Crossing T’s And DOTing I’s: Is DOTS Enough To Improve Treatment Adherence?-Molly McCoy
Public Health Problem: Long-Term Medication Adherence in Tuberculosis
Tuberculosis (TB) infection and disease is an ongoing, long-existent global public health problem. TB is the leading infectious cause of adult death and disability in the world and is estimated to infect up to one third of the world's population and result in between two and three million deaths annually.(1) Although TB is treatable with antibiotics with a high cure-rate for those who are immune-competent, multi-drug resistant tuberculosis (MDR-TB) has emerged as a major obstacle for the control of TB worldwide.(2) MDR-TB is a result of incomplete or ineffective TB treatment. MDR-TB cases range up to 27% of cases as reported by the World Health Organization (WHO) and occur in areas with already established TB control programs, such as the WHO DOTS (directly observed treatment, short course) program.(3)
In 2009, the estimates for global burden of Tuberculosis were: 9.4 million incident cases, 14 million prevalent cases, and 1.3 million deaths among HIV-negative people.(4) These rates persist despite effective tuberculosis antibiotics having been available since the 1940’s.(5) Prevention, diagnosis, and treatment of tuberculosis latent infection and disease are becoming increasingly complex due to the development of drug-resistance and co-infection with Human Immunodeficiency Virus (HIV).
One of the biggest challenges faced in treatment of both active disease and latent infection is adherence to the treatment regimen.(6) The problem of low retention rates in treatment can be attributed to 1) the regimen’s length, which is nine months in the short-course regimen, 2) the number of pills in the regimen and side-effects, 3) low access to medical care, and 4) the effect of feeling better before treatment is complete, which can occur even months prior to completion.(6) All of these factors can lead to the behavior of stopping treatment. In addition, patients who are HIV-infected have even more complicated treatment regimens, which may lead to poorer adherence in this sub-population despite likelihood of more severe TB symptoms.(6)
The result of treatment default has severe consequences for both the individual and the community in which they live. For the individual, it can result in prolonged disease, relapse, development of drug-resistance, or even death.(5,6) Drug resistances is a problem because second round treatment is difficult, as some drugs may no longer work against that patient’s strain and second-line drugs to which it would be susceptible still are expensive and may be inaccessible. Treatment failure is also a problem for the greater community, because if the patient relapses he/she can infect others. If the strain of M. tuberculosis has developed drug-resistance, any infection transmission to others will be with this already resistant strain. At some DOTS program sites, adherence is reported to be as low as 50%.(5) Therefore, effective public health interventions, or the bolstering of current programs, are desperately needed to increase treatment adherence, particularly for high burden countries.
Intervention: Directly Observed Therapy, Short-course (DOTS)
The goal of TB control is to break the cycle of transmission by treating TB cases as early and efficiently as possible. In this effort, the WHO launched the ‘Directly Observed Therapy, Short-course’ (DOTS) strategy in 1994 in areas where tuberculosis disease burden was high.(7) The broader program strategy includes five key elements: political commitment, accessible laboratory services, strict supervision of each dose of treatment (DOT), uninterrupted supply of medications, and effective surveillance and monitoring systems for patient follow-up.(8) This strategy involves patients being directly observed when they take their medication every day over the six or nine months of treatment (short-course for latent infection and active disease respectively).(9) Observers can be “health workers, employers, or any responsible community member”.(9) The objective of DOTS is to ensure that patients complete their treatment course, and this in turn improves cure rates.(9) Cure rates have been reported up to 95% at various DOTS sites, unfortunately these results have not been replicated consistently under everyday conditions as opposed to clinical trials.(8) With such a comprehensive approach, it is hard to see why in some places the DOTS strategy could fail.
According to their 2010 global report, WHO declared that “between 1995 and 2009, a total of 41 million TB patients were successfully treated in DOTS programmes, and up to 6 million lives were saved including 2 million among women and children”.(4) This is evidence of great strides in the fight against TB. It is also important to note that as their target for treatment completion is 85%, and that for 2009 13/22 (59%) high burden countries met the target.(4) DOTS is considered to be the gold standard in treatment of TB.(7) However, some studies have found no significant differences in cure rates for patients in DOT compared with the control group who had self-administered treatment.(10) It is important to determine the effectiveness of the DOTS intervention, and where it falls short of the mark.
