Table 1 Characteristics of studies included in the meta-analysis (n = 15)
First author | Location | Study design | Data collection | Age of children (years) | Exposure | Measurement of exposure prevalence used for meta-analysis | Main results |
|---|---|---|---|---|---|---|---|
Comprehensive Smoke-Free Law | |||||||
Kabir et al. (2010) [25] | Ireland Legislation: 2004 | Repeated cross-sectional, N = app. 10,640 children | ISAAC (1995, 1998, 2002, 2003, 2007) Follow-up period: 1 measurement after approx. 3 years | 13–14 | Parental smoking at home. Measurement: Q | Reported prevalence’s for exposure in each survey year | Q: SHS exposure at home remained unchanged. |
Sims et al. (2012) [26] | England Legislation: 2007 | Repeated cross-sectional, N = 23,680 children | HSE (1996, 1997, 1998, 2001, 2002, 2003, 2005, 2006, 2007, 2008) Follow-up period: 1 measurement after approx. 1 year | 4–15 | Parental smoking at home. Measurement: Q, CL (more than 1.7 ng/ml) | Reported proportions of household smoking status | Q and CL:SHS exposure at home decreased. (CL more than 1.7 ng/ml) |
Huang et al. (2012) [27] | Southern Taiwan Legislation: 2009 | Cross-sectional, N = 4450 children | Control of School-aged Children Smoking Study Survey (2008,2009) Follow-up period: 1 measurement after few months | 8–13 | Smoking children, family members or visitors at home. Measurement: Q | Reported changes in proportions of household SHS exposure (summed up for men and women and None, 1–3 or 4+ days/ week) | Q: SHS exposure at home remained unchanged. |
Fernández et al. (2015) [28] | Spain Legislation: 2011 | Prospective cohort study, N = 118 boys and their parents | INMA-Network (2005–2006, 2011–2012) Follow-up period: 1 measurement after approx. 1 year | 4–5 | Parents (mother, father, both) smoking at home. Measurement: Q, CL | Reported proportions of exposure to SHS at home (yes, at least one smoker) | Q and CL: SHS exposure at home increased. |
Ho et al. (2010) [10] | Hong Kong Legislation: 2007 | Cross-sectional, N_06 = 3243 N_08 = 4965 children | Data from randomly selected schools (2006, 2008) Follow-up period: 1 measurement after approx. 1 year | 7–10 | Parental smoking at home. Measurement: Q, HNC | Reported prevalences of SHS exposure based on HNC (summarized: None, 1–3, 4–7, any days exposed) | Q with HNC: SHS exposure at home increased. |
Chan et al. (2014) [29] | Hong Kong Legislation: 2007 | Cross-sectional, (RCT), N_(05–06) = 333 N (07–08) = 742 | Data from the maternal/child/Student Health Centers (2005–2006, 2007–2008) Follow-up period: 1 measurement after approx. 1 year | 0–6 | Smoking father at home. Measurement: Q, HNC | Reported proportions of children’s exposure by smoking father reported by mother | Q and HNC: SHS exposure at home decreased. |
Jarvis et al. (2012) [30] | England Legislation: 2007 | Repeated cross-sectional, N = 10,825 children | HSE (1998, 2001, 2002, 2003, 2005, 2006, 2007, 2008) Follow-up period: 1 measurement after approx. 1 year | 4–15 | Smoking parents or any other people at home. Measurement: I, CL | Reported proportions of children with smoking parents. | I and CL: SHS exposure at home decreased slightly. |
Bolte et al. (2015) [31] | Germany (Bavaria), Legislation: 2008 | Repeated cross-sectional, N = 17,892 parents with their children | Health monitoring units (GME) (2004–2005, 2005–2006, 2008–2009), Follow-up period: 1 measurement after approx. 1 year | 5–6 | Smoking parents at home, in cars. Measurement: I | Reported prevalences of SHS exposure at home | I: SHS exposure at home decreased slightly. |
Holliday et al. (2009) [32] | Wales, Legislation: 2007 | Repeated cross-sectional, N = 3216 children | CHETS (2007,2008) Follow-up period: 1 measurement after approx. 1 year | 10–11 | Parents or any other people smoking at home. Measurement: Q, CL | Reported prevalences of SHS exposure at home | Q and CL: SHS exposure at home remained unchanged. |
Jarvis et al. (2015) [33] | England Legislation: 2007 | Repeated cross-sectional, N = 13,327 children | HSE (1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011,2012) Follow-up period: 5 measurements during 5 years | 0–15 | Parents or any other people smoking at home. Measurement: I, CL | Reported percentages of children with smoking parents. | I and CL: SHS exposure at home decreased. |
Akhtar et al. (2007) [34] | Scotland Legislation: 2006 | Repeated cross-sectional, N = 4676 children | CHETS (2006,2007) Follow-up period: 1 measurement after approx. 1 year | 10–11 | Parents or any other people smoking at home. Measurement: Q, CL | Reported prevalence of SHS exposure at home | Q: SHS exposure at home remained unchanged. CL: Proportion of pupils with higher cotinine remained unchanged, mean cotinine concentration fell by 39% |
Mixed Smoke-Free Law | |||||||
Sinha et al. (2008) [35] | India Legislation: 2005 | Cross-sectional, N_1 = 68,077 N_2 = 12,086 children | GYTS (2003,2006) Follow-up period: 1 measurement after approx. 1 year | 13–15 | Smoking parents or other smoking people at home. Measurement: Q | Reported exposure prevalences in the week prior to the survey, for each survey year | Q: SHS exposure at home decreased after legislation. |
Hawkins et al. (2012) [36] | USA Legislation: NA | Repeated cross-sectional N_1 = 67,607, N_2 = 62,768 families | NSCH (2003,2007) Follow-up period: 1 measurement after approx. 1 year | 6–17 | Smoking parents at home. Measurement: Q | Reported prevalences of household tobacco use (yes/no) for each survey (only in the text) | Q: SHS exposure at home decreased slightly. |
Yao et al. (2016) [37] | USA Legislation: NA | Repeated cross-sectional N_1 = 18,731 children, 44,049 nonsmoking adults | National Health Survey Cancer Control Supplements (2000,2010) Follow-up period: 1 measurement after approx. 1 year | 0–17 | Smoking parents or other smoking people at home. Measurement: Q | Reported prevalence of SHS exposure at home | Q: SHS exposure at home decreased. |
Kuntz et al. (2016) [38] | Germany Legislation: 2008 | Cross-sectional, N_1 = 6680 N_2 = 4455 children | KiGGS (2003–2006, 2009–2012) Follow-up period: 1 measurement after approx. 1 year | 0–6 | Smoking parents or other smoking people at home. Measurement: Q | Reported prevalence of domestic exposure | Q: SHS exposure at home decreased. |