Predictive validity of the Belfast rule of thumb and patient-reported outcomes following ossiculoplasty

BACKGROUND: The Belfast Rule of Thumb (BRT) is a tool used to estimate subjective hearing improvement based on binaural hearing following middle ear surgery, however, evidence for its association with patient-reported outcomes remains limited. AIMS/OBJECTIVES: To assess the predictive validity of BRT for subjective hearing improvement following ossiculoplasty and to identify additional factors influencing surgical satisfaction. MATERIALS/METHODS: Data were obtained from the Swedish Quality Registry for Ear Surgery. Audiometric results from 340 patients who underwent ossiculoplasty between 2013 and 2019 were analysed in relation to patient‑reported outcome measures. RESULTS: BRT criteria were met by 61.5% of patients, of whom 80.9% reported subjective hearing improvement. The BRT showed a positive predictive value of 80.9% (95% CI, 75.0-85.6), negative predictive value of 59.5% (95% CI, 51.0-67.6), sensitivity of 76.1%, and specificity of 66.1%. Overall, 77.3% of patients were satisfied with surgery. Hearing improvement was the strongest predictor of satisfaction, while postoperative ear discomfort, tinnitus, and water intolerance were the most common adverse factors. CONCLUSION/SIGNIFICANCE: The BRT is a useful tool for preoperative counselling in ossiculoplasty. However, failure to meet its criteria does not preclude meaningful postoperative benefit. Patient satisfaction is influenced by factors beyond hearing improvement, including perioperative care and complications.