Turkish Motivation and Energy Inventory–Short Form in obstructive sleep apnea: factor structure, reliability, and concordance with hospital anxiety and depression scale

Purpose: The Motivation and Energy Inventory–Short Form (MEI-SF) is an 18-item self-report measure of motivation and energy in clinical populations; however, the psychometric properties of its Turkish adaptation (MEÖ-KF) have not been examined in patients with obstructive sleep apnea syndrome (OSAS). This study aimed to evaluate the factor structure, internal consistency, and criterion validity of the MEÖ-KF and to assess its utility for screening sub-syndromal anxiety and depressive symptoms in treatment-naïve patients with OSAS.Materials and Methods: Treatment-naïve patients with OSAS (N = 95; comorbid psychiatric disorders excluded by structured interview) completed the MEÖ-KF, the Hospital Anxiety and Depression Scale, and the Chalder Fatigue Scale. Six confirmatory factor models—including the developer-specified three-factor structure—were tested using maximum-likelihood estimation; a diagonally weighted least-squares sensitivity analysis was attempted but did not yield interpretable fit indices at this sample size. A receiver operating characteristic analysis was conducted using apparent, 10-fold cross-validated, and bootstrap-optimism-corrected estimates. Williams’ t-test and a bootstrap confidence interval for the difference between standardized coefficients were used to test the differential predictive strength of anxiety and depression.Results: Internal consistency was high for the total scale (Cronbach’s α = .91; McDonald’s ω = .91) and the Energy and Motivation factor (α = .92), but was lower for the Social Motivation factor (α = .61). Convergent correlations ranged from moderate to strong (anxiety: ρ = .67; depression: ρ = .59; fatigue: ρ = .71). Confirmatory model fit was sub-threshold across all six configurations, including the three-factor model (comparative fit index = .75), in which the standardized correlation between mental and physical energy reached r = .93. Concordance with sub-syndromal symptoms was high (area under the curve [AUC] = .86 for anxiety and .90 for depression), although the depression estimate was threshold-dependent (AUC = .75 at HADS-D ≥ 7). In a joint regression model, anxiety and depressive symptoms were independently associated with motivational–energetic impairment (R² = .60), although the difference favoring anxiety was not statistically significant (Δβ 95% CI [−.498, +.114]).Conclusion: Within these boundary conditions—single-center recruitment, modest sample size, psychiatric exclusion by structured interview, and sub-threshold confirmatory fit—the MEÖ-KF shows promise as a screening adjunct for sub-syndromal anxiety and depressive symptom burden in OSAS; however, it is not yet ready for routine clinical use. Item-level refinement of the social motivation subscale and large-sample (N ≥ 300) replication with adequately powered, ordinal-estimator confirmatory factor analysis are the required next steps.