Sarah Walpole discusses the controversial DOT-Directly Observed Therapy

Tuberculosis is the most prevalent infectious disease worldwide. Due to its highly infectious nature, effective treatment is crucial to prevent the spread of tuberculosis. Ensuring a substantial reduction in the incidence of tuberculosis requires treatment success rates of at least 70-85%, (1) as an infected individual may pass the disease on to between 10 and 15 people per year if they are not treated. (2)

The standard recommended regimen for treatment of patients with tuberculosis is an intensive two-month phase of treatment with rifampicin, isoniazid, pyrazinamide and ethambutol, followed by four months of treatment with rifampicin and isoniazid only. (3) For this treatment to be effective, it not only requires the correct drugs to be available and accessible to the patient, but it also requires the patient to accept the medication.

The burden of tuberculosis is greatest in developing countries, and it is with this in mind that World Health Organisation (WHO) has focused its efforts on designing a treatment system. The treatment system that WHO advocates is DOTS, or directly-observed therapy short-course. DOTS is a system for treatment which addresses government commitment, case detection, drug supply and monitoring and evaluation, but this article will focus on a fifth part of the DOTS strategy: treatment supervision and patient support.

Treatment plan
DOT or directly observed treatment is promoted by WHO and involves a key worker giving and observing a patient taking medication. The key worker may be a trained healthcare worker, but could also be a member of the public, such as a relative or a shop keeper, in which case there is another party involved in the treatment plan.

Direct observation has been criticized for reducing patient autonomy, (4) but in the context of a plan designed by patient-provider partnership, direct observation can help to overcome barriers such as travel and fitting treatment into daily activities. Many studies find that the overall cost of treatment of tuberculosis is less where DOT is used, (5) (6) and based on a review of papers about tuberculosis treatment, Chan and Iseman (7) find that DOT can ensure effective treatment of patients. They claim that falling case rates of tuberculosis between 2000 and 2005 in the USA are partly attributable to successful implementation of DOT.

A treatment plan should be formulated taking into account external environmental, financial and psychosocial factors, which can all affect the treatment regime. The frequency of, setting and observer for directly observed treatment should be decided by the patient and their key worker. For example, an intermittent treatment regime can be used, where treatment is given three times weekly, instead of daily.

Partnership
Effective treatment can only be achieved where there is an effective patient-provider partnership. If treatment fails it is not only the fault of the patient, as a shared responsibility exists. The partnership requires mutual understanding; each party being aware of and understanding the other’s perspective and priorities, as well as being aware of external factors that affect the treatment regime.

The provider should be aware of the patient’s beliefs and understanding, and the patient should be aware of understand the aims and mechanisms of treatment. The initial intensive phase of the standard regime is designed to rapidly kill tuberculosis bacteria, and, as well as leaving a patient non-infectious, this phase of treatment reduces symptoms. When a patient is very unwell, the benefit of treatment is more apparent, and treatment becomes a higher priority, but where an asymptomatic patient is unlikely to make sacrifices to access treatment unless they understand the rationale behind the medication.

Barriers
Barriers to successful treatment include both structural and social factors. Anthropological research is useful in highlighting what patients perceive to be barriers to treatment. In America, a Refugee Preventive Health Service provides treatment to refugees, and an ethnographic study found that the services provided to this group were a barrier to treatment. Narratives from 24 individuals found that the setting of the clinic and attitude of the staff were barriers to compliance. Homeless people slept outside the clinic overnight, and some of the service users did not feel safe attending the clinic. (8)

Structural barriers include the cost and availability of drugs, and the ability of a patient to reach healthcare. Direct observation demands a large amount of time from a key worker and human or financial resources for this are not always available. Financial barriers are especially relevant where the cost of medication is a high proportion of a person’s income, but even in the UK, the recent removal of prescription costs for tuberculosis treatment is heralded as an important step in ensuring patient compliance. It is also important to recognise peripheral costs of accessing treatment, which include financial transport costs and time costs. A patient is often forced to prioritise, and given a choice between buying tuberculosis treatment and buying food for their family, the latter is likely to take priority.

Social barriers can also include stigma and cultural beliefs. For example, in a Vietnamese refugee population in America, difficulties with compliance arise from a perception that anti-tuberculosis medicines are “hot”, that is they can upset a person’s internal balance and health. (8)

However, cultural beliefs are often blamed for late presentation and ineffective treatment, where economic factors may be more important. For example, Valeza and McDougall doubled compliance in an area in the Philippines by making medication more accessible. (9) Farmer’s research in Haiti finds that hunger and poverty are key factors contributing to non-compliance. (10)

Patient Autonomy
Successful treatment allows a patient to be autonomous, that is, to govern his / herself. Autonomy requires both license and the resources to make decisions. Therefore, someone with tuberculosis not only needs information, understanding and support to make their own decisions to take treatment, but they also require the resources to be available.

It is often not possible to provide optimum services, but discussion should lead to mutual understanding and permit patients to capitalize on whatever resources are available. To be in with any chance of reducing the global burden of TB, local partnerships between patients and healthcare providers must be encouraged and supported.

Sarah Walpole
Fourth Year Medical student
Leeds Medical School
Worsley Building
Clarendon Way
Leeds
LS2 9NL
argotomunky@yahoo.co.uk

(1) Bock N (2004) What is the significance of default (treatment interruption) in the treatment of tuberculosis? In: WHO, Toman’s Tuberculosis: Case detection, treatment, and monitoring, questions and answers. 2^nd ed. Geneva: WHO.

(2) WHO, Tuberculosis fact sheet. http://www.who.int/mediacentre/factsheets/fs104/en/index.html,

(3) National Institute for Clinical Excellance (2006) CG33 Tuberculosis: NICE guideline, 22 March 2006.http://guidance.nice.org.uk/CG33/niceguidance/pdf/English, 2007.

(4) Walley JD, Khan MA, Newell JN, Khan MH Effectiveness of the direct observation component of DOTS for tuberculosis: a randomised controlled trial in Pakistan. The Lancet, 357; 9257: 664-669, 3 March 2001.

(5) Burman WJ, Dalton CB, Cohn DL, Butler JRG, Reves RR. A cost-effectiveness analysis of directly observed therapy vs self-administered therapy for treatment of tuberculosis. Chest 1997; 112: 63-70.

(6) Chaulk CP, Kazandjian VA. Directly observed therapy for treatment completion of pulmonary tuberculosis: consensus statement of the Public Health Tuberculosis Guidelines Panel. JAMA 1998; 279: 943-948.

(7) Chan ED, Iseman MD, Current medical treatment for tuberculosis. BMJ, Nov 2002; 325: 1282-1286.

(8) Ito KL, Health Culture and the Clinical Encounter: Vietnamese Refugees’ Responses to Preventive Drug Treatment of Inactive Tuberculosis. Medical Anthropology Quarterly, New Series, Vol. 13, No. 3. (Sep., 1999): 338-364.

(9)Valeza, McDougall, cited in Sumartoho E, “When tuberculosis treatment fails: a social behavioural account of patient adherence.” Am. Rev of Resp. Dis., 147: 1314, 1993.

(10) Farmer P “Infections and inequalities: the modern plagues“. London: University of California Press, 1999.

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