Effectiveness of the direct observation component of DOTS for tuberculosis: a randomised controlled trial in Pakistan

Clinical and laboratory observations of tuberculosis at a Mumbai (India) clinic

OBJECTIVES

To study the positivity of sputum acid fast bacilli (AFB) smears in patients with pulmonary tuberculosis using 24 hour sputum collection. To detect HIV seropositivity in patients suffering from tuberculosis, and to analyse the pattern of tuberculosis disease in this subgroup. To determine the outcome of patients treated with directly observed therapy.

SETTING

The tuberculosis referral unit of a tertiary care hospital.

DESIGN

A total of 893 consecutive patients with tuberculosis, diagnosed between 1 November 2000 and 30 September 2002, were included in the study. An HIV test was performed in all patients, with adequate counselling and informed consent. Treatment was prescribed as per World Health Organisation treatment categories.

RESULTS

Out of 893 patients with tuberculosis, 695 had pulmonary tuberculosis and 198 had extrapulmonary tuberculosis. Out of the 695 pulmonary tuberculosis patients, 673 (96.8%) were sputum smear AFB positive. Overall, 71 patients (8.0%) were HIV positive. The pattern of tuberculosis was the same in HIV seropositive and seronegative patients. Treatment outcome could be analysed in 112 out of 150 patients: 78 patients (70%) were declared cured or completed treatment.

CONCLUSIONS

Sputum smear AFB could be a very sensitive test when a large quantity of sputum is used. The presence of HIV coinfection does not alter the clinical presentation. Only 70% of patients treated were cured/completed treatment, in spite of a strict directly observed therapy.

Critical reflections on evidence, ethics and effectiveness in the management of tuberculosis: public health and global perspectives

Background

Tuberculosis is a major cause of morbidity and mortality globally. Recent scholarly attention to public health ethics provides an opportunity to analyze several ethical issues raised by the global tuberculosis pandemic.

Discussion

Recently articulated frameworks for public health ethics emphasize the importance of effectiveness in the justification of public health action. This paper critically reviews the relationship between these frameworks and the published evidence of effectiveness of tuberculosis interventions, with a specific focus on the controversies engendered by the endorsement of programs of service delivery that emphasize direct observation of therapy. The role of global economic inequities in perpetuating the tuberculosis pandemic is also discussed.

Summary

Tuberculosis is a complex but well understood disease that raises important ethical challenges for emerging frameworks in public health ethics. The exact role of effectiveness as a criterion for judging the ethics of interventions needs greater discussion and analysis. Emerging frameworks are silent about the economic conditions contributing to the global burden of illness associated with tuberculosis and this requires remediation.

The role of DOTS in tuberculosis treatment and control

Directly Observed Therapy Shortcourse (DOTS) is composed of five distinct elements: political commitment; microscopy services; drug supplies; surveillance and monitoring systems and use of highly efficacious regimens; and direct observation of treatment. The difference in the way the term 'DOTS' as defined by WHO and interpreted by many observers has led to some misunderstanding. WHO generally uses the term to mean the five components of DOTS. But the word 'DOTS' is an acronym for Directly Observed Therapy Shortcourse. Many workers therefore interpret DOTS purely as direct supervision of therapy. DOTS is not an end in itself but a means to an end. In fact it has two purposes, to ensure that the patient with tuberculosis (TB) completes therapy to cure and to prevent drug resistance from developing in the community. The main criticism of DOTS rightly derives from the fact that some properly conducted randomized, controlled trials of directly observed therapy with or without the other components have shown no benefit from it. The problem is that it is impossible to design a study of modern directly observed therapy against the previous self-administered, poorly-resourced programs. As soon as a study is implemented, the attention to patients in the control (non-directly observed therapy) arm inevitably improves from the previous non-trial service situation. What is of concern is that in some trials less than 70% cure rates were achieved even in the direct observation arm. With no new drugs or adjuvant treatment available to bring the length of treatment down to substantially less than 6 months, DOTS offers the best means we have at our disposal for TB control.

