Outcomes
death
As part of the cost-effectiveness analyses initially planned, incremental cost-effectiveness ratios (ICER) were to be calculated taking into account the cost differential and the survival differential between the two groups. The ratios would have been expressed as the additional cost per life-year gained using the innovative technique (VATS) compared with the reference technique (thoracotomy), at 30 days and at 3 months after surgery. However, since death was infrequent and not different at these time horizons, only the cost differential was considered. This led us to perform cost-minimisation analyses [As part of the cost-utility analyses, incremental cost-utility ratios (ICER) were estimated by relating the cost differential to the average differential in quality adjusted life years (QALYs) between the two strategies, at 30 days and at 3 months. The ICER represent the additional cost necessary to gain one additional QALY using the innovative technique (VATS) compared with the reference technique (thoracotomy).