The value of urine testing for verifying adherence to anti-tuberculosis chemotherapy in children and adults in Uganda.
METHODS
Mulago Hospital, Kampala, Uganda.


OBJECTIVE
To evaluate the usefulness of urine dipsticks for monitoring adherence to anti-tuberculosis chemotherapy.


METHODS
In-house urine dipsticks for detection of isoniazid (INH) metabolites were compared to commercial test strips. The value of n-butanol to detect rifampicin was compared to coloration of the urine. Non-adherence was assessed through a questionnaire and reviews of the Mulago Hospital TB register.


RESULTS
Urine was obtained from 236 patients (127 adults and 109 children) on daily chemotherapy. Using commercial test strips as standard, the sensitivity of in-house urine dipsticks was 99.5% and specificity was 96.4%. The sensitivity and the specificity of n-butanol and of coloration of urine to detect rifampicin were low (64.0% and 54.9%, and 85.5% and 64.8%, respectively). Fifty patients (21.2%) admitted non-adherence to treatment during the previous month. An additional 15 (6.8%) were detected through urine testing. Of 911 patients in the TB register of Mulago Hospital who had started treatment in the first 3 months of 2000, 39.7% did not complete their treatment. Two-thirds of these had discontinued treatment in the first 2 months.


CONCLUSIONS
In-house INH test strips are as effective as commercially available strips for detecting isoniazid in the urine. They are a simple tool for monitoring adherence. Adherence to anti-tuberculosis chemotherapy as determined by the use of isoniazid test strips and review of the TB register showed poor compliance. Tests for rifampicin are less sensitive and specific.
D020001:1-Butanol; D000328:Adult; D000995:Antitubercular Agents / Q000627:therapeutic use* / Q000652:urine*; D002648:Child; D005188:False Negative Reactions; D005189:False Positive Reactions; D006801:Humans; D007538:Isoniazid / Q000627:therapeutic use* / Q000652:urine*; D010349:Patient Compliance; D015203:Reproducibility of Results; D012293:Rifampin / Q000627:therapeutic use* / Q000652:urine*; D012680:Sensitivity and Specificity; D014376:Tuberculosis / Q000188:drug therapy*; D014454:Uganda; D016482:Urinalysis
D000995:Antitubercular Agents; D020001:1-Butanol; D007538:Isoniazid; D012293:Rifampin