How to encourage smokers to participate in web-based computer-tailored smoking cessation programs: a comparison of different recruitment strategies

The reach, retention and costs of four strategies aimed to recruit smokers for participation in a computer-tailored smoking cessation intervention was explored. The study was part of a randomized controlled trial whereby 832 respondents were randomized to three conditions. Smokers were invited by general practitioners (GPs), newspapers, Internet and other strategies (i.e. mailing organizations) to take part. ANOVA's/Chi-square tests explored sample differences. Logistic regression analyses investigated differences between the samples regarding retention and smoking behaviour. Smokers recruited via GPs (N = 144) had a lower educational level and suffered more from chronic obstructive pulmonary disease compared with respondents recruited via Internet (N = 307) (chi(2) = 11.554, df = 3, P = 0.009). Less motivated respondents recruited by GPs were more likely to return to study compared with the less motivated respondents recruited by 'other recruitment' strategies (chi(2) = 6.416, df = 3, P = 0.093). Highly addicted respondents recruited from newspapers (N = 213) were less likely to make a quit attempt compared with highly addicted respondents recruited by GPs (OR = 0.334, P = 0.035). Females from newspapers were less likely to remain abstinent compared with the GP sample (OR = 0.337, P = 0.005). Recruitment via GPs showed highest costs. Recruitment strategy influenced the type of smokers. Group differences were associated with different patterns of quitting.