This calculator is provided for informational and educational purposes only. It is not intended to replace professional medical advice, diagnosis, or treatment. Always consult with a qualified healthcare professional before making any medical decisions. The results from this calculator should be used as a reference guide only and not as the sole basis for clinical decisions.
DOTS TB Treatment Tracker
Monitor tuberculosis patient progress through directly observed treatment, short-course (DOTS). Track dose adherence, sputum smear conversion at months 2 and 5, WHO treatment phase milestones, and classify treatment outcomes per the 2020 WHO definitions for drug-susceptible and drug-resistant TB.
| WHO Outcome | Definition (2020) | Current Patient Status |
|---|---|---|
| Cured | Pulmonary TB patient with bacteriologically confirmed TB at start, completed treatment with evidence of bacteriological response and no failure | Not Yet Assignable |
| Treatment Completed | Completed treatment as recommended without evidence of failure; does not meet definition of Cured (bacteriology unavailable or incomplete) | Not Yet Assignable |
| Treatment Failed | Regimen terminated or permanently changed to a new regimen or treatment strategy (e.g. smear positive at Month 5) | Not Triggered |
| Died | Patient who died for any reason before starting treatment or during the course of treatment | Not Triggered |
| Lost to Follow-Up | Patient who did not start treatment or whose treatment was interrupted for 2 or more consecutive months for any reason | Not Triggered |
| Not Evaluated | Patient for whom no treatment outcome was assigned at the end of expected treatment period | Not Applicable |
| Programme Indicator | Formula | Your Cohort Result | WHO Target | Status |
|---|---|---|---|---|
| Treatment Success Rate | (Cured + Completed) / Total x 100 | 81.7% | more than or equal to 90% | Below Target |
| Cure Rate | Cured / Total x 100 | 56.7% | Component of success rate | Reference |
| Lost to Follow-Up Rate | LTFU / Total x 100 | 6.7% | less than 5% | Above Target |
| Case Fatality Rate | Died / Total x 100 | 5.0% | less than 5% | Monitor |
| Treatment Failure Rate | Failed / Total x 100 | 3.3% | less than 5% | Within Target |
| Not Evaluated Rate | Not Eval / Total x 100 | 3.3% | Minimise | Reference |
About This DOTS TB Treatment Tracker
This DOTS TB treatment tracker is designed for healthcare workers, TB programme managers, and clinical staff monitoring patients through directly observed treatment, short-course (DOTS). The tool calculates dose adherence rates, tracks sputum smear conversion at the critical Month 2 and Month 5 milestones, and auto-classifies treatment outcomes using the 2020 WHO definitions for drug-susceptible tuberculosis.
The calculator applies the standard 2HRZE/4HR regimen framework endorsed by WHO, where the 2-month intensive phase uses four drugs (isoniazid, rifampicin, pyrazinamide, and ethambutol) and the 4-month continuation phase uses two (isoniazid and rifampicin). It supports retreatment regimens and MDR-TB DOTS-Plus monitoring. Risk assessment follows established thresholds - adherence below 90%, consecutive interruptions of 2 or more months triggering lost-to-follow-up classification, and a positive smear at Month 5 meeting treatment failure criteria.
The four tabs present treatment progress bars showing completion percentages across both phases, the WHO outcome classifier mapping current patient data to mutually exclusive outcome categories, a traffic-light risk assessment with actionable clinical recommendations, and a programme metrics calculator for cohort-level treatment success rate, LTFU rate, and case fatality rate reporting. Consult a qualified clinician for all treatment decisions - this tool supports documentation and monitoring, not clinical diagnosis.
DOTS TB Treatment Tracker: A Complete Guide to Directly Observed Treatment, Short-Course Monitoring
Tuberculosis remains one of the most consequential infectious diseases globally, responsible for more deaths annually than any other single pathogen. The directly observed treatment, short-course (DOTS) strategy has been the cornerstone of TB control for three decades, and its systematic application to treatment monitoring remains the most reliable method of ensuring patients complete therapy and achieve cure. This guide explains how to use the DOTS TB treatment tracker, interpret its outputs, and apply the WHO 2020 treatment outcome definitions in clinical and programmatic contexts.
What Is DOTS and Why Does Direct Observation Matter?
