Cataract surgery is the single most frequent surgical procedure in developed countries, including the United States, where approximately 3 million cases are performed annually on Medicare patients. It is presently the largest single source of Medicare expenditures, and rates of surgery are rising. Between 1990 and 2010, incidence of cataract surgery increased between 2.5- and 6.5-fold, varying by region. This is a trend likely only to continue, given improved technology, an aging population with higher expectations for visual function, and expanding surgical criteria, including lower visual acuity thresholds for surgery, more bilateral surgery, and surgery in younger patients. Despite extremely high rates of surgical success, broader criteria and large surgical volume yield a significant number of complications, simply as a proportion of total cases.

Several international population studies have examined aggregate incidence and risk factors for surgery-related complications —including national efforts in the United Kingdom, Australia, Sweden, and Malaysia, among others, as well as newer initiatives to collect internationally standardized outcomes data (International Consortium for Health Outcomes Measurement, American Academy of Ophthalmology Intelligent Research In Sight registry, and the European Registry of Quality Outcomes for Cataract and Refractive Surgery). There is more limited evidence in the United States regarding complication rates, risk factors, and their relative impact. A retrospective cross-sectional analysis of Medicare claims data examined adjusted 1-year rates of severe postoperative complications (endophthalmitis, suprachoroidal hemorrhage, and retinal detachment) and found declining rates of serious adverse events between 1994 and 2006, with a 0.5% rate of at least 1 severe complication.

National quality analysis and reporting is increasingly relying on standardized metrics across specialties—particularly post-hospitalization readmissions, or post-procedure readmissions for surgical disciplines. Although cataract patients (and ophthalmology patients more generally) are seldom admitted or readmitted to the hospital, readmissions—broadly defined as revisits, including return to the operating room or unscheduled visits in an ambulatory care setting—are a robust choice for analyzing significant complications in cataract surgery. Detected events may encompass retained cataract lens fragments, wound leakage/dehiscence, severe endophthalmitis, and retinal detachment, among others. With the exception of a 1999 Canadian study that looked broadly at readmissions following outpatient (including cataract) surgeries at a single high-volume ambulatory surgery center with a 0.2% rate of complication-related readmissions for cataract surgery after 30 days, little has been published regarding readmissions as a marker for cataract surgery quality.

Although they do not capture all complications, readmissions do identify the most serious that have an impact on cost as well as on quality of life. Readmissions are also less subject to the accuracy concerns implicit in using claims data to identify specific complications by International Classification of Diseases, Ninth Revision (ICD-9) diagnosis and Current Procedural Terminology (CPT) procedure codes. And, with increased focus on value-based payment systems, including Affordable Care Act mandates to tie payments to quality outcomes, understanding how cataract surgery will be viewed by policymakers in a broader context is increasingly important—part of identifying, tracking, and predicting complications as well as their cost and outcomes.

In this study, we sought to evaluate the incidence of complications and revisits requiring a return for additional evaluation or treatment (in the clinic, operating room, or emergency department setting) as a reliable quality indicator for cataract surgery in a large, multipayer, population-based observational study. We characterized patterns of readmissions following cataract surgery, identified key patient characteristics (such as age and comorbidities) associated with higher readmission rates, and analyzed data at the state level to identify important geographic trends.