Endophthalmitis Rates among Medicare Beneficiaries Undergoing Cataract Surgery between 2011 and 2019

Abstract

Purpose: To determine national incidence and risk factors associated with developing endophthalmitis after cataract surgery in the United States.

Design: Retrospective, cross-sectional analysis.

Participants: Medicare beneficiaries aged ≥65 years undergoing cataract surgery between 2011 and 2019.

Methods: Medicare claims were used to identify all patients who underwent ≥1 cataract surgery between 2011 and 2019. Endophthalmitis cases within 90 days of the cataract surgery were identified using diagnostic codes. Patients with a history of endophthalmitis 12 months before their cataract surgery procedure were excluded. Annual and aggregate 9-year incidences were determined for all cataract surgeries and for stand-alone cataract procedures. A stepwise multivariable logistic regression model using generalized estimating equations was used to evaluate factors associated with occurrence of postoperative endophthalmitis.

Main outcome measures: The 90-day postoperative endophthalmitis rate and patient risk factors associated with onset of endophthalmitis after cataract surgery.

Results: A total of 14 396 438 cataract surgeries were performed among Medicare beneficiaries between 2011 and 2019. The overall 90-day postoperative endophthalmitis rate was 1.36 per 1000 cataract surgeries for all cataract procedures and 1.30 per 1000 cataract surgeries for stand-alone cataract procedures. A decreasing trend was noted for postoperative endophthalmitis rates during the 9-year study period. On multivariable analysis, the risk of endophthalmitis after cataract surgery was increased for cases performed among those aged ≥75 years versus those aged <75 years (odds ratio [OR], 1.14; 95% confidence interval [CI], 1.11-1.18), Blacks (OR, 1.13; 95% CI, 1.07-1.20), Native Americans (OR, 1.43; 95% CI, 1.19-1.73), and eyes with any history of invasive glaucoma surgery (OR, 1.40; 95% CI, 1.18-1.65). Cataract cases combined with retinal surgery (OR, 2.60; 95% CI, 2.15-3.16) and those performed when the Charlson Comorbidity Index (CCI) was greater than 0 also had an increased likelihood of developing endophthalmitis. The risk of endophthalmitis was lower for cases performed on women versus men (OR, 0.89; 95% CI, 0.86-0.92).

Conclusions: The overall 90-day postoperative endophthalmitis rate after cataract surgery was 1.36 per 1000 cataract surgeries between 2011 and 2019. Patient age, gender, race, and CCI were associated with risk of endophthalmitis.

Keywords: Cataract surgery; Endophthalmitis; Incidence; Risk factors.