles
<R$140·00 (1st tertile)	340	32·66	0·28, 0·36
R$140·00–243·57 (2nd tertile)	333	32·38	0·26, 0·38
≥R$243·57 (3rd tertile)	346	34·95	0·27, 0·42
Economic status
Better economic conditions	539	53·52	45·90, 61·11
Worst economic conditions	480	46·47	38·88, 54·06
Education level of the head of the family
≤4th grade	306	29·54	24·68, 34·41
5th to 8th grade	319	30·87	26·17, 35·58
College or university level	394	39·57	32·68, 46·46
Agglomeration (number of individuals per room)
<2·0	644	61·54	53·32, 69·75
≥2·0	375	38·45	30·24, 46·67

R$, Brazilian reais.

^*The percentages shown are adjusted for the complex design of the sample.