The global age-standardized QCI for cervical and ovarian cancer increased from 1990 to 2019 in all income levels. However, the gap between the highest and lowest QCI for both cancers in 2019 was higher than 1990, might be indicating a more inequitable access to and quality of health care in recent years. This is despite the fact that low-income countries had the greatest improvements. Among different age groups, generally, younger ages had higher QCIs, and in a particular age group, the QCI was positively associated with the income level. Plus, high income countries demonstrated higher QCIs in all age groups. Disparities were also observed in QCI among different age groups for ovarian cancer, and generally, QCI decreased as people aged.
In case of cervical cancer, the prevention through systematic vaccination and screening programs plays a critical role in the management of this cancer in health systems. The Human Papilloma Virus (HPV) infection is the main cause of developing cervical cancer which is preventable by vaccines. Moreover, the treatment of precancerous lesions diagnosed through the screening protocols have shown proper efficacy (24). Up to one third of all diagnosed cancers in many low-resource countries is cervical cancer. In contrast, this proportion is less than 10% in many high-resource countries (25). Therefore, in high-income countries with sufficient resources for these programs, the incidence and mortality of cervical cancer have more than halved since the last 30 years (1, 26). i.e., Ethiopia, Eritrea, and Equatorial Guinea, all of which as Sub-Saharan African countries had remarkable improvements in quality of care for cervical cancer. This improvement in the QCI in the region might be associated to the GDP increase since late 1990s. Moreover, the expenditure shares of GDP on the health sector in Sub-Saharan Africa region has increased (27). Another example in the support of these programs effect on the quality of care of cervical cancer is Japan. Japan reached to the second rank of QCI for cervical cancer as a high SDI country with widespread screening and vaccination programs (28, 29). It is also evident that low-resource countries had been slow in implementing HPV vaccination programs (30). Although there have been increasing controversies concerning the effectiveness of these programs (31, 32), even though cervical cancer is uncommon, United States is another high income country possessing systemic screening and vaccination programs resulting in declining incidence and mortality rates of cervical cancer (33).
Furthermore, in the Central Asian countries relatively high incidence of cervical cancer is challenged by the income level in those countries (34). On the other hand, in 2019, countries in the same SDI levels spread across different QCI levels for both cervical and ovarian cancers (Figs. 2 and 5), indicating that the developmental state was not the only predicting factor in the quality of care of these cancers. Hence, policy actions and focused non-financial investments including increasing public awareness in seeking health care services might be playing roles (35–38).
Cervical cancer most commonly develops in women at 30 to 40 ages. However, there is a second incident increase after the age of 70 (39). This study’s results suggest that the greatest QCI in each income level belongs to younger age groups, which might be primarily due to the better prognosis of cervical cancer in younger ages. Indeed, age seems to be an independent negative prognostic factor. Besides, commonly, the elderly receives more conservative treatments for cervical cancer (40). Furthermore, pertinent awareness and health seeking behaviors are more sensible among the younger age groups (35).
However, due to the advances in healthcare and an increase in the life expectancy, the elderly population is increasing (41). Therefore, it is still crucial yet challenging to address the gaps in the cervical cancer health care quality that have resulted in the lower QCIs in these age groups. Naturally, due to the physiological aging processes and comorbidities, cervical cancer management in the elderly is associated with complications, causing lower quality of care (39).
As mentioned above, vaccination and screening programs are potential tools in managing the cervical cancer burden. The target population of the HPV vaccination is the women before sexual debut. After that, screening programs step in to diagnose more manageable precancerous lesions (42). However, the efficacy of the vaccination programs is variable and the efficacy of screening programs are discussable due to various influencing factors (31, 32, 43). Therefore, increasing the quality of care of cervical cancer might be within the realm of possibility through proper decisions on resource allocation and policy makings. Accordingly, these decisions have to address the barriers against increasing the efficacy of these programs based on the cost-effectiveness of each program and specific circumstances of each country. For instance, since the low-and middle-income countries lack the infrastructure required for the cytological screening methods, the World Health Organization has suggested alternative screening methods for these countries such as visual inspection with acetic acid (VIA) (44–46).
In case of ovarian cancer, despite the advances in the screening and treatment methods, it remains the most lethal gynecological cancer. The younger age is usually associated with early stages of the disease that enhances the survival time of younger patients (47). In addition, unlike cervical cancer, there is no definite prevention approach for ovarian cancer. However, oral contraceptive usage (48), parity (49), breast feeding (50), NSAID usage (51), healthy diet (52), physical activity (53), and surgical approaches have been demonstrated to be protective against ovarian cancer (54–56).
Countries with higher resources do not necessarily demonstrate better access to and quality of health care, which might be a reflection of the importance of proper resource management. Furthermore, the increased global QCI for ovarian cancer is consistent with the decreased mortality of this cancer (57, 58); which might be a result of improvements in disease managements.
Similar to the cervical cancer, Sub-Saharan African countries including Equatorial Guinea and Ethiopia had the greatest improvements in the QCI for ovarian cancer. Taiwan had the highest QCI level for ovarian cancer in 2019. Taiwan is a high SDI East Asian country that managed to improve ovarian cancer prognosis since 2000. It is believed that this improvement might be associated with upgraded treatment strategies and a better quality of care given by the well-trained gynecologic oncologists (59).
As mentioned above, younger patients have better survival time than the elderly. In an income level, there were disparities in QCIs among age groups which might be a reflection of the youngster-weighed resource allocation. However, in a specific age group, the QCI was positively associated with the SDI level.