According to data from the Global Burden of Disease study 2019, osteoarthritis (OA) is still globally prevalent and is expected to increase due to rising obesity and the aging of populations.
Age-standardized prevalence rates (ASRs) and secular trends of OA are expected to continually increase, the report said
To come to this finding, the authors collected data from the Global Burden of Disease study 2019 and used ASRs and their estimated annual percentage changes (EAPCs) to understand the secular trends of OA based on age group, sex, region, country, territory, and the joints involved—knee, hip, hand, and other joints, not including spine.
The data on site-specific OA came from 204 countries and territories between 1990 and 2019. According to the authors, this was the first time these data were used to analyze the secular trends of OA prevalence.
The authors found that prevalent cases of OA increased globally by 113.25% in nearly 3 decades, more than doubling from 247.51 million cases in 1990 to 527.81 million cases in 2019.
ASRs saw an increased EAPC of .12% (95% CI, 0.11%-0.14%). Overall, ASRs slightly increased from 6173.38 per 100,000 in 1990, to 6348.25 per 100,000 in 2019. Specific to joints involved, ASRs increased for knee, hip, and other joint OA, but decreased for hand OA. EAPC was 0.32 for knee, 0.28 for hip, 0.18 for other joints, and -0.36 for hand. Knee OA was noted as contributing most to overall burden, and hip OA had the highest EAPC in most regions.
“OA in large joints, such as the knee and the hip, is considered to cause the largest disability and may require joint replacement at end-stage if available, thus indicating a significant proportion of disease burden,” the authors explained. They later added, “Relatively low prevalence and conversely more serious severity distribution and sequelae of the hip compared to other larger joints may result in such a conclusion.”
OA was more prevalent in females and prevalence increased with age. Socio-demographic Index (SDI) also played a role, as countries with a high SDI level—more developed countries—saw higher OA prevalence, which was also noted in a prior study.
The authors cited body mass index (BMI) as a potential factor for varying regional data.
“As higher BMI (e.g., overweight/obesity) is a substantial risk factor for OA, geographical diversity in OA prevalence may be related to the distribution of adult obesity,” the authors said. “Moreover, epidemiological and genetic investigation have established that OA is a disease with multifactorial components on both ecology and genetics, contributing to the geographical diversity.”
They noted that the prevalence of obesity has nearly tripled since 1975. According to the World Health Organization (WHO), in 2016, more than 1.9 billion adults and more than 340 million children and adolescents were overweight or obese.
Increasing population and aging were also cited as causes for the increase in OA prevalence. According to data from WHO, the global population increased from 5.32 billion in 1990, to 7.71 billion in 2019, marking a 45% increase. Additionally, the proportion of people aged 60 years and older increased from 9.2% to around 13.5% in the same time frame.
According to the authors, joint injuries involving ligaments can sometimes lead to joint degeneration, and may contribute to the increase of OA prevalence, as well as increased awareness and diagnosis of OA compared with 1990.
“Public awareness of the modifiable risk factors, and potential education programs of prevention disease occurrence are essential to alleviate the enormous burden of OA,” the authors said.
Long H, Liu Q, Yin H, et al. Prevalence trends of site-specific osteoarthritis from 1990 to 2019: findings from the Global Burden of Disease study 2019. Arthritis Rheum. Published online March 2, 2022. doi:10.1002/art.42089