Assessment of participation biases for a confidential non-anonymous adolescent study: A based population study

•A non-anonymous adolescent study using home contact data may receive a participation rate of 60%.•Factors reducing the participation rate were: male gender, non-European immigrant, single parent, low parents’ education and manual-worker family.•They also included body-mass-index measurement refusal, no regular physical/sports activity, poor social relationships and poor living environment.•They further included low academic performance, school dropout ideation, cannabis and other illicit drugs use, sexual abuse and suicidal ideation in bivariate analysis.•These findings help understand participation risk patterns in adolescent studies. A prospective study often receives a low participation rate that may alter the results quality. This study assessed the participation bias for a confidential non-anonymous adolescent survey among 1559 middle-school adolescents from north-eastern France (mean age 13.5 ± 1.3). They completed an anonymous questionnaire gathering demographic/socioeconomic features as well as school, behavior and health-related difficulties, and adolescent's assent to participate with perceived parents’ consent (APC) if they were contacted for a confidential non-anonymous survey at home. Such a survey received an APC of 60%. The logistic model including all socioeconomic factors and school, behavior and health-related difficulties showed that the adolescents with APC were less often male (adjusted odds ratio = 0.77, p = 0.014), non-European immigrant (0.48, p = 0.016), living with a single parent (0.72, p = 0.046), in manual-worker families (0.69, p = 0.007), had less often low parents’ education (0.70, p = 0.002), body-mass-index measurement refusal (0.60, p = 0.010), no regular physical/sports activity (0.70, p = 0.035), poor social relationships (0.73, p = 0.046) and poor living environment (0.63, p = 0.007). The percentage of subjects with APC steadily decreased with the number of these criteria: from 74% for 0 criterion to 19% for 6–8 criteria. Because of these possible strong participation biases the construction of adolescent cohorts and the results interpretation should be made with prudence.