Influence of experience on performance of individual surgeons in thyroid surgery: prospective cross sectional multicentre study

Objective To determine the association between surgeons' experience and postoperative complications in thyroid surgery. Design Prospective cross sectional multicentre study. Setting High volume referral centres in five academic hospitals in France. Participants All patients who underwent a thyroidectomy undertaken by every surgeon in these hospitals from 1 April 2008 to 31 December 2009. Main outcome measures Presence of two permanent major complications (recurrent laryngeal nerve palsy or hypoparathyroidism), six months after thyroid surgery. We used mixed effects logistic regression to determine the association between length of experience and postoperative complications. Results 28 surgeons completed 3574 thyroid procedures during a one year period. Overall rates of recurrent laryngeal nerve palsy and hypoparathyroidism were 2.08% (95% confidence interval 1.53% to 2.67%) and 2.69% (2.10% to 3.31%), respectively. In a multivariate analysis, 20 years or more of practice was associated with increased probability of both recurrent laryngeal nerve palsy (odds ratio 3.06 (1.07 to 8.80), P=0.04) and hypoparathyroidism (7.56 (1.79 to 31.99), P=0.01). Surgeons' performance had a concave association with their length of experience (P=0.036) and age (P=0.035); surgeons aged 35 to 50 years had better outcomes than their younger and older colleagues. Conclusions Optimum individual performance in thyroid surgery cannot be passively achieved or maintained by accumulating experience. Factors contributing to poor performance in very experienced surgeons should be explored further.