Dots therapy in community health nursing
This article is about the tuberculosis treatment strategy. For the brand of gumdrops, see Dots (candy)
Directly observed treatment, short-course (DOTS, also known as TB-DOTS) is the name given to the tuberculosis (TB) control strategy recommended by the World Health Organization. According to WHO, “The most cost-effective way to stop the spread of TB in communities with a high incidence is by curing it. The best curative method for TB is known as DOTS.” DOTS has five main components:
- Government commitment (including political will at all levels, and establishment of a centralized and prioritized system of TB monitoring, recording and training)
- Case detection by sputum smear microscopy
- Standardized treatment regimen directly of six to nine months observed by a healthcare worker or community health worker for at least the first two months
- Drug supply
- A standardized recording and reporting system that allows assessment of treatment results
The technical strategy for DOTS was developed by Karel Styblo of the International Union Against TB & Lung Disease in the 1970s and 80s, primarily in Tanzania, but also in Malawi, Nicaragua and Mozambique. Styblo refined “a treatment system of checks and balances that provided high cure rates at a cost affordable for most developing countries.” This increased the proportion of people cured of TB from 40% to nearly 80%, costing up to $10 per life saved and $3 per new infection avoided.
In 2007, WHO and the World Bank began investigating the potential expansion of this strategy. In July 2008, the World Bank invited Styblo and WHO to design a TB control project for China. By the end of 2007 this pilot project was achieving phenomenal results, more than doubling cure rates among TB patients. China soon extended this project to cover half the country.
During the early 1990s, WHO determined that of the nearly 700 different tasks involved in Styblo’s meticulous system, only 100 of them were essential to run an effective TB control program. From this, WHO’s relatively small TB unit at that time, led by Arata Kochi, developed an even more concise “Framework for TB Control” focusing on five main elements and nine key operations. The initial emphasis was on “DOT, or directly observed therapy, using a specific combination of TB medicines known as short-course chemotherapy as one of the five essential elements for controlling TB. In 1993, the World Bank’s Word Development Report claimed that the TB control strategies used in DOTS were one of the most cost-effective public health investments.
In the Fall of 1994, Kraig Klaudt, WHO’s TB Advocacy Officer, developed the name and concept for a marketing strategy to brand this complex public health intervention. To help market “DOTS” to global and national decision makers, turning the word “dots” upside down to spell “stop” proved a memorable shorthand that promoted “Stop TB. Use Dots!”
According to POZ Magazine, “You know the worldwide epidemic of TB is entering a critical stage when the cash-strapped World Health Organization spends a fortune on glossy paper, morbid photos and an interactive, spinning (!) cover for its 1995 TB report.” India’s Joint Effort to Eradicate TB NGO observed that, ”DOTS became a clarion call for TB control programmes around the world. Because of its novelty, this health intervention quickly captured the attention of even those outside of the international health community.”
The DOTS report was released to the public on March 20, 1995, at New York City’s Health Department. At the news conference, Tom Frieden, head of the city’s Bureau of TB Control captured the essence of DOTS, “TB control is basically a management problem.” Frieden had been credited for using the strategy to turn around New York City’s TB outbreak a few years earlier.
On March 19, 1997, at the Robert Koch Institute in Berlin, Germany, WHO announced that “DOTS was the biggest health breakthrough of the decade.” According to WHO Director-General Hiroshi Nakajima, “We anticipate that at least 10 million deaths from TB will be prevented in the next ten years with the introduction and extensive use of the DOTS strategy.”  Upon Nakajima’s death in 2013, WHO recognized that the promotion of DOTS was one of WHO’s most successful programs developed during his ten-year administration.
There has been a steady uptake of DOTS TB control services over the subsequent decades. Whereas less than 2% of infectious TB patients were being detected and cured, with DOTS treatment services in 1990 approximately 60% have been benefitted from this care. Since 1995, 41 million people have been successfully treated and up to 6 million lives saved through DOTS and the Stop TB Strategy. 5.8 million TB cases were notified through DOTS programs in 2009.
A systematic review of randomized clinical trials found no difference for cure rates as well as the treatment completion rates between directly observed therapy (DOT) and self-administered drug therapy. A 2013 meta-analysis of both clinical trials and observational studies too did not find any difference between DOTS and self-administered therapy. However, the WHO and all other TB programs continue to use DOTS as an important strategy for TB delivery for fear of drug resistance.
DOTS-Plus is for multi-drug-resistant tuberculosis (MDR-TB).
