Temporal trend of simultaneous risk factors for chronic non-communicable diseases: National School Health Survey...

To analyze the temporal trend of simultaneous occurrence of behavioral risk factors for chronic non-communicable diseases in Brazilian school adolescents.

Ecological time-series study that analyzed data from the three editions of the National Survey of School Health with students in the 9th year of public and private schools. Cluster analysis was performed to identify the simultaneity of the following factors: irregular consumption of fresh or minimally processed foods, regular consumption of processed and ultra-processed foods, insufficient level of physical activity during leisure time, consumption of alcoholic beverages, use of cigarettes and illicit drugs. The cluster trend was tested using simple linear regression.

The sample was composed of 173,310 school adolescents. Sixty-four possible combinations were evaluated, resulting in the formation of six clusters. The grouping formed by all factors showed the highest ratios observed/expected prevalence in the last two years of the series. The highest ratios were observed for combinations in which alcohol and cigarettes were present. These substances integrated five of the six clusters. One of the groups (insufficient level of physical activity during leisure time + consumption of alcoholic beverages + use of cigarettes and illicit drugs) had an upward trend throughout the series.

The trend analysis showed four out of six clusters remaining stable throughout the series, which shows that the factors are persistently present among school adolescents.