Silicosis prevalence and incidence among Medicare beneficiaries

Abstract

Introduction: Existing epidemiologic information on silicosis relies on mortality data.

Methods: We analyzed health insurance claims and enrollment information from 49 923 987 fee-for-service (FFS) Medicare beneficiaries aged ≥65 from 1999 to 2014. Three different definitions were developed to identify silicosis cases and results are presented as ranges of values for the three definitions.

Results: Among FFS beneficiaries, 10 026-19 696 fit the silicosis case definitions (16-year prevalence: 20.1-39.5 per 100 000) with the highest prevalence among North American Natives (87.2-213.6 per 100 000) and those in New Mexico (83.9-203.4 per 100 000). The annual average prevalence had a significant (P < 0.05) 2-5% annual decline from 2005 to 2014. The average annual number of incident cases had a significant 3-16% annual decline from 2007 to 2014.

Conclusions: Silicosis is a prevalent disease among Medicare beneficiaries aged ≥65, with variation across the country. Morbidity data from health insurance claims can provide a more complete picture of silicosis burden.

Keywords: Medicare; insurance; silicosis.

FIGURE 1

Silicosis prevalence per 100 000 fee-for-service Medicare beneficiaries by case definition and state, 1999–2014. Shading denotes quartiles of state silicosis prevalence

FIGURE 2

Annual number and rate of prevalent silicosis cases among fee-for-service Medicare beneficiaries, by case definition, 1999–2014

FIGURE 3

Silicosis incidence per 100 000 fee-for-service Medicare beneficiaries, by case definition and state, 2010–2014. Shading denotes quartiles of state silicosis incidence. Incident cases had at least 3 years of continuous Medicare coverage without a silicosis (ICD-9-CM = “502”) claim during that period. The denominator in the incidence rates are FFS beneficiaries who had at least 3 years of continuous enrollment in Medicare

FIGURE 4

Annual number and rate of incident silicosis cases among fee-for-service Medicare beneficiaries, by case definition, 2002–2014. Incident cases had at least 3 years of continuous Medicare coverage without a silicosis (ICD-9-CM = “502”) claim during that period. The denominator in the incidence rates are FFS beneficiaries who had at least 3 years of continuous enrollment in Medicare