Strong general health care systems: a prerequisite to reach global tuberculosis control targets

We argue that tuberculosis control cannot reach its proposed global targets without investment in an adequate network of accessible, effective and comprehensive health services. Lessons from the past are reviewed. They underscore that passive case-detection and adequate case management is the central technical strategy for tuberculosis control. There is no compelling evidence to support active case-detection in the general population. We elaborate on why a strong health care system is a prerequisite in the framework of case-detection and treatment. The necessity to improve quality and accessibility of general health services for ensuring early detection and subsequent cure is demonstrated. It is argued why the need for strong public health care system becomes even more eminent in the light of the tuberculosis/HIV dual epidemics and of the rapid growth of unregulated private-for-profit services. We finally examine the financial gaps for tuberculosis control and discuss the need for allocating more resources to the strengthening of general health care systems.

Identifying the determinants of tuberculosis control in resource-poor countries: insights from a qualitative study in The Gambia

Despite the availability of effective treatment, tuberculosis (TB) remains a major cause of death from an infectious disease in the world, particularly in resource-poor countries. Among the chief reasons for this are deficiencies in case tracing and in adherence to treatment. In order to investigate the contribution of non-biological factors to these deficiencies, we carried out a qualitative study in The Gambia, West Africa, from October 2000 to March 2001. The methods used were focus group discussions, interviews, participant and non-participant observation, and case histories. Four domains were distinctively investigated: the TB patients, the community, the health care providers (including programme staff), and the donors and policy makers. Analysis of the data from all these sources indicated the contribution of a wide range of socio-anthropological factors which influence the success or otherwise of the TB control programme in The Gambia, i.e. gender, urban/rural residence, recourse to traditional healers, adherence to national health policies, knowledge about TB, migration, and socio-economic factors. It is concluded that all these factors must be taken into account in formulating interventions to improve detection of TB cases and patient adherence to treatment within the framework of the national TB control programmes, and proposals have been made for targeted interventions.

Adherence to tuberculosis treatment: lessons from the urban setting of Delhi, India

The Revised National Tuberculosis Control Programme (RNTCP), which incorporated the WHO DOTS strategy was introduced in India in the mid-1990s. An operational research project was conducted between 1996 and 1998 to assess the needs and perspectives of patients and providers in two chest clinics in Delhi, Moti Nagar and Nehru Nagar, during the introduction of the new strategy. This paper reports on the findings of the project, concentrating on information collected from 40 in-depth interviews with patient defaulters and from non-participant observations in clinics and directly observed treatment centres. In Moti Nagar chest clinic, 117 of 1786 (6.5%) patients and 195 of 1890 (10%) patients in Nehru Nagar left care before their treatment was complete. It was argued that the reasons for default stem from a poor correlation between patient and programme needs and priorities, and from particular characteristics of the disease and its treatment. Patient needs that were not met by the health system included convenient clinic timings, arrangements for the provision for treatment in the event of a family emergency and provision for complicated cases like alcoholics. The problems facing the provider were poor interpersonal communication with the health staff, lack of attention and support at the clinic, difficulty for patients to re-enter the system if they missed treatment and, in certain areas, long distances to the clinic. Problems related to diseases were inability of the staff to deal with drug side-effects, and patients' conception of equating well-being with cure. Simple, practical measures could improve the provision of tuberculosis (TB) treatment: more flexible hours, allowances for poor patients to reach the clinics and training health care staff for respectful communication and monitoring drug side-effects. The findings indicate a need to rethink the label of 'defaulter' often given to the patients. The important areas for future operational research is also highlighted.

Doubts about DOT: antiretroviral therapy for resource-poor countries

INTRODUCTION

Directly observed therapy programs developed for tuberculosis (TB) have been suggested as a model for the provision of HIV medications in resource-poor countries in order to ensure adherence and prevent drug resistance.

METHODS

Opinions were formed based on a review of scientific literature regarding the effectiveness of witnessed dosing in directly observed TB therapy programs, adherence to HIV antiretroviral therapy in resource-rich and resource-poor settings, relationship between adherence and HIV antiretroviral drug resistance, HIV viral load and risk of HIV transmission, and stigmatization concerns related to HIV and TB in resource-poor settings.

RESULTS/CONCLUSIONS

We suggest that the enthusiasm for HIV directly observed therapy programs is premature based on: equivocal evidence that witnessed dosing is superior to self administered therapy; mistaken assumptions that resource-poor countries are a 'special case' with respect to adherence; possible paradoxical impact of good adherence on HIV drug resistance; unproven efficacy of antiretroviral therapy in preventing HIV transmission; and potential stigmatization of daily antiretroviral dosing.

