Health Technology Assessment (Nov 2014)
The clinical effectiveness and cost-effectiveness of second-eye cataract surgery: a systematic review and economic evaluation
Abstract
Background: Elective cataract surgery is the most commonly performed surgical procedure in the NHS. In bilateral cataracts, the eye with greatest vision impairment from cataract is operated on first. First-eye surgery can improve vision and quality of life. However, it is unclear whether or not cataract surgery on the second eye provides enough incremental benefit to be considered clinically effective and cost-effective. Objective: To conduct a systematic review of clinical effectiveness and analysis of cost-effectiveness of second-eye cataract surgery in England and Wales, based on an economic model informed by systematic reviews of cost-effectiveness and quality of life. Data sources: Twelve electronic bibliographic databases, including MEDLINE, EMBASE, Web of Science, The Cochrane Library and the Centre for Reviews and Dissemination databases were searched from database inception to April 2013, with searches updated in July 2013. Reference lists of relevant publications were also checked and experts consulted. Review methods: Two reviewers independently screened references, extracted and checked data from the included studies and appraised their risk of bias. Based on the review of cost-effectiveness, a de novo economic model was developed to estimate the cost-effectiveness of second-eye surgery in bilateral cataract patients. The model is based on changes in quality of life following second-eye surgery and includes post-surgical complications. Results: Three randomised controlled trials (RCTs) of clinical effectiveness, three studies of cost-effectiveness and 10 studies of health-related quality of life (HRQoL) met the inclusion criteria for the systematic reviews and, where possible, were used to inform the economic analysis. Heterogeneity of studies precluded meta-analyses, and instead data were synthesised narratively. The RCTs assessed visual acuity, contrast sensitivity, stereopsis and several measures of HRQoL. Improvements in binocular visual acuity and contrast sensitivity were small and unlikely to be of clinical significance, but stereopsis was improved to a clinically meaningful extent following second-eye surgery. Studies did not provide evidence that second-eye surgery significantly affected HRQoL, apart from an improvement in the mental health component of HRQoL in one RCT. In the model, second-eye surgery generated 0.68 incremental quality-adjusted life-years with an incremental cost-effectiveness ratio of £1964. Model results were most sensitive to changes in the utility gain associated with second-eye surgery, but otherwise robust to changes in parameter values. The probability that second-eye surgery is cost-effective at willingness-to-pay thresholds of £10,000 and £20,000 is 100%. Limitations: Clinical effectiveness studies were all conducted more than 9 years ago. Patients had good vision pre surgery which may not represent all patients eligible for second-eye surgery. For some vision-related patient-reported outcomes and HRQoL measures, thresholds for determining important clinical effects are either unclear or have not been determined. Conclusions: Second-eye cataract surgery is generally cost-effective based on the best available data and under most assumptions. However, more up-to-date data are needed. A well-conducted RCT that reflects current populations and enables the estimation of health state utility values would be appropriate. Guidance is required on which vision-related, patient-reported outcomes are suitable for assessing effects of cataract surgery in the NHS and how these measures should be interpreted clinically. Study registration: This project is registered as PROSPERO CRD42013004211. Funding: This project was funded by the National Institute for Health Research Health Technology Assessment programme.
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