Meningitis, a critical infection that impacts the meninges — protective membranes surrounding the brain and spinal cord — presents a significant public health challenge due to its life-threatening nature (1). Insights from the Global Burden of Disease (GBD) study exposed an increase of 320,000 worldwide meningitis cases between 1990 and 2016 (1). Given its extensive population, China ranks among the top 10 nations globally for meningitis-associated mortalities. Despite prior research investigating worldwide trends in meningitis mortality, there remains a paucity of understanding regarding national trends and the discrepancies between urban and rural areas. The current study dissected changing patterns in China’s meningitis mortality rate from 1987 to 2021 and spotlighted age-period-cohort effects influencing mortality changes. These revelations will equip the government with valuable insights into long-term trends and guide the development of targeted prevention strategies.
The mortality rates related to meningitis were extracted from the death registration system managed by the National Health Commission in China (2). This registry amalgamates several sources of data, including 1) death certificates and population demographics from the Department of Health, 2) changes in registered residences from the Department of Public Security, 3) cremation data from the Department of Civil Affairs, and 4) termination of social security information from the Department of Social Security. Age-standardized mortality rates (ASMR) were tabulated employing the direct method and the World Standard Population as a frame of reference (3). A joinpoint regression analysis was performed to detect fluctuations in meningitis mortality over time (4). Furthermore, an age-period-cohort model was used to ascertain the independent influence of age, period, and birth cohort on meningitis mortality rates in China (5). This research disclosed a steady decrease in meningitis mortality rates throughout urban and rural China over the past thirty years. Importantly, children, specifically those aged 0–4, present the highest risk of meningitis. These results effectively demonstrate the evolving trends of meningitis mortality and underscore the critical demographics for prevention strategies in China, offering valuable insights for future preventative measures against meningitis.
Figure 1 depicts the longitudinal trends in crude mortality rates and ASMR for meningitis among urban and rural populations in China, stratified by sex, from 1987–2021. Both crude mortality rates and ASMR saw a significant decrease from 1987 to 2002, and largely remained stable after 2002, despite some fluctuations observed between 2010 and 2013. Throughout the study period, higher ASMRs were typically seen in males and rural residents when compared to females and urban dwellers, respectively.Figure 1.
Trends in the crude and age-standardized mortality rates from meningitis in urban and rural areas of China, by sex, 1987–2021. (A) Crude mortality rates in urban areas. (B) Crude mortality rates in rural areas. (C) Age-standardized mortality rates in urban areas. (D) Age-standardized mortality rates in rural areas.
Table 1 details the results of the joinpoint regression analysis. The ASMR displayed a general decreasing trend in both urban and rural areas, although the substage trends were not consistent. The decline in urban ASMR was marginally steeper compared to the rural regions. In urban settings, ASMR experienced a rapid decrease from 1987–2003, followed by a gradual rebound from 2003–2016, and a stark decline again from 2016–2021. Conversely, in rural areas, ASMR showed a slow reduction from 1987–1999, a rapid decline from 1999–2002, and a flat rebound from 2002–2021. Notably, a slight disparity was observed between sexes in meningitis mortality in urban and rural areas.
Residence Mortality rate†
Entire range§ Segment 1 Segment 2 Segment 3 1987 2021 AAPC (%) 95% CI Period APC (%) 95% CI Period APC (%) 95% CI Period APC (%) 95% CI Urban Total 0.53 0.07 −6.5* (−8.6, −4.3) 1987–2003 −10.0* (−11.8, −8.1) 2003–2016 1.9 (−1.4, 5.2) 2016–2021 −15.4* (−25.2, −4.4) Male 0.53 0.08 −6.3* (−8.8, −3.7) 1987–2003 −9.4* (−11.7, −7.0) 2003–2015 2.4 (−2.1, 7.2) 2015–2021 −14.3* (−23.5, −4.0) Female 0.53 0.05 −6.7* (−9.3, −4.1) 1987–2004 −10.5* (−12.4, −8.6) 2004–2017 2.5 (−1.2, 6.2) 2017–2021 −18.0* (−32.5, −0.5) Rural Total 0.52 0.09 −3.7* (−9.6, 2.6) 1987–1999 −2.9 (−6.9, 1.3) 1999–2002 −28.4 (−65.0, 46.4) 2002–2021 0.4 (−1.7, 2.6) Male 0.57 0.12 −3.3 (−9.5, 3.3) 1987–1999 −3.2 (−7.4, 1.2) 1999–2002 −32.1 (−68.0, 44.0) 2002–2021 2.2 (−0.1, 4.5) Female 0.48 0.07 −3.7* (−13.9, 7.7) 1987–2000 −3.0 (−9.3, 3.7) 2000–2003 −29.6 (−80.3, 151.4) 2003–2021 0.9 (−3.2, 5.1) Abbreviation: APC=annual percent change; AAPC=average annual percent change; CI=confidence interval.
* Significant difference from zero (P<0.05).
† Standardization employed is based on the world standard population from the World Health Organization.
§ The time frame considered ranges from 1987 to 2021.
Table 1. Joinpoint analysis of age-standardized mortality rates due to meningitis in urban and rural areas.
Figure 2 illustrates the net and local drifts of mortality rates due to meningitis. The net drift indicates the yearly percentage fluctuation in the predicted age-standardized mortality, as the local drift signifies the similar change over time. This pattern was consistently seen in both urban and rural areas of China. Throughout the study period, there was a substantial reduction in mortality resulting from meningitis (urban: −5.22%, 95% CI: −5.66% to −4.78%; rural: −4.51%, 95% CI: −5.04% to −3.98%). However, slight variances were observed in the annual changes between both genders. The decline in overall meningitis mortality was noticeably sharper in females compared to males in both urban (−5.49% vs. −4.83%) and rural areas (−5.25% vs. −3.88%). Also, the local drift curves for rural and urban locales displayed a predominantly positive U-shape. The decline was steepest for the 20–29 age group and routinely decreased with age in the 0–19 and 20–89 age groups. The curves demonstrated relative consistency between urban and rural areas, with the exception of the advanced age group.Figure 2.
Net and local changes in mortality rates from meningitis and the associated gender disparities observed across different regions in China, 1987–2021. (A) Net and local drifts in urban areas. (B) Net and local drifts in rural areas.
Figures 3, 4, and 5 delineate estimates of age, period, and cohort effects on the mortality rates due to meningitis. The impact of age on mortality remained consistent across both genders and geographical locations, viz., urban and rural regions. Mortality rates due to meningitis were observed to peak during the 0–4 age range, after which they noticeably plummeted in the 5–9 age range. Post this decrease, the rates were largely stable, maintaining a minimal level across the 10–89 age brackets. Period effects demonstrated a similar consistently diminishing trend from 1987 to 2006 before entering a period of stability post-2007, irrespective of gender and location. Despite this, variations were noted in the period effects of urban and rural mortality rates due to meningitis, with the disparity between genders being less pronounced in urban areas in comparison to rural areas. Furthermore, cohort rate ratios exhibited a similar downward trend across genders and geographical locations. For cohorts born post-1952, the mortality rates due to meningitis have maintained a uniformly low level.Figure 3.
Parameter estimates of the effect of age on mortality rates due to meningitis in China from 1987 to 2021. (A) Age effects in urban areas. (B) Age effects in rural areas.Figure 5.
Estimated parameters of the cohort effect on the mortality rate from meningitis in China, 1987–2021. (A) Cohort effects in urban areas. (B) Cohort effects in rural areas.