Antai and Moradi Results from model 1 indicate a 30% and (order 2–4 and 24–47 months). The com- After further adjustment for mother-level 50% increase in under-5 deaths among the munity-level variance decreased further while characteristics in model 3 relative risks of more disadvantaged children compared with remaining significant (τ = 0.103, p = 0.035), under-5 deaths increased as the level of disad- the least disadvantaged UADI quintile. The indicating clustering of mothers of children vantaged UADI quintiles increased. Under-5 associations were, however, statistically sig- with similar risk factors within disadvantaged deaths among children of mothers in the nificant only for class II and class III com- communities, a similar compositional effect. most disadvantaged UADI quintiles (class V) pared with class I (class II: OR = 1.32; 95% The PCV of the odds of under-5 mortality were double relative to under-5 deaths among CI, 1.19–1.54; and class III: OR = 1.39; 95% in this model was 20.1% across communities children of mothers in the least disadvantaged CI, 1.26–1.56). The community-level varia- and 24.6% across mothers. UADI quintile (class I; OR = 2.14; 95% tion decreased from model 0 but remained significant (τ = 0.129, p = 0.063), indicat- 18 ing some clustering of mothers of children U5MR 16 with similar risks of death within disadvan- 14 taged communities—a compositional effect; that is, the increased risks are explained by ) 12 the increased risks of the residents who live % ( ge10 in that neighborhood. The PCV indicated a t en 8 that 52.7% and 44.9% of the variance in the c r odds of under-5 mortality across communi- eP 6 ties and mothers, respectively, were explained 4 by the UADI. Inclusion of child-level char- acteristics in model 2 did not affect associa- 2 tions of under-5 deaths with children in the 0 more disadvantaged UADI quintiles, but the Class I Class II, Class III, Class IV, Class V (least disadvantaged, (n = 856) (n = 490) (n = 33) (most disadvantaged, relative risk was double for children of high n = 338) n = 391) birth order after short birth interval (order ≥ 5 UADI quintile (total observations) and < 24 months) compared with children Figure 2. Distribution of under-5 mortality rate (U5MR) according to UADI among participants in the Nigeria of intermediate birth order and birth interval Demographic and Health Survey (2003). Table 1. Sociodemographic characteristics of the urban population according to UADI [n (%)]. Class I Class V (least disadvantaged; Class II Class III Class IV (most disadvantaged; Total Characteristic n = 338) (n = 856) (n = 490) (n = 43) n = 391) (n = 2,118) Child’s sex Male 172 (51) 424 (49) 238 (49) 24 (56) 218 (56) 1,076 Female 166 (49) 432 (51) 252 (51) 19 (44) 173 (44) 1,042 Child’s birth order, birth interval First birth (order 1) 71 (21) 247 (29) 83 (17) 11 (26) 52 (13) 464 (22) Order 2–4, < 24 months 46 (13) 89 (10) 36 (7) 2 (5) 41 (10) 214 (10) Order 2–4, 24–47 months 104 (31) 241 (28) 96 (20) 17 (39) 83 (21) 541 (26) Order 2–4, ≥ 48 months 41 (12) 74 (9) 46 (9) 1 (2) 27 (7) 189 (9) Order ≥ 5, < 24 months 13 (4) 24 (3) 40 (8) 2 (5) 49 (13) 128 (6) Order ≥ 5, 24–47 months 47 (14) 129 (15) 148 (30) 6 (14) 101 (26) 431 (20) Order ≥ 5, ≥ 48 months 16 (5) 52 (6) 41 (8) 4 (9) 38 (10) 151 (7) Mother’s age (years) 15–18 1 (0) 27 (3) 22 (4) 3 (7) 23 (6) 76 (4) 19–23 29 (9) 171 (20) 88 (18) 9 (22) 45 (11) 342 (16) 24–28 100 (29) 283 (33) 126 (26) 11 (25) 123 (32) 643 (30) 29–33 97 (29) 188 (22) 97 (20) 11 (25) 87 (22) 480 (23) ≥ 34 111 (33) 187 (22) 157 (32) 9 (21) 113 (29) 577 (27) Mother’s marital status Single 6 (2) 26 (3) 2 (0) 12 (28) 5 (1) 51 (3) Married 327 (97) 783 (91) 464 (95) 30 (70) 356 (91) 1,960 (92) Divorced 5 (1) 47 (6) 24 (5) 1 (2) 30 (8) 107 (5) Mother’s education No education 1 (0) 37 (4) 400 (82) 13 (30) 292 (75) 743 (35) Primary 71 (21) 327 (38) 55 (11) 12 (28) 68 (17) 533 (25) Secondary or higher 266 (79) 492 (58) 35 (7) 18 (42) 31 (8) 842 (40) Mother’s occupation Not working 45 (14) 313 (37) 187 (38) 19 (44) 136 (35) 700 (33) Clerical/sales/services/skilled manual 231 (68) 479 (56) 293 (60) 14 (33) 249 (64) 1,266 (60) Professional/technician/management 62 (18) 64 (7) 10 (2) 10 (23) 6 (1) 152 (7) Wealth index Poorest 0 (0) 0 (0) 3 (1) 10 (23) 107 (27) 120 (6) Poorer 0 (0) 0 (0) 7 (1) 3 (7) 203 (52) 213 (10) Middle 1 (0) 97 (11) 162 (33) 21 (49) 70 (18) 351 (16) Richer 24 (7) 356 (42) 272 (56) 9 (21) 11 (3) 672 (32) Richest 313 (93) 403 (47) 46 (9) 0 (0) 0 (0) 762 (36) 880 118 | number 6 | June 2010 • Environmental Health Perspectives ovlume