To estimate the cost-effectiveness of immediate septoplasty compared with 6 months of medical management with the option for delayed septoplasty in individuals with nasal obstruction associated with septal deviation.

Economic evaluation alongside a multicentre, open label, randomised controlled trial.

17 otolaryngology clinics in the UK, recruiting from January 2018 to December 2019.

Adults aged≥18 years with symptoms of nasal obstruction associated with septal deviation with at least moderate symptoms of nasal obstruction (score>30 on the Nasal Obstruction and Symptom Evaluation scale).

Participants were randomised to receive either septoplasty within 12 weeks of recruitment or 6 months of medical management (nasal steroid and saline spray) with the option for delayed septoplasty.

Incremental cost per quality-adjusted life year (QALY) gained at 12 months. A UK National Health Service perspective was adopted, and surgery costs were estimated using a tariff and micro-costing. QALYs were estimated based on responses to the Short Form-36 (SF-36). Seemingly unrelated regression was used to estimate incremental costs and QALYs. A model-based analysis was used to extrapolate costs and effects to 24 months. Sensitivity analyses were used to illustrate uncertainty.

In the within-trial analysis, immediate septoplasty was on average more costly (mean difference (95% CI) £1193 (£1018 to £1368)) and more effective (mean difference (95% CI) 0.044 QALYs (0.03 to 0.06)) when compared with 6 months of medical management with the option for deferred septoplasty. Immediate septoplasty had an incremental cost per QALY gained of £27 114 in the base case analysis, which decreased to £16 682 when micro-costing was used to estimate surgery costs. Immediate septoplasty had a 15% and 78% probability of being considered cost-effective at a £20 000 threshold for an additional QALY, respectively. In the model-based analysis, immediate septoplasty remained more costly and more effective than 6 months of medical management with the option for deferred septoplasty but had a 99% probability of being considered cost-effective at a £20 000 threshold for an additional QALY.

Over a 24-month time horizon, immediate septoplasty would be cost-effective in the management of deviated nasal septum.

ISRCTN16168569.