To Örebro University

Introduction: The increasing prevalence of psychological health problems among adolescent girls is alarming. Knowledge of beneficial effects of physical activity on psychological health are widespread. Dance is a popular form of exercise also known to increase a sense of self-control which can contribute to reduced stress. The purpose of this study was to investigate if dance intervention for adolescent girls with internalizing problems influenced self-rated health. A secondary aim was to assess the cost-effectiveness of the intervention in addition to usual school health services, compared with usual school health services alone.

Methods: Randomized controlled intervention trial with follow-up measures of self-rated health at 8, 12 and 20 months after baseline. A total of 112 girls, 13–18 years old, with internalizing problems, i.e. stress and psychosomatic symptoms, were randomized to intervention group or control group. The intervention comprised dance classes twice weekly during 8 months. Each dance class lasted 75 minutes and the focus was on the joy of movement, not on performance. Costs for the stakeholder of the intervention, treatment effect and healthcare costs were considered. Gained quality-adjusted life-years (QALY) were used to measure the effects. Quality of life (QOL) was measured with the Health Utility Index Mark 3 (HUI 3). Cost-effectiveness ratios were based on the changes in QALY and net costs for the intervention group compared with the control group. Net monetary benefit (NMB) was also calculated.

Results: A year after baseline 65% of the girls in the intervention group and 32% of the girls in the control group had increased their self-rated health. The differences in change score between groups were significant at all follow-ups. After 8-months U = 895.5 (P = .037), after 12-months U = 680.0 (P = .001), and after 20-months U = 801 (P = .022).

Cost effectiveness showed that after 20 months, QOL had increased by 0.083 units more in the intervention group than in the control group (P = .04), translating to 0.095 gained QALY. The cost-effectiveness ratio was $7187.4 and the NMB was $3846.0 (Willingness to pay $50 000 for a gained QALY).

Discussion: This study suggests that an 8-month dance intervention can improve self-rated health for adolescent girls with internalizing problems. The improvement remained a year after the intervention. The intervention in addition to usual school health services showed cost-effectiveness compared with usual school health services alone. The cost-effectiveness ratio was far below the recommended threshold value.