Patient-cost survey for tuberculosis in the context of patient-pathway modelling.

ETTING: Eight tuberculosis treatment sites in Cavite Province, the Philippines, including two sites specialising in management of multidrug-resistant tuberculosis (MDR-TB).OBJECTIVE: To evaluate costs incurred by TB patients and to determine the proportion of households that faced catastrophic costs, then to consider cost survey responses alongside results of detailed patient-pathway modelling.DESIGN: Clustered cross-sectional survey using a field testing version of the WHO TB patient-costing tool and protocol; face-to-face interviews with 194 patients conducted in May-August 2016. Costs included direct-medical, direct non-medical and indirect costs using the human capital approach. Patients were deemed to incur catastrophic expenditure if TB-related costs exceeded 20% of annual household income. Patient pathways were modelled following multiple health staff interviews.RESULTS: Estimated mean cost incurred by patients with drug-susceptible TB was US$321 vs.$2356 for MDR-TB patients. Catastrophic costs were suffered by 28% of drug-susceptible and 80% of MDR-TB patients, with lost income being the largest contributor. Patient-pathway modelling suggested most patients had under-reported health visits.CONCLUSION: Survey results indicate that patient costs are large for all patients in Cavite, particularly for MDR-TB patients. Patient-pathway modelling suggests these costs are an underestimate due to poor recollection of health visits, suggesting that the WHO instrument and protocol could be improved to better capture the diagnostic journey

Point-of-care breath test for biomarkers of active pulmonary tuberculosis

Rationale: Volatile organic compounds (VOCs) in breath provide biomarkers of tuberculosis (TB) because Mycobacterium tuberculosis manufactures VOC metabolites that are detectable in the breath of infected patients. Objectives: We evaluated breath VOC biomarkers in subjects with active pulmonary TB, using an internet-linked rapid point-of-care breath test. Methods: 279 subjects were studied at four centers in three countries, Philippines, UK, and India, and data was analyzed from 251 (130 active pulmonary TB, 121 controls). A point-of-care system collected and concentrated breath and air VOCs, and analyzed them with automated thermal desorption, gas chromatography, and surface acoustic wave detection. A breath test was completed in 6 min. Chromatograms were converted to a series of Kovats Index (KI) windows, and biomarkers of active pulmonary TB were identified by Monte Carlo analysis of KI window alveolar gradients (abundance in breath minus abundance in room air). Measurements and main results: Multiple Monte Carlo simulations identified eight KI windows as biomarkers with better than random performance. Four KI windows corresponded with KI values of VOCs previously identified as biomarkers of pulmonary TB and metabolic products of M. tuberculosis, principally derivatives of naphthalene, benzene and alkanes. A multivariate predictive algorithm identified active pulmonary TB with 80% accuracy (area under curve of receiver operating characteristic curve), sensitivity = 71.2%, and specificity = 72%. Accuracy increased to 84% in age-matched subgroups. In a population with 5% prevalence, the breath test would identify active pulmonary TB with 98% negative predictive value and 13% positive predictive value. Conclusions: A six-minute point-of-care breath test for volatile biomarkers accurately identified subjects with active pulmonary TB. © 2011 Elsevier Ltd. All rights reserved

Breath biomarkers of active pulmonary tuberculosis

Background: Volatile organic compounds (VOCs) in breath may contain biomarkers of active pulmonary tuberculosis derived from the infectious organism (metabolites of Mycobacterium tuberculosis) and from the infected host (products of oxidative stress). Methods: We analyzed breath VOCs in 226 symptomatic high-risk patients in USA, Philippines, and UK, using gas chromatography/mass spectroscopy. Diagnosis of disease was based on sputum culture, smear microscopy, chest radiography and clinical suspicion of tuberculosis (CSTB). Chromatograms were converted to a series of 8 s overlapping time slices. Biomarkers of active pulmonary tuberculosis were identified with a Monte Carlo analysis of time-slice alveolar gradients (abundance in breath minus abundance in room air). Results: Breath VOCs contained apparent biomarkers of active pulmonary tuberculosis comprising oxidative stress products (alkanes and alkane derivatives) and volatile metabolites of M. tuberculosis (cyclohexane and benzene derivatives). Breath biomarkers identified active pulmonary tuberculosis with C-statistic (area under curve of receiver operating characteristic) = 0.85 (i.e. 85% overall accuracy, sensitivity = 84.0%, specificity = 64.7%) when sputum culture, microscopy, and chest radiography were either all positive or all negative. Employing a single criterion of disease, C-statistic = 0.76 (smear microscopy), 0.68 (sputum culture), 0.66 (chest radiography) and 0.65 (CSTB). Conclusion: A breath test identified apparent biomarkers of active pulmonary tuberculosis with 85% accuracy in symptomatic high-risk subjects. © 2010 Elsevier Ltd. All rights reserved

