Gender and diagnostic shifts in TB trends: Insights from 15-year data in Northwest China.

BACKGROUND: China faces a severe tuberculosis (TB) situation, particularly in Xinjiang. This study analyzed the influence of age, period, and birth cohort on TB incidence trends in the region.

METHODS: Trends in incidence and inflection points were analyzed using a joinpoint regression model (JPR) based on pooled data of pulmonary tuberculosis (PTB) case reports from 2006 to 2020. An age-period-cohort (APC) model based on intrinsic estimation (IE) was used to analyze the impact coefficients, which were transformed into relative risks (RR) to estimate trends.

RESULTS: From 2006 to 2020, the incidence of TB in Urumqi declined at an average rate of 4% per year, according to JPR. APC analysis model showed the highest age effect at ages 20-24 years (RR = 1.81) and 80-84 years (RR = 2.22). Females aged 85-89 showed a decreasing trend in incidence, while males experienced a sharp increase. The risk of the two diagnostic types was initially the same; bacteriological diagnoses had a higher risk of morbidity (RR = 1.14) compared to clinical diagnoses during 2016-2020. The cohort effect was highest in 1973-1977 (RR = 2.71) and then declined rapidly, particularly in bacteriological diagnosis from 1978 onwards.

CONCLUSIONS: While TB incidence in Urumqi has declined, young adults (20-24) and the elderly (≥70) remain high-risk groups. The effects of gender and diagnosis type varied by age, period, and cohort. These findings help identify at-risk populations and inform targeted interventions.