Purpose: Differences in respondent characteristics may lead to bias in prevalence estimates and bias in associations. Both forms of non-response bias are investigated in a study on psychosocial factors and cancer risk, which is a sub-study of a large-scale monitoring survey in the Netherlands.
Methods: Respondents of a cross-sectional monitoring project (MORGEN; N = 22,769) were also asked to participate in a prospective study on psychosocial factors and cancer risk (HLEQ; N = 12,097). To investigate diverse aspects of non-response in the HLEQ on prevalence estimates and associations are studied, based on information gathered in the MORGEN-project.
Results: A response percentage of 45% was obtained in the MORGEN-project. Response rates were found to be lower among men and younger people. The HLEQ showed a response percentage of 56%, and respondents reported higher socioeconomic status, better subjective health and healthier lifestyle behaviors than non-respondents. However, associations between smoking status and either socioeconomic status or subjective health based on respondents only were not statistically different from those based on the entire MORGEN-population.
Conclusion: Non-response leads to bias in prevalence estimates of current smoking, current alcohol intake, and low physical activity or poor subjective health. However, non-response did not cause bias in the examined associations.