TY - JOUR
T1 - Should we take a history of prior treatment, and check sputum status at 2-3 months when treating patients for tuberculosis?
AU - Wilkinson, David
AU - Bechan, S.
AU - Connolly, C.
AU - Standing, E.
AU - Short, G. M.
PY - 1998
Y1 - 1998
N2 - SETTING: Pinetown, South Africa (1975-1983). OBJECTIVE: To determine the value of previous treatment history and sputum smear examination at 2-3 months in predicting treatment failure and relapse in tuberculosis patients treated with four drugs given twice weekly for six months under direct observation. DESIGN: Four cohort studies among 562 ambulant adults with culture positive pulmonary tuberculosis, designed to test the effectiveness of isoniazid 600-900 mg, rifampicin 600 mg, pyrazinamide 2-3 g, and streptomycin 1-2 g, given twice weekly. The same drug regimen was given to all patients irrespective of previous treatment history. Therapy was not changed if smears remained positive at 2-3 months. RESULTS: Positive predictive values of a history of previous treatment for a positive smear at 2-3 months (18.3%), treatment failure (5.2%), and relapse (9.4%) were poor. Although patients with positive smears at 2-3 months were more likely to fail therapy than patients with negative smears (relative risk = 4.5, 95% Confidence Interval [CI]: 1.6-12.8), positive predictive value for treatment failure was only 12.5%. Although relapse was more frequent in patients with positive smears than those with negative smears (9.7% vs 6.2%; P = 0.4), most patients who relapsed had been smear negative at 2-3 months (18/21). CONCLUSION: A four-drug rifampicin-containing regimen can safely be given twice weekly under direct observation to both new and retreatment cases, and the 2-3 month smear examination can safely be omitted.
AB - SETTING: Pinetown, South Africa (1975-1983). OBJECTIVE: To determine the value of previous treatment history and sputum smear examination at 2-3 months in predicting treatment failure and relapse in tuberculosis patients treated with four drugs given twice weekly for six months under direct observation. DESIGN: Four cohort studies among 562 ambulant adults with culture positive pulmonary tuberculosis, designed to test the effectiveness of isoniazid 600-900 mg, rifampicin 600 mg, pyrazinamide 2-3 g, and streptomycin 1-2 g, given twice weekly. The same drug regimen was given to all patients irrespective of previous treatment history. Therapy was not changed if smears remained positive at 2-3 months. RESULTS: Positive predictive values of a history of previous treatment for a positive smear at 2-3 months (18.3%), treatment failure (5.2%), and relapse (9.4%) were poor. Although patients with positive smears at 2-3 months were more likely to fail therapy than patients with negative smears (relative risk = 4.5, 95% Confidence Interval [CI]: 1.6-12.8), positive predictive value for treatment failure was only 12.5%. Although relapse was more frequent in patients with positive smears than those with negative smears (9.7% vs 6.2%; P = 0.4), most patients who relapsed had been smear negative at 2-3 months (18/21). CONCLUSION: A four-drug rifampicin-containing regimen can safely be given twice weekly under direct observation to both new and retreatment cases, and the 2-3 month smear examination can safely be omitted.
KW - Sputum smear examination
KW - Treatment history
KW - Tuberculosis
UR - http://www.scopus.com/inward/record.url?scp=0031935245&partnerID=8YFLogxK
M3 - Article
C2 - 9562111
AN - SCOPUS:0031935245
SN - 1027-3719
VL - 2
SP - 52
EP - 55
JO - International Journal of Tuberculosis and Lung Disease
JF - International Journal of Tuberculosis and Lung Disease
IS - 1
ER -