Despite DOTS program implementation across the world, there are still close to 9.5 million new cases per year worldwide.(4) Some countries still cannot achieve the WHO target of at least 85% treatment compliance.(4) Some reviews of the strategy find no difference in cure rates or rates of treatment completion between DOTS and the previously used self-administered treatment (SAT) model.(5,8)
Daunting questions remain: With treatment made readily available, why are some DOTS programs failing where others succeed? Why would people make the irrational health decision to discontinue treatment? What can public health do to rectify the flaws of DOTS interventions, as they currently exist?
To begin to answer these questions, we must first identify key elements of the DOTS program that are flawed. This critique will use theories of health behavior to explain where DOTS went wrong, and to formulate innovative strategies to increase TB treatment adherence in future interventions. First, although the overall program approach is composed of five key elements that take into consideration factors outside clinic treatment, the intervention itself is still rooted in individual-centered health behaviors models. Second, the DOTS approach fails to account for environmental and social factors influencing patient treatment adherence behavior. Finally, there is even potential for negative labeling and stigma under the current DOTS intervention.
Critique One: Use of Health Belief Model
The DOTS approach is inherently based on the patient making the rational decision to seek treatment, once diagnosed, and finish that treatment course until they are cured, based on weighing the pros and cons of that decision. If the patient were to make an irrational decision, as in not to accept or to discontinue treatment, the program fails. The only barriers to making the irrational decision that the program employs is the rigid approach at strict adherence through DOT, which makes patients accountable to the care-giver, and thus keeping them in treatment. Basically, this approach assumes that people will want to be cured of tuberculosis so they will go through the treatment plan as advised by the clinician. This foundation philosophy is similar to the health belief model.
The health belief model views health behavior change as based on a rational appraisal of the balance between the barriers to and benefits of action.(11) According to this model, the perceived seriousness of, and susceptibility to, a disease influence individual's perceived threat of disease.(11) So if tuberculosis is perceived to be a serious condition by the individual, and they are susceptible to death due to TB if they do not seek treatment, and the perceived threat of death is great, then they will seek treatment. Also, if they are in treatment, and they perceive the seriousness of their symptoms to be great, and believe they are susceptible to relapse if they quit treatment, then they will perceive that the treat of re-infection is great and will stay in treatment.
Similarly, perceived benefits and perceived barriers influence perceptions of the effectiveness of health behavior, which is this case in submitting to DOT.(11) Perceived benefits would be disease cure, assuming the patients believe the drugs will lead to a cure. Perceived barriers considered by the DOTS approach include drug supply and funding, which they impart as key elements of the program. The patient may or may not be aware of these measures, and may believe he/she does not have the money to pay for treatment, which would make going to the clinic at all an ineffective behavior if they believe they cannot access the treatment even if they do believe it works. There are other potential perceived barriers to treatment effectiveness, which the approach does not account for, some of which will be discussed later in this analysis.
This theory focuses on cognitive variables as part of behavior change, and assumes that attitudes and beliefs, as well as expectations of future events and outcomes, are major determinants of health related behaviors.(11) In the face of certain alternatives, this theory proposes that individuals will choose the action that will most likely lead to positive outcomes.(11) The program makes the assumption that patients will believe that the medications work, and therefore want the treatment. Depending on the region, there may be distrust of western medicine, alternative/traditional beliefs about cause and cure of tuberculosis, and numbers of patients stopping treatment early who then get sick again. All of these factors could affect the individual’s attitudes about the behavior of accepting treatment for nine months, and are not considered in individual-level models.
High-perceived threat, low barriers and high-perceived benefits to action increase the likelihood of engaging in the recommended behavior.(11) It has been suggested that the health belief model focuses on a single threat and prevention behavior and do not include possible additional threats competing for the individual's attention.(11) The DOTS approach functions mainly in the developing world, where these programs are most needed, so there are numerous competing threats the patient may weigh in when considering taking medication according to the regimen or not, as well as perceived barriers.