This systematic review and meta-analysis of eight studies that compared treatment outcomes of CB DOT with clinic DOT showed that CB DOT was associated with higher treatment success than clinic DOT. There was substantial inter-study heterogeneity associated with this pooled analysis. However, the benefit from CB DOT for treatment success compared to clinic DOT was also seen when including only prospective studies in the meta-analysis, with markedly less heterogeneity among studies. There was no significant difference between CB DOT and clinic DOT for the secondary outcome of loss to follow-up.
Strengths of our review are strict in- and exclusion criteria with clear definitions for CB DOT and clinic DOT, study selection and data extraction by independent reviewers and selection of the primary and secondary outcome prior to performing the review.
Our review also has several limitations. It is possible that we may have missed some studies despite a comprehensive literature search. The meta-analysis was limited by substantial inter-study heterogeneity. However, there was significantly less heterogeneity among prospective studies only, and a meta-analysis of this subgroup confirmed a higher treatment success rate with CB DOT compared to clinic DOT. Furthermore, the quality of the reviewed studies was generally low (see quality assessment in Additional file 4). As in all systematic reviews, reporting bias has to be considered. However, as there are less than ten studies in this meta-analysis, funnel plot asymmetry tests are not appropriate as “the power of the tests is too low to distinguish chance from real asymmetry” (, section 10.4.3.1). Following from these limitations, the result of the meta-analysis for treatment success needs to be interpreted with caution.
Studies in which CB DOT and clinic DOT programmes could not be directly compared (criterion 5), or where an allocation bias was evident (criterion 6), were excluded from this review (these are listed in Additional file 2). However, the included studies were still subject to risk of bias (see Additional file 4 for these assessments). Some points warrant further examination to ensure that the higher treatment success for CB DOT found in our meta-analysis was truly due to type of DOT supervision rather than due to systematic differences between the clinic DOT and CB DOT groups.
In the RCT from Tanzania, the largest treatment centre in the study was randomised to clinic DOT . According to the study authors, this centre was likely to have had a higher proportion of patients with relatively more severe TB and thus with a lower likelihood of treatment success, compared to other study areas. This was a weakness of the cluster randomisation design and the authors note that their study “may have resulted in an overestimate of the benefits of CBDOT”. Other potential sources of bias in this RCT were unclear method of randomisation, inadequate (or unclear) allocation concealment and blinding of assessors, and a 31% loss to follow-up. This overall risk of bias means that this RCT constitutes relatively low quality evidence according to the GRADE criteria . The study that allowed for supervisor self-selection for those patients randomly allocated to DOT (as opposed to SAT) was obviously prone to a substantial risk of selection bias . Another important source of potential allocation bias was involvement of health workers in the decision who would receive CB DOT or clinic DOT [26,30,31]. None of these studies outlined any criteria to guide this allocation. While we cannot exclude that some of the potential selection biases discussed above impacted on overall treatment success for CB DOT and clinic DOT, none of the included studies had an apparent systematic selection bias for including patients in either the CB DOT or clinic DOT group, thus making it likely that the type of DOT was indeed the major cause of the difference in treatment outcomes.
While patient self-selection of DOT supervisor and/or consultation with a health worker adds potential study bias, patient-centred DOT allocation may be an important factor in treatment success. The authors of the study from Thailand, in which DOT led to higher cure and treatment completion rates than SAT, noted that: “Giving patients a variety of supervision options and focusing on their convenience may have contributed to the comparatively favourable results in this study” . CB DOT removes the need to attend the clinic daily for TB treatment and this may help to address some of the barriers– which include time away from work–faced by patients receiving DOT . Non-randomised studies where CB DOT and clinic DOT were assigned to patients from ‘unmatched’ geographical locations (e.g. rural for CB DOT versus urban for clinic DOT) were excluded from the review [12,49,50]. While this exclusion was made to increase the likelihood that differences in treatment outcomes were attributable to the DOT type rather than other factors, it may be that patients living greater distances from health facilities will benefit most from CB DOT being made available as a treatment option. Indeed, the results for CB DOT in terms of cure were at least equivalent to clinic DOT in each of these three studies [12,49,50]. While it may be beneficial in many cases, some risks, such as stigma, can still be associated with CB DOT. In the study from Zambia, many of the patients not previously registered with the ‘home care programme’ which delivered CB DOT, opted for clinic DOT instead (see risk of bias assessment in Additional file 4 for more details) . This was due to the perception that community members would assume that they had HIV as well as TB if they saw community observers visiting them .
