Digital health technologies and adherence to tuberculosis treatment

Assessing efficacy in non-inferiority trials with non-adherence to interventions: Are intention-to-treat and per-protocol analyses fit for purpose?

BACKGROUND

Non-inferiority trials comparing different active drugs are often subject to treatment non-adherence. Intention-to-treat (ITT) and per-protocol (PP) analyses have been advocated in such studies but are not guaranteed to be unbiased in the presence of differential non-adherence.

METHODS

The REMoxTB trial evaluated two 4-month experimental regimens compared with a 6-month control regimen for newly diagnosed drug-susceptible TB. The primary endpoint was a composite unfavorable outcome of treatment failure or recurrence within 18 months post-randomization. We conducted a simulation study based on REMoxTB to assess the performance of statistical methods for handling non-adherence in non-inferiority trials, including: ITT and PP analyses, adjustment for observed adherence, multiple imputation (MI) of outcomes, inverse-probability-of-treatment weighting (IPTW), and a doubly-robust (DR) estimator.

RESULTS

When non-adherence differed between trial arms, ITT, and PP analyses often resulted in non-trivial bias in the estimated treatment effect, which consequently under- or over-inflated the type I error rate. Adjustment for observed adherence led to similar issues, whereas the MI, IPTW and DR approaches were able to correct bias under most non-adherence scenarios; they could not always eliminate bias entirely in the presence of unobserved confounding. The IPTW and DR methods were generally unbiased and maintained desired type I error rates and statistical power.

CONCLUSIONS

When non-adherence differs between trial arms, ITT and PP analyses can produce biased estimates of efficacy, potentially leading to the acceptance of inferior treatments or efficacious regimens being missed. IPTW and the DR estimator are relatively straightforward methods to supplement ITT and PP approaches.

Effectiveness of a digital medication event reminder and monitor device for patients with tuberculosis (SELFTB): a multicenter randomized controlled trial

BACKGROUND

Tuberculosis remains the leading cause of death from a single infectious disease worldwide. Trials evaluating digital adherence technologies for tuberculosis in low- and middle-income countries are urgently needed. We aimed to assess whether a digital medication event reminder and monitor (MERM) device-observed self-administered therapy improves adherence and treatment outcomes in patients with tuberculosis compared with the standard in-person directly observed therapy (DOT).

METHODS

We did a two-arm, attention-controlled, effectiveness-implementation type 2 hybrid, randomized controlled trial in ten healthcare facilities in Addis Ababa, Ethiopia. We included adults with new or previously treated, bacteriologically confirmed, drug-sensitive pulmonary tuberculosis who were eligible to start anti-tuberculosis therapy. Participants were randomly assigned (1:1) to receive a 15-day tuberculosis medication supply in the evriMED500® MERM device to self-administer and return every 15 days (intervention arm) or visit the healthcare facilities each day to swallow their daily dose with DOT by healthcare providers (control arm). Both arms were followed throughout the standard two-month intensive treatment phase (2RHZE). For control participants, some provider-approved take-home doses might be allowed for extenuating circumstances in real-world practice. Data were collected on patient information (demographic, socioeconomic, behavioral, social, and clinical information), medication adherence measures (MERM vs. DOT records, IsoScreenTM urine colorimetric isoniazid test, and adherence self-report), and clinical measures (pre-post treatment sputum Xpert MTB/RIF assay or microscopy, and adverse treatment outcomes). The intention-to-treat (ITT) primary endpoints were (1) individual-level percentage adherence over the two-month intensive phase measured by adherence records compiled from MERM device vs. DOT records that also considered all take-home doses as having been ingested and (2) sputum smear conversion following the standard two-month intensive phase treatment. Secondary endpoints were (1) individual-level percentage adherence over the two-month intensive phase measured by adherence records compiled from the MERM device vs. DOT records that considered all take-home doses as not ingested, (2) negative IsoScreen urine isoniazid test, (3) adverse treatment outcome (having at least one of the three events: treatment not completed; death; or loss to follow-up), and (4) self-reported adherence. The MERM device has an electronic module and a medication container that records adherence, stores medication, emits audible and visual on-board alarms to remind patients to take their medications on time and refill, and enables providers to download the data and monitor adherence.

RESULTS

Participants were enrolled into the study between 02 June 2020 and 15 June 2021, with the last participant completing follow-up on 15 August 2021. A total of 337 patients were screened for eligibility, of whom 114 were randomly assigned and included in the final analysis [57 control and 57 intervention participants]. Participants were 64.9% male, 15% with HIV, 10.5% retreatment, and 5.3% homeless. Adherence to TB medication was comparable between the intervention arm [geometric mean percentage (GM%) 99.01%, geometric standard deviation (GSD) 1.02] and the control arm [GM% 98.97%, GSD 1.04] and was within the prespecified margin for non-inferiority [mean ratio (MR) 1.00 (95% CI 0.99-1.01); p = 0.954]. The intervention arm was significantly superior to the control arm in the secondary analysis that considered all take-home doses in the control were not ingested [control GM% 77.71 (GSD 1.57), MR 1.27 (95% CI 1.33-1.43)]. Urine isoniazid testing was done on 443 (97%) samples from 114 participants; 13 participants had at least one negative result; a negative test was significantly more common among the control group compared with the intervention group [11/57 (19.3%) vs 2/57 (3.5%); p = 0.008]. There was no significant difference between the control and intervention arms for smear conversion [55 (98.2%) vs 52 (100%); p>0.999], adverse treatment outcomes [0 vs 1 (1.9%); p = 0.48], and self-report non-adherence [5 (8.9%) vs 1 (1.9%); p = 0.21].

