Abstract: Objective To optimize strategies for pulmonary tuberculosis (PTB) case finding in elderly people through cost-effectinveness analyses, and provide scientific evidences of such cases finding strategies for policy maker in China. Methods Using decision tree to conduct cost-effectiveness analysis of different straregies which are used for finding PTB patients, then to get an optimal strategy. It is assumed that there is a crowd of 500000 people, and the elderly people(≥60 years old) of it are the target group in this study. Using sofeware TreeAge ProSuite 2011 to build decision tree models, including 3 strategies: (1) For the elderly people who have PTB symptoms and can see a doctor actively: chest X-ray and sputum smear microscopy should be taken. (2)Firstly, clue investigation should be taken to the target groups. And then, chest X-ray and sputum smear microscopy may be given to those who are symptomatic candidates going to clinic actively and from clue investigation. (3) For all the elderly people: firstly, symptom screening and chest X-ray should be taken. And then, sputum smear microscopy may be given to those who have clinical manifestation or have been suspected pulmonary tuberculosis by chest X-ray. To collect parameters and scopes of the parameters, carry out cost-effectiveness analyses to confirm the optimal strategy, and carry out sensitivity analyses to check out the stability of the models. Results Strategy 3 (For all the elderly people: firstly, symptom screening and chest X-ray should be taken. And then, sputum smear microscopy may be given to those who have clinical manifestation or have been suspected pulmonary tuberculosis by chest X-ray) was the most productive one for PTB case finding, which could find 713 PTB patients; strategy 1(For the elderly people who have PTB symptoms and can see a doctor: chest X-ray and sputum smear microscopy should be taken) was the most efficient one, which would cost 551 Yuan for one PTB patient. The sensitivity analyses showed that the results of the model analyses were not affected by the scopes of the parameters. Conclusion To find more PTB patients, case finding in elderly people should strategy 3. To be most efficient, case finding should take strategy 1 in elderly people. By now, it is not fit to the cost-effectiveness principle to finding PTB patients in elderly people all alone. It may be considered to do research in groups with multiple risks in future.

Key words: Tuberculosis, pulmonary/economics, Cost-benefit analysis, Decision trees, Aged