Study | Inclusion criteria | No of subjects with longitudinal data | Age at first measurement of lung function | Follow up | Assessment of exposure | Findings | ||||||
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Six Cities 70 | All first and second grade school children in 6 US cities. Analyses restricted to non-smoking white children | 8706 | 6–9 | Subsequently up to 12 annual assessments | Detailed parental smoking data were collected annually as well as prior smoking. Analyses focused on exposure in first 5 years of life, cumulative exposure between age 6 and testing and current exposure. | Current maternal smoking was associated with slower growth rates in children 6–10 year of age for: | ||||||
FVC -2.8 ml/yr (−5.5 to 0.0) | ||||||||||||
FEV1 -3.8 ml/yr (−6.4 to −1.1) | ||||||||||||
FEF25−75 –14.3 ml/s/yr (−29.0 to 0.3) | ||||||||||||
In older children the only significant effect was: | ||||||||||||
FEF25−75 –7.9 ml/s/yr (−14.4 to −1.4) | ||||||||||||
Neither paternal smoking nor maternal smoking during the first 5 years of life were related to lung growth. | ||||||||||||
East Boston85 | A 34% random sample of children 5–9 years at school in East Boston in 1974–5. These index children + their sibs formed the cohort. | 852 children at initial examination of whom 633 were still followed at examination 6 | 6–19 | Children were subsequently examined at yearly intervals on up to 5 occasions | Questionnaire assessment of maternal smoking at each examination as well as smoking prior to initial examination. | Current maternal smoking was associated with slower growth in: FEV1 -27.88ml/yr (−5.5 to 50.1). This is equivalent to a 7% deficit over 5 years. | ||||||
Similar effects were seen if the child smoked on top of the effect of active smoking. No effects of paternal smoking were observed. | ||||||||||||
Tucson 71 86 | Multistage stratified cluster sample of white non-Mexican Americans in Tucson area | Children aged 4–19 from 344 households | 4–19 | Data from 1st 10 surveys | Questionnaire based assessment of maternal smoking at each survey. | No effect was observed on growth overall. A re-analysis has suggested that boys with low initial lung function may have reduced growth if passively exposed87. However, no interaction tests were performed to demonstrate that the effect of passive smoking was significantly different from that in high initial lung function boys or in girls. | ||||||
Dutch 58 | Children attending 10 schools in a rural area in south-east Netherlands. 832 (84%) of children participated | 331 | 6–10 | Pulmonary function subsequently measured 3 times over 2 years | Questionnaire based—smoking daily inside home v not | Cross sectional effects were seen based on larger numbers of subjects (cf Tables 2 and 4). | ||||||
Lung growth (adjusted for height and weight change, mean age, parental education and URTI at testing) was not significantly related to ETS. | ||||||||||||
Regression coeffs for FEV1 were: | ||||||||||||
in girls +7 (6) ml/yr | ||||||||||||
in boys −12 (7) ml/yr | ||||||||||||
Dunedin Cohort42 | Birth cohort initially seen at age 3 years | 634 original cohort at age 3 was 1139 | 9 | Spirometry subsequently measured at ages 11, 13 and 15 | Maternal and paternal smoking was assessed at ages 7, 9 and 11. Non-exposed children were those whose parents did not smoke in previous year at any of these examinations. Smoking habit of mother during pregnancy was obtained retrospectively at age 9 years. | The FEV1/VC was lower in children whose parents both smoked (but significant only in boys) and declined faster with age in those with wheeze (significant for both sexes). Complicated modelling make interpretation of data difficult. | ||||||
Very selected presentation of FEV1 and VC were made, with suggestions of effects in some subgroups. | ||||||||||||
No significant changes in any pulmonary function measure were found in subjects where mothers reported smoking during and/or after pregnancy. | ||||||||||||
Arizona 30 | Children attending schools in 3 small communities in Arizona. | 472 subjects with a minimum of 2 consecutive annual tests | 8–10 | Up to 3 annual follow up tests | Neither parent v one parent v both parents, smoke | FEV1 growth standardised for height was lower if both parents smoked compared to neither smoking in 3 out of 4 age groups. No overall estimate of effect, standard errors or p value is available. |