Temporal trends in the incidence of adverse effects of medical treatment in BRICS countries from 1990 to 2021: an age-period cohort analysis

Abstract

Background: Significant disability-adjusted life year (DALY) losses are caused annually by adverse effects of medical treatment (AEMT), a serious public health concern worldwide that continuously strains nations' socioeconomic progress. As they account for more than half of the world's population and exhibit notable variation in healthcare resource distribution, the BRICS nations-Brazil, Russia, India, China, and South Africa-have emerged as a crucial observational cohort for researching healthcare safety issues. This study evaluated trends in the incidence of AEMT across BRICS nations from 1990 to 2021.

Methods: This study evaluated trends in the incidence of AEMT in the BRICS nations between 1990 and 2021, utilizing data from the Global Burden of Disease (GBD) 2021 database. We employed Joinpoint regression to determine the average annual percentage change (AAPC) in incidence. Additionally, net drift, localized drift, age-specific curves, and period/cohort relative risk were estimated through an age-period-cohort (APC) model implementing the intrinsic estimator (IE) algorithm.

Results: Between 1990 and 2021, the incidence of AEMT decreased in both South Africa and China. Notably, China exhibited a more pronounced decline, with an AAPC of -1.30% (from 36.94 per 100,000 to 24.65 per 100,000), compared to South Africa's AAPC of -0.98% (from 117.82 per 100,000 to 86.57 per 100,000). In contrast, Brazil and Russia showed upward trends. Brazil experienced the most substantial increase, rising from 23.06 per 100,000 to 75.09 per 100,000 (AAPC +3.88%), while Russia's incidence grew less markedly, from 153.97 to 188.67 cases per 100,000 (AAPC +0.65%). Notably, China exhibited a consistently lower incidence of AEMT compared to other BRICS nations. The burden of AEMT disproportionately affected the older adult population in Brazil, South Africa, India, and Russia, whereas in China, the highest incidence was observed among newborns and young children. Regarding cohort risk, all nations demonstrated a reduction over time, except for Brazil and Russia, where cohort relative risk increased significantly.

Conclusion: Over the past three decades, divergent trends in AEMT incidence have been observed across the BRICS nations. To strengthen AEMT prevention, these countries should prioritize optimizing existing healthcare resources, such as workforce training and surveillance systems. Additionally, targeted interventions-including enhanced care for vulnerable populations (e.g., young children, preschoolers, and the older adult)-are critical to further reducing AEMT incidence.

Keywords: AEMT; BRICS; age-period-cohort; incidence; trend.

Figure 1

Number of new cases and incidence of AEMT in Brazil, China, India, Russian Federation and South Africa from 1990 to 2021. (A) All-age incidence cases. (B) Age-standardized incidence rate.

Figure 2

Age-specific incidence of AEMT in Brazil by period, 1990–2021. (A) Age-specific incidence rate for males in Brazil. (B) Age-specific incidence rate for females in Brazil.

Figure 3

Age-specific incidence of AEMT in China by time period, 1990 to 2021. (A) Age-specific incidence rate for males in China. (B) Age-specific incidence rate for females in China.

Figure 4

Age-specific incidence of AEMT in India by period, 1990 to 2021. (A) Age-specific incidence rate for males in India. (B) Age-specific incidence rate for females in India.

Figure 5

Age-specific incidence of AEMT in Russia by period, 1990 to 2021. (A) Age-specific incidence rate for males in Russia. (B) Age-specific incidence rate for females in Russia.

Figure 6

Age-specific incidence of AEMT in South Africa by period, 1990 to 2021. (A) Age-specific incidence rate for males in South Africa. (B) Age-specific incidence rate for females in South Africa.

Figure 7

Localized and net drift in the incidence of AEMT in Brazil, China, India, Russia, and South Africa, 1990–2021. (A) Local drift and net drift for male incidence. (B) Local and net drift for female incidence.

Figure 8

Parameter estimates of the impact of age effects on the incidence of AEMT in Brazil, Russia, India, China and South Africa, 1990 to 2021. (A) Age effects in male incidence. (B) Age effect of female incidence.

Figure 9

Parameter estimates of the impact of period effects on the incidence of AEMT in Brazil, Russia, India, China and South Africa from 1990 to 2021. (A) Period effect of male incidence. (B) Period effect of female incidence.

Figure 10

Parameter estimates of the impact of cohort effects on the incidence of AEMT in Brazil, Russia, India, China and South Africa from 1990 to 2021. (A) Cohort effect of male incidence. (B) Cohort effect of female incidence.