Useful research into human behaviour should take into account a wide range of approaches to enquiry, including qualitative and quantitative research methods. A review of the current literature on adherence to TB treatment has revealed a variety of research objectives, ranging from social and anthropological to clinical and programmatic studies. Further studies should be designed with the following aims:

• Define the theoretical models that underlie interventions to promote adherence to TB therapy.

• Describe the extent of various patterns of adherence (patients who take their medication sporadically, regularly take less than prescribed, and those who discontinue it completely).

• Explore the "active ingredients" of effective alliances between health providers and patients in a variety of sociocultural settings.

• Identify time-points in the case management at which different types of adherence strategy may have increased impact.

• Determine the efficacy and cost-effectiveness of specific interventions to improve adherence, as part of a complex health intervention necessary to achieve a high rate of treatment success.

• Priority should be given to studies in middle- and low-income countries to ensure the relevance of interventions to the settings in which most of the TB caseload occurs.