Epidemiological trends and age-period-cohort effects on periodontal diseases incidence across the BRICS from 1992 to 2021

Abstract

Background: Periodontal diseases are prevalent oral conditions, particularly burdensome in developing countries. This study examines global and BRICS countries' changing trends in periodontal diseases incidence from 1992 to 2021, focusing on associations with age, period, and cohort effects.

Materials and methods: A cross-sectional burden of disease study was conducted. Data on the total population and periodontal diseases cases, all-age incidence rate, age-standardized incidence rate, and relative change in periodontal diseases incidence from 1992 to 2021 within BRICS were obtained from the Global Burden of Disease study (GBD) 2021. Furthermore, the Age-Period-Cohort (APC) model with an intrinsic estimator (IE) algorithm was employed to assess the effects of net drift, local drift, age, period, and cohort on the incidence rates of periodontal diseases over specific time periods.

Results: Globally, the new cases of periodontal diseases in 2021 were reported at 8961 thousand (95% uncertainty intervals: 7907, 10101), reflecting a 71.21% increase compared to 1992. In 2021, the age-standardized incidence rate of periodontal diseases across the BRICS countries ranged from 600.50 (95% uncertainty intervals: 481.27, 763.54) per 100,000 population in South Africa to 1268.96 (95% uncertainty intervals: 1119.16, 1409.94) per 100,000 population in India. The age distribution of periodontal diseases cases was relatively stable globally and among BRICS countries from 1992 to 2021. Countries exhibited similar age-effect patterns, with increasing risk with increasing age, and varying period and cohort effects, indicative of differential control measures and temporal incidence trends.

Conclusions: Brazil, India, and China experienced an increasing trend in the age-standardized incidence rates of periodontal diseases from 1992 to 2021, in contrast to the declining trends observed in the Russian Federation and South Africa. Furthermore, the APC analysis indicates the intricate dynamics of age, period, and cohort influences on periodontal diseases incidence. Distinct national trajectories, shaped by varying socioeconomic, cultural, and historical frameworks, highlight that public health initiatives must be meticulously customized to mitigate and control the periodontal diseases burden across diverse settings.

Keywords: Age-period-cohort; BRICS; Incidence; Periodontal diseases; Trend.

Fig. 1

Local drifts of incidence rate and age distribution of incidences in global and BRICS, 1992–2021. (A) Local drifts of periodontal diseases incidence rate (estimates from age-period-cohort models) for age groups (15–19 to 90–94 years), 1992–2021. The dots and shaded areas indicate the annual percentage change of incidence rate (% per year) and the corresponding 95% CIs. (B) Temporal change in the relative proportion of periodontal diseases incidences across age groups, 1992–2021

Fig. 2

Age, period and cohort effects on periodontal diseases incidence in global and BRICS. (A) Age effects are shown by the fitted longitudinal age curves of incidence rate (per 100,000 person-years) adjusted for period deviations. (B) Period effects are shown by the relative risk of incidence rate (incidence rate ratio) and computed as the ratio of age-specific rates from 1992–1996 to 2017–2021, with the referent cohort set at 2002–2006. (C) Cohort effects are shown by the relative risk of incidence rate and computed as the ratio of age-specific rates from the 1902 cohort to the 2002 cohort, with the referent cohort set at 1952. The dots and shaded areas denote incidence rates or rate ratios and their corresponding 95% CIs