Abstract:

Objective To explore the effects and roles of active and passive methods in detection of patients with pulmonary tuberculosis (PTB) by comparing and analyzing the characteristics of detected TB cases in 9 districts/counties in Sichuan Province.Methods The information and data of active PTB patients, who were detected through active screening method at township level (hereinafter referred to as “active case detection”) in 9 counties in Sichuan Province from 2012 to 2016, were collected; at the same time, the information and data of active PTB patients, who were detected through passive method (such as sought of health care with symptoms, referral and tracing) and notified in the China CDC’s TB recording and reporting system (hereinafter referred to as “passive case detection”) in the same areas and same period, were also collected. The social and demographical characteristics, clinical features, as well as the results of laboratory examinations, etc. in two groups of patients were compared. The count variables were analyzed by using Chi-square test and P<0.05 was regarded as a statistically significant difference.Results A total of 272 active PTB patients were detected through active case detection method and the detection rate was 498.87/100000 (272/54523); among those 272 cases, 71 cases were asymptomatic (26.10%, 71/272). In the same areas and same period, a total of 1868 active PTB cases were detected through passive case detection method and registered. The registration rate was 67.04/100000 (347/517584) and 78.36/100000 (374/472596), 63.76/100000 (300/470504) respectively in 2014, 2015 and 2016. The registration rate of active PTB patients in these 3 years was no significantly difference ($\chi^2_{趋势}$=0.288, P=0.591). The average age of the patients in the active case detection group was (56.76±16.64) years old, which was higher than that of patients in the passive case detecting group ((44.70±18.38) years old) (U=158318.500, P=0.000). The proportion of patients aged ≥60 years in the active case detection group (52.57%, 143/272) was significantly higher than that of patients in the passive case detection group,(25.37%, 474/1 868) (χ²=99.831, P=0.000); the proportion of patients living in village in the active case detect group (80.51%, 219/272) was significantly higher than that of patients in the passive case detection group (45.88%, 857/1 868) (χ²=113.941, P=0.000). In the active case detection group, the proportions of patients with sputum smear positive (19.12%, 52/272) and cavities (11.03%, 30/272) were significantly lower than those of patients in the passive case detection group (31.16%, 582/1 868 and 24.68%, 461/1868 respectively) (χ²=23.311 and 25.020, P=0.000). The constituent ratios of the patients detected by active and passive case detection methods in 9 counties were significantly different in the 5 years (χ²=90.000, P=0.000); the constituent ratio of the patients living in villages and detected through passive case detection method (79.65%, 857/1076) was significantly lower than that of patients living in cities (95.02%, 1011/1064)(χ²=113.941, P=0.000).Conclusion Active case detection method can be a helpful supplement to passive case detection method. It has great value on improving case detection, especially in rural areas and the elderly.

Key words: Tuberculosis, pulmonary, Epidemiology, Multiphasic screening, Office visits, Comparative study