Optimistic bias: the more you do, the better you think it goes. Survey analysis of reverse shoulder arthroplasty

OBJECTIVE: Even though heuristics are very helpful, several biases have been described related to their use. The aim of this study is to analyze the influence of surgery volume on the surgeon’s perception of pain improvement in patients after having received a reverse total shoulder arthroplasty. DESIGN: Successive independent samples study. SETTING: Shoulder surgeons attending four shoulder meetings. PARTICIPANTS: 149 Shoulder surgeons were included. INTERVENTION: Physicians were asked to postulate the preoperative and postoperative pain of patients receiving a reverse shoulder arthroplasty and respond by putting a mark on two visual pain scales. MAIN OUTCOME MEASURES: Pain improvement, years of shoulder practice, number of shoulder studies read over 6 months and the number of reverse shoulder arthroplasties performed per year. To compare the answers of the survey-study, a cohort of 95 patients who had undergone reverse shoulder Arthroplasty because of a rotator cuff arthropathy were prospectively followed. RESULTS: Regarding the pain score before and after surgery, the patient cohort showed a mean improvement of 6.84 points. In terms of the doctors, the more years of surgical practice, led them to have a greater expectation of improvement (p=0.004). Moreover, the greater the number of prostheses they implanted, the greater the expectation of improvement (p=0.0005). It was the same in terms of the number of studies read by them (p=0.001). CONCLUSIONS: Years of practice, hospital position and the number of shoulder arthroplasties done per year all favor the surgeon’s perception that their patients obtain a greater pain relief after receiving a shoulder arthroplasty than the real improvement in pain relief the patients experience.