Sreeramareddy et al. BMC Public Health 2011, 11:403 http://www.biomedcentral.com/1471-2458/11/403 Page 7 of 10 Table 5 Multivariable analysis of size at birth with type of fuel and other variables Variable Model 1 Model 2 Type of fuel Low Pollution Fuels 1 1 High Pollution Fuels 1.41 (1.29, 1.57) *** 1.21 (1.06, 1.32) ** Gender of the baby Male 1 1 Female 0.88 (0.83, 0.94) *** 0.88 (0.83, 0.94) *** Birth order 1 1 1 2 0.88 (0.82, 0.95) ** 0.88 (0.81, 0.95) ** 3 0.89 (0.82, 0.98) ** 0.86 (0.78, 0.94) ** ≥ 4 0.91 (0.83, 0.99) ** 0.83 (0.75, 0.92) ** Mother’s age at childbirth ≤ 24 1 25-34 1.08 (0.95, 1.22) 35-49 1.15 (0.52, 2.55) Mother’s Body Mass Index ≤ 18 1 18-23 0.92 (0.85, 0.99) *** 23-28 0.74 (0.66, 0.84) ** 28-40 0.77 (0.61, 0.97) ** Mother’s education No education 1 Primary 0.96 (0.87, 1.07) Secondary 0.86 (0.78, 0. 94) * Higher 0.62 (0.51, 0.76) * Mother smokes No 1 Yes 1.25 (0.94, 1.66) Mothers haemoglobin level (adjusted for altitude) in mg/dl § 1 0.99 (0.99, 0.99) ** Wealth Index Poorest to richest Type of residence Urban Rural Religion Hindu Muslim Christian Others § beta coefficient = -0.00134, standard error = 0.000428* p < 0.05, ** p < 0.01, *** p < 0.001. Model 3 1 1.07 (0.94, 1.22) 1 0.88 (0.83, 0.93) *** 1 0.87 (0.81, 0.94) ** 0.85 (0.77, 0.94) ** 0.81 (0.74, 0.89) ** 1 1.08 (0.95, 1.23) 1.16 (0.52, 2.59) 1 0.93 (0.86, 1.01) 0.77 (0.68, 0.87) * 0.79 (0.63, 1.01) 1 0.99 (0.89, 1.10) 0.92 (0.83, 1.02) 0.67 (0.54, 0.82) ** 1 1.24 (0.93, 1.65) 1 0.99 (0.99, 0.99) ** 1 0.93 (0.89, 0.97) ** 1 0.97 (0.87, 1.09) 1 0.94 (0.83, 1.05) 0.81 (0.63, 1.04) 1.38 (1.12, 1.72) *