Assessment and diagnosis of insomnia in non-pharmacological intervention studies

A number of non-pharmacologic interventions have been developed and studied for the treatment of primary insomnia in adults. Fifty-four non-pharmacological intervention studies published over the last 20 years were reviewed to determine how primary insomnia was assessed and to characterize patients participating in the studies. The main objectives were to inform clinicians who look to the literature for information on the treatment of insomnia about selection and diagnosis of participants, and to examine differences between clinic-based and research-based studies. Mean age for all patients was 47 years; 65% were women. Studies typically used interview procedures to assess participants. The most common exclusion criteria overall was insomnia secondary to medical illness or psychiatric disorder. Methods for assessing these criteria varied widely across studies. Inclusion most commonly required a 6-month duration of insomnia, and sleep difficulty at least 3 nights per week. There were significant differences between clinic- and research-based studies in the screening assessments, exclusion criteria, and participant drop-out rate. The heterogeneity in assessment and diagnosis complicates comparison across studies. Some studies were more likely to include severe insomnia sufferers and/or individuals with secondary insomnia. Comprehensive assessment and complete reporting of research methods is essential to determining the relative efficacy and clinical utility of interventions. Clinicians should be aware of the differences across studies from research vs. clinical settings. To enhance the generalizability of research-based studies to clinical practice, careful screening and description of study participants is essential. When participants are well-described, research-based studies can be useful and informative to clinicians.