Tuberculosis - What are Directly Observed Therapies?

08/03/2019 By Wilson

Tuberculosis (TB) has managed to reach the same ranking as HIV as one of the leading infectious disease cause of death worldwide and incurs a global economic burden of over $12 billion annually. Directly observed therapy (DOT) recommends that TB patients complete the course of treatment under direct observation of treatment support who’s been trained and overseen by health services to ensure that patients are taking their drugs as instructed too. Though the current WHO End TB Strategy does not mention DOT, only “supportive treatment supervision by treatment partners”, many TB programs still utilize it even though it has not been demonstrated to be statistically significantly superior to self-administered treatment in making sure treatment success or cure.


The DOT aspect, which makes up for a total of 75% of the provider cost of TB treatment, recommends that patients complete the course of treatment while under the observation of a treatment partner or support who is properly trained and overseen by health services to ensure that patients are taking the drugs on time. DOT was created to promote proper adherence to the full course of drug therapy to improve the patient's chances of recovery and prevent the development of drug resistance. Even so, over 8 million dollars is spent each year to treat TB and thousands undergo GOT for all or part of their course treatment, despite the absence of any serious evidence supporting the complete effectiveness of DOT over self-administration for achieving drug-susceptible TB cure. Furthermore, the DOT aspect burdens the patient with financial and opportunity costs and the potential for intensified stigma.


Why use DOT?

Healthcare workers can't predict who will take medication as directed, and who will not. People from all sorts of social classes, educational backgrounds, ages, genders, and ethnicities can have problems when taking medication properly. Studies have revealed that over 86-90% of patients are receiving DOT complete therapy, compared to 61% for those on self-administered therapy, DOT also helps patients finish TB therapy as quickly as possible without any necessary problems, and prevents the chance of spreading TB to others as well. DOT decrease the chances of drug resistance occurring from erratic or incomplete treatment and decreases the chance of treatment failure and relapse.


Who can deliver DOT?

Either a nurse or supervised outreach worker from the patient’s county public health department usually provides DOT. In certain situations, it works best for clinics, home care agencies, correctional facilities, treatment centers, schools, employers, and other facilities to provide DOT, under the guidance of the local health department. Family members are not allowed to be used for DOT since providers must remain objective throughout the treatment. For any complex regimens including IV/IM medications or twice daily dosing, home care agencies can provide DOT or share responsibilities with the local health department. If resources become depleted for providing DOT, priority should be given to patients most at risk.



How is DOT administered?

DOT includes:

●     delivering the prescribed medication

●     checking for side effects

●     watching the patient swallow the medication

●     documenting the visit

●     answering questions


DOT should be immediately initiated when TB treatment starts. The patient should not be allowed to try self-administering medications and missing doses before providing DOT. If the patient views DOT as an outrageous measure, there is a chance of the therapy completing successfully will decrease. The prescribing physician should show support for DOT by explaining to the patient that DOT is widely used and incredibly effective. The DOT provider should continue to reinforce this message until the therapy has concluded.


DOT is at its best when used with a patient-centered case management approach, including such things as:


●     helping patients keep medical appointments

●     providing ongoing patient education

●     offering incentives and/or enablers

●     connecting patients with social services or transportation


DOT VS. self‐administered

Six trials were conducted in South Africa, Australia, Pakistan, Thailand, and Taiwan to compare DOT with self-administered therapy for treatment. These trails included DOT at home by family members, community health works (who were under supervision); Dot at home by health staff, and DOT at health facilities. TB cure was on the lower scale with self-administration across each study, and direct observation did not substantially improve these statistics as well. In a subgroup analysis stratified by frequency of contact between health services and the self-treatment arm, daily DOT can possibly improve TB cure when compared to self-administered treatment were patients in the self-administered group only the clinic once every month, but with a contact in the control becoming much more frequent, this small effect was not noticeable


Treatment completions revealed a similar pattern, extending from 59% to 78% in the self-treatment groups, and direct observation did not manage to improve the results at all.


DOT at home VS DOT at health facility

With four trials conducted to compare DOT at home by family members, or community health workers, with DOT by health workers at a health facility there are little or no difference  in cure or treatment completion.


DOT by family member VS. DOT by community health worker

This one had two trials conducted to compare DOT at home by family members with DOT at home by community health workers. There was also minimal or no difference in cure or treatment completion as well.