The use of computational QSAR analysis in the toxicological evaluation of a series of 2-pyridylcarboxamidrazone candidate anti-tuberculosis compounds

A series of N(1)-benzylidene pyridine-2-carboxamidrazone anti-tuberculosis compounds has been evaluated for their cytotoxicity using human mononuclear leucocytes (MNL) as target cells. All eight compounds were significantly more toxic than dimethyl sulphoxide control and isoniazid (INH) with the exception of a 4-methoxy-3-(2-phenylethyloxy) derivative, which was not significantly different in toxicity compared with INH. The most toxic agent was an ethoxy derivative, followed by 3-nitro, 4-methoxy, dimethylpropyl, 4-methylbenzyloxy, 3-methoxy-4-(-2-phenylethyloxy) and 4-benzyloxy in rank order. In comparison with the effect of selected carboxamidrazone agents on cells alone, the presence of either N-acetyl cysteine (NAC) or glutathione caused a significant reduction in the toxicity of INH, as well as on the 4-benzyloxy derivative, although both increased the toxicity of a 4-N,N-dimethylamino-1-naphthylidene and a 2-t-butylthio derivative. The derivatives from this and three previous studies were subjected to computational analysis in order to derive equations designed to establish quantitative structure activity relationships for these agents. Twenty-five compounds were thus resolved into two groups (1 and 2), which on analysis yielded equations with r(2) values in the range 0.65-0.92. Group 1 shares a common mode of toxicity related to hydrophobicity, where cytotoxicity peaked at logP of 3.2, while Group 2 toxicity was strongly related to ionisation potential. The presence of thiols such as NAC and GSH both promoted and attenuated toxicity in selected compounds from Group 1, suggesting that secondary mechanisms of toxicity were operating. These studies will facilitate the design of future low toxicity high activity anti-tubercular carboxamidrazone agents.

Global plagues and the Global Fund: Challenges in the fight against HIV, TB and malaria

BACKGROUND: Although a grossly disproportionate burden of disease from HIV/AIDS, TB and malaria remains in the Global South, these infectious diseases have finally risen to the top of the international agenda in recent years. Ideal strategies for combating these diseases must balance the advantages and disadvantages of 'vertical' disease control programs and 'horizontal' capacity-building approaches. DISCUSSION: The Global Fund to Fight AIDS, Tuberculosis and Malaria (GFATM) represents an important step forward in the struggle against these pathogens. While its goals are laudable, significant barriers persist. Most significant is the pitiful lack of funds committed by world governments, particularly those of the very G8 countries whose discussions gave rise to the Fund. A drastic scaling up of resources is the first clear requirement for the GFATM to live up to the international community's lofty intentions. A directly related issue is that of maintaining a strong commitment to the treatment of the three diseases along with traditional prevention approaches, with the ensuing debates over providing affordable access to medications in the face of the pharmaceutical industry's vigorous protection of patent rights. SUMMARY: At this early point in the Fund's history, it remains to be seen how these issues will be resolved at the programming level. Nevertheless, it is clear that significant structural changes are required in such domains as global spending priorities, debt relief, trade policy, and corporate responsibility. HIV/AIDS, tuberculosis and malaria are global problems borne of gross socioeconomic inequality, and their solutions require correspondingly geopolitical solutions.

Evaluation of efficacy of community-based vs. institutional-based direct observed short-course treatment for the control of tuberculosis in Kilombero district, Tanzania

Tuberculosis (TB) has reappeared as a serious public health problem. Non-compliance to antituber-culous drug treatment is cited as one of the major obstacles to the containment of the epidemic. Compliance may be optimized by Directly Observed Treatment (DOT) and short-course treatment regimens. Since 1986, Tanzanian TB patients have received daily DOT at health facilities for the first 2 months of the treatment course. However, adherence and cure rates have been falling as the number of TB cases continues to increase and the burden on already stretched health facilities threatens to become unmanageable. We used an open cluster randomized controlled trial to compare community-based DOT (CBDOT) using a short-course drug regimen with institutional-based DOT (IBDOT). A total of 522 (301 IBDOT and 221 CBDOT) patients with sputum-positive TB were recruited. Overall, there was no significant difference in conversion and cure rates between the two strategies [M-H pooled odds ratio (OR) 0.62; 95% confidence interval (CI) 0.23, 1.71 and OR = 1.58; 95% CI 0.32, 7.88, respectively] suggesting that CBDOT may be a viable alternative to IBDOT. CBDOT may be particularly useful in parts of the country where people live far from health facilities.

