Research Brief: The authors of this study set out to determine if telephone follow-up during the course of brief intervention for alcohol increased the retention for follow up screenings.
Objectives. Telephone follow-up is not currently recommended as a strategy to improve retention in randomized trials. The aims of this study were to estimate the effect of telephone follow-up on retention, identify participant characteristics predictive of questionnaire completion during or after telephone follow-up, and estimate the effect of including participants who provided follow-up data during or after telephone follow-up on balance between randomly allocated groups in a trial estimating the effect of electronic alcohol screening and brief intervention on alcohol consumption in hospital outpatients with hazardous or harmful drinking.
Method. Trial participants were followed up six months after randomization (June – December 2013) using emails containing a hyperlink to a web-based questionnaire when possible and by post otherwise. Telephone follow-up was attempted after two written reminders and participants were invited to complete the questionnaire by telephone when contact was made.
Results. Retention before telephone follow-up was 62.1% (520/837) and 82.8% (693/837) afterward: an increase of 20.7% (173/837). Therefore, 55% (95% CI 49% to 60%) of the 317 participants who had not responded after two written reminders responded during or after the follow-up telephone call. Age < 55 years, a higher AUDIT-C score and provision of a mobile/cell phone number were predictive of questionnaire completion during or after telephone follow-up. Balance between randomly allocated groups was present before and after inclusion of participants who completed the questionnaire during or after telephone follow-up.
Conclusion. Telephone follow-up improved retention in this randomized trial without affecting balance between the randomly allocated groups.