The burden of DOT

The Financial and psychological burden of DOT on patients can be substantial, even with a health program in place to provide drugs at no direct cost to the patient. From DOT programs requiring patients to make multiple clinic or community center visits per week, patients may incur a significant financial and time costs of travel if reimbursement or subsidies to offset these costs are not provided for them. Over the course of six or more months of DOT treatment, these costs can and will stack up. Although some TB treatment programs will have a health worker conduct DOT in patients homes rather than health facilities, no official number currently exist on how many programs administer TV treatment with the use of this method. Aside from direct costs, frequent visits to health facilities for DOT may interfere with a patient’s working schedule or home production responsibilities (such as housework), leading to loss of wages, or cause the loss of their employment. Additionally, frequent visits to TB treatment facilities or from DOT health workers may increase the stigma that usually associated with TB and diminishes a patient’s capability to maintain any privacy about their health situation. Fear of being ostracized and the burden of DOT may prevent the patient from fully completing TB treatment, or seeking TB testing in the first place.



Patients who are suspected of having contracted TB should have appropriate specimens collected for microscopic examination and mycobacterial culture. When the lung is the area of the disease, three sputum specimens should be obtained. Sputum induction with hypertonic saline may be required to obtain specimens and bronchoscopy may be considered for patients who are incapable of producing sputum, depending on the clinical circumstances. Susceptibility testing for INH, RIF, and EMB should be performed on a positive initial culture, regardless of the source of the specimen. Second-line drug susceptibility testing should be conducted only in reference laboratories and be limited to specimens from patients who have had prior therapy, who are contacts of patients with drug-resistant tuberculosis, who have demonstrated resistance to drugs, or who have positive cultures after more than three months of treatment.


During the treatment process of the patient with pulmonary tuberculosis, a sputum specimen for microscopic examination and culture should be obtained at a minimum of monthly intervals until two consecutive specimens are negative on culture. Increased AFB smears may be helpful for assessing the early response treatment and to provide an indication of infectiousness. For the patient who contracted extra pulmonary tuberculosis the frequency and kinds of evaluations will all come down to the site involved. Additionally, it’s critical that patients have clinical evaluations at least monthly to identify possible adverse effects of anti-tuberculosis medications and to assess adherence. Usually, patients are not required follow-u after completion of therapy but should be instructed to seek care promptly if any signs or symptoms do recur.


Completion of Treatment

A complete course of therapy is determined more accurately by the total number of doses taken, not solely by the duration of therapy. For instance, the six-month daily regimen should consist of a minimal amount of 182 doses of INH and RIF, and 56 doses of PZA. Hence, six months is the minimum duration of treatment and accurately indicates the amount of time the drugs are administered only if there are no interruptions in drug administration. In certain cases, either because of drug toxicity or non-adherence to the treatment regimen, the specified number of doses cannot be administered within the usually estimated time frame. During these such cases, the objective is to deliver the specified number of doses within a recommended maximum time. For instance, for six months daily regimen the 182 doses should be administered within nine months of beginning treatment. If treatment is not achieved within this time frame, the patient should be assessed to determine the appropriate action to take, continuing the treatment for a longer duration or restarting treatment from the start, either of which may require more restrictive measures to be used to ensure success in the treatment.


Experience on the clinical level suggests that patients being managed by DOT administered five days/week have a rate of successful therapy equivalent to those being administered seven days/week. Hence, daily therapy can be interpreted to mean DOT has given either five days/week and the required number of doses adjusted accordingly. For example, for the six-month daily regimen given five days/week the planned total number of doses is set at 130. As an available option, patients may be given medications to take without DOT on weekends.


Any interruptions in treatment may have a significant impact on the duration of therapy. The re-institution of treatment must take into account the bacillary load of the patient, the point in time when the interruption occurred, and the duration of the interruption. Generally, the earlier in treatment and the longer the duration of the interruption, the more serious the effect and the greater the need to restart therapy from the start.



Overall, there is probably little to no difference in TB cure or treatment completion when the direct observation was conducted at home or at the clinic. It is probably very little or no difference in TB cure direct observation is conducted by community health workers or family members and there may be minimal or no difference in treatment completion either.