Abstract
Purpose :
To investigate whether late age-related macular degeneration (AMD) or its subtypes are associated with increased risk for inpatient hospital admission in 2015 California (CA) Medicare beneficiaries.
Methods :
A cross-sectional study was conducted using the 2015 Medicare claims databases from the Centers for Medicare & Medicaid Services to examine all CA Medicare beneficiaries with AMD who had an inpatient hospital admission in 2015. Inclusion criteria were: age 65 years or older, CA residence, coverage with Medicare Part A and B, and one or more part B claims in 2015. Outcome of interest was inpatient hospital admission, defined as having at least one claim for inpatient service. The exposure variable— AMD diagnosis—was defined by having ICD-9-CM/ICD-10-CM diagnosis codes for AMD or its subsets: dry AMD (geographic atrophy) and wet AMD (choroidal neovascularization). Multivariable logistic regression models were utilized to assess odds of inpatient admission based on a diagnosis of AMD or its sub-diagnoses, adjusting for age, sex, race/ethnicity.
Results :
The study sample included 2,574,641 CA Medicare beneficiaries. About 6.8% (n=173,811) of beneficiaries had a diagnosis of AMD, with 4.8% (n=124,205) having dry AMD and 1.9% (n=49,606) wet AMD. 15.3% (n=394,004) of all beneficiaries had at least one inpatient claim during 2015. Beneficiaries with AMD had 1.38 times the unadjusted odds of inpatient stay (95% CI, 1.36-1.40) compared with subjects without AMD. In our multivariable model, adjusted analyses indicated that beneficiaries with AMD had 1.04 times the odds of inpatient admission (95% CI, 1.03-1.05) compared to beneficiaries without AMD. In the analyses by subtypes of AMD, both dry and wet AMD were also associated with a greater unadjusted odds of inpatient stay, 1.32 (95% CI, 1.30-1.34) for dry AMD and 1.54 (95% CI, 1.51-1.57) for wet AMD, respectively. In the adjusted analyses by subtypes of AMD, both dry and wet AMD were associated with a greater odds of inpatient stay, 1.03 (95% CI, 1.02-1.05) for dry AMD and 1.05 (1.03-1.08) for wet AMD, respectively.
Conclusions :
In the CA Medicare population, AMD was associated with a greater odds of inpatient admission after adjusting for demographic factors. These findings demonstrate a need for further studies to better characterize the mechanism of association between AMD and increased burden of inpatient hospitalization.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.