Comparison of a urine spot test and blood tests as indicators of patient compliance

Irregular drug intake has been a concern of leprosy control programmes for many years and various methods have been used to monitor and encourage patient compliance. This study compares the results of a urine spot test for dapsone as proposed by Huikeshoven, with blood levels measured in the same patients by the modified Bratton Marshall method and by high performance liquid chromatography. Two hundred-sixty urine and blood specimens were obtained from subjects who were taking supervised and unsupervised medications as well as from controls who were taking no medications. The results indicate that the urine spot test is simple and easily performed, and for monitoring patient compliance under routine clinical conditions (hospital or field work) it compares favourably with blood levels of dapsone estimated by the Bratton Marshall method or by high performance liquid chromatography. The study also shows that dapsone level is not a good indicator of compliance in patients who are also taking daily rifampicin but the urine spot test remains useful in such patients.