Content Comparison of Quality-of-Life Instruments Used in Economic Evaluations of Sleep Disorder Interventions: A Systematic Review

Background Assessment of quality of life (QoL) in people living with sleep disorders using questionnaires is necessary to compare intervention benefits. Knowledge of the content and concepts covered by specific QoL instruments is essential to determine which instruments are best suited for conducting economic evaluations of sleep-related interventions. Objectives This review aims to identify the QoL instruments that have been applied in economic evaluations of sleep disorder interventions and compare their conceptual overlap and content coverage using the framework of the International Classification of Functioning, Disability and Health (ICF). Methods A systematic review of full economic evaluations in sleep published in peer-reviewed journals from conception to 30 May, 2023 was conducted. MEDLINE, PsychInfo, ProQuest, Cochrane, Scopus, CINAHL, Web of Science and Emcare were searched for eligible studies. Studies incorporating either generic or sleep-specific QoL instruments as the primary or secondary measures of effectiveness within a full economic evaluation were included. Quality appraisal against the JBI Critical Appraisal Checklist for Economic Evaluations and EURONHEED checklists and mapping of QoL items to ICF categories were performed by two reviewers, with a third helping settle any potential differences. Results Sixteen instruments were identified as having been used in sleep health economic evaluations. The EQ-5D-3L, Epworth Sleepiness Scale, and Insomnia Severity Index were the most widely used, but the latter two are predominantly diagnostic tools and not specifically designed to guide economic evaluations. Other instruments with broader ICF content coverage have been least used, and these include the Sleep Apnea Quality of Life Index, Functional Outcomes of Sleep Questionnaire, 15 Dimensions, Short-Form 6 Dimensions, 12-item Short Form Survey, 36-item Short Form Survey and the GRID Hamilton Rating Scale for Depression. Conclusions This study provides an overview of current QoL instruments used in economic evaluations of sleep with respect to their content coverage. A combination of generic and sleep-specific instruments with broader ICF content coverage is recommended for such evaluations.