The utility of the Pittsburgh Sleep Quality Index in US military personnel

Sleep disturbances are endemic in military personnel with nonclinical populations averaging 6 hours of sleep. The Pittsburgh Sleep Quality Index (PSQI), however, has not been validated in this population. It is thus unknown if the PSQI can differentiate clinically significant sleep disorders from sleep disturbances resulting from military duties with restricted sleep periods. After a clinical evaluation and polysomnogram, participants (N = 148) were classified as having insomnia only, obstructive sleep apnea (OSA) only, comorbid insomnia and OSA (CIO), service-related illnesses only (SRI–; pain, depression, posttraumatic stress disorder, traumatic brain injury), and controls. Military personnel in the insomnia only, and the CIO groups had higher PSQI scores (13.5 ± 2.8 and 14.7 ± 3.5, respectively) compared to the controls (8.9 ± 3.9). A cut-off score of ≥10 was optimal (90% sensitivity and 69% specificity) for determining clinically significant insomnia (≥12 for CIO; 84% sensitivity, 77% specificity). In military personnel, a PSQI score >5 is not necessarily indicative of a clinically significant sleep disorder. The use of elevated cut-off PSQI scores are likely better suited to differentiate military personnel who require further clinical evaluation versus a more conservative sleep improvement protocol.