A limitation of the meta-analysis was that it did not allow to definitely establish the reason for increased treatment success among patients receiving CB DOT. Increased treatment success could be the consequence of lower rates of loss to follow-up (the secondary outcome for our study), lower rates of treatment failure or lower rates of death. While it is generally justified to assume that a significant proportion of treatment failures is caused by lack of adherence to TB treatment, undiagnosed drug-resistance of M. tuberculosis can substantially contribute to treatment failures in settings with relatively high proportions of drug-resistance in the community and lack of routine testing for drug-susceptibility . However, it is unlikely that patients with epidemiological and medical risk factors for drug-resistant (DR) TB (such as retreatment cases, all data for meta-analyses were for newly diagnosed patients) were over-represented in the clinic DOT group, which would have affected treatment outcomes. This is again due to the exclusion of studies with apparent systematic selection bias for patient allocation to CB DOT or clinic DOT.
The forest plot for the secondary outcome – loss to follow up (Figure 4) – showed a wide spread of results. Brief discussion of the study showing higher loss to follow-up for CB DOT relative to clinic DOT in our meta-analysis is provided in Additional file 3 . While numbers lost to follow-up can be seen as being patients who ‘defaulted’ on treatment, it is also possible that in some cases this outcome was a reflection of the quality of the research study as well as of outcomes of the DOT programme. The authors of the RCT report that the pragmatic nature of the trial “was largely the reason for a higher than-desirable number of missing outcomes” , reflecting the difficulties conducting this kind of research. In most of the included studies a specific definition for the loss to follow-up (or default) outcome was not provided [13,20,27,29,31]. Thus there is a risk that in some cases the patients assigned as being lost to follow-up were actually ‘not evaluated’ (e.g. ‘transferred out’) according to WHO treatment outcome definitions . Even so, results for ‘transferred out’ were reported for all but one of the studies where the loss to follow-up definition was not specifically defined  meaning that this should have had a limited impact on the secondary outcome meta-analysis, and no impact on the treatment success meta-analysis result.
A Cochrane review assessed TB treatment success of DOT compared to SAT and if this was affected by the type of supervision provided in the DOT group . The authors only identified one RCT that compared CB DOT and clinic DOT. This RCT- that we have also included in our meta-analysis- did not show any significant difference between CB DOT and clinic DOT in terms of cure .
A systematic review and meta-analysis published in 2009 examined the impact of different designs of CB DOT programmes on treatment outcomes . Components of CB DOT programmes were categorised into patient, operational, and organisational characteristics. Studies in which the community-based supervisor was a health professional, family member, CHW or CV were included; though supervision needed to be at a place other than a health facility or ‘TB club’. It showed a possible (albeit plausibly due to chance) benefit from offering a financial reward to DOT supervisors (85.7% versus 77.6% for treatment completion, p = 0.15). The effectiveness in terms of treatment outcomes of CB DOT compared to clinic DOT was not examined in that review.
In the studies included in our systematic review, financial incentives to CHWs or CVs were not offered for providing DOT, or it was not stated whether these were provided or not (see Additional file 3 for further details about individual studies). However, using incentives as a motivator for DOT supervisors appears to be a common practice. This could be in the form of a regular salary, for example in the case of health extension workers in southern Ethiopia  or treatment supporters in South Africa . Other forms of remuneration for treatment supervisors, sometimes involving patient co-payments, are also described in the literature .
Additional qualitative and quantitative aspects of community involvement in TB care have also been discussed in a review article and a WHO report [4,32]. These focused on the design of CB DOT programmes and their place in a wider policy context. Issues of accountability of CHWs or CVs, the need for training and variation in the quality of community-based supervision were raised by individual studies included in our review and these are important to consider during CB DOT programme design and monitoring.
While we acknowledge that the result of this systematic review has to be interpreted with caution, given the limitations outlined above, the result of higher treatment success is encouraging given the potential role of CB DOT as a means of treatment supervision, especially in resource-constrained settings.
CB DOT may also provide a means by which DR TB (multidrug-resistant (MDR)-TB or extensively drug-resistant (XDR) TB) can be supervised effectively, although all of the included studies in this review reported outcomes for patients treated with regimens for drug-sensitive TB. A recently published systematic review and meta-analysis – published prior to but indexed after our database search – has reported treatment outcomes from community-based DR TB programmes, though it did not compare the treatment success of CB DOT with conventional clinic DOT and none of the included studies were eligible for our review . The review showed a pooled treatment success of 65% for 1,288 patients across ten studies with community-based interventions (including DOT by family members, neighbours, co-workers, local health care workers and former patients). This is comparable to outcomes seen in earlier meta-analyses of DR-TB treatment success [55-57].