Comparison of Wilson’s Score and Intubation Prediction Score for Prediction of Difficult Endotracheal Intubation: A Prospective Observational Analytical Study

Introduction: Prediction of a difficult airway is of utmost importance, as an unanticipated difficult airway can lead to severe adverse events. Clinically, prediction is done using independent bedside tests; however, these often lack accuracy. Moreover, most airway assessment scores are cumbersome and subject to interobserver variability because of subjective parameters. Wilson’s Score and the Intubation Prediction Score (IPS) are commonly used scoring systems for preoperative airway evaluation. Aim: To determine the diagnostic accuracy of the Wilson Score and IPS in predicting difficult airways. Materials and Methods: This prospective, observational, analytical, single-blind study was conducted among 120 patients aged 18 to 70 years who underwent surgeries requiring endotracheal intubation. All patients underwent airway assessment using both the Wilson Score and IPS. General anaesthesia with endotracheal intubation was performed by an anaesthesiologist who was unaware of the patients’ scores. The ease of laryngoscopy and intubation was assessed using the Intubation Difficulty Scale (IDS), where an IDS score greater than 5 indicated a difficult airway. Sensitivity, specificity, Positive Predictive Value (PPV), Negative Predictive Value (NPV), and overall accuracy of both scoring systems were calculated. McNemar’s test was used to compare diagnostic performance, with p-value <0.05 considered statistically significant. Results: A total of 120 patients were assessed, of whom 58 (48.33%) were male and 62 (51.67%) were female. The mean age and weight of the patients were 40.47±12.14 years and 70.53±13.76 kg, respectively. Sixty-six (55%) patients belonged to American Society of Anaesthesiologists (ASA) Grade I, and 54 (45%) to ASA Grade II. The actual incidence of difficult airway was 11.67%. Wilson’s Score showed a sensitivity of 21.43%, specificity of 93.40%, PPV of 30.00%, NPV of 90.00%, and accuracy of 85.00%. IPS demonstrated significantly better sensitivity (71.43%; p-value=0.014), PPV (83.33%; p-value=0.023), and overall accuracy (95.00%; p-value=0.012). Both systems showed high specificity (IPS: 98.11%; Wilson’s: 93.40%; p-value=0.172), while NPV was higher for IPS (96.30% vs. 90.00%; p-value=0.057). Conclusion: The IPS outperforms Wilson’s Score in predicting difficult endotracheal intubation, particularly in terms of sensitivity, PPV, and overall accuracy. Incorporating IPS into routine preoperative assessment may enhance patient safety. Therefore, it can be preferred as a simple and accurate bedside tool for predicting difficult airways in patients undergoing endotracheal intubation under general anaesthesia.