Nonresponse in a follow-up to a representative telephone survey of adult drinkers

Objective: Examined predictors of nonresponse among respondents who agreed to receive a follow-up questionnaire on alcohol use after participating in a representative telephone survey, and among respondents who did and did no t return the follow-up questionnaire. 12 Method: A total of 2,072 (52.2% female) respondents to a representative mon thly telephone survey were assessed on sociodemographic variables and alcoh ol use. Respondents were asked whether they would be willing to fin out an additional mailed questionnaire on alcohol use and attitudes toward drinkin g. Almost half (n = 956; 46%) of respondents agreed to participate in the f ollow -up survey; 430 (45%) of those individuals completed and returned the questionnaire. Results. Agree ment to receive the follow-up questionnaire was unrelated to alcohol use. Regarding gender, men were 1.42 times more likely than women to exhibit nonresponse in returning the follow-up questionnaire (95% CI: 1. 08-1.42). After adjusting for the impact of demographic factors, re sponden ts who consumed alcohol at least once per week were 1.43 times more likely than respondents who drank less frequently to exhibit nonresponse in return ing the questionnaire (95% CI: 1.05-1.93). Respondents who consumed five or more standard drinks at least once per week were 1.83 times more likely to exhibit nonresponse in returning the questionnaire, compared with responde nts who engaged in heavy drinking less frequently (95% CI: 1.15-2.92). Conclusions: Mailout questionnaires following a representative telephone su rvey may bias samples toward obtaining fewer men, fewer weekly drinkers and fewer heavier drinkers. Although the magnitude of these biases were relati vely small, epidemiological studies on alcohol use may wish to oversample m en and heavier drinkers in follow-up studies recruiting from population sur veys.