In 2011 an electronical questionnaire study was performed by one of the researchers currently working at NIOM. The survey was distributed to all public dental health-employed dentists in Norway to investigate their opinions, knowledge and diagnosis of dental erosive wear. A response rate of 60% was achieved after two reminders. The questionnaire included a patient case where the dentists were asked which clinical advice they would give the patient and which treatment they recommended.
Questionnaires are often used for data collection in epidemiological studies and are a relatively inexpensive way to collect information for research purposes. The aim of a questionnaire is to generalize replies from a small sample to a larger population. If people do not reply to the questionnaires (so called “non-responders”), the research results will tend to be less accurate. Non-responders reduce the effective sample size and can introduce bias. Thus, when performing questionnaires a crucial point is to obtain a sufficiently high response rate. Some ways to obtain that are presented here. First, the odds of response are almost doubled if the respondents are paid for their participation. However, some more inexpensive factors can be easily adjusted to attract the respondents’ interest.