Five studies were included in the review: two RCTs (573 participants) and three cross-sectional studies (436 participants). The RCTs were considered to be at low risk of bias with all criteria addressed adequately. The cross-sectional studies were classed as moderate (two studies assessed as inadequate on sample representativeness and response rate ) to low risk of bias (one study).
Favourable differences in health care utilisation between intervention and control groups were reported in terms of fewer negative thoracic imaging tests that imparted more than 5mSv radiation (9% versus 20%, 95 % CI for the difference 3.8% to 18%; one RCT), reduced cardiac stress testing (75% versus 91%, absolute difference 16%, 95% CI 15% to 18%; one RCT) and fewer ED revisits within seven days (4% versus 11%, 95% CI for the difference, 2.5% to 13.2%; one RCT). There were no differences between groups on median length of stay and adverse cardiac events after hospital discharge (two RCTs). Compared to standard care, knowledge was increased in relation to short-term risk of acute coronary syndrome and radiation exposure (mean difference between groups 0.67, 95% CI 0.34 to 1.0; one RCT). Satisfaction with the clinician's explanation improved between intervention and control (49% versus 38%, 95% CI 0.9% to 21%; one RCT).
Cross-sectional studies demonstrated the relevance of parental preference in relation to choice of hydration method for their child (one study) and in highlighting the importance of being involved in decision making (two studies).