The patient may lose time and wages by making the required trip to the clinic every day, which may be substantial barriers for the patient in accessing treatment. The competing threat of job loss may be perceived as a greater threat than that of infection relapse or even infecting others. The occurrence of other illnesses may deter a patient from traveling as that may pose a greater thereat than the chronic TB. In addition, the side effects of taking medication may be severe enough to compete with severity of symptoms, or may hinder work performance, again posing the threat of job loss or forced time away from work. These outside threats may become a greater weight on the decision scale especially in the last months of treatment, when the patient will feel much better, even though there are still low levels of bacilli circulating that could multiply and cause a complete relapse. One study found that the largest contributing factor in patient non-adherence was due to patients “beginning to feel better” and that this accounted for 45.1% of treatment dropout among those who left treatment.(12)
While the health belief model may predict adherence in some situations, it has not been found to do so for "risk reduction behaviors that are more linked to socially determined or unconscious motivations".(11) When applying this theory to long-term medication adherence, it is also important for the influence of socio- psychological factors to be considered. For example, cultural beliefs about TB – such as its relationship with witchcraft or belief in traditional versus western medicine, could reduce an adherence intervention's effectiveness.(11) The theory is limiting in its dependence largely on rational processes and does not allow explicitly for the impacts of emotions or self-esteem on behavior, which may be related to a stigmatized disease such as tuberculosis.(11)
In the broader scope, the DOTS approach intends to control the spread of TB by one prevention method, which is treatment of all active cases. It is as if the DOTS plan has blinders on to all the outside factors that could cause it to fail.
Critique Two: DOTS Approach Does Not Account for Behavior-Influencing Social and Environmental Factors
The DOTS overall approach tries to incorporate “political commitment, accessible laboratory services, strict uninterrupted supply of medications, and effective surveillance and monitoring systems for patient follow-up”(4,8) in addition to supervision of each dose of treatment (DOT). Despite consideration of many practical issues that could arise in facilitation of DOTS strategy, it fails to consider social or environmental factors of the area in which it will be introduced.
The advantages of DOT are that people can be closely monitored and that there is a social process with peer pressure that may improve adherence.(5) In this way, one aspect of social influence is considered, but this is the only allowance for it. The disadvantages associated with DOT are that it moves away from adherence models of communication with cooperation between patient and provider back to a traditional medical approach with the patient as the passive recipient of advice and treatment.(5)
Patients may not like feeling as though they have no power in their treatment plan, as in the DOTS program, which is entirely clinician-managed. The paternalistic enforcement of observed drug swallowing may cue the natural human tendency to rebel, especially after months of forced directives. This method could actually make it less likely that the patient will return for subsequent treatments, if they feel they have no control, as the doctor has all of the power. Finally, it may make adherence worse if it is rigidly applied in an authoritarian setting or where people are expected to travel considerable distances to have their treatment supervised. The alternative of course, is to simply not return to the clinic for treatment. After months of medication, and finally feeling better, the odds that the patient will return under such conditions may be unlikely, considering the reduction in perceived severity of disease and risk of relapse with mitigation of symptoms. Not returning to the clinic may be perceived by the patient as a way to take back that control.
Another social factor that should be taken into consideration are role of the family in decision-making, which may be very different depending on the age and sex of the patient. If the patient is female or a child, in some cultures the decision to attend or not attend treatment may not be up to the patient.
Resource implications for a DOTS policy are substantial, particularly in low and middle-income countries where the caseload is high. Therefore, the strategy should be proven effective in the area before wasting countries already limited resources. DOTS strives for an uninterrupted supply chain of medication, yet one study found that “running out of drugs at home” was the patient-reported cause of treatment default in 25.4% of those who dropped out of treatment, which could occur in programs implemented with the pill-count method of observation.(12)
DOTS also does not directly account for staff time to manage DOT, which can put a great strain on the overall system. A chaotic clinic environment may influence the patient’s perception that his/her attendance causes problems for the rest of the clinic, and that doctors do not have time for them. Doctors may even lose credibility if the patient sees they are struggling and begin to question whether the treatment will really work.
In a study of risk factors for treatment discontinuation in DOTS programs in India, it was reported that alcoholism, illiteracy, having other commitments during treatment, inadequate knowledge of TB, poor patient provider interaction, lack of support from health staff, and dissatisfaction with services provided were all factors independently associated with treatment default.(13) Another environmental factor that could affect medication adherence is when care providers do not provide adequate explanation of treatment course and the importance of adherence. One study cited that 25.7% of dropout rate was due to “lack of knowledge on the benefits of completing the course” of treatment.(12) A study conducted in Nepal found that non-adherence was significantly associated with unemployment, low-status occupation, low annual income, and cost of travel to TB treatment facility.(14) This shows that socio-economic status is yet another factor for treatment default which should be considered when developing interventions.
There is strong evidence that there are many social and environmental factors that should be considered when running a DOTS program. Currently, social and environmental factors as not considered in DOTS implementation.
