Background: We evaluated the diagnostic discrimination of serum endothelin-1 (ET-1), copeptin, and chemerin in adults evaluated for acute pulmonary embolism (PE). Methods: This prospective, single-center diagnostic study included 65 adults with CTPA-confirmed PE and 64 CTPA-negative controls recruited from the same emergency-department source population of patients evaluated for suspected PE. Controls were consecutively enrolled among dyspneic patients in whom CTPA excluded PE; no individual matching was used. Biomarkers were compared with D-dimer and the Wells score. Results: ET-1 was higher in the PE group (median, 12.96 vs. 6.41 pg/mL; p < 0.001) and showed moderate discrimination (AUROC, 0.731; 95% CI, 0.644–0.818), but was inferior to D-dimer (AUROC, 0.905; 95% CI, 0.852–0.958). Adding ET-1 to D-dimer changed the AUROC from 0.905 to 0.923 (DeLong p = 0.128), and adding ET-1 to Wells plus D-dimer changed it from 0.966 to 0.971 (DeLong p = 0.224). An age-adjusted D-dimer threshold preserved sensitivity (96.9%) and increased specificity from 48.4% to 56.3% relative to 0.50 mg/L FEU. Conclusions: ET-1 was associated with acute PE in this selected sample but did not materially improve discrimination beyond established comparators. Because the near-ceiling Wells–D-dimer model and selected sampling frame limit inference, external validation in an unselected diagnostic cohort is required.

Background: Residency combines supervised learning with service delivery, and adverse learning and working conditions may prompt withdrawal while physicians remain in training. We described quiet-quitting scores among resident physicians and examined workplace correlates and associations with burnout, work engagement, and turnover intention. Methods: This single-center cross-sectional study included resident physicians at a tertiary university hospital in Malatya, Türkiye, from 20 to 31 May 2026. Quiet quitting was assessed using the Quiet Quitting Scale for Health Professionals (QQS-HP); burnout, work engagement, and turnover intention were assessed using Turkish-language instruments. Five study-specific items assessed workplace violence during the preceding 12 months. Spearman correlations used Benjamini–Hochberg false-discovery-rate adjustment, and linear regression models used HC3-robust inference. To address construct overlap, sensitivity analyses used the 14-item Employee Disengagement subscale, which excludes six QQS-HP items overlapping with burnout dimensions. Results: The sample comprised 284 residents. The median QQS-HP score was 40 (IQR, 33–48); using the scale-development study’s descriptive bands, 62 residents (21.8%) were in the moderate or severe bands. In the adjusted model, higher scores were associated with psychological violence from managers or senior colleagues (B = 5.59; 95% CI, 2.91–8.28; p < 0.001) and perceived income inadequacy (B = 4.57; 95% CI, 1.45–7.69; p = 0.004). These associations remained evident in the Employee Disengagement sensitivity model. Employee Disengagement correlated with turnover intention (ρ = 0.636), lower work engagement (ρ = − 0.563), emotional exhaustion (ρ = 0.765), and depersonalization (ρ = 0.623; all false-discovery-rate-adjusted p < 0.001). The most frequently reported violence exposures were verbal violence from patients or their relatives (77.1%) and psychological violence from managers or senior colleagues (59.5%). Quiet-quitting scores increased with the cumulative number of violence types experienced (Jonckheere-Terpstra trend test, p < 0.001). Conclusions: In this single-center sample, higher quiet-quitting scores were associated with psychological violence from managers or senior colleagues and perceived income inadequacy. Employee Disengagement was correlated with greater turnover intention, lower work engagement, and higher emotional exhaustion and depersonalization. Multicenter longitudinal studies are needed to evaluate temporal relationships, generalizability, and whether interventions addressing supervisory conduct and working conditions improve resident engagement.