Background

More than 80% of patients seeking metabolic and bariatric surgery (MBS) report disturbance in at least one area of sleep function (Salwen-Deremer, et al, 2021). No studies have assessed the psychometric properties of sleep measures in bariatric samples. This study assessed the reliability and validity of the Pittsburgh Sleep Quality Index (PSQI) and the Insomnia Severity Index (ISI) in a large, racially diverse sample of patients seeking MBS. Participants (N = 845) were primarily female (83.7%) with a mean age of 41.8 (11.1) years, and identified as African-American (53.8%), Asian-American (0.4%), Caucasian (34.7%), Hispanic (3.8%), Multi-racial (5.4%), and Other (1.9%). Mean BMI was 47.6 (9.0) kg/m2. The PSQI, ISI, and the Quick Inventory of Depressive Symptomatology (QIDS) were administered at the pre-surgical psychiatric evaluation; demographic and clinical data were abstracted from the electronic medical record. Internal consistency for the PSQI (0.74) and the ISI (0.88) were at least adequate, and consistent with values observed in the general population. The PSQI and ISI were strongly correlated with each other (r = .80, p < .001), and with the QIDS (p < .001). Notably, the PSQI and ISI were moderately correlated with QIDS items assessing sleep function (p < .001), but not correlated with items assessing appetite change (p > .05). Participants diagnosed with sleep apnea were more likely to score in the clinically significant range on the PSQI and ISI (p < .01), indicating convergent validity. Results support the reliability and validity of the PSQI and ISI for patients undergoing MBS.