Abstract
Background: Extrapulmonary tuberculosis (EPTB) is a significant health problem which can lead to severe morbidity and mortality. In clinical practice, EPTB can have a variety of nonspecific clinical manifestations and can be concurrent with other types of EPTB. As information pertaining to concurrent EPTB is scarce, research efforts are needed to find concurrent EPTB types and to explore the association networks and rules of concurrent EPTB. Materials and Methods: An observational multicenter study was carried out at 21 hospitals from 15 provinces in China from Jan 1, 2011, to Dec 31, 2017. All the adult EPTB inpatients (≥ 15 years) were included. Multivariable logistic regression analysis was used to examine the associations of gender and age group for concurrent EPTB. The association network and rules for concurrent EPTB were analyzed by the Apriori algorithm. Results: A total of 75,993 adult EPTB inpatients (not including EPTB concurrent with PTB) were included. The ratio of male:female was 1.32. The most common types of EPTB lesions were tuberculous pleurisy (46.47%). In the fully adjusted multivariable logistic regression models, it was found that female EPTB patients (aOR = 1.129, 95% CI: 1.081-1.178) were more likely to have concurrent EPTB. As age increased, the risk of concurrent EPTB decreased (aOR < 1, p value for trend < 0.001). The association network graph showed that almost all the EPTB diseases may be concurrent with other types of EPTB. Ureteric tuberculosis and sacral tuberculosis diseases existed mainly in concurrence with other types of EPTB (about 80%). Tuberculous pleurisy and tuberculous lymphadenitis of the neck could be concurrent with more than 60 other types of EPTB disease. The most common concurrent EPTB types were tuberculous peritonitis concurrent with tuberculous pleurisy (1.64%). Sacral tuberculosis concurrentwith lumbar vertebra tuberculosis had the highest confidence value (68.56%). The strongest association rule was found for vesical tuberculosis concurrent with ureteric tuberculosis (lift = 166.18) and ureteric tuberculosis concurrent with vesical tuberculosis (lift = 166.18). Conclusion: The present study revealed the occurrence of concurrent EPTB types and analyzed the association network and rules among adult EPTB for the first time in a large sample population. Clinicians should be alert to the incidence of concurrent EPTB and that these patients require administration of customized treatment regimens in order to achieve the best outcomes.