Background Telephonic interactive voice response (IVR) systems and Internet-based surveys have provided new methods of collecting longitudinal data for injury researchers. A choice of multiple survey modes has been shown to increase response rate. Different survey methods can lead to different responses to same questions.

Objectives This study examined data equivalency and loss to follow-up rate from these two survey modes.

Methods 475 workers from 36 limited-service restaurants participated in a 12-week prospective-cohort study of slipping. Participants were given a choice of reporting their weekly experience by telephone using an IVR system, Internet-based survey, or by completing and mailing postal questionnaire forms. All survey materials were made available in three languages: English, Spanish and Portuguese. Demographic differences, loss to follow-up and reported rate of slipping were compared among those who chose internet-based survey and IVR.

Results Out of 475 participants, 315 chose IVR (66.3%), 154 chose internet-based survey (32.4%), and 6 chose paper based survey (1.3%) to complete their weekly surveys. Younger participants, English speakers, high school students and college graduates were more likely to choose the Internet-based survey mode over the IVR mode. Loss to follow-up rate was not significantly different by survey mode. Rate of slipping was also not significantly different by survey mode (RR 0.78 95% CI 0.57 to 1.06).

Significance Results provided no evidence of differential loss to follow-up or difference in the reported rate of slipping by survey mode. It should be possible to combine Internet-based survey and IVR to collect longitudinal information about injury causing events and near misses.