DOTS stands for Directly Observed Treatment, Short-Course. It is a strategy in which a trained treatment supporter physically observes every dose being swallowed by the patient throughout the course of treatment. The supporter can be a community health worker, clinic-based staff member, trained family member, or increasingly, a remote observer using video technology.
Direct observation matters for two reasons rooted in the biology of tuberculosis treatment. First, Mycobacterium tuberculosis is exceptionally difficult to eliminate - it can persist in a dormant, drug-tolerant state inside macrophages, and full clearance requires months of bactericidal drug pressure. Interrupting this pressure prematurely allows surviving mycobacteria to multiply. Second, patients frequently feel well before bacterial clearance is complete. Symptoms typically resolve within the first four to eight weeks of treatment, creating a powerful incentive to stop taking medication. Without direct observation, self-reported adherence is unreliable in virtually all populations studied.
The Five Core Components of the DOTS Strategy
WHO defines DOTS as a five-component strategy, not merely direct observation of drug ingestion. Understanding all five components is essential for interpreting programme performance data.
The first component is sustained government commitment, expressed as stable funding for drug procurement, staff salaries, laboratory services, and patient support. Without this, the remaining four components collapse. The second is case detection through quality-assured bacteriology - sputum smear microscopy, rapid molecular tests such as Xpert MTB/RIF, and culture where available. Finding cases is the precondition for treating them.
The third component is the standardised treatment regimen with direct supervision and patient support. This is where direct observation occurs. The fourth is an uninterrupted supply of all essential anti-tuberculosis drugs. Even the most adherent patient cannot take drugs that are unavailable. Drug stockouts are a programme failure, not a patient failure. The fifth component is a standardised recording and reporting system that enables systematic evaluation of treatment outcomes by cohort, facility, and national programme.
Direct observation is the most visible element of DOTS, but drug supply, laboratory quality, government commitment, and outcome recording are equally essential. A programme that achieves high adherence rates but suffers regular drug stockouts or poor laboratory quality will still fail to achieve WHO treatment success targets.
The Standard 2HRZE/4HR Regimen: What Each Letter Means
The standard regimen for new drug-susceptible pulmonary TB is written as 2HRZE/4HR. The number at the start indicates the duration in months. The letters are the internationally standardised abbreviations for each drug: H = isoniazid, R = rifampicin, Z = pyrazinamide, E = ethambutol.
The intensive phase (2HRZE) lasts two months and uses all four drugs simultaneously. This phase achieves rapid bactericidal kill of actively dividing mycobacteria and is responsible for most of the early symptom relief. Pyrazinamide penetrates the acidic intracellular environment where dormant bacteria reside, and ethambutol provides additional protection against resistance emergence during this high-bacterial-load phase.
The continuation phase (4HR) uses only isoniazid and rifampicin for four months. This phase sterilises remaining persister mycobacteria that survived the intensive phase. Rifampicin is the most critical sterilising drug and must be taken throughout the continuation phase without interruption. Shortening the continuation phase, even by a few weeks, substantially increases relapse risk.
Continuation Phase = Months 3-6 (4HR)
Sputum Smear Examination: The Key Bacteriological Milestone
Sputum smear microscopy at Month 2 is the primary bacteriological milestone in DOTS monitoring for smear-positive pulmonary TB. A negative result - termed sputum conversion - confirms that the intensive phase has achieved sufficient bactericidal kill to clear acid-fast bacilli from sputum. Conversion by Month 2 is a strong prognostic indicator and supports continuation with the standard 4HR continuation phase.
A positive smear at Month 2 warrants clinical review. It does not automatically indicate treatment failure - patients with very heavy initial bacillary loads (3+ positive at baseline) may convert later - but it prompts assessment of adherence, drug tolerance, possible drug-drug interactions, and consideration of drug susceptibility testing. The Month 2 smear is not itself a failure criterion under 2020 WHO definitions.
A positive smear at Month 5 is a treatment failure criterion. It indicates that active bacilli persist after four months of correctly administered therapy, which may reflect acquired resistance, pre-existing undetected resistance, or severe immunosuppression. All Month 5-positive patients require drug susceptibility testing and clinical reassessment before any regimen change.
OR Permanent Change of Regimen Required
WHO 2020 Treatment Outcome Definitions
WHO revised its treatment outcome definitions in 2020 to align DS-TB and DR-TB frameworks. The six mutually exclusive outcomes are applied to every registered patient at the end of the expected treatment period. Programmes are assessed by the distribution of their registered patients across these outcomes.
