Parental consent rules slash survey response rates by a third, study finds
A Norwegian trial found that requiring active parental consent before surveying teens about mental health cut participation by 32 percentage points—a dramatic loss that could skew research findings. The discovery matters for policymakers weighing privacy protections against the risk of collecting incomplete data on adolescent mental health trends.
Originaltitel: Effects of requiring active parental consent on participation, sample composition, and mental health outcomes in school-based adolescent surveys: A cluster randomized trial.
Aktiv föräldrargodkännande i skolhälsoundersökningar reducerar deltagandefrekvensen dramatiskt med 32 procentenheter, visar en norsk randomiserad kontrollerad studie från 20 grundskolor. Forskare randomiserade 259 klasser till antingen aktivt föräldrargodkännande eller elevsamtycke. Online-enkäter om mental hälsa genomfördes hösten 2025. Trots massiv deltagandeminskning vid föräldrargodkännande förblev könsfördelning, ålder och socioekonomisk status nästan identisk mellan grupperna. Elever med två utrikesfödda föräldrar underrepresenterades dock med 7 procentenheter i föräldrargodkännande-gruppen. Institutionen för barns hälsa vid Folkhälsomyndigheten i Oslo och Karolinska Institutet genomförde studien. För beslutsfattare är fyndet kritiskt: försämrad administrativa kostnader och längre datainsamling vägs mot begränsad väljningsfel. Elever med invandrarbakgrund kräver särskild uppmärksamhet vid studiedesign av känslig data.
BACKGROUND: Requiring active parental consent in school-based adolescent surveys may reduce participation rates and introduce response bias, particularly in studies assessing sensitive outcomes such as mental health. However, experimental evidence on its impact remains limited. METHODS: A cluster randomized controlled trial within 20 Norwegian lower secondary schools: 259 classes were randomized to either (1) active parental consent, or (2) adolescent self-consent. Data were collected with online questionnaires administered during school hours in the autumn of 2025. Differences in class-level participation rates were examined, as well as sample composition (sex, age, immigrant background, subjective socioeconomic status) and a broad range of mental health-related measures. The data were analyzed using fixed-effects regression models. RESULTS: Requiring active parental consent substantially reduced participation (average marginal effect: -32.2 percentage points, 95% CI -35.5, -28.8). Despite this large difference, sample composition was highly similar across conditions with respect to sex, age, and socioeconomic status. However, a lower proportion of students with two parents born abroad participated in the active parental consent condition (average marginal effect: -7.1 percentage points, 95% CI -9.4, -4.7). For mental health outcomes, no statistically significant differences were observed. CONCLUSIONS: Requiring active parental consent can markedly reduce participation in school-based adolescent surveys, but it does not appear to meaningfully bias sample composition or estimates of mental health outcomes, although students with immigrant backgrounds may be underrepresented. These findings can inform ethical and methodological debates regarding adolescent autonomy, survey validity, and consent procedures in public health research.