Cost-effectiveness of incisional negative pressure wound therapy compared with standard care after caesarean section in obese women: a trial-based economic evaluation

Objective To evaluate the cost-effectiveness of incisional negative pressure wound therapy (iNPWT) in preventing surgical site infection in obese women after caesarean section. Design A cost-effectiveness analysis conducted alongside a clinical trial. Setting Five obstetric departments in Denmark. Population Women with a pregestational body mass index (BMI) >= 30 kg/m(2). Method We used data from a randomised controlled trial of 876 obese women who underwent elective or emergency caesarean section and were subsequently treated with iNPWT (n = 432) or a standard dressing (n = 444). Costs were estimated using data from four Danish National Databases and analysed from a healthcare perspective with a time horizon of 3 months after birth. Main outcome measures Cost-effectiveness based on incremental cost per surgical site infection avoided and per quality-adjusted life-year (QALY) gained. Results The total healthcare costs per woman were euro5793.60 for iNPWT and euro5840.89 for standard dressings. Incisional NPWT was the dominant strategy because it was both less expensive and more effective; however, no statistically significant difference was found for costs or QALYs. At a willingness-to-pay threshold of euro30,000, the probability of the intervention being cost-effective was 92.8%. A subgroup analysis stratifying by BMI shows that the cost saving of the intervention was mainly driven by the benefit to women with a pre-pregnancy BMI >= 35 kg/m(2). Conclusion Incisional NPWT appears to be cost saving compared with standard dressings but this finding is not statistically significant. The cost savings were primarily found in women with a pre-pregnancy BMI >= 35 kg/m(2).