Cured applies to a pulmonary TB patient with bacteriologically confirmed TB at the start of treatment who completed the recommended treatment duration with evidence of bacteriological response and without evidence of failure. Evidence of bacteriological response means a negative smear or culture at the end of the treatment period and on at least one previous occasion.
Treatment Completed applies to a patient who completed the recommended duration without evidence of failure but without a record confirming bacteriological cure. This applies to smear-negative patients, extrapulmonary TB patients, and patients where end-of-treatment sputum was not collected.
Treatment Failed applies to patients whose regimen was terminated or permanently changed due to lack of bacteriological response, as indicated by a positive smear or culture at Month 5 or later. It also applies if a new regimen is started for any reason indicating clinical failure.
Died applies to a patient who died for any reason before starting or during the course of treatment. Cause of death does not affect this classification - death from road traffic injury during treatment is still classified as Died.
Lost to Follow-Up applies to a patient who did not start treatment after diagnosis, or whose treatment was interrupted for 2 or more consecutive months. The previous term Defaulted was retired in recognition that many interruptions reflect system failures rather than patient behaviour.
Not Evaluated applies to patients for whom no outcome was recorded at the expected end of treatment. A high proportion of not-evaluated outcomes often signals weaknesses in patient tracking and inter-facility communication.
Lost to Follow-Up: Definition, Detection, and Response
Lost to follow-up (LTFU) is classified when treatment is interrupted for 2 or more consecutive months. This threshold exists because interruptions of this duration substantially increase relapse risk and provide sufficient drug-free time for resistance to develop. LTFU is among the most preventable adverse outcomes in TB programmes.
Active LTFU tracing is a core DOTS programme responsibility. When a patient misses doses for more than 2 consecutive weeks, the treatment supporter should visit the patient or contact them through their registered contacts. Many patients who appear lost have moved, changed phone numbers, or have been admitted to another facility - active tracing recovers a substantial proportion.
When a patient is traced after an LTFU episode, the clinical approach depends on the duration of interruption. Patients who interrupted for less than 2 months can generally resume treatment from where they left off with clinical review. Those who interrupted for 2 months or longer require clinical assessment and drug susceptibility testing before resuming, given the risk of acquired resistance during the interruption period.
HIV Co-Infection and Special Populations
People living with HIV face a 20-30 times higher risk of developing active TB due to immune suppression. HIV co-infection substantially increases mortality risk during TB treatment and requires specific management adjustments. WHO recommends initiating antiretroviral therapy (ART) within 2-8 weeks of starting TB treatment for most HIV-positive patients, regardless of CD4 count. The exception is TB meningitis, where ART initiation is delayed to 8 weeks due to paradoxical reaction risk.
Rifampicin is a potent inducer of the cytochrome P450 enzyme system and significantly reduces plasma levels of many antiretrovirals, including protease inhibitors. Efavirenz is generally preferred as the NNRTI backbone in HIV-TB co-treatment because its metabolism is less affected by rifampicin. Dolutegravir dose adjustments may also be required. All HIV-TB co-infected patients should be managed with input from both TB and HIV specialists.
Diabetes mellitus is an increasingly recognised risk factor for poor TB treatment outcomes. Diabetic patients have higher rates of treatment failure and relapse, lower rates of sputum conversion by Month 2, and a higher risk of drug-resistant TB. This is attributed to hyperglycaemia impairing macrophage-mediated bacterial killing, reduced drug bioavailability, and higher rates of lung cavitation. Glucose control during TB treatment improves outcomes.
Children with TB are predominantly smear-negative, making bacteriological confirmation and conversion monitoring less feasible than in adults. DOTS monitoring in children relies more heavily on clinical response - weight gain, resolution of fever, improved activity levels - and radiological improvement where facilities allow. Dosing is weight-based and should be reviewed at each visit as children may gain weight rapidly during treatment.
HIV-positive TB patients have higher mortality during treatment and require antiretroviral therapy initiated within 2-8 weeks of starting TB treatment. Drug-drug interactions between rifampicin and antiretrovirals require specific drug selection - consult HIV treatment guidelines for your region before prescribing.
DOTS-Plus for Drug-Resistant Tuberculosis
DOTS-Plus is the application of DOTS principles to patients with multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB). Standard DOTS uses four first-line drugs for 6 months; DOTS-Plus uses second-line and newer drugs in longer or more complex regimens depending on resistance pattern.