A literature review of the problems of delayed presentation for treatment and non-completion of treatment for tuberculosis in less developed countries and ways of addressing these problems using particular implementations of the DOTS strategy

Tuberculosis is the cause of a large burden of disease in less developed countries. With the development of drug resistance and the co-epidemic of HIV, tuberculosis has already started to make a comeback in wealthier countries. The WHO's solution to this global tuberculosis epidemic is the DOTS strategy, the implementation of which presents many problems. The two issues most common to the majority of locations are delay in presentation for treatment and non-completion of treatment. This review looks at the reasons for these problems in the less developed world, and addresses some solutions. The main reasons for delayed presentation are: a lack of understanding about TB; the stigma associated with the disease; the inaccessibility of treatment; and a preference for private practitioners. The main reasons for non-completion of treatment are: the stigma of the disease; a lack of information; dissatisfaction with the treatment and its delivery; and inaccessibility of treatment. Successful implementations of the DOTS strategy need to address all these issues. There is little evidence that DOT enhances treatment completion unless combined with other strategies. Community-based, patient-orientated DOTS appears to be an appropriate way of addressing many of these issues. The involvement of volunteers in community-based strategies is common, but needs more research in order for this strategy to realise its full potential.

The relationship between disease control strategies and health system development: the case of TB

This paper focuses on the lack of dialogue and policy consonance between those taking the lead in health systems change and those developing specific disease control strategies. In the first part, the origins and characteristics of this situation are explained using, as an example, TB control. Attention is then paid to the development of disease control friendly health systems. Four aspects of policy development are analysed paying particular attention to TB control: analysis of policy context, mechanisms for collaboration between policy actors; agreement on decision-making processes; development of common aims and objectives. Although the focus is on TB control, the principles illustrated carry some relevance for other disease control programmes.

Directly administered antiretroviral therapy in the treatment of HIV infection: benefit or burden?

While combination antiretroviral treatment has had a profound impact on the morbidity and mortality of human immunodeficiency virus (HIV) infection, the adherence demands of this therapy are high and failure to maintain viral suppression is common. Directly administered antiretroviral therapy (DAART) has garnered attention recently as a strategy to improve medication adherence and clinical outcomes in HIV-infected individuals. This review is intended to provide an update on the use of DAART and the challenges posed by this strategy, explore settings in which DAART may be used, discuss the role of antiretroviral regimens with improved pharmacokinetic features, and propose future directions for DAART strategies. DAART is modeled on directly observed therapy (DOT) for the treatment of tuberculosis. However, differences in curability, medication dosing frequency, duration of treatment, and the biologic dynamics of infection, pose unique challenges to DAART strategies. Numerous settings have been proposed for DAART, including community based outreach programs, prisons, long-term care facilities, substance abuse treatment sites, and resource-poor countries. Experience with DAART to date has been limited to pilot studies or retrospective comparisons. The prospect of simplified, once-daily antiretroviral therapy holds promise for DAART. However, improvements in antiretroviral therapy may also improve outcomes in patients taking therapy on a self-administered basis. Randomized controlled trials of DAART are needed before this strategy can be embraced in any setting. In future studies it will be important to compare DAART with self-administered therapy in terms of initial virologic and immunologic responses, durability of responses, the development of antiretroviral resistance, and cost effectiveness.

The prevention of mental disorders in young people

The prevention of some mental disorders in young people appears to be possible. Several small and medium randomised controlled trials show that some anxiety, affective and substance-use disorders can be prevented. These trials show that the interventions are efficacious, but whether they will be effective in routine practice is not known. The evidence is sufficiently good to warrant a large community trial in which the roll-out is staged and school communities evaluated before and after the roll-out.

Research that influences policy and practice - characteristics of operational research to improve malaria control in Mpumalanga Province, South Africa

BACKGROUND

Much communicable disease control research has had little impact on local control programme policy and practice for want of an operational component. The operational research model - the systematic search for knowledge on interventions, tools or strategies that enhance programme effectiveness - is gaining recognition as an appropriate method for addressing perplexing questions within public health programmes.

