Effects of statewide health promotion in primary schools on children's sick days, visits to a physician and parental absence from work: a cluster-randomized trial

Background: Based on the World Health Organization's global school health initiative we investigate intervention effects of statewide health promotion in schools on the numbers of children's sick days and visits to a physician, and parental days off work due to child illness.

Methods: Cluster-randomized trial with 1-year follow-up in primary schools in the state of Baden-Württemberg, Germany. Anthropometric measurements of first and second grade school children were taken by trained staff. Parents filled in questionnaires for information about socio-demographics, health-related variables, numbers of children's sick days, visits to a physician, and days parents had to stay off work to care for a sick child. Longitudinal differences in the outcome variables were calculated between baseline and follow-up. Intraclass correlation coefficients were determined to quantify a possible clustering of data in schools. Accordingly, linear models and linear mixed models were applied to identify relationships and ascertain significances.

Results: Data from 1943 children (1^st grade n = 1024, 6.6 ± 0.4 years old; 2^nd grade n = 919, 7.6 ± 0.4 years old) were available at baseline. Unadjusted differences regarding both grades were found between mean longitudinal changes in intervention and control group in children's sick days (-3.2 ± 7.1 vs. -2.3 ± 5.6, p = 0.013), and maternal days off work (-0.9 ± 2.4 vs. -0.5 ± 2.8, p = 0.019). The intervention effect on sick days was adjusted in a linear regression for baseline values, gender and migration background and confirmed for first grade children (B = -0.83, p = 0.003). The intervention effect on maternal days off work lost its significance after adjusting for baseline values. No significant differences were detected in the numbers of children's visits to a physician and paternal days off work.

Conclusions: School-based health promotion slightly reduces sick days in first grade children. Subsequently, parents may not need to stay off work themselves. Small individual effects add up to larger benefits in a statewide implementation of health promotion. Additionally, health promotion may also positively contribute to school success.

Trial registration: The study was registered on the German Clinical Trials Register (DRKS), Freiburg University, Germany, under the DRKS-ID: DRKS00000494 . Registered: 25 August 2010.