In the Journals

Prevalence of arthritis in US 'substantially underestimated'

S. Reza Jafarzadeh

Arthritis prevalence in the United States has been “substantially underestimated” by as much as 68%, according to research published in Arthritis & Rheumatology.

The researchers noted that current estimates particularly underestimate arthritis prevalence among adults younger than 65 years.

Arthritis is a major public health concern and significantly impacts US adults health and wellbeing including younger Americans,” S. Reza Jafarzadeh, DVM, MPVM, PhD, study co-author and a member of the clinical epidemiology research and training unit at the Boston University School of Medicine, told Healio Rheumatology. “The under-investment in arthritis research, awareness, and prevention is going to cost us significant healthcare expenditure and loss of productivity as a result of disability down the road.”

To estimate arthritis prevalence in the United States, based on an expansive, surveillance-focused definition that is also adjusted for the errors present in the current system, Jafarzadeh and David T. Felson, MD, MPH, of the University of Manchester, U.K., analyzed data from the 2015 National Health Interview Survey. The researchers developed a Bayesian multinomial latent class model for arthritis surveillance based on physician-diagnosed arthritis, chronic joint symptoms and whether symptom duration exceeded 3 months.

Among the 33,672 participants, 19.3% of men and 16.7% of women aged 18 to 64 years reported joint symptoms without doctor-diagnosed arthritis, the researchers found. Among participants aged 65 years and older, 15.7% of men and 13.5% of women similarly affirmed joint symptoms without a concurrent diagnosis.

According to the researchers, the error-adjusted prevalence of arthritis was 29.9% in men (95% Bayesian probability interval, 23.4-42.3) and 31.2% among women (95% PI, 25.8-44.1) aged 18 to 64. Meanwhile, among those aged 65 years and older, the error-adjusted prevalence of arthritis was 55.8% in men (95% PI, 49.9-70.4) and 68.7% in women (95% PI, 62.1-79.9).

The researchers found that in 2015 arthritis affected 91.2 million adults (of 247.7 million; 36.8%) across the United States, including 61.1 million (of 199.9 million; 30.6%) people aged 18 to 64 years. They estimated that arthritis prevalence in the United States is 68% higher than previously reported national estimates.

“While our inference was limited to aggregate-level population surveillance on the burden of arthritis, further studies are needed to evaluate potential changes in the specific causes of arthritis, especially among adults below the age of 65,” the researchers wrote. “Arthritis causes an enormous economic and public health implications. Arthritis-attributable health care direct costs or long-term indirect costs as a result of loss of productivity and disability need be revised to account for the corrected prevalence of arthritis affecting individuals at younger age than previously perceived.” – by Jason Laday

Disclosure: The authors report funding support through an NIH grant.

S. Reza Jafarzadeh

Arthritis prevalence in the United States has been “substantially underestimated” by as much as 68%, according to research published in Arthritis & Rheumatology.

The researchers noted that current estimates particularly underestimate arthritis prevalence among adults younger than 65 years.

Arthritis is a major public health concern and significantly impacts US adults health and wellbeing including younger Americans,” S. Reza Jafarzadeh, DVM, MPVM, PhD, study co-author and a member of the clinical epidemiology research and training unit at the Boston University School of Medicine, told Healio Rheumatology. “The under-investment in arthritis research, awareness, and prevention is going to cost us significant healthcare expenditure and loss of productivity as a result of disability down the road.”

To estimate arthritis prevalence in the United States, based on an expansive, surveillance-focused definition that is also adjusted for the errors present in the current system, Jafarzadeh and David T. Felson, MD, MPH, of the University of Manchester, U.K., analyzed data from the 2015 National Health Interview Survey. The researchers developed a Bayesian multinomial latent class model for arthritis surveillance based on physician-diagnosed arthritis, chronic joint symptoms and whether symptom duration exceeded 3 months.

Among the 33,672 participants, 19.3% of men and 16.7% of women aged 18 to 64 years reported joint symptoms without doctor-diagnosed arthritis, the researchers found. Among participants aged 65 years and older, 15.7% of men and 13.5% of women similarly affirmed joint symptoms without a concurrent diagnosis.

According to the researchers, the error-adjusted prevalence of arthritis was 29.9% in men (95% Bayesian probability interval, 23.4-42.3) and 31.2% among women (95% PI, 25.8-44.1) aged 18 to 64. Meanwhile, among those aged 65 years and older, the error-adjusted prevalence of arthritis was 55.8% in men (95% PI, 49.9-70.4) and 68.7% in women (95% PI, 62.1-79.9).

The researchers found that in 2015 arthritis affected 91.2 million adults (of 247.7 million; 36.8%) across the United States, including 61.1 million (of 199.9 million; 30.6%) people aged 18 to 64 years. They estimated that arthritis prevalence in the United States is 68% higher than previously reported national estimates.

“While our inference was limited to aggregate-level population surveillance on the burden of arthritis, further studies are needed to evaluate potential changes in the specific causes of arthritis, especially among adults below the age of 65,” the researchers wrote. “Arthritis causes an enormous economic and public health implications. Arthritis-attributable health care direct costs or long-term indirect costs as a result of loss of productivity and disability need be revised to account for the corrected prevalence of arthritis affecting individuals at younger age than previously perceived.” – by Jason Laday

Disclosure: The authors report funding support through an NIH grant.