Critique Three: Potential for Negative Labeling and Stigmatization Associated with Tuberculosis Treatment
There is an ongoing presence of stigmatization associated with TB disease particularly in developing nations that has been well documented.(15) Understanding the origins of TB stigma is integral to reducing its impact on health.(15) As beliefs about the origins and transmission of TB may vary by culture, often resulting in stigmatism, seeking treatment can be a very delicate matter.(11) Although there is geographic and cultural variation in the explanations for why TB is stigmatized, most authors identify the perceived contagiousness of TB as a leading cause of stigmatization.(15) Lack of knowledge regarding routes of TB transmission may also contribute to TB stigma.(15)
In areas with high HIV prevalence, where HIV and TB co-infection is common, the association between the two diseases has contributed to the stigmatization of TB.(15) TB is perceived as a marker for HIV positivity; therefore, HIV-associated stigma is transferred to TB-infected individuals, regardless of their HIV-status.
Other causes of TB stigma include the perceived associations of TB with malnutrition, poverty, being foreign-born (U.S.), and of low social class.(15) Finally, TB stigma may occur because an affected individual’s community believes he or she must have done something to deserve to be infected.(15) This judgment may reflect the belief that TB is divine punishment for a moral or personal failing, which then justifies the stigmatization.
Social stigmatization can also lead to negative labeling of TB patients. Internalization of negative labels brought on by stigma associated with transmission of TB can have great psychological effects and could affect treatment adherence. TB-infected individuals perceive themselves to be at risk for a number of stigma-related social and economic consequences. Because the most common result of TB stigma is isolation from other members of the community, TB infection can substantially impact economic opportunities.(15) For those who do seek treatment, studies suggest an increasingly negative and demoralizing effect of DOT on patients.(5)
Several studies suggest that health-care providers and at-risk community members perceive TB stigma to have a more substantial impact on women’s health-care-seeking behavior than on men’s.(7,12,15) This could in part account for the lower disease rates in women, if women fear TB as a diagnosis and decide not to seek care.
Fear of stigmatization can delay diagnosis, and deter acceptance of treatment, and even continuing treatment once it has begun. Developing a reputation as a dirty or diseased individual could be a great deterrent in continuation of treatment. Unfortunately, the DOTS program as of now does nothing to ensure confidentiality of treatment. If treatment were self-administered at home, it would be unlikely that the community would know what pills the person was taking, whereas attendance to a TB clinic or to a general facility on a daily basis may not be conspicuous enough to hide the truth.
Revamping the DOTS Strategy
Tuberculosis is an extremely complicated disease, with a long and complex treatment regimen that must be followed consistently to achieve a good outcome. There is no easy answer to why the DOTS program fails in some places. It is a challenge to design, create, implement, and evaluate an intervention to increase treatment adherence. The DOTS approach has made a great impact in most places. It is not easy to create dynamic, sound interventions that account for the multitude of factors that contribute to the complexity of this disease and the human behaviors that affect its treatment. However, improvements can be made to address the shortcomings of the program using social and behavioral health principles.
As shown in the critique of the DOTS approach, there are several flaws that require development or expansion. The first critique addressed the use of the health belief model as the underlying foundation of the DOTS strategy. As an alternative, incorporation of other more comprehensive models could be used to account for more influences of human behavior in making new interventions. For example, learning theories presume that adherence to medical regimens requires social support and freedom from physical and social barriers.(16) One study’s results support the use of these theories in that adherence counseling had a positive effect on adherence, while engaging in other risk behaviors had a negative effect on adherence.(16) These models allow for irrational behavior, which the health belief model does not. This would be an improvement because it will allow for expansion to factors other than perceived severity and susceptibility and perceived barriers and benefits. By allowing for the possibility that humans may make irrational decisions, the influences that lead to irrationality could more clearly be seen. Considering internal impacts of emotions and self-esteem and external impacts such as social and environmental factors can help to accomplish this.
The second criticism of the DOTS strategy was that it failed to account for social and environmental factors. Leaving these factors out of consideration came at great losses of patients not returning to clinic for treatment.(17) In order for the DOTS intervention to work, it must be bolstered with consideration of social and environmental factors that are site specific where feasible. In many studies it has been reported that while patients found the overall TB care approach efficient and economical in general, they faced numerous barriers to regular attendance for the direct observation of drug-taking (most especially, time, travel costs, ill health and need to pursue their occupation).(3,9,10) This suggests that there are significant environmental barriers that must be taken into consideration in updating the DOTS strategy. If used, DOT should be flexible and convenient regardless if conducted at a health facility or in patients home with a nurse. The emphasis should shift in practice from pill counting towards patient-centered treatment support, together with education on what to expect from disease and medication.
