3.4.4. Blinding
The subjects were asked to guess their group allocations (FIR pajamas, sham pajamas, or no idea). Although the proportions of subjects with no idea which pajamas they had received were similar (25% vs. 26.3%), a significantly higher proportion of subjects in the intervention group guessed that they had received FIR pajamas (60.0% vs. 15.8%, chi-squared test, 