The relative merits of a fully supervised twice weekly regimen of Streptomycin and INH (SHtW) and an unsupervised daily regimen of INH and Thioacetazone (TH) in routine programme conditions in an urban area are compared in terms of acceptability and response to treatment at one year. Of the 474 newly diagnosed sputum positive cases at Lady Willingdon TB Demonstration & Training Centre, Bangalore during 1968-69, 134 were allocated to SHtW regimen and 189 to TH regimen. All others who were unwilling to take the allocated regimen or were excretors of bacilli resistant to INH and or SM were analysed as a subsidiary group.

About 25% of the patients allocated to SHtW regimen expressed unwillingness to start treatment on account of unsuitability of working hours and or distance. Refusal to TH regimen was negligible (5%). As regards drug acceptability after start of treatment, while the duration of treatment taken was similar for both the regimens, the level of drug intake achieved by the SHtW patients was lower compared with TH patients i.e., 31.3% of the SHtW patients and 56.1% of TH patients took more than 80% of treatment. If concealed irregularity among TH patients is taken into consideration, it is likely that the drug intake among TH patients would be similar to the drug intake among SHtW patients. The acceptability was therefore almost similar among SHtW and TH patients. Very low level (28%) of treatment completion was achieved by SHtW patients. With TH regimen, 46% had made 10 or more monthly collections during 12 months. Among the SHtW patients there was greater irregularity in the later months which was not apparent among TH patients. However, the favourable response among patients on SHtW and on TH regimen was 68% and 60% respectively. Deaths among SHtW patients were 4%, 13.5% among TH patients, the difference being statistically significant. The response was directly related to the level of drug collection or supervised consumption. The large proportion of the patients who stopped treatment prematurely, continued to remain positive with drug sensitive organisms, if initially they were so. In the subsidiary group there were 62 patients who were excretors of drug resistant organisms. They were treated with drugs to which their organisms were resistant and nearly 30% of these patients had negative culture at the end of one year.

It is concluded that (i) SHtW regimen was superior to TH as it prevented deaths and showed better bacteriological conversion among patients with level 3 & 4 of treatment and (ii) treatment organization is the most important factor in obtaining better results in routine chemotherapy with available drug regimens.