One study reported that provider attitudes were poor: health facility workers expressed cynical and uncaring views; community health workers were more positive, but still arranged direct observation to suit their schedules, rather than their patients’.(12) This is clearly not an example of a supportive environment. Interventions are needed to improve clinician-patient communications and staff attitudes so that patients do not encounter a clinic environment in which they feel demeaned.
A social factor not previously incorporated in the DOTS strategy is family involvement. As noted, the head of the household may make decisions on whether or not other members of the family will be permitted to go to treatment everyday. Factors that could affect this decision include economic feasibility, social stigma, or mode of transport to TB treatment site. By involving the family from the beginning of treatment, there is a higher likelihood of treatment adherence, resulting from receiving the same education the patient receives. Incorporation of the family in treatment could work in TB control by screening family members for the disease while they’re at the clinic. If a patient feels supported by his/her family, they may be more likely to feel acceptance of their disease and receive the treatment without default. Family support could also work to increase self-efficacy and self-esteem, even in the face of stigmatism from others in community. In a similar intervention, improvement of patient education messages and adherence counseling should also me implemented.
Another social intervention that proved to be successful in practice was a ‘cultural intervention’ which involved five elements: 1) the same interventionist nurse was used for the same patient at each clinic visit in order to establish a relationship, 2) family members names were noted in medical chart in order for the nurse to inquire about the patients family at subsequent visits, 3) A common Latino proverb was stated by the nurse at each visit, which subsequently became the logo for the study and was put onto stickers and small gifts for nurses to distribute to participants at random visits, 4) Educational materials were culturally adapted and written at sixth-grade reading level, 5) All nurses were fluent in Spanish.(18) These elements were all based around core Latino values and culture, which made the intervention tailored to the population they were serving. This intervention uses the principle of liking in order to help the patients relate to the nurse and in turn, improves their adherence to treatment.
The final flaw in this critique was failure of the DOTS program to address stigmatism in its strategy, and the potential for negative labeling that this could incur. One possible intervention would be widespread education campaigns. One reason stigmatism is so prevalent is a lack of knowledge on routes of transmission, as well as association with many negative characteristics, such as poverty, poor hygiene, malnutrition etc. Collective cognitive change is slow, so an education campaign certainly will not change social norms on its own to eliminate stigmatism towards TB, but it could reduce it with time. While some studies report lack of knowledge as a main factor in stigma development, others have noted that education campaigns are ineffective.(15) Therefore, tailoring education campaigns to a specific audience and using effective social theories and principles is imperative in their development.
Although community and institutional norms ultimately mediate stigmatization, wide-scale interventions to change these norms can be difficult. A smaller-scale intervention that could be utilized is support groups for people who are in treatment. The groups extend a social support and sense of belonging that could help to limit the internalization of negative associations with TB as labels. These have been effective in reducing HIV/AIDS stigmatization in Voluntary Counseling and Testing (VCT) centers that hold support groups. This seems to be a promising approach in helping TB-infected individuals resist TB stigma, particularly through TB clubs, says one assessment.(15)
Finally, it is essential to continue to develop other interventions—for example, counseling TB-infected patients or introducing default-screening policies in high TB prevalence areas—to reduce TB stigma. It is also important to supplement this bottom-up approach to reducing TB stigma with an assessment of interventions designed to directly address stigmatizing community norms about TB.
Since its implementation in 1994, DOTS has accomplished great things in TB treatment. However, treatment adherence continues to be a serious problem in TB control. The DOTS strategy is built on traditional health belief models that fail to consider environmental and social factors contributing to alternative behaviors. Overall, the DOTS approach’s biggest downfall is in its failure to customize each implementation program site. By not tailoring the program to account for the social and environmental factors that will potentially influence behavior in that region, and making the assumption that patients behave rationally and stay in treatment without additional interventions, significant numbers of patients quit treatment. With several modifications, including integration of more comprehensive theories such as learning theories, increasing flexibility of treatment plans, opening communication lines between patients and providers, moving towards patient-centered care, improving patient education, instituting adherence counseling, developing evidence-based education campaigns, forming support groups and involving families in treatment, and utilizing core values of the culture to improve clinic and treatment experience.
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