METHODS

A series of operational research studies were conducted to refine malaria diagnosis in Mpumalanga Province, South Africa between 1995 and 1999. The grounded theory approach was used with groups of experienced Masters of Public Health students in South Africa and Australia to analyse a compilation of these studies for determining positive and negative attributes of operational research that affect its ability to influence communicable disease control policy and practice.

RESULTS

The principal positive attributes of the operational research studies were high local relevance, greater ability to convince local decision-makers, relatively short lag-time before implementation of findings, and the cost-effective nature of this form of research. Potential negative features elicited included opportunities forfeited by using scarce resources to conduct research and the need to adequately train local health staff in research methodology to ensure valid results and accurate interpretation of findings.

CONCLUSIONS

Operational research effectively influenced disease control policy and practice in rural South Africa, by providing relevant answers to local questions and engaging policy-makers. This resulted in accelerated inclusion of appropriate measures into a local communicable disease control programme.

Has directly observed treatment improved outcomes for patients with tuberculosis in southern Thailand?

OBJECTIVE

To validate the practice of directly observed treatment (DOT) and evaluate its effect on treatment outcomes.

METHODS

This follow-up study conducted in 24 districts in southern Thailand included 411 new, smear-positive, pulmonary tuberculosis (TB) patients who started treatment between February and September 1999. Patients and/or their observers were interviewed about their actual DOT practice during the first 2 months of treatment. Treatment outcomes were evaluated at the end of the second month and at the end of treatment.

RESULTS

Of 411 patients, 379 were assigned to DOT but only 68 practised strict DOT for every dose during the first 2 months. Adjusted odds ratios (ORs) for 'no sputum conversion' and 'unsuccessful treatment' were 1.1 (95% CI 0.6-2.1) and 1.3 (95% CI 0.6-2.8), respectively, for those who practised strict DOT vs. the rest.

CONCLUSIONS

Actual practice of DOT was quite different from what was intended at the assignment. Practice of strict DOT during the first 2 months was not associated with sputum conversion or treatment success in this study area.

The global tuberculosis situation. Progress and problems in the 20th century, prospects for the 21st century

Mycobacterium tuberculosis has been identified in prehistoric remains of humans. Despite references to TB by Hippocrates and Galen, humankind had limited understanding of and few tools to defend itself against TB until the later 19th century. Subsequently, landmark advances in the 20th century provided the means to control and prevent this disease. At the same time, epidemiological developments and fundamental problems related to human behavior, socioeconomic conditions, and political circumstances continue to thwart efforts to diminish the burden of suffering and death caused by TB. This article reviewed some of these issues including the global failure of TB control in the late 20th century, the worldwide emergence of drug-resistant TB, the extensive spread of HIV infection and its impact on TB incidence; and changing health care and political environments. The obstacles to TB control remain and will remain challenges in the coming years. Still, recent developments in immunology, biochemistry, and molecular biology suggest that new knowledge and tools are just around the corner. These will enhance the ability to conquer this microbe by the end of the current century.

Pharmaceuticals and the developing world

Pharmaceuticals have greatly improved health in developing countries, but many people in developing countries do not obtain even inexpensive pharmaceuticals and little pharmaceutical R&D is oriented toward products needed by developing countries, such as a malaria vaccine. Access to existing products could be improved by facilitating differential pricing, for example by subsidizing donation programs, and reforming health care delivery. R&D incentives could be improved if rich countries or international organization committed to purchase needed products when they are developed and make them available to the poor.

Missed opportunities? Coercion or commitment: policies of prevention

The DOTS strategy (directly observed therapy, short course) has been the cornerstone of international TB control policy since the early 1990s. This strategy has provided the international community with an advocacy tool to harness funds for TB as well as a method for helping country programs to achieve high cure rates for TB. But as much as the strategy is seen as successful by some, it is perceived as unsuccessful by others. This paper looks at the results of the introduction of DOTS into control programs and discusses research relating to direct observation of treatment. It asks how policies like DOTS are created, and how they are administered and transferred from the international to the national and finally to the local level. The discipline of public health policy is used to interrogate the creation and history of the DOTS strategy in order to find ways of aiding the transfer of the policy to national and local levels. Finally, the paper asks whether the concepts of "control" and "elimination" continue to be useful in the management of infectious diseases. We ask whether it is time to change the perspective to policies that focus more on the context of implementation and the importance of the development of care, integration, and flexibility rather than cure, targets, and short-term solutions.