Comparison of personal characteristics, sociodemographics and exposures of adolescents aged 13–15 in urban Lima and rural Tumbes; Peru 2009–2010
| Lima | Tumbes | p Value | |
| No. of participants | 725 | 716 | |
| No. of males (%) | 355 (49%) | 387 (54%) | 0.06 |
| Mean age in years (SD) | 14.9 (0.9) | 14.9 (0.9) | 1.00 |
| Born in site | 696 (96%) | 659 (92%) | 0.002 |
| Both parents born in site | 84 (11.6%) | 564 (78.8%) | <0.001 |
| ≥1 parent from highlands | 556 (76.7%) | 20 (2.8%) | <0.001 |
| ≥1 parent from rainforest | 17 (2.3%) | 3 (0.4%) | <0.001 |
| Income <175 US$/month | 181 (25%) | 451 (63%) | <0.001 |
| Electricity 24 h/day | 722 (100%) | 612 (85%) | <0.001 |
| Water 24 h/day | 668 (92%) | 40 (6%) | <0.001 |
| Concrete as predominant floor material | 272 (37.5%) | 398 (55.9%) | <0.001 |
| Propane gas as main fuel for cooking | 705 (97.2%) | 609 (85.1%) | <0.001 |
| Regular use of wood-burning stoves | 72 (8.6%) | 301 (42.0%) | <0.001 |
| Mean number of people per house (SD) | 5.7 (1.9) | 5.1 (1.6) | <0.001 |
| Households with ≥6 residents (%) | 355 (49%) | 212 (30%) | <0.001 |
| Mean no. of rooms per house (SD) | 4.9 (1.8) | 4.9 (1.2) | 1.00 |
| Time spent inside house | <0.001 | ||
| 0–6 h per day | 20 (2.8%) | 14 (2.0%) | |
| 7–10 h per day | 198 (27.3%) | 271 (37.8%) | |
| 11–15 h per day | 507 (69.9%) | 428 (59.8%) | |
| ≥15 h per day | 0 (0%) | 3 (0.4%) | |
| Sanitation facilities in home | <0.001 | ||
| Private | 668 (92.1%) | 197 (27.2%) | |
| Latrine | 0 (0.0%) | 170 (23.7%) | |
| Blind hole | 32 (4.4%) | 212 (27.8%) | |
| Open field | 0 (0.0%) | 113 (15.8%) | |
| Household owns car | 95 (13.1%) | 70 (9.7%) | 0.06 |
| Household owns land line telephone | 446 (61.5%) | 74 (10.3%) | <0.001 |
| Household owns cellular telephone | 628 (86.6%) | 658 (91.9%) | 0.002 |
| Mean paternal education in years (SD) | 9.8 (3.1) | 8.5 (4.2) | <0.001 |
| Mean maternal education in years (SD) | 8.2 (3.7) | 8.2 (4.1) | <0.001 |
| Height (cm)* | (n=651) | (n=661) | |
| Boys, mean (SD, Z-score) | 162.0 (7.4); z=1.0 | 163.1 (8.3); z=0.9 | 0.07 |
| Girls, mean (SD, Z-score) | 152.8 (5.5); z=1.5 | 155.1 (5.7); z=1.0 | <0.001 |
| Weight (kg) | (n=651) | (n=661) | |
| Boys, mean (SD) | 56.5 (11.2) | 53.5 (10.2) | <0.001 |
| Girls, mean (SD) | 52.1 (9.4) | 51.1 (8.1) | 0.15 |
| Body mass index* | (n=651) | (n=661) | |
| Boys, mean (SD, percentile) | 21.4 (3.3);65th | 20.0 (2.8);50th | 0.001 |
| Girls, mean (SD, percentile) | 22.3 (3.5);75th | 21.2 (3.1);60th | <0.001 |
| Haematocrit | (n=552) | (n=579) | |
| Boys, mean (SD) | 44.9 (3.1) | 42.6 (2.8) | <0.001 |
| Girls, mean (SD) | 41.0 (2.9) | 39.2 (2.4) | <0.001 |
↵* Z-scores and percentiles as per 2007 WHO reference.