A double-blind randomised controlled study of a brief intervention of bedtime restriction for adult patients with primary insomnia

INTRODUCTION: Bedtime restriction is effective for volunteer patients with primary insomnia. AIM: To determine the effectiveness of bedtime restriction in adult volunteers with primary insomnia. METHODS: Patients were recruited in response to articles in local newspapers. The study hypothesis was not given in the articles. Patients were assessed as to whether or not they had primary insomnia. They completed a two-week sleep diary after which they met the investigators and were randomised to either bedtime restriction and basic sleep hygiene or the control group with basic sleep hygiene only. A total of 224 potential participants applied to be in the study. Of the 52 who had primary insomnia, 45 were randomly allocated to either control or intervention group and only two did not complete the study. Randomisation was concealed and participants were blinded regarding the treatment. The primary outcome was also measured in a blinded fashion. RESULTS: The outcome evaluated was patient description of 'better' or 'much better' quality of sleep versus the 'same', 'worse' or 'much worse' quality of sleep at six weeks. Overall, 73% (16/22) of those in the intervention group were either having better or much better quality of sleep after treatment, while in the control group this was 35% (8/23). The number needed to treat was 3 [95% CI 2-11] for bedtime restriction and sleep hygiene versus sleep hygiene alone. DISCUSSION: This is the first study using bedtime restriction designed to be feasible in primary care by using a brief intervention and a patient-oriented outcome.