Clustering of noncommunicable disease risk factors among adolescents attending higher secondary schools in Kasaragod District, Kerala, India [version 2; peer review: 1 approved with reservations].

Background: Limited evidence exists on the presence of collective non-communicable disease (NCD) risk factors among adolescents in Kerala, India. We aimed to assess the prevalence and factors associated with multiple NCD risk factors and the clustering of these risk factors among adolescents in Kasaragod District, Kerala. Methods: We selected 470 adolescents (mean age 16.6 years, male 53.8%) through multi-stage cluster sampling from higher secondary schools of Kasaragod district. Self-administered questionnaires were used, and anthropometric measurements were taken using standard techniques and protocols. Tobacco use, alcohol consumption, low fruits and vegetable consumption, inadequate physical activity, extra salt intake, overweight, consumption of soft drinks and packed foods were the eight NCD risk factors included.The factors associated with one, two and three or more NCD risk factors were analysed using multinomial logistic regression and the standard errors were adjusted for the four clusters. Results: Risk factor clusters with two risk factors (dyads) and three risk factors (triads) were observed in 163 (34.7%) and 102 (21.7%) of the sample, respectively. Adolescents residing in urban areas (odds ratio (OR) = 3.55; 95% confidence interval (CI) = 1.45-8.73), whose father's education level was lower (OR = 3.54; 95% CI = 1.24-10.10), whose mother's education was lower (OR= 4.13; 95% CI = 1.27-13.51), who had restrictions on physical activity (OR = 5.41; 95% CI = 1.20-24.30) and who did not have a kitchen garden (an area where fruits and vegetables are grown for domestic use) (OR=4.51;95% CI = 1.44-14.12) were more likely to have three or more NCD risk factors compared to their counterparts. Conclusions: Clustering of NCD risk factors was prevalent in more than half of the adolescents. Efforts are warranted to reduce multiple risk factors, focussing on children of low educated parents and urban residents.