Global, regional, and national burden of osteoarthritis, 1990-2020 and projections to 2050: a systematic analysis for the Global Burden of Disease Study 2021

Background Osteoarthritis is the most common form of arthritis in adults, characterised by chronic pain and loss of mobility. Osteoarthritis most frequently occurs after age 40 years and prevalence increases steeply with age. WHO has designated 2021-30 the decade of healthy ageing, which highlights the need to address diseases such as osteoarthritis, which strongly affect functional ability and quality of life. Osteoarthritis can coexist with, and negatively effect, other chronic conditions. Here we estimate the burden of hand, hip, knee, and other sites of osteoarthritis across geographies, age, sex, and time, with forecasts of prevalence to 2050. Methods In this systematic analysis for the Global Burden of Disease Study, osteoarthritis prevalence in 204 countries and territories from 1990 to 2020 was estimated using data from population-based surveys from 26 countries for knee osteoarthritis, 23 countries for hip osteoarthritis, 42 countries for hand osteoarthritis, and US insurance claims for all of the osteoarthritis sites, including the other types of osteoarthritis category. The reference case definition was symptomatic, radiographically confirmed osteoarthritis. Studies using alternative definitions from the reference case definition (for example self-reported osteoarthritis) were adjusted to reference using regression models. Osteoarthritis severity distribution was obtained from a pooled meta-analysis of sources using the Western Ontario and McMaster Universities Arthritis Index. Final prevalence estimates were multiplied by disability weights to calculate years lived with disability (YLDs). Prevalence was forecast to 2050 using a mixed-effects model. Findings Globally, 595 million (95% uncertainty interval 535-656) people had osteoarthritis in 2020, equal to 7 center dot 6% (95% UI 6 center dot 8-8 center dot 4) of the global population, and an increase of 132 center dot 2% (130 center dot 3-134 center dot 1) in total cases since 1990. Compared with 2020, cases of osteoarthritis are projected to increase 74 center dot 9% (59 center dot 4-89 center dot 9) for knee, 48 center dot 6% (35 center dot 9-67 center dot 1) for hand, 78 center dot 6% (57 center dot 7-105 center dot 3) for hip, and 95 center dot 1% (68 center dot 1-135 center dot 0) for other types of osteoarthritis by 2050. The global age-standardised rate of YLDs for total osteoarthritis was 255 center dot 0 YLDs (119 center dot 7-557 center dot 2) per 100 000 in 2020, a 9 center dot 5% (8 center dot 6-10 center dot 1) increase from 1990 (233 center dot 0 YLDs per 100 000, 109 center dot 3-510 center dot 8). For adults aged 70 years and older, osteoarthritis was the seventh ranked cause of YLDs. Age-standardised prevalence in 2020 was more than 5 center dot 5% in all world regions, ranging from 5677 center dot 4 (5029 center dot 8-6318 center dot 1) per 100 000 in southeast Asia to 8632 center dot 7 (7852 center dot 0-9469 center dot 1) per 100 000 in high-income Asia Pacific. Knee was the most common site for osteoarthritis. High BMI contributed to 20 center dot 4% (95% UI -1 center dot 7 to 36 center dot 6) of osteoarthritis. Potentially modifiable risk factors for osteoarthritis such as recreational injury prevention and occupational hazards have not yet been explored in GBD modelling. Interpretation Age-standardised YLDs attributable to osteoarthritis are continuing to rise and will lead to substantial increases in case numbers because of population growth and ageing, and because there is no effective cure for osteoarthritis. The demand on health systems for care of patients with osteoarthritis, including joint replacements, which are highly effective for late stage osteoarthritis in hips and knees, will rise in all regions, but might be out of reach and lead to further health inequity for individuals and countries unable to afford them. Much more can and should be done to prevent people getting to that late stage. Funding Bill & Melinda Gates Foundation, Institute of Bone and Joint Research, and Global Alliance for Musculoskeletal Health.Copyright (c) 2023 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.