Oral and hand hygiene practices among adolescents aged 12-17 years in 72 countries: a cross-sectional study using...

Oral and hand hygiene constitute fundamental determinants of adolescent health. However, globally comparable estimates of these behaviours remain limited. We aimed to estimate the prevalence of toothbrushing and handwashing practices among adolescents aged 12-17 years and to quantify disparities by sex, age, geographical region, and national income level.

We used nationally representative data from the Global School-based Student Health Survey (GSHS) collected between 2010 and 2019, covering 244,040 adolescents from 72 countries. Toothbrushing frequency was categorised as <1 time/day, 1 time/day, and ≥2 times/day. Hand hygiene was assessed via three items: never or rarely washing hands before eating, after using the toilet, and using soap. The overall, subgroup-specific, and country-specific prevalence estimates were calculated accounting for primary sampling units, strata, and sampling weights.

The overall prevalence of brushing teeth <1 time/day was 10.9% (95%CI = 10.0-11.8), ranging from 2.6% in Benin to 35.2% in Yemen. Brushing ≥2 times/day was reported by 70.5% (68.8-72.0). Never or rarely washing hands before eating, after toilet use, and using soap were reported by 6.5% (6.1-7.0), 5.5% (5.1-5.9), and 9.0% (8.5-9.5), respectively. Boys exhibited inferior hygiene practices relative to girls (for instance, brushing <1 time/day: 13.1% vs. 8.6%; never/rarely using soap: 10.4% vs. 7.6%). Younger adolescents (12-14 years) showed a higher prevalence of inadequate brushing (12.2% vs. 9.4%) but marginally better handwashing before eating than older adolescents (15-17 years). The Eastern Mediterranean Region displayed the highest prevalence of inadequate brushing (30.7%), whereas the Region of the Americas showed the lowest (5.3%). A marked economic gradient was observed for toothbrushing (inadequate brushing declined from 12.5% in the poorest quintile to 4.4% in the richest), but hand hygiene showed no monotonic income gradient.

Inadequate oral and hand hygiene practices remain prevalent among adolescents globally, with substantial heterogeneity by sex, age, region, and national income. Targeted school-based interventions, particularly for boys and in low-income and Eastern Mediterranean countries, are urgently needed.