Determining the burden of hip/knee osteoarthritis and rheumatoid arthritis using disability-adjusted life-years (DALYs) United States, 1996 Arthritis Program

Charles G. Helmick, MD Catherine Michaud, MD, PhD Margaret Lethbridge-Cejku, PhD Jennifer Hootman, PhD Meghna Majmudar Arthritis Program

Arthritis--A public health problem 100+ types of arthritis and other rheumatic conditions high prevalence (43 million in 1997) –60 million by 2020 high cost ($65 billion in 1992) most frequent cause of disability

Arthritis Program Leading causes of disability, U.S. adults, 1999 (SIPP) Percent of 41.2 million persons with a disability Arthritis/rheumatism Back/spine problem Heart trouble Respiratory problem Deafness/hearing problem Limb/extremity weakness Mental/emotional problem Diabetes Blindness/vision problem Stroke

Arthritis Program The problem--severity and societal burden Given high prevalence varying severity of specific conditions What is the absolute and relative societal burden of arthritis using a measure that incorporates severity (DALYs)?

Arthritis Program Methods--Outcome DALYs (disability adjusted life years) –mortality (YLL) –disability (YLD)

Arthritis Program Methods Focus on 2 arthritis conditions –Hip/knee osteoarthritis –Rheumatoid arthritis Determine absolute DALYs Determine relative ranking

Arthritis Program Methods--Hip/knee osteoarthritis Incidence of radiographic hip and knee osteoarthritis % symptomatic Dutch disability weights for –grade 2 symptomatic = 0.14 –grade 3-4 symptomatic = 0.42 –age/sex specific weights

Arthritis Program Methods--Rheumatoid arthritis Incidence of rheumatoid arthritis GBD disability weight = –untreated = –treated = no age/sex specific weights

Arthritis Program Results--hip/knee osteoarthritis US DALYs Rank% total Overall 941,321 10th2.83 Women 507,098 7th3.31 Men 434,223 13th2.42

Arthritis Program Results--rheumatoid arthritis US DALYsRank Overall201,676>20th Women140,929>20th Men 60,747>20th

Arthritis Program Top 10 causes of DALYs, US, ischemic heart disease9.5 % 2. cerebrovascular disease unipolar major depression road traffic accidents lung/trachea/bronchial cancer chronic obstructive pulmonary disease alcohol use HIV/AIDS diabetes hip/knee osteoarthritis2.8

Arthritis Program #11-20 causes of DALYs, US, dementias2.7% 12. congenital abnormalities homicide and violence asthma suicide drug use breast cancer perinatal conditions colon/rectum cancer cirrhosis of the liver1.2

Arthritis Program Discussion Strengths –standard, summary measure (DALY) –first US DALY estimates for arthritis Limitations –many types of arthritis excluded –limited data on prevalence, incidence, distribution, weights

Arthritis Program Conclusions Incorporating severity into a disability measure –hip/knee osteoarthritis alone makes the top ten DALY list –adding 100+ other types of arthritis would raise the ranking higher

Arthritis Program Conclusion arthritis remains a large absolute and relative societal burden arthritis interventions warrant greater attention as a means of reducing disability