Objective   To study risk factors of pulmonary tuberculosis(TB)among farmers who ou-tmigrated for work.

  Methods   A case-control study method was conducted; 51 new smear positive pulmonary TB patients, who had ou-tmigrated for work during the last 3 years, in the ag-egroup 25~60, notified and registered by four county's anti-TB institutions in Henan from October 2002~March 2004, were selected as cases; at the same time, 57 healthy persons in the same age-group with the case, who had also out-migrated for work in the past 3 years, were selected as controls from right and left neighbors of the cases.Each interview was carried out with a unifoumly designed questionnaire in the home of the surveyed subjects; models of the univariate and multivariate logistic regressions were used for statistics analysis.

  Results   The results of univariate analysis showed four factors of ou-tmig rating for work were significantly associated with TB(P < 0.05)i.e.poor workplace condition, long work hours a day, no rest day each week and not taking meals at regular time.Two other factors were alsor isks for TB, marital status(single)and positive smoking history.Multivariate analysis by logistic regression showed that after adjusting for effects of each of the other determinants in the model, poor workplace conditions, long work hours a day, no rest day each week and single marital status, all remained significantly associated with TB(P < 0.05), with Odds Ratios equal to 3.82, 4.45, 3.30 and 5.61, respectively.

  Conclusion   Poor workplace conditions, long work hours(> 8 hours/day)and not having a rest day each week are all work-related risk factors of pulmonary TB among rural adults out-migrating for work.It will do good to the health of farmers of ou-tmig rating for work and TB control in Henan to improve the work environment and safeguard the legal rest time of farmers of ou-tmigrating for work.