Deterioration is not the only prospect for adolescents' health: improvement in self-reported health status among boys and girls from age 15 to age 19.

AIM: To assess changes in the mental and physical health of adolescents between the ages of 15 and 19.
METHODS: The study included a four-year follow-up of 844 students from 31 secondary schools located in Kosice, Slovakia (response rate 45.6%). The 36-item short form (SF-36) scales were used to assess vitality and mental health, self-rated health, long-term well-being, long-standing illness, and the number of perceived health complaints at the age of 15 and four years later.
RESULTS: Both boys and girls reported significant deterioration in vitality (mean difference boys 5.3; girls 3.3; P=0.001) and mental health (mean difference boys 7.7; girls 5.7; P=0.001), while only boys reported deterioration in self-rated health (P=0.047). The proportion of boys who reported an improvement ranged from 8%-40%, while the proportion of girls who reported an improvement ranged from 8%-45%. Significantly more girls than boys reported an improvement in mental health (27% of boys vs 34% of girls) and vitality (32% of boys vs 39% of girls), while more boys than girls reported a deterioration in vitality(55% of boys vs 48% of girls)). These differences were trivial according to the effect size (Cohen's H<0.20).
CONCLUSION: Although significant deterioration in mental health and vitality was detected among both genders, with boys deteriorating more substantially in self-rated health than girls, the differences between the proportion of those with improved and those with deteriorated status were trivial in size.