Patient choice promotes adherence in preventive treatment for latent tuberculosis

The aim of the present study was to compare the effect of patient choice on completion rates and adverse drug reactions for patients treated for latent tuberculosis infection (LTBI) using 3-month rifampicin and isoniazid treatment (3RH) or 6-month isoniazid treatment (6H). Data for all patients treated using 3RH or 6H for LTBI between 1998 and 2004 were analysed. In total, 675 patients attended for chemoprophylaxis. Of these, 314 received 3RH and 277 received 6H. From April 1, 2000, patients were offered a choice of regimen; 53.5% completed the regimen successfully, a further 10.3% potentially completed it successfully and 36.2% failed to complete treatment. Logistic regression analysis suggested that successful completion was more likely in patients who were younger (an association that was lost after removing all patients aged <16 yrs), were offered a choice of regimen and attended all clinic visits before commencing treatment. Treatment was discontinued due to adverse reactions in 16 (5.1 %) patients who were prescribed 3RH and 16 (5.8%) who were prescribed 6H. Treatment failure was most likely during the first 4 weeks of treatment for both regimens. At 13 weeks of treatment, more patients taking 6H had stopped compared with those completing the 3RH regimen. Drug costs were greater using 6H compared with 3RH. In conclusion, offering a choice of regimen improves completion. Most patients chose the 3-month rifampicin and isoniazid treatment over the 6-month isoniazid treatment. Adverse drug reaction rates between the two regimens were similar.