Background: Japanese national tuberculosis control program (NTP) has included indiscriminate chest X-ray examination for adult population.
Methods: A comparative study on the severity of pulmonary tuberculosis cases in a hospital in Tokyo by the mode of detection (between cases found by periodical check and cases found by symptomatic visit) and previous history of X-ray examination (among cases detected by periodical check, cases detected by symptomatic visit but with previous history of periodical check and cases without history of chest X-ray examination during the past 3 years).
Results: The comparison between patients found by symptomatic visit with and without previous history of periodical check showed that there was no difference in the grade of sputum smear positivity at the time of diagnosis but that those without previous history of periodical check were more serious as to chest X-ray findings. The comparison between patients found by symptomatic visit with previous history of periodical check and those detected by the periodical check showed that the grade of smear positivity was less among those found by the periodical check but no difference as to chest X-ray findings, however, comparing cases of these two categories in the age group of 40-59, those detected by the periodical check were less serious as to both X-ray findings and smear result. There were 21 persons who were indicated requiring further investigation but actually were not examined. The severity of tuberculosis among these 21 persons were more serious as to the grade of smear positivity than those detected by periodical X-ray examination.