Evidence mapping of tuberculosis case finding studies essential for site-specific modeling: a scoping review

Background: Strides and benefits in finding active TB patients beyond health facilities using active case finding (ACF) strategies have been documented in several countries. The Philippines is in favorable position to explore strategies and gather insights on modelling cost-effectiveness of ACF in localized settings. Design/Methods: Scoping review, search peer-reviewed papers from research databases and hand-searched reference lists. Included studies from 2009 onwards, ACF strategies\u27 systematic reviews, and mathematical modelling of ACF strategies with effectiveness measures, settings at middle-to-high-burden countries. Result: Twelve paper (8 reviews, 3 mathematical modelling, 1 observational) fulfilled the eligibility criteria. Common ACF strategies considered to be cost-effective were contact tracing and targeted screening. Conclusions: Modelling different ACF strategies is feasible in the Philippines provide that target population, key parameters and assumptions were identified properly. Availability of localized data on TB epidemiology and target groups of ACF initiatives may pose challenge

Implementing the TB-fit project: lessons learned

The TB-FIT project is a 3-year project that focused on the health system model development of new diagnostic tools and algorithms. The study looked into the cost-effectiveness of strategies and determined the most suitable strategy for sites modeled in Cavite. Under the umbrella of this project there has been successful endeavors and fair share of struggles that was overcome. This paper shares the lessons learned from the experiences garnered from the TB-FIT Project

Use of GeneXpert and the role of an expert panel in improving clinical diagnosis of smearnegative tuberculosis cases

© 2019 Abong et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Setting A high proportion of notified tuberculosis cases in the Philippines are clinically diagnosed (63%) as opposed to bacteriologically confirmed. Better understanding of this phenomenon is required to improve tuberculosis control. Objectives To determine the percentage of smear negative presumptive tuberculosis patients that would be diagnosed by GeneXpert; compare clinical characteristics of patients diagnosed as tuberculosis cases; and review the impact that the current single government physician and a reconstituted Tuberculosis Diagnostic committee (expert panel) may have on tuberculosis over-diagnosis. Design This a cross-sectional study of 152 patients 15-85 years old with two negative Direct Sputum Smear Microscopy results, with abnormal chest X-ray who underwent GeneXpert testing and review by an expert panel. Results Thirty-two percent (48/152) of the sample were Xpert positive and 93% (97/104) of GeneXpert negatives were clinically diagnosed by a single physician. Typical symptoms and X-ray findings were higher in bacteriologically confirmed tuberculosis. When compared to the GeneXpert results the Expert panel\u27s sensitivity for active tuberculosis was high (97.5%, 39/ 40), specificity was low (40.2%, 35/87). Conclusion Using the GeneXpert would increase the level of bacteriologically confirmed tuberculosis substantially among presumptive tuberculosis. An expert panel will greatly reduce overdiagnosis usually seen when a decision is made by a single physician

Use of GeneXpert and the role of an expert panel in improving clinical diagnosis of smearnegative tuberculosis cases

© 2019 Abong et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Setting A high proportion of notified tuberculosis cases in the Philippines are clinically diagnosed (63%) as opposed to bacteriologically confirmed. Better understanding of this phenomenon is required to improve tuberculosis control. Objectives To determine the percentage of smear negative presumptive tuberculosis patients that would be diagnosed by GeneXpert; compare clinical characteristics of patients diagnosed as tuberculosis cases; and review the impact that the current single government physician and a reconstituted Tuberculosis Diagnostic committee (expert panel) may have on tuberculosis over-diagnosis. Design This a cross-sectional study of 152 patients 15-85 years old with two negative Direct Sputum Smear Microscopy results, with abnormal chest X-ray who underwent GeneXpert testing and review by an expert panel. Results Thirty-two percent (48/152) of the sample were Xpert positive and 93% (97/104) of GeneXpert negatives were clinically diagnosed by a single physician. Typical symptoms and X-ray findings were higher in bacteriologically confirmed tuberculosis. When compared to the GeneXpert results the Expert panel\u27s sensitivity for active tuberculosis was high (97.5%, 39/ 40), specificity was low (40.2%, 35/87). Conclusion Using the GeneXpert would increase the level of bacteriologically confirmed tuberculosis substantially among presumptive tuberculosis. An expert panel will greatly reduce overdiagnosis usually seen when a decision is made by a single physician

Rosuvastatin adjunctive therapy for rifampicin-susceptible pulmonary tuberculosis: a phase 2b, randomised, open-label, multicentre trial

