The long-term direct and indirect economic burden among Parkinson's disease caregivers in the United States

Abstract

Background: Parkinson's disease is a progressive, disabling neurodegenerative disorder associated with significant economic burden for patients and caregivers. The objective of this study was to compare the direct and indirect economic burden of Parkinson's patients' caregivers with demographically matched controls in the United States, in the 5 years after first diagnosis of Parkinson's disease.

Methods: Policyholders (18-64 years old) linked to a Parkinson's disease patient (≥2 diagnoses of Parkinson's disease; first diagnosis is the index date) from January 1, 1998 to March 31, 2014, were selected from a private-insurer claims database and categorized as Parkinson's caregivers. Eligible Parkinson's caregivers were matched 1:5 to policyholders with a non-Parkinson's dependent (controls). Multivariable regression adjusted for baseline characteristics estimated direct costs (all-cause insurer cost [medical and prescription] and comorbidity-related medical costs; patient out-of-pocket costs) and indirect costs (disability and medically related absenteeism costs). Income progression was also compared between cohorts.

Results: A total of 1211 eligible Parkinson's caregivers (mean age, 56 years; 54% female) were matched to 6055 controls. In adjusted analyses, Parkinson's caregivers incurred significantly higher year 1 total all-cause insurer costs ($8999 vs $7117) and medical costs ($7081 vs $5568) (both P < 0.01) and higher prescription costs (range for years 1-5, $2506-2573 vs $1405-$1687) and total out-of-pocket costs ($1259-1585 vs $902-$1192) in years 1-5 (all P < 0.01). Parkinson's caregivers had significantly higher adjusted indirect costs in years 1-3 (range for years 1-3, $2054-$2464 vs $1681-$1857; all P < 0.05) and higher cumulative income loss over 5 years ($5967 vs $2634 by year 5; P for interaction = 0.03).

Conclusions: Parkinson's caregivers exhibited higher direct and indirect costs and greater income loss compared with matched controls. © 2018 International Parkinson and Movement Disorder Society © 2018 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Keywords: Parkinson's disease; direct costs; income; indirect costs; work loss.

Figure 1

Sample selection. ICD‐9‐CM, International Classification of Diseases, Ninth Revision, Clinical Modification; N, number; PD, Parkinson's disease.

Figure 2

Regression‐adjusted cumulative income loss for PD caregivers versus matched controls.^a‐d PD, Parkinson's disease; USD, United States dollars. ^aThe study period for each patient was index date to the earliest date of end of eligibility, end of continuous employment, or until the patient was age 65 (maximum follow‐up of 5 years). ^bEmployer‐reported annualized income (including wage and salary, and excluding variable components such as equity options) available in the eligibility records for each patient were used. Employees’ income for each calendar year of observation was calculated as the average of the annualized employer‐reported income reported at each month of the corresponding calendar year in the database. Income was adjusted for inflation to 2014 USD using the Consumer Price Index from the Bureau of Labor Statistics. ^cThe regression model used was a generalized linear mixed model with a gamma distribution and log link, which accounted for the correlation in income between the PD caregivers and their matched controls as well as the correlation within patients because of the repeated measures of income. ^dThe regression‐adjusted annual income presented here represents geometric means to account for the skewness of income distribution. These were calculated by taking the average of the ln (annual income) across patients, then exponentiating this average.