Patient Adherence to Tuberculosis Treatment: A Systematic Review of Qualitative Research

Background: Tuberculosis (TB) is a major contributor to the global burden of disease and has received considerable attention in recent years, particularly in low- and middle-income countries where it is closely associated with HIV/AIDS. Poor adherence to treatment is common despite various interventions aimed at improving treatment completion. Lack of a comprehensive and holistic understanding of barriers to and facilitators of, treatment adherence is currently a major obstacle to finding effective solutions. The aim of this systematic review of qualitative studies was to understand the factors considered important by patients, caregivers and health care providers in contributing to TB medication adherence. Methods and Findings: We searched 19 electronic databases (1966–February 2005) for qualitative studies on patients', caregivers', or health care providers' perceptions of adherence to preventive or curative TB treatment with the free text terms “Tuberculosis AND (adherence OR compliance OR concordance)”. We supplemented our search with citation searches and by consulting experts. For included studies, study quality was assessed using a predetermined checklist and data were extracted independently onto a standard form. We then followed Noblit and Hare's method of meta-ethnography to synthesize the findings, using both reciprocal translation and line-of-argument synthesis. We screened 7,814 citations and selected 44 articles that met the prespecified inclusion criteria. The synthesis offers an overview of qualitative evidence derived from these multiple international studies. We identified eight major themes across the studies: organisation of treatment and care; interpretations of illness and wellness; the financial burden of treatment; knowledge, attitudes, and beliefs about treatment; law and immigration; personal characteristics and adherence behaviour; side effects; and family, community, and household support. Our interpretation of the themes across all studies produced a line-of-argument synthesis describing how four major factors interact to affect adherence to TB treatment: structural factors, including poverty and gender discrimination; the social context; health service factors; and personal factors. The findings of this study are limited by the quality and foci of the included studies. Conclusions: Adherence to the long course of TB treatment is a complex, dynamic phenomenon with a wide range of factors impacting on treatment-taking behaviour. Patients' adherence to their medication regimens was influenced by the interaction of a number of these factors. The findings of our review could help inform the development of patient-centred interventions and of interventions to address structural barriers to treatment adherence. From a systematic review of qualitative research, Munro and coauthors found that a range of interacting factors can lead to patients deciding not to complete their course of tuberculosis treatment. Background.: Every year nearly nine million people develop tuberculosis—a contagious infection, usually of the lungs—and about two million people die from the disease. Tuberculosis is caused by Mycobacterium tuberculosis, bacteria that are spread in airborne droplets when people with active tuberculosis sneeze or cough. Tuberculosis can be cured by taking several strong antibiotics daily for at least six months but many patients fail to complete this treatment because the drugs have unpleasant side-effects and the treatment is complicated. In addition, people often feel better soon after starting treatment so they stop taking their tablets before all the bacteria in their body are dead. Poor treatment adherence (poor compliance) means that people remain infectious for longer and are more likely to relapse and die. It also contributes to the emergence of drug-resistant tuberculosis. To help people complete their treatment, the World Health Organization recommends a strategy known as DOTS (directly observed treatment, short course). As part of this strategy, a health worker or a tuberculosis treatment supporter—a person nominated by the health worker and the patient—watches the patient take his/her antibiotics. Why Was This Study Done?: Although DOTS has contributed to improved tuberculosis control, better patient compliance is needed to halt the global tuberculosis epidemic. Treatment adherence is a complex behavioral issue and improving treatment outcomes for tuberculosis (and for other diseases) requires a full understanding of the factors that prevent people taking medicines correctly and those that help them complete their treatment. In this study, the researchers have done a systematic review (a study in which the medical literature is surveyed and appraised using defined methods to reach a consensus view on a specific question) of qualitative studies that asked patients, carers, and health workers which factors contributed to adherence to tuberculosis treatment. Qualitative studies collect non-quantitative data so, for example, a qualitative study on tuberculosis treatment might ask people how the treatment made them feel whereas a quantitative study might count bacteria in patient samples. What Did the Researchers Do and Find?: The researchers searched electronic databases and reference lists for qualitative studies on adherence to tuberculosis treatments and also consulted experts on tuberculosis treatment. They carefully read the 44 published papers that met their predefined inclusion criteria and then used a method called “meta-ethnography” to compare the factors (themes) associated with good or bad adherence in the different studies and to synthesize (reach) a consensus view of which factors influence adherence to tuberculosis treatment. The researchers identified eight major factors associated with adherence to treatment. These included: health service factors such as the organization of treatment and care; social context (family, community and household influences); and the financial burden of treatment. Finally, the researchers interpreted the themes that emerged from the studies to build a simple model that proposes that adherence to tuberculosis treatment is influenced by four interacting sets of factors—structural factors (including poverty and gender discrimination), social context factors, health service factors, and personal factors (including attitudes towards treatment and illness). What Do These Findings Mean?: The findings of this systematic review of qualitative research on patient adherence to tuberculosis treatment are inevitably limited by the quality and scope of the original research. Consequently, further studies into patients' understanding of tuberculosis and its treatment are needed. Nevertheless, the findings and the model proposed by the researchers indicate that patients often take their tuberculosis medications under very difficult conditions and that they cannot control many of the factors that prevent them taking their drugs. So, although current efforts to improve adherence to tuberculosis treatments emphasize instilling a willingness to take their medications into patients, this systematic review suggests that more must be done to address how factors such as poverty and gender affect treatment adherence and to tailor support systems to patients' needs. Most importantly, it indicates that future interventions should involve patients more in the decisions made about their treatment. Additional Information.: Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0040238.