Abstract: Objective To recheck the accuracy of PT H of cases enrolled in WHO DRS in Henan and to evaluate the role of PTH rechecki ng and its influent factors.Method Doctors from 30 DRS counties were trained and 1?080 cas es without PTH in the first inquiry were rechecked.Survey was conducted by arous ing and recalling of PTH,and unified forms were filled.Cases rechecked by provin cial level randomly.Results The rechecking agreement rate is 95.7% between the prov incial and county level.Out of which,cases with and without PTH is 84.4% and 100 % respectively,42.7% cases without PTH in the first inquiry recalled their PTH.T he rate with PTH of drug resistant cases is 62.0%,and it is 31.7% for drug sensi tive cases.Cases with PTH because of non_tuberculosis infectious diseases were more than those because of tuberculosis(1.17∶1).Out of cases with PTH more than one month,drug resistant group is more than drug sensitive group(37.2% and 16.8 %,respectively)and TB group is more than non_TB infectious disease group(82.0% a nd 35.9% respectively).In TB group,INH and RFP were mainly used,and in non_TB gr oup,SM and RFP were mainly used.Conclusion PTH rechecking is an effective quality control meth od for DRS.It will make DRS results more accurate.During PTH inquiring,guideline ,content,method should be unified,technicians should be trained.This work can be done accompanied with regular supervision.Results which got by trained doctors, are reliable.TB drugs were used for non_TB infection should not be ignored.PTH<1 month will be classified as new case in WHO DRS guideline.This criterion is not scientific.It will affect accuracy of initial drug resistance rate.

Key words: Tuberculosis, Drug resistance, Surveillace, Treament history