Crossover Studies of Pediatric Dental Sedation are Inappropriate.

Crossover studies continue to be published in spite of warnings about their inherent risks in relation to behavioral outcomes. This study took the opportunity of access to secondary data analysis in order to demonstrate the impact of a crossover design on the outcomes of randomized clinical trials aimed at the behavior of children during dental treatment. We evaluated the effect of the sequence of sedative administration, the sedative and the participant's age on the behavior of children undergoing two sequential dental visits. Eighteen uncooperative healthy young children were equally randomly assigned to: (G1) 1.0 mg/kg oral midazolam (first session) and oral placebo (second session); (G2) oral placebo (first) and 1.0 mg/kg oral midazolam (second). One trained observer assessed children's behavior. Data were analyzed by three-way mixed ANOVA. Both midazolam [mean(SD); 71.7%(16.5)] and placebo [48.6%(33.1)] produced more struggling behavior when they were administered in the first session compared to the second one (p=0.001). For the placebo, children aged 2-3 years exhibited more struggling behavior [G1 54.9%(36.2); G2 80.5%(8.3)] than those aged 4-5 years (p=0.04). Also, the reduction of percentage of struggling behavior was higher in G1 for older children (76.2%) and in G2 for younger children (32.9%). There were significant interactions between drug and sequence of administration, and between drug and age. The results of our study confirm the conventional wisdom that crossover study design is inappropriate to evaluate children's behavior/anxiety related-dental treatment under sedation and the results of crossover studies of dental sedation should be treated with extreme caution.