Lechner 2012.
| Methods | Country: USA, Oklahoma Setting: University Design: Uncontrolled before‐and‐after study Analysis: Chi², ANOVA |
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| Participants | 4 cross‐sectional surveys over 4 years pre‐ and post‐ban. Likert scale 6 points SHS exposure, 7‐point Likert scale for attitudes and beliefs. Cluster sampling of undergraduate students. Undergraduate courses selected were picked at random from a Registrar's list. Informed consent in group Participants enrolled in university between 2007 and 2010. Aged 18 ‐ 44 years Sample: 4947 undergraduate students. Baseline N = 1185 , 2008 N = 1197, 2009 N = 1257, 2010 N = 1242 Ages ranged from 18 ‐ 44 , mean age 20.3 yrs Women constituted 52.5% of the sample; 82.8% self‐identified as white, 4.1% as African‐American, 2.3% as Asian, 6.0% as Native American, and 2.3% as other Sex and ethnic distributions were typical of the campus |
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| Interventions | 100% Tobacco‐free campus policy introduced in July 2008. The use, sales and promotion of tobacco products was prohibited | |
| Outcomes | Self‐reported prevalence Self‐reported exposure to SHS over 1 week period outside buildings and in walkways Attitudes to ban and to smoking | |
| Notes | National Ban: No Biochemical Verification: No, self‐reported smoking status Follow‐up period: 2 years follow‐up 4 groups were formed. Nonsmokers are classified as individuals who have not smoked over 100 cigarettes in their lifetime and have not smoked in the last 30 days. Former smokers are classified as individuals who have smoked at least 100 cigarettes in their lifetime but not in the last 30 days. Less frequent smokers are individuals who have smoked 1 ‐ 9 days in the last 30 (no cap on lifetime number). More frequent smokers are individuals who have smoked over 100 cigarettes and who consumed cigarettes on at least 10 of the last 30 days. Used CDC definitions |
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| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | High risk | Not applicable |
| Allocation concealment (selection bias) | High risk | Not applicable |
| Sampling bias (selection bias) | Unclear risk | Undergraduate courses were selected at random from Registrar's list. Explanation of randomization not reported |
| Blinding of participants and personnel (performance bias) All outcomes | High risk | Not applicable |
| Blinding of outcome assessment (detection bias) All outcomes | Unclear risk | Self‐reported smoking |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Expected outcomes reported |
| Selective reporting (reporting bias) | Unclear risk | Analysis limited to 2 groups containing active smokers |
| Other bias | Unclear risk | Self‐reported smoking status No control group and unclear whether downward trend in smoking related to policy or anti‐smoking activity |