Adequacy of anti-tuberculosis drug prescriptions in Viet Nam

SETTING: National Tuberculosis Program, Viet Nam, 2008. OBJECTIVES: To determine drug prescription adherence to national guidelines, to examine factors associated with an erroneous dosage of rifampin (RMP) and to evaluate the impact of an insufficient RMP dosage on treatment outcome. METHODS: A representative sample of 30 treatment units was randomly selected. All patient treatment cards enrolled in these units were obtained, and data were double-entered and validated before calculating the adequacy of the individual drug prescriptions. RESULTS: Of 3412 tuberculosis treatment cards, 3225 (94.5%) had information on treatment regimen and the patient's weight. Treatment was successful in 89.4%. Prescriptions of tablets/vials conforming to recommendations were found for respectively 91.2%, 89.9%, 92.3% and 94.6% of the patients for RMP/isoniazid, pyrazinamide, ethambutol and streptomycin. Patients in the 25-39 kg weight bracket received insufficient dosages. This was almost entirely attributable to patients at the end of the weight bracket. Nevertheless, no significant association was found between treatment failure and death, body weight and insufficient RMP dosage. CONCLUSIONS: Adherence to national recommendations was high. RMP was given in insufficient dosage for patients at the end of a weight range bracket, but the under-dosage was small and did not measurably affect treatment outcome.