Background: Shorter treatments are needed for drug-susceptible tuberculosis. Adjunctive statins increase bactericidal activity in preclinical tuberculosis models. We investigated the safety and efficacy of adjunctive rosuvastatin in people with tuberculosis. We tested the hypothesis that adjunctive rosuvastatin accelerates sputum culture conversion within the first 8 weeks of treatment of rifampicin-susceptible tuberculosis. Methods: This phase 2b, randomised, open-label, multicentre trial conducted in five hospitals or clinics in three countries with high tuberculosis burden (ie, the Philippines, Viet Nam, and Uganda) enrolled adult participants aged 18–75 years with sputum smear or Xpert MTB/RIF positive, rifampicin-susceptible tuberculosis who had received less than 7 days of previous tuberculosis treatment. Participants were randomly assigned via a web-based system to receive either 10 mg rosuvastatin once per day for 8 weeks plus standard tuberculosis therapy (rifampicin, isoniazid, pyrazinamide, and ethambutol; rosuvastatin group) or standard tuberculosis therapy alone (control group). Randomisation was stratified by trial site, history of diabetes, and HIV co-infection. Laboratory staff and central investigators involved in data cleaning and analysis were masked to treatment allocation, but study participants and site investigators were not. Both groups continued standard treatment to week 24. Sputum samples were collected once per week for the first 8 weeks after randomisation, and then at weeks 10, 12, and 24. The primary efficacy outcome was time to culture conversion (TTCC; days) in liquid culture by week 8, assessed in randomised participants who had microbiological confirmation of tuberculosis, took at least one dose of rosuvastatin, and who did not show resistance to rifampicin (modified intention-to-treat population), for which groups were compared with the Cox proportional hazards model. The main safety outcome was grade 3–5 adverse events by week 24, assessed in the intention-to-treat population, for which groups were compared with Fisher\u27s exact test. All participants completed 24 weeks of follow-up. This trial is registered with ClinicalTrials.gov (NCT04504851). Findings: Between Sept 2, 2020, and Jan 14, 2021, 174 participants were screened and 137 were randomly assigned to the rosuvastatin group (70 participants) or control group (67 participants). In the modified intention-to-treat population of 135 participants, 102 (76%) were men and 33 (24%) were women. Median TTCC in liquid media was 42 days (95% CI 35–49) in the rosuvastatin group (68 participants) and 42 days (36–53) in the control group (67 participants; hazard ratio 1·30 [0·88–1·91], p=0·19). Grade 3–5 adverse events occurred in six (9%) of 70 in the rosuvastatin group (none were considered related to rosuvastatin) and four (6%) of 67 in the control group (p=0·75). There were no serious adverse events that were considered to be related to rosuvastatin. Interpretation: Adjunctive rosuvastatin at 10 mg once per day was safe but did not produce substantive benefits on culture conversion in the overall study population. Future trials could explore the safety and efficacy of higher doses of adjunctive rosuvastatin. Funding: National Medical Research Council, Singapore

Treatment Strategy for Rifampin-Susceptible Tuberculosis

BACKGROUND: Tuberculosis is usually treated with a 6-month rifampin-based regimen. Whether a strategy involving shorter initial treatment may lead to similar outcomes is unclear. METHODS: In this adaptive, open-label, noninferiority trial, we randomly assigned participants with rifampin-susceptible pulmonary tuberculosis to undergo either standard treatment (rifampin and isoniazid for 24 weeks with pyrazinamide and ethambutol for the first 8 weeks) or a strategy involving initial treatment with an 8-week regimen, extended treatment for persistent clinical disease, monitoring after treatment, and retreatment for relapse. There were four strategy groups with different initial regimens; noninferiority was assessed in the two strategy groups with complete enrollment, which had initial regimens of high-dose rifampin-linezolid and bedaquiline-linezolid (each with isoniazid, pyrazinamide, and ethambutol). The primary outcome was a composite of death, ongoing treatment, or active disease at week 96. The noninferiority margin was 12 percentage points. RESULTS: Of the 674 participants in the intention-to-treat population, 4 (0.6%) withdrew consent or were lost to follow-up. A primary-outcome event occurred in 7 of the 181 participants (3.9%) in the standard-treatment group, as compared with 21 of the 184 participants (11.4%) in the strategy group with an initial rifampin-linezolid regimen (adjusted difference, 7.4 percentage points; 97.5% confidence interval [CI], 1.7 to 13.2; noninferiority not met) and 11 of the 189 participants (5.8%) in the strategy group with an initial bedaquiline-linezolid regimen (adjusted difference, 0.8 percentage points; 97.5% CI, -3.4 to 5.1; noninferiority met). The mean total duration of treatment was 180 days in the standard-treatment group, 106 days in the rifampin-linezolid strategy group, and 85 days in the bedaquiline-linezolid strategy group. The incidences of grade 3 or 4 adverse events and serious adverse events were similar in the three groups. CONCLUSIONS: A strategy involving initial treatment with an 8-week bedaquiline-linezolid regimen was noninferior to standard treatment for tuberculosis with respect to clinical outcomes. The strategy was associated with a shorter total duration of treatment and with no evident safety concerns. (Funded by the Singapore National Medical Research Council and others; TRUNCATE-TB ClinicalTrials.gov number, NCT03474198.)