BackgroundFor years, the benefits of septoplasty have been questioned. Due to the scarce and inconclusive literature, several National Health Service (NHS) Clinical Commissioning Groups in England decided to add septal surgery to their list of restricted procedures with low clinical value. Recently, evidence was obtained that septoplasty is actually more effective than non-surgical management for nasal obstruction in adults with a deviated septum. However, the relation between costs and effects of septoplasty remains unknown.MethodsWe conducted an economic evaluation alongside an open, multicenter, pragmatic randomized controlled trial in two tertiary and 16 secondary referral hospitals in the Netherlands. Adults with nasal obstruction and a deviated septum were randomized to (1) septoplasty with or without concurrent turbinate surgery or (2) non-surgical management consisting of (a combination of) medical treatment and watchful waiting. Analyses were performed on an intention-to-treat basis. Single imputation nested in the bootstrap percentile method (using 5000 bootstrap replications) was performed to assess the effect of missing data. After 12 and 24 months, we assessed the incremental costs per quality-adjusted life year (QALY) gained from a healthcare and a societal perspective.ResultsA total of 203 adults were randomly assigned to septoplasty (N = 102) or non-surgical management (N = 101). After 12 months, the mean cost difference between septoplasty and non-surgical management using a healthcare or societal perspective was €1181 (95%CI €1038 to €1323) or €2192 per patient (95%CI €1714 to €2670), respectively. The mean QALY difference was 0.03 per patient (95%CI − 0.01 to 0.07). Incremental costs per QALY gained from a healthcare or societal perspective were €41,763 or €77,525, respectively. After 24 months, the mean cost difference between the two groups using a healthcare or societal perspective decreased to €936 (95%CI €719 to €1153) or €1671 per patient (95%CI €952 to €2390), respectively. The mean QALY difference increased to 0.05 per patient (95%CI − 0.03 to 0.14). Incremental costs per QALY gained from a healthcare or societal perspective became €17,374 or €31,024, respectively. Analyses of imputed data did not alter our findings.ConclusionsDepending on the selected perspective, cost-effectiveness threshold, and time horizon, septoplasty has the potential to be cost-effective. Despite considerable uncertainty, septoplasty seems to be cost-effective from a healthcare perspective, after 24 months against a threshold of €20,000 per QALY. From a societal perspective, septoplasty is not yet cost-effective after 24 months, but it comes closer to the cost-effectiveness threshold as time passes by.Trial registrationNederlands Trial Register, NTR3868 (https://www.trialregister.nl/trial/3698). Prospectively registered on February 21, 2013.