Our study indicated that during the period of 1990–2019, the global ASIR, ASPR, and age-standardized YLD rate for PCOS showed an increasing trend. However, EAPC varied widely across different SDI regions and GBD regions. The examinations of age, period, and cohort effects differentiate the source of trends in incidence, prevalence, and YLD by different ages, periods, and birth cohorts for the globe and different SDI regions. It was estimated that the incidence, prevalence, and YLD of PCOS would increase from 2020 to 2040.
From 1990 to 2019, the incidence, prevalence, and YLDs of PCOS were on the rise worldwide, highlighting a growing concern in public health. However, this upward trend varies widely across SDI regions and GBD regions, suggesting divergent epidemiological patterns in different socioeconomic settings. The EAPC being highest in the low-middle SDI regions may reflect burgeoning health awareness and improved diagnostic capabilities in these areas, furthermore an increasingly prosperous diet content with urbanization may lead to the increasing probability of developing PCOS(Kulkarni et al., 2019). Conversely, the minimal change in high SDI regions might indicate a plateau in medical care consciousness or possibly the impact of better healthcare access and preventive strategies attenuating the rise in incident cases. This variation necessitates targeted public health strategies that address the specific needs and challenges of each region.
Our joinpoint regression analysis further delineates the complexity of PCOS epidemiology, revealing that ASRs of incidence, prevalence, and YLD have a tendency to rise first, then decline, and then rise again across different periods in high SDI regions. These fluctuating trends suggest the impact of health awareness activities, policy changes, or the evolution of diagnostic criteria over time. For example, before the 21st century, the diagnostic criteria for PCOS were not standardized or unified. The Rotterdam criteria and the Androgen Excess-PCOS Society criteria, established in 2003 and 2006 respectively, made the diagnosis of PCOS more accurate, reflecting an increased attention to polycystic ovary syndrome in related countries during this period.
The age-based description of PCOS burden, with high incidence rates in young age groups of 10–19 years old sets the target population for early detection and treatment of this condition. However, it is difficult to diagnose PCOS during adolescence(Legro et al., 2013), as the manifestations overlap with the physiological changes of puberty(Witchel et al., 2019). Therefore, pediatric and gynecologic medical personnel must use accurate methods to distinguish between the early manifestations of PCOS and the physiology of puberty. High prevalence and YLD rates in the 20-44-year-olds, underscores the chronic nature of PCOS and its significant impact on women’s health throughout their reproductive years. The highest burden in high SDI regions might mirror better diagnostic practices and greater health-seeking behavior, on the other hand, due to the high compliance of developed countries with Westernized diets, the risks of obesity, insulin resistance, and early puberty are higher, all of which are associated with PCOS(Chen et al., 2018; Kopp, 2019). Limitations in accessing screening, treatment, and disease management services may also lead to an underestimation of PCOS in developing countries. These dynamics emphasize the need for early intervention and sustained management to mitigate PCOS’s long-term impacts.
The analysis of the age, period, and cohort effects on PCOS revealed the complexity of the epidemiology of this condition, showing varying trends across different SDI regions. The incidence of PCOS was observed to be highest in the 10-20-year age group, then sharply declined with increasing age. This may reflect the biological reality that PCOS begins during adolescence and early adulthood, a phase when significant hormonal changes occur in the body(Bremer, 2010), and when teenagers are subjected to a slew of emotional fluctuations caused by setbacks, interpersonal relationships, and peer pressure(Adone & Fulmali, n.d.), all of which could trigger PCOS. Both prevalence and YLDs increase then decline with advancing age, further emphasizing the significant impact of PCOS on women of reproductive age. In Global and most SDI regions, the period RR and cohort RR of prevalence and YLD are on an upward trend, indicating that with time, new generations face an increased risk of the disease. However, in high SDI regions, the period RR is always less than 1, suggesting that the risk of PCOS is not increasing but decreasing or stabilizing. Overall, these results highlight the complex interplay of generations, social role changes, and potential exposure factors influencing the burden of PCOS. These findings call for global public health policymakers to adopt customized preventive measures and treatment strategies for populations across different regions and age groups(Teede et al., 2018).
Predictions indicate that the burden of PCOS will continue to rise globally, with obesity driven by globalization and urbanization cited as one of the significant reasons(Mu et al., 2019). Lifestyle changes around the world, such as unhealthy dietary habits, lack of exercise, smoking, and others, are risk factors for PCOS(Eleftheriadou et al., 2012; Kulkarni et al., 2019; Tao et al., 2021). In addition, environmental changes, including pollution and exposure to chemical substances, can also lead to women developing PCOS and causing reproductive disorders(Chiang et al., 2017). The continuous growth of the global population and the aging demographic structure imply that more women will enter the age range potentially affected by PCOS. With increasing public awareness of PCOS and advances in medical technology, more undiagnosed cases may be identified and recorded, thus increasing the number of cases. Therefore, the prevention, diagnosis, and treatment strategies for PCOS will need to adapt to these changes and challenges. The global health system will need to increase resource allocation and enhance public awareness to address this growing disease burden.
This study is the first to parametrically analyze the disease burden of PCOS globally using the age-period-cohort model and predict the future epidemiological trends of PCOS using the Bayesian age-period-cohort model. Our research conducted an in-depth secondary analysis of global PCOS based on GBD data, but there are still some limitations. Firstly, this study was based on summarized data rather than individual-level data, which means we could not comprehensively describe incidence, prevalence, and YLDs in detail. Secondly, the predictions were based on the GBD 2019 database, which means the quality of the data from original registries greatly affects the accuracy and robustness of estimates in the database, potentially leading to bias in the estimates. Thirdly, in the APC model analysis, it's assumed that the cohort is equal to the period minus the age, hence there's an issue of multicollinearity among these three variables. Although there are several algorithms available for this issue(Luo, 2013), more factors should be considered when using the model and interpreting the results. Finally, given the differences in the burden and influential factors of PCOS among women of different ethnic backgrounds(VanHise et al., 2023), it would be meaningful to provide subgroup analyses by ethnicity, future research may focus on this issue.