Osteoarthritis Affects 15% of People Over Age 30

Osteoarthritis, the most common form of arthritis, currently affects 14.8% of the global population over the age of 30. The number of cases is predicted reach 1 billion by the year 2050, with aging, population growth, and obesity cited as key factors, according to a study published in The Lancet.¹

Osteoarthritis, often diagnosed after the age of 40, is the leading cause of adult chronic pain and long-term disability. The World Health Organization (WHO) declared 2021 – 2030 as the “decade of healthy living,” with a focus on increased life expectancy and quality of life. With this in mind, the organization is determined to use this designation as an opportunity to focus on the burden of osteoarthritis. This is of particular importance as osteoarthritis can develop in relatively early adulthood and, therefore, prevention and management could mitigate decades of reduced quality of life.²

“With the key drivers of people living longer and a growing world population, we need to anticipate stress on health systems in most countries,” stated lead investigator Jaimie Steinmetz, PhD, lead research scientist at the Institute for Health Metrics and Evaluation. “There is no effective cure for osteoarthritis right now, so it’s critical that we focus on strategies of prevention, early intervention, and making expensive, effective treatments like joint replacements more affordable in low- and middle-income countries.”

In the systematic analysis for the Global Burden of Disease Study, investigators estimated the burden of hand, knee, hip, and other sites of osteoarthritis on a global scale, along with analyses for age, sex, and time, and predictions of prevalence to the year 2050. Incidence of osteoarthritis was estimated in 204 countries and territories between 1990 – 2020 using population-based surveys conducted in 42 countries for hand osteoarthritis, 26 countries for knee osteoarthritis, 23 countries for hip osteoarthritis, and United States-based insurance claims for all osteoarthritis sites.

References cases were defined as symptomatic, radiographically confirmed osteoarthritis. The alternative definitions, including patients with self-reported osteoarthritis, were adjusted to the reference case using regression models.

Disease severity distribution was obtained using a pooled meta-analysis of sources using the Western Ontario and McMaster Universities Arthritis Index. Prevalence estimates were multiplied by disability weights to determine years lived with disability (YLDs).

In 2020, a total of 595 million patients had osteoarthritis worldwide, which equated to 7.6% of the global population. This number represented an increase of 132.2% in total cases since 1990 (n = 256 million). In patients aged ≥30 years in 2020, 14.8% had an osteoarthritis diagnosis and in working-age adults (aged 30 – 60 years) 3.5% lived with osteoarthritis. Compared with data from 2020, cases of osteoarthritis are estimated to increase 78.6% for hip osteoarthritis, 74.9% for knee, 48.6% for hand, and 95.1% for other types by 2050.

The age-standardized rate of YLDs for total osteoarthritis was 255.0 YLDs per 100,000 in 2020, representing a 9.5% increase from 1990. Osteoarthritis was ranked as the 7th cause of YLDs for patients aged ≥70 years. The age-standardized prevalence in 2020 was ≥5.5% in all world regions, which ranged from 5677.4 per 100,000 in Southeast Asia to 8631.7 per 100,000 in high-income Asia Pacific.

The most common site for osteoarthritis was the knee. A high body mass index (BMI) was linked to 20.4% of osteoarthritis cases and was responsible for 4.6 million osteoarthritis YLDs. Other possible modifiable risk factors, including recreational injury prevention and occupational hazards, were not evaluated.

“Addressing burden in the long term requires a focus on prevention and access to highly effective treatments including joint replacement, and further research into risk factors that cause osteoarthritis or increase severity and disease progression,” investigators concluded.

References

1. ^{Steinmetz, J D, Culbreth, G T, Haile, L M, et al. (2023, September). Global, regional, and national burden of osteoarthritis, 1990–2020 and projections to 2050: a systematic analysis for the Global Burden of Disease Study 2021. https://www.thelancet.com/journals/lanrhe/article/PIIS2665-9913(23)00163-7/fulltext}
2. ^{Snoeker B, Turkiewicz A, Magnusson K, et al. Risk of knee osteoarthritis after different types of knee injuries in young adults: a population-based cohort study. Br J Sports Med. 2020; 54: 725-730}