Osteoarthritis related absenteeism and activity limitations

Abstract

Purpose: Osteoarthritis is the most common form of arthritis, affecting millions of individuals in the United States. Due to aging and increasing life expectancy, osteoarthritis is expected to become the world's fourthleading cause of disability by 2020. This study assessed the incremental workplace absenteeism and incremental activity limitation associated with osteoarthritis over one year. Methods: Data source for this study was the 2011 household component of Medical Expenditure Panel Survey (MEPS), a United States nationally representative survey maintained by the Agency for Healthcare Research and Quality (AHRQ). Inclusion criteria for analyses were all working, employed people eighteen years of age or older. Using the system of International Classification of Diseases, 9th Revision, Clinical Modification(ICD-9-CM), employees with osteoarthritis were identified. Individuals suffering from osteoarthritis were linked in a 1:1 ratio to individuals without osteoarthritis on age, sex, hypertension, hyperlipidemia, diabetes, obesity, anxiety, and asthma. Exclusion criteria for analysis assessing absenteeism were individuals missing any information on number of days missed at work. Exclusion criteria for analysis assessing activity limitations were individuals missing any information on limitations to activity. Individuals, who could not find work, took maternity or paternity work, took some time off from working for reasons not related to health problems, waited to start a new job, individuals going to school, or retired individuals were also excluded for both analyses. In order to assess association of osteoarthritis on number of working days lost, a zero-inflated negative binomial model was employed. Annual days missed at work, a count variable, was employed as response variable. The predictor variable was a binary variable indicating the presence or absence of osteoarthritis. Covariates for the model included age, sex, education, race, marital status, occupation, region, health insurance type, and comorbid conditions including hypertension and hyperlipidemia. Charlson comorbidity index was calculated and was also included as a covariate in the analysis. To assess associations between osteoarthritis and activity limitations, a binary logistic model was employed. A binary variable indicating whether or not an individual's activities' were limited was employed as response variable. Predictor variable was a binary variable indicating the presence or absence of osteoarthritis. Covariates for the model included age, sex, education, race, region, marital status,- occupation, health insurance type, charlson comorbidity index and comorbid conditions for osteoarthritis including hypertension, and hyperlipidemia. Data management and analysis was carried out using SAS for UNIX version 9.3 and STATA for UNIX version 12.1. An a priori alpha level of 0.05 was used for the analyses. Results: Out of the total sample of 26,992 individuals, 351 individuals with osteoarthritis reported zero or more days of absence from their workplaces, and were linked to a comparison group. Individuals younger than sixty years of age comprised 51% of the sample, 67% of the sample were females, 75% of the sample were Caucasians, and 42% had high school diploma. Individuals with osteoarthritis weremore likely to miss work days annually(1.40 days, p=0.042) as compared to individuals without osteoarthritis. Using MEPS sampling weights to produce population estimates, mean annual work days missed was 9.72 days for individuals with osteoarthritis, while mean annual work days missed for individuals without osteoarthritis was 7.44 days, with an unadjusted mean difference of 2.28 days. Out of a total sample of 26,992 individuals, 418 individuals with osteoarthritis reported either limitation to activity or not, and were linked to a comparison group. Individuals younger than sixty years of age were 47% of the sample, 66% were females, 77% were Caucasians, and 41% had high school diploma. For individuals with osteoarthritis, the odds of having limitations in heir activities increased by a factor of 3.68 (p=0.000) as compared to individuals without osteoarthritis, holding all other variables constant. Conclusions: Individuals suffering from osteoarthritis have significantly more limitations in their activities and missed more workdays than individuals who do not have osteoarthritis.