Table 1.
Studies included in the systematic review and meta-analysis (N = 26)
| First author (year), country |
Study design |
N | Recruitment | Participants | Sex | Exposure variable |
Outcome measures |
Number of outcome events/ cases | Comparison |
|---|---|---|---|---|---|---|---|---|---|
| Anuntaseree (2001), Thailand | Cross-sectional | 1142 | Community | Children aged 6–13 years | Boys and girls | Household smoking | Ali’s questionnaire | Smoking in household: 47; non-smoking in household: 38 | Habitual snoring: most nights |
| Brunetti (2001), Italy | Cross-sectional | 1207 | Community | Children aged 3–11 years | Boys and girls | Passive smoking | PSG | Passive smoking: 4; non passive smoking: 10 | AHI > 3 |
| Castronovo (2002), Australia | Cross-sectional | 604 | Community | Children aged 2–8 years | Boys and girls | Passive smoking | Snoring questionnaire | Passive smoking: 80; non passive smoking: 74 | Habitual snoring: always and often |
| Corbo (1989), Italy | Cross-sectional | 940 | Community | Children aged 6–13 years | Boys and girls | Parental smoking | Snoring questionnaire | Parental smoking exposure: 82; non parental smoking exposure: 36 | Habitual snoring: snoring often |
| Corbo (2001), Italy | Cross-sectional | 2209 | Community | Children aged 10–15 years | Boys and girls | Parental smoking | Snoring questionnaire | Parental smoking exposure: 89; non parental smoking exposure: 34 | Habitual snoring: snoring often |
| Ersu (2004), Turkey | Cross-sectional | 2147 | Community | Children aged 5–13 years | Boys and girls | Paternal smoking | Brouillette’s questionnaire | Paternal smoking exposure: 21; non- paternal smoking exposure: 5 | High risk of OSAS: the questionnaire criteria by Brouillette et al |
| Franklin (2004), Sweden | Cross-sectional | 15,555 | Community | Adult (25–54 years) | Men and women combined | Passive smoking | Basic Nordic Sleep Questionnaire | Passive smoking exposure: 86; non-passive smoking exposure: 807 | Habitual snoring: loud and disturbing snoring at least 3 nights a week |
| Gill (2012), New Zealand | Cross-sectional | 823 | Community | Children aged 3 years 0 months to 3 years 12 months | Boys and girls | Household smoking | Goldstein’s questionnaire | NR | Habitual snoring: often (4–6 night/week) or always (every night/day) |
| Gozal (2008), USA | Cross-sectional | 16,321 | Community | Children aged 5–7 years | Boys and girls | Household smoking | Gozal’s sleep questionnaire | Household smoking: 666; non household smoking: 1178 | Habitual snoring: almost always (> 4 nights/week) or always on snoring frequency and medium loud to loud on loudness of snoring |
| Huang (2019), China | Retrospective | 209 | Clinic | Older than 18 years | Men and women combined | SHS | PSG | SHS exposure: 87; non- SHS exposure: 61 | AHI≧5 |
| Kaditis (2004), Greece | Cross-sectional | 3666 | Community | Children and adolescents aged 1–18 years | Boys and girls | Passive smoking | Brouilette’s questionnaire | Passive smoking exposure:106; non passive smoking exposure: 48 | Habitual snoring: snoring every night |
| Kannan (2017), USA | Prospective cohort | 609 | Community | Child at age 4 | Boys and girls | SHS | Snoring questionnaire | SHS exposure: 52; non-SHS exposure: 77 | Habitual snoring ≧ 3 nights/week |
| Kheirandish-Gozal (2014), Iran | Cross-sectional | 6000 | Community | Children aged 6–12 years | Boys and girls | Parental smoking | Gozal’s sleep questionnaire | NR | Habitual snoring ≧ 3 nights/week |
| First author (year), country | Study design | N | Recruitment | Participants | Sex | Exposure variable | Outcome Measures | Number of outcome events/ cases | Comparison |
| Kuehni (2008), UK | Cross-sectional | 3245 | Community | Children aged 1–4 years | Boys and girls | Parental smoking | Corbo’s questionnaire | Parental smoking exposure: 241; non-parental smoking exposure: 290 | Habitual snoring: snoring almost always |
| Li AM (2010), Hong Kong | Cross-sectional | 9172 | Community | Children aged 5–14 years | Boys and girls | Household smoking | Hong Kong Children Sleep Questionnaire | Household smoking: 143; non household snoring: 311 | Habitual snoring: frequently, three nights or more per week |
| Li S (2010), China | Cross-sectional | 20,152 | Community | Children aged 5.08–11.99 years | Boys and girls | Household passive smoking | Children’s Sleep Habits Questionnaire | Household passive smoking: 666; non household passive smoking: 1750 | Habitual snoring: frequently (2–4 nights/week) or always (5–7 nights/week) |
| Nosetti (2011), Italy | Case–control | 1610 | Community | Children aged 0–14 years | Boys and girls | SHS | PSG | SHS exposure: 274; non-SHS exposure: 306 | AHI (NR) |
| Ohida (2007), Japan | Cross-sectional | 19,386 | Clinic | Pregnant women | Women | SHS | 7 items questionnaire | SHSexposure: 10,269; non-SHS exposure: 9023 | Snoring (often or always) |
| Owen (1996), | Cross-sectional | 245 | Community | Children aged 0–11 years | Boys and girls | Parental smoking | Owen’s questionnaire | Parental smoking exposure: 39; non parental smoking exposure: 27 | Snoring (sometimes or often) |
| Sahin (2009), Turkey | Cross-sectional | 1605 | Community | Children aged 7–13 years | Boys and girls | Household smoking | Ersu’s questionnaire | Household smoking: 28; non household smoking: 14 | Habitual snoring: frequently or almost every day |
| Sogut (2005), Turkey | Cross-sectional | 1344 | Community | Children aged 3–11 years | Boys and girls | Passive smoking | PSG | Passive smoking: 11; non passive smoking: 4 | AHI > 3 |
| Sogut (2009), Turkey | Cross-sectional | 1030 | Community | Adolescents aged 12–17 | Boys and girls | Exposure to father smoking | 55-item questionnaire | Exposure to father smoking: 25; non-father smoking: 16 | Habitual snoring: often and always |
| Urschitz (2004), Germany | Cross-sectional | 1760 | Community | Children aged 9 ± 0.7 years | Boys and girls | Household smoking | Sleep-disordered breathing questionnaire | Household smoking: 62; non household smoking: 50 | Habitual snoring: frequently and always |
| Włodarska (2020), Poland | Cross-sectional | 160 | Community | Children aged 6–18 years | Boys and girls | Exposure to tobacco smoke at home | PSG | Exposure group: 17; non exposure group: 3 | Children aged < 13 years, AHI > 1.5; children aged > 13, AHI > 5 |
| Zhang (2004), Australia | Cross-sectional | 985 | School | Children aged 4–12 years | Boys and girls | Household smoking | Rumchev’s questionnaire | Household smoking exposure: 84; non-household smoking exposure: 65 | Habitual snoring more than 4 times/week |
| Zhu (2013), Hong Kong | Cross-sectional | 2954 | Community population | Preschool children aged 2–6 years | Boys and girls | Household smoking | The Hong Kong Paediatric Sleep Survey | household smoking exposure: 52; non-household smoking exposure: 68 | Habitual snoring ≧ 3 nights/week |
SHS Secondhand Smoke, AHI Apnea–Hypopnea Index, PSG Polysomnography, NR Not reported