Overnight call is associated with poor resting heart rate and heart rate variability in orthopaedic surgeons

Objectives The purpose of this study was to determine orthopaedic surgery residents' and attending surgeons' resting heart rate (RHR) and heart rate variability (HRV) and if there is a correlation between subject-specific variables (age, attending surgeon, resident, postgraduate year (PGY) level, gender, number of calls, total hours worked, and total hours of sleep) and surgeon RHR and HRV. Methods Orthopaedic surgery residents and attending surgeons at a single institution were prospectively enrolled and provided a validated wearable device to determine hours of sleep, RHR and HRV. Demographic information, hours worked and overnight calls were recorded. Bivariate correlations were determined using the Spearman rank correlation. Multiple linear regression models were constructed to determine the effect of relevant variables. All p values were reported, and a significance level of alpha =0.05 was used (p<0.05). Results Twenty-one of 26 enrolled subjects completed the 4-week study. The average RHR and HRV for orthopaedic surgeons was 61.8+10.0bpm and 42.96+21.2ms, respectively. Residents had a significantly higher RHR (66.4+8.4 vs 55.6+8.9, p=0.011) compared with attending surgeons. Overnight calls had the strongest association with decreased HRV (r=-0.447; p=0.038), moderate positive correlation with RHR (r=0.593; p=0.005) and weak negative correlation with HRV (r=-0.469; p=0.032). There was no significant correlation between PGY level, gender, total hours worked and total hours of sleep with RHR or HRV. Conclusion Orthopaedic surgeons have poor RHR and HRV. Additionally, the number of overnight calls had the strongest correlation with worse RHR and HRV. Level of evidence Level II; diagnostic, individual cross-sectional study with a consistently applied reference standard.