Logistic regression analysis of risk factors for post-operative morbidities in parotidectomy: a retrospective cohort study

Objective In this study, we reviewed the post-operative complications in parotidectomy and its association with various patient, tumour and surgical factors. Methods All parotidectomies performed in our regional unit between 2013 to 2020 were identified. Electronic medical record and clinic letters were reviewed for any post-operative complications. A logistical regression model was applied on data collected on twelve patient factors, three tumour factors and four surgical factors. Results 379 cases of parotidectomy were identified in the eight-year study period. 55% ( n = 210) were documented with nine types of post-operative complications. This study identified age >80 (odds ratio = 1.89, p = 0.018), active smoker (odds ratio = 0.94, p = 0.018), total parotidectomy approach (odds ratio = 1.77, p = 0.012), longer operation time (odds ratio = 0.006, p = 0.015) and hypertension (odds ratio = 1.23, p = 0.019) were associated with a higher risk of facial nerve palsy. Predictive factors were also identified for auricular nerve numbness and Frey syndrome. Conclusion This study revealed the incidences and potential predictors of post-operative complications in parotidectomy. Notably, the grade of operator (consultants/ registrars) had no effect on the possibility of adverse outcome, reflecting patient safety was not compromised for training. These findings can be used in patient counselling and guide treatment options to minimise post-operative complications.