Background: This study aimed to identify the burden and risk of venous thromboembolism (VTE) associated with cholecystectomy in England. Methods: An historical cohort study of cholecystectomy patients from 2001 to 2011 was undertaken using linked primary (Clinical Practice Research Datalink) and secondary (Hospital Episode Statistics) care data. Crude rates and adjusted hazard ratios (HRs) were calculated for risk of VTE following cholecystectomy using Cox regression. Results: 24,677 patients were identified with a rate of VTE in the first year following cholecystectomy of 2.80 per 1,000 person years (95% CI 2.18–3.59). Patients aged ≥70 vs. aged < 50 had 8.3-fold increase in risk of VTE (HR 8.27, 95% CI 3.72–18.35); patients with body mass index (BMI) > 30 vs. BMI < 30 had 2.4-fold increase in risk (HR 2.42, 95% CI 1.40–4.18); open vs. laparoscopic operation had 3-fold increase in risk (HR 2.94, 95% CI 1.55–5.55). Compared to general population, VTE risk was the highest in the first 30 days post-operatively with 9.9-fold risk following emergency cholecystectomy and 4.5-fold risk after inpatient cholecystectomy (HR 9.90, 95% CI 4.42–22.21; HR 4.54, 95% CI 2.85–7.21). Conclusions: Cholecystectomy is associated with a low absolute risk of VTE and we have identified high risk groups including the elderly, obese and those having open surgery.

ImportanceRetinal vein occlusion is the second most common retinal vascular disease. Bevacizumab was demonstrated in the Study of Comparative Treatments for Retinal Vein Occlusion 2 (SCORE2) to be noninferior to aflibercept with respect to visual acuity in study participants with macular edema due to central retinal vein occlusion (CRVO) or hemiretinal vein occlusion (HRVO) following 6 months of therapy. In this study, the cost-utility of bevacizumab vs aflibercept for treatment of CRVO is evaluated.ObjectiveTo investigate the relative cost-effectiveness of bevacizumab vs aflibercept for treatment of macular edema associated with CRVO or HRVO.Design, Setting, and ParticipantsThis economic evaluation study used a microsimulation cohort of patients with clinical and demographic characteristics similar to those of SCORE2 participants and a Markov process. Parameters were estimated and validated using a split-sample approach of the SCORE2 population. The simulated cohort included 5000 patients who were evaluated 100 times, each with a different set of characteristics randomly selected based on the SCORE2 trial. SCORE2 data were collected from September 2014 October 2019, and data were analyzed from October 2019 to July 2021.InterventionsBevacizumab (followed by aflibercept among patients with a protocol-defined poor or marginal response to bevacizumab at month 6) vs aflibercept (followed by a dexamethasone implant among patients with a protocol-defined poor or marginal response to aflibercept at month 6).Main Outcomes and MeasuresIncremental cost-utility ratio.ResultsThe simulation demonstrated that patients treated with aflibercept will have an expected cost $18 127 greater than those treated with bevacizumab in the year following initiation. When coupled with the lack of clinical superiority over bevacizumab (ie, patients treated with bevacizumab had a gain over aflibercept in visual acuity letter score of 4 in the treated eye and 2 in the fellow eye), these results demonstrate that first-line treatment with bevacizumab dominated aflibercept in the simulated cohort of SCORE2 participants. At current price levels, aflibercept would be considered the preferred cost-effective option only if treatment restored the patient to nearly perfect health.Conclusions and RelevanceWhile there will be some patients with CRVO-associated or HRVO-associated macular edema who will benefit from first-line treatment with aflibercept rather than bevacizumab, given the minimal differences in visual acuity outcomes and large cost differences for bevacizumab vs aflibercept, first-line treatment with bevacizumab is cost-effective for this condition.