Incidence and risk factors of tuberculosis among the elderly population in China: a prospective cohort study

Abstract

Background: China is facing challenges of the shifting presentation of tuberculosis (TB) from younger to elderly due to an ageing population, longer life expectancy and reactivation disease. However, the burden of elderly TB and influence factors are not yet clear. To fill the gap, we generated a cohort study to measure the magnitude of TB incidence and associated factors among the elderly population aged 65 years and above in China. Methods: In this cohort established in 2013 through a prevalence survey conducted in selected sites, a total of 34 076 elderlies without TB were enrolled into two-year follow-up. We used both active and passive case findings to find out all TB patients among them. The person-year (PY) incidence rates for both bacteriologically positive TB and active TB were calculated. Cox proportional regression model was performed to test effect of risk factors, and the population attributable fraction (PAF) of each risk factor contributing to incident TB among elderlies was calculated. Results: Over the two-year follow-up period, a total of 215 incident active TB were identified, 62 of which were bacteriologically positive. The incidence rates for active TB and bacteriologically positive TB were 481.8 per 100 000 PY (95% CI: 417.4-546.2 per 100 000 PY) and 138.9 per 100 000 PY (95% CI: 104.4-173.5 per 100 000 PY), respectively. Incident cases detected by active case finding were significantly higher (P < 0.001). Male, non-Han nationality, previously treated TB, ex/current smoker and body mass index (BMI) < 18.5 presented as independent predictors for developing TB disease. For developing bacteriologically positive TB, the biggest contribution was from self-reported ex or current smoker (18.06%). And, for developing active TB, the biggest contribution was from non-Han nationality (35.40%), followed by male (26.80%) and age at 75 years and above (10.85%). Conclusions: Ageing population in China had a high TB incidence rate and risk to develop TB disease, implying that National TB Program (NTP) needs to prioritize for elderly. Active case finding should be applied capture more active TB cases among this particular population, especially for male, non-Han nationality, and those with identified risk factors.

The Epidemiological Characteristics of Pulmonary Tuberculosis — Kashgar Prefecture, Xinjiang Uygur Autonomous Region, China, 2011–2020

“…Overall, the distribution trend was similar to that of other prefectures of Xinjiang Uygur Autonomous Region and other provincial-level administrative divisions (10). The rise in the rate of reported PTB in the age groups above 50 years of age was similar to that of the whole Xinjiang Uygur Autonomous Region (11). The elderly population had lower immunity and was prone to comorbidity with other underlying diseases, making them a high-risk group for the reactivation of latent TB and development of new TB.…”

<p>Primary Drug-Resistance Pattern and Trend in Elderly Tuberculosis Patients in Shandong, China, from 2004 to 2019</p>

“…It means that we should put our sights on primary tuberculosis among the elderly, especially DR-TB, to face the problem which the aging population will bring. Previous studies on elderly TB in China showed that an aging population had a higher TB incidence rate and risk to develop TB disease, [11][12][13] Nevertheless, the studies on DR-TB in the elderly are few. Therefore, we investigated epidemiological characteristics and trend of primary DR-TB among the elderly in this study.…”

Analysis of the current status and associated factors of tuberculosis knowledge, attitudes, and practices among elderly people in Shenzhen: a cross-sectional study

“…As the population has aged rapidly in China in recent years, the WHO estimates that the number of elderly people in China will reach 402 million by 2040, accounting for 28% of the total population [ 2 ]. A cohort study in 2020 showed that the incidence and risk of TB among the elderly population increased with the ageing of the population in China, and the detection rate of TB among the elderly population was 481.8/100,000 [ 3 ]. The high incidence of TB among elderly people has introduced considerable challenges to the lives of Chinese people and China’s economy.…”