Traditional MDR-TB regimens lasted 18-24 months and were associated with significant adverse effects from second-line drugs including aminoglycosides, ethionamide, and cycloserine. The newer BPaLM regimen (bedaquiline, pretomanid, linezolid, moxifloxacin) achieves high cure rates in 6 months with a more tolerable side effect profile, and is being rolled out in many high-burden countries following the TB-PRACTECAL trial results.
DOTS-Plus monitoring relies on monthly sputum cultures rather than smear microscopy because culture sensitivity is required to detect the lower bacterial loads typical of MDR-TB and to assess resistance patterns during treatment. Culture conversion - two consecutive negative cultures obtained one month apart - is the key bacteriological milestone in DR-TB management.
Video Observed Therapy: DOTS in the Digital Era
Video Observed Therapy (VOT) allows patients to record themselves swallowing medication and upload the video for review by a healthcare worker, rather than requiring in-person observation. This removes the logistical burden of daily physical presence for both patient and supporter.
Randomised trials from the United Kingdom and other settings have demonstrated non-inferior adherence rates with VOT compared to standard in-person DOT. The Cochrane review and the UK VOTA trial found that VOT achieved comparable completion rates with greater patient satisfaction and lower programme costs. WHO now endorses VOT as a component of patient-centred DOTS delivery.
VOT is most effective when combined with responsive clinical support - patients who miss video uploads should receive a call within 24 hours. VOT should not be offered as a cost-cutting measure without the clinical monitoring infrastructure to detect and respond to missed doses promptly.
Programme Performance Metrics and Cohort Analysis
DOTS programme quality is evaluated through cohort analysis - the systematic tracking of treatment outcomes for all patients registered in a defined period. For drug-susceptible TB, cohorts are evaluated at the end of the expected treatment period: 12 months after the date of notification for 6-month regimen patients (to allow for treatment plus follow-up).
The treatment success rate is the primary summary indicator. WHO targets 90% or above for DS-TB. The global average has remained around 87-88% for the past decade, indicating that progress has stalled and that intensified efforts to address LTFU and mortality are needed.
LTFU Rate (%) = Lost to Follow-Up / Total Registered x 100
Recording and Reporting: The Fifth Component in Practice
Every registered TB patient requires a complete treatment card recording: unique registration number, date of notification and registration, TB site and bacteriological status at registration, HIV status, previous treatment history, prescribed regimen with start date, a day-by-day or week-by-week dose observation record, sputum results at months 2, 5, and end of treatment, any regimen changes with dates and reasons, and the final treatment outcome with the date assigned.
Treatment cards must be retained for at least 5 years after treatment completion to enable retrospective cohort analysis and individual patient follow-up in case of relapse or contact investigation. In many countries, paper treatment cards are being supplemented or replaced by electronic case management systems, though paper backup remains important in settings with unreliable electricity or connectivity.
A high not-evaluated rate allows a programme to appear more successful than it is, because patients without recorded outcomes are excluded from success rate denominators in some reporting systems. WHO requires that not-evaluated outcomes be reported separately and minimised through improved inter-facility patient tracking.
Frequently Asked Questions
Conclusion
The DOTS strategy has transformed global TB control, enabling more than 41 million treatment successes since 1995. The DOTS TB treatment tracker brings this monitoring framework into a structured digital tool, allowing health workers to track every patient from registration through outcome classification without losing any of the detail that makes cohort analysis meaningful.
The tracker's combined panel grid, progress bars, and stacked input workflow reflect the multi-dimensional nature of TB monitoring: adherence is necessary but not sufficient; sputum conversion confirms bacteriological response; outcome classification provides the programme-level intelligence that drives quality improvement. Used alongside official patient registers and clinical oversight, this tool supports the fifth DOTS component - standardised recording and reporting - in any setting where TB patients receive directly observed therapy.
Always seek qualified clinical guidance for individual patient management decisions. This tool supports documentation and programme monitoring - it does not replace the clinical relationship between healthcare worker and patient that remains at the heart of effective DOTS implementation.
This calculator is provided for informational and educational purposes only. It is not intended to replace professional medical advice, diagnosis, or treatment. Always consult with a qualified healthcare professional before making any medical decisions. The results from this calculator should be used as a reference guide only and not as the sole basis for clinical decisions.