Self-reported data in environmental health studies: mail vs. web-based surveys

Area of Science:

• Epidemiology
• Survey Methodology
• Public Health

Background:

• The internet facilitates epidemiological surveys, offering a cost-effective alternative to traditional methods.
• Mixed-mode approaches combine Web-based surveys with other modes, allowing participant choice.
• Different survey modes can yield varying responses, posing challenges for mixed-mode validity.

Purpose of the Study:

• To statistically compare mixed-mode survey responses from mail and Web methods.
• To analyze differences in socio-demographic characteristics between mail and Web respondents.
• To assess the impact of reminder letters on response rates across modes.

Main Methods:

• A cross-sectional study in non-urban Denmark compared mail and Web survey responses.
• Statistical analyses included t-tests, Chi-squared tests, and multinomial logistic regression.
• Key comparisons focused on response rates, demographics, health symptoms, and attitudes.

Main Results:

• Mail surveys led to higher reporting of health symptoms and negative environmental attitudes.
• Socio-demographic characteristics significantly differed between mail and Web respondents.
• Reminder letters were more effective in boosting Web survey response rates.

Conclusions:

• Mail and Web surveys can yield different responses and reach distinct respondent groups.
• The trade-off between increased response rates and potential measurement changes in mixed-mode surveys requires careful consideration.
• Future survey studies should weigh the benefits of mixed-mode approaches against potential data variations.