CONCLUSIONS

In this randomized trial of patients with drug-sensitive pulmonary tuberculosis, medication adherence among participants assigned to MERM-observed self-administered therapy was non-inferior and superior by some measures when compared with the standard in-person DOT. Further research is needed to understand whether adherence in the intervention is primarily driven by allowing self-administered therapy which reduced challenges of repeated clinic visits or by the adherence support provided by the MERM system. To avoid contributing to patient barriers with DOT, tuberculosis medical programs should consider alternatives such as medication event monitors.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04216420.

Effect of Digital Medication Event Reminder and Monitor-Observed Therapy vs Standard Directly Observed Therapy on Health-Related Quality of Life and Catastrophic Costs in Patients With Tuberculosis: A Secondary Analysis of a Randomized Clinical Trial

Importance

Little is known about whether digital adherence technologies are economical for patients with tuberculosis (TB) in resource-constrained settings.

Objective

To test the hypothesis that for patients with TB, a digital medication event reminder monitor (MERM)-observed therapy provides higher health-related quality of life (HRQoL) and lower catastrophic costs compared with standard directly observed therapy (DOT).

Design, Setting, and Participants

This study was a secondary analysis of a randomized, 2-arm, open-label trial conducted in 10 health care facilities in Ethiopia. Eligible participants were adults with new or previously treated, bacteriologically confirmed, drug-sensitive pulmonary TB who were eligible to start first-line anti-TB therapy. Participants were enrolled between June 2, 2020, and June 15, 2021, with the last participant completing follow-up on August 15, 2021.

Interventions

Participants were randomly assigned (1:1) to receive a 15-day TB medication supply dispensed with a MERM device to self-administer and return every 15 days (intervention arm) or the standard in-person DOT (control arm). Both groups were observed throughout the standard 2-month intensive treatment phase.

Main Outcomes and Measures

Prespecified secondary end points of the original trial were HRQoL using the EuroQoL 5-dimension 5-level (EQ-5D-5L) tool and catastrophic costs, direct (out-of-pocket) and indirect (guardian and coping) costs from the individual patient perspective using the World Health Organization's Tool to Estimate Patient Costs, and common factors associated with lower HRQoL and higher catastrophic costs.

Results

Among 337 patients screened for eligibility, 114 were randomly assigned, and 109 were included in the final complete-case intention-to-treat analysis (57 control and 52 intervention participants). The mean (SD) age was 33.1 (11.1) years; 72 participants (66.1%) were men, and 15 (13.9%) had HIV coinfection. EQ-5D-5L overall median (IQR) index value was 0.964 (0.907-1). The median (IQR) value was significantly higher in intervention (1 [0.974-1]) vs control (.908 [0.891-0.964]) (P < .001). EQ-5D-5L minimum and maximum health state utility values in intervention were 0.906 and 1 vs 0.832 and 1 in control. Patients' overall median (IQR) postdiagnosis cost was Ethiopian birr (ETB) 80 (ETB 16-ETB 480) (US $1.53). The median cost was significantly lower in intervention (ETB 24 [ETB 16-ETB 48]) vs control (ETB 432 [ETB 210-ETB 1980]) (P < .001), with median possible cost savings of ETB 336 (ETB 156-ETB 1339) (US $6.44) vs the control arm. Overall, 42 participants (38.5%; 95% CI, 29.4%-48.3%) faced catastrophic costs, and this was significantly lower in the intervention group (11 participants [21.2%]; 95% CI, 11.1%-34.7%) vs control (31 participants [54.4%]; 95% CI, 40.7%-67.6%) (P < .001). Trial arm was the single most important factor in low HRQoL (adjusted risk ratio [ARR], 1.49; 95% CI, 1.35-1.65; P < .001), while trial arm (ARR, 2.55; 95% CI, 1.58-4.13; P < .001), occupation (ARR, 2.58; 95% CI, 1.68-3.97; P < .001), number of cohabitants (ARR, 0.64; 95% CI, 0.43-0.95; P = .03), and smoking (ARR, 2.71; 95% CI, 1.01-7.28; P = .048) were the most important factors in catastrophic cost.

Conclusions and Relevance

In patients with TB, MERM-observed therapy was associated with higher HRQoL and lower catastrophic costs compared with standard DOT. Patient-centered digital health technologies could have the potential overcoming structural barriers to anti-TB therapy.

Trial Registration

ClinicalTrials.gov Identifier: NCT04216420.

Sildenafil, a Type-5 Phosphodiesterase Inhibitor, Fails to Reverse Myeloid-Derived Suppressor Cell-Mediated T Cell Suppression in Cells Isolated