College students' response rate to an incentivized combination of postal and web-based health survey.

A questionnaire survey on health among students of higher education was planned. To produce a response rate high enough for the analysis in a cost-effective manner, a pilot study was carried out to test various methods of data collection. Electronic invitation by the university messaging system to fill a Web-based questionnaire, invitation by the same means to fill paper-based questionnaires at a predefined place and time with or without conditional incentives yielded response rates below 10%. Therefore, a combination of postal and Internet-based questionnaires was used for data collection enhanced with a small up-front gift and conditional incentives suggested by a student focus group. This modality resulted in a 68.6% response rate (65.2% after data cleaning). Those who responded through the Web were more likely to be males and residing in larger settlements. However, no statistically significant differences were observed on the primary health status variables with respect to modality. Use of Web-based questionnaires is recommended in combination with other data collection methods and incentives.