Table 3.
Associations between internal living environment and hospital admission for an acute respiratory infection during the first five years of life
| Variable | Incidence per 1000 person-years | Crude HR (95% CI) | Adjusted HR1a (95% CI) | Adjusted HR2b (95% CI) | Adjusted HR3 (95% CI) |
|---|---|---|---|---|---|
| Housing tenure | |||||
| Owner occupancy | 27.73 (25.19-30.46) | 1.00 | 1.00 | 1.00 | 1.00 |
| Tenancy | 39.11 (36.00-42.43) | 1.41 (1.22-1.63) | 1.02 (0.88-1.18) | 1.02 (0.88-1.18) | 1.00 (0.87-1.16)c |
| Crowding index | |||||
| <1-2 (low and medium) | 29.19 (27.06-31.44) | 1.00 | 1.00 | 1.00 | 1.00 |
| 2+ (high) | 47.68 (42.61-53.19) | 1.63 (1.42-1.88) | 1.11 (0.95-1.29) | 1.07 (0.91-1.25) | 1.07 (0.91-1.26)c |
| Maternal cigarette smoking | |||||
| Yes | 55.23 (48.47-62.66) | 1.87 (1.60-2.18) | 1.14 (0.90-1.45) | 1.06 (0.83-1.36) | 1.10 (0.84-1.44)c |
| No | 29.61 (27.57-31.77) | 1.00 | 1.00 | 1.00 | 1.00 |
| Cigarette smoking by others in the household | |||||
| Yes | 44.58 (40.36-49.11) | 1.57 (1.37-1.80) | 0.99 (0.85-1.16) | 0.97 (0.83-1.14) | 0.94 (0.79-1.11)c |
| No | 28.40 (26.19-30.75) | 1.00 | 1.00 | 1.00 | 1.00 |
| Heating the house | |||||
| Yes | 31.41 (29.34-33.58) | 0.65 (0.54-0.78) | 0.99 (0.82-1.19) | 0.87 (0.72-1.06) | 0.87 (0.72-1.05)c |
| No | 48.58 (41.35-56.71) | 1.00 | 1.00 | 1.00 | 1.00 |
| Form/s of heating used in the housed (N = 5298) | |||||
| Electric heater | |||||
| Yes | 28.97 (26.87-31.19) | 0.56 (0.47-0.68) | 0.70 (0.58-0.83) | 0.74 (0.61-0.89) | 0.74 (0.61-0.89)e |
| No | 51.33 (43.52-60.15) | 1.00 | 1.00 | 1.00 | 1.00 |
| Flued gas heater | |||||
| Yes | 31.95 (26.55-38.12) | 1.02 (0.83-1.25) | 1.12 (0.92-1.37) | 1.07 (0.88-1.31) | 1.08 (0.89-1.32)e |
| No | 31.32 (29.09-33.67) | 1.00 | 1.00 | 1.00 | 1.00 |
| Unflued portable gas heater | |||||
| Yes | 31.91 (26.15-38.55) | 1.02 (0.82-1.27) | 0.89 (0.73-1.10) | 0.92 (0.75-1.13) | 0.90 (0.73-1.11)e |
| No | 31.34 (29.13-33.66) | 1.00 | 1.00 | 1.00 | 1.00 |
| Wood burner | |||||
| Yes | 26.70 (23.13-30.67) | 0.80 (0.68-0.95) | 0.79 (0.67-0.94) | 0.78 (0.66-0.93) | 0.79 (0.66-0.93)e |
| No | 33.19 (30.70-35.83) | 1.00 | 1.00 | 1.00 | 1.00 |
| Form/s of heating used in the room where child sleeps at nightd (N = 5298) | |||||
| No heating | |||||
| Yes | 32.33 (26.89-38.56) | 1.03 (0.84-1.27) | 0.76 (0.63-0.93) | 0.82 (0.67-0.99) | 0.82 (0.67-1.00)e |
| No | 31.26 (29.03-33.60) | 1.00 | 1.00 | 1.00 | 1.00 |
| Electric heater | |||||
| Yes | 29.27 (27.04-31.64) | 0.74 (0.62-0.87) | 0.95 (0.81-1.12) | 0.94 (0.80-1.11) | 0.94 (0.80-1.10)e |
| No | 39.74 (34.68-45.33) | 1.00 | 1.00 | 1.00 | 1.00 |
| Flued gas heater | |||||
| Yes | 60.79 (43.81-82.17) | 1.98 (1.42-2.77) | 1.96 (1.43-2.68) | 1.69 (1.21-2.36) | 1.69 (1.21-2.36)e |
| No | 30.64 (28.58-32.82) | 1.00 | 1.00 | 1.00 | 1.00 |
| Unflued portable gas heater | |||||
| Yes | 70.04 (45.75-102.63) | 2.27 (1.49-3.45) | 1.78 (1.20-2.64) | 1.68 (1.12-2.36) | 1.68 (1.12-2.53)e |
| No | 30.87 (28.81-33.05) | 1.00 | 1.00 | 1.00 | 1.00 |
| Wood burner | |||||
| Yes | 32.08 (22.81-43.86) | 1.02 (0.72-1.44) | 0.93 (0.67-1.29) | 1.01 (0.73-1.41) | 1.02 (0.73-1.42)e |
| No | 31.38 (29.26-33.60) | 1.00 | 1.00 | 1.00 | 1.00 |
| Dampness of the house | |||||
| Never or hardly ever | 27.86 (25.15-30.77) | 1.00 | 1.00 | 1.00 | 1.00 |
| Not very often | 30.79 (27.09-34.85) | 1.07 (0.92-1.25) | 0.93 (0.79-1.08) | 0.95 (0.82-1.11) | 0.96 (0.83-1.13)c |
| Quite often | 38.62 (32.71-45.29) | 1.47 (1.23-1.75) | 1.13 (0.95-1.34) | 1.08 (0.91-1.29) | 1.13 (0.94-1.36)c |
| Always or almost always | 51.30 (39.81-65.07) | 1.81 (1.43-2.30) | 1.13 (0.89-1.43) | 1.07 (0.84-1.37) | 1.15 (0.89-1.50)c |
| Heavy condensation in the room where child sleeps at night | |||||
| Never or hardly ever | 29.90 (27.12-32.89) | 1.00 | 1.00 | 1.00 | 1.00 |
| Not very often | 29.61 (25.84-33.76) | 1.05 (0.90-1.23) | 0.95 (0.81-1.11) | 1.00 (0.86-1.17) | 1.01 (0.86-1.17)f |
| Quite often | 35.63 (30.12-41.87) | 1.29 (1.08-1.54) | 1.08 (0.90-1.28) | 1.02 (0.86-1.22) | 1.05 (0.88-1.27)f |
| Always or almost always | 43.04 (33.15-54.95) | 1.47 (1.15-1.86) | 0.97 (0.76-1.23) | 0.94 (0.74-1.20) | 1.00 (0.77-1.31)f |
| Mould or mildew in the walls or ceilings in the room where child sleeps at night in the past two weeks | |||||
| Yes | 33.88 (27.66-41.08) | 1.24 (1.03-1.49) | 0.92 (0.77-1.10) | 0.88 (0.73-1.41) | 0.81 (0.67-0.99)c |
| No | 31.10 (28.92-33.40) | 1.00 | 1.00 | 1.00 | 1.00 |
aAdjusted for all maternal factors (age, ethnicity, education, area of residence, neighbourhood deprivation, pre-pregnancy BMI, pre-pregnancy self-rated health, history of asthma, use of supplements, maternal smoking, parity and pregnancy planning)
bAdjusted for all maternal factors as above and all child factors (gender, gestation, birth-weight, season of birth, proxy-rated health at 9 months, health or developmental problems, feeding practices, time spent outdoors and child immunisation)
cAdjusted for all maternal and child factors as above and each other
dRestricted to those who reported heating the house
eAdjusted for all maternal and child factors as above and environmental factors (household tenure, crowding, household smoking, dampness of the house and mould or mildew in the child’s bedroom)
fAdjusted for all maternal and child factors as above and environmental factors (household tenure, crowding, household smoking, heating the hose and mould or mildew in the child’s bedroom). A separate model was used here as heavy condensation was moderately correlated with dampness of the house