Evaluation of the Arkansas method of urine testing for isoniazid in South Africa
International Journal of Tuberculosis and Lung Disease
Aurum Institute for Health Research, Johannesburg, South Africa; Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa; London School of Hygiene and Tropical Medicine, London, United Kingdom; Aurum Institute for Health Research, 47 Main Street, Marshalltown, 2107, South Africa
SETTING: A South African hospital serving gold mine employees. OBJECTIVE: To determine the sensitivity and specificity of the Arkansas method for detecting isoniazid (INH) metabolites among South African adults and to examine the effect of smoking status on positive results. DESIGN: Urine specimens were collected from in-patients taking INH as part of tuberculosis treatment at 6, 12 and 24 h after a directly observed 300 mg oral dose. As a control group, a single urine specimen was collected from surgical in-patients not taking INH. Specimens were tested for INH using a commercially available dipstick. RESULTS: A total of 153 patients on INH and 60 controis were recruited. The sensitivity of the test was 93.3% (95%CI 88.1-96.8) at 6 h post INH, 93.4% (95%CI 88.2-96.8) at 12 h and 77% (95%CI 69.1-83.7) at 24 h. The specificity of the test was 98.3% (95%CI 91.1->99.9). There was no association between smoking status and colour change of positive results. CONCLUSIONS: This test is a useful method of monitoring adherence to TB treatment or preventive therapy among South Africans. However, it is less than 100% sensitive, especially with increasing time post dose, which should be taken into consideration when interpreting results for individual patients. © 2007 The Union.
drug metabolite; isoniazid; tuberculostatic agent; adult; article; cigarette smoking; controlled study; female; human; major clinical study; male; medical assessment; priority journal; sensitivity and specificity; South Africa; tuberculosis; United States; urinalysis; Adult; Antitubercular Agents; Cross-Sectional Studies; Humans; Isoniazid; Male; Middle Aged; Patient Compliance; Sensitivity and Specificity; Smoking; South Africa; Tuberculosis