Cataract Surgery and Mortality in the United States Medicare Population
Purpose
To determine the association between cataract surgery and all-cause mortality in United States Medicare patients with cataract.
Design
Retrospective cohort study.
Participants
A 5% random sample of United States Medicare beneficiaries with a diagnosis of cataract from the 2002 through 2012 Denominator and Physician/Supplier Part B files.
Methods
The exposure of interest was cataract surgery and the outcome of interest was all-cause mortality. Baseline characteristics that were examined included demographics, systemic comorbidities, and ocular comorbidities. Cox proportional hazards regression modeling was used to assess the association between cataract surgery and mortality. Additional subgroup analyses were performed in propensity score deciles and within strata of age, gender, region, systemic disease burden, and in patients with versus without severe cataract subtypes.
Main Outcome Measures
All-cause mortality.
Results
The 5% Medicare sample included 1 501 420 patients with cataract, of whom 544 984 (36.3%) underwent cataract surgery. Patients with cataract surgery were followed up for a mean of 11.4 quarters (standard deviation [SD], 10.8 quarters; range, 0.0–44.0 quarters), whereas patients without cataract surgery were followed up for a mean of 12.9 quarters (SD, 12.2 quarters; range, 0.0–44.0 quarters). Mortality incidence was 2.78 deaths per 100 person-years in patients with cataract surgery and 2.98 deaths per 100 person-years in patients without surgery (P < 0.0001). Overall, patients with cataract surgery had a lower adjusted hazard of mortality compared with patients without surgery (hazard ratio [HR], 0.73; 95% confidence interval [CI], 0.72–0.74). The strongest associations were observed in patients with a high propensity score decile (HR, 0.52; 95% CI, 0.50–0.54), patients 80 to 84 years of age (HR, 0.63; 95% CI, 0.62–0.65), women (HR, 0.69; 95% CI, 0.68–0.70), patients in the western United States (HR, 0.52; 95% CI, 0.32–0.86), patients with a moderate systemic disease burden (HR, 0.71; 95% CI, 0.69–0.72), and patients with severe cataract (HR, 0.68; 95% CI, 0.66–0.70).
Conclusions
In a national cohort of United States Medicare beneficiaries with cataract, cataract surgery was associated with decreased all-cause mortality. Further studies are needed to examine mechanisms surrounding the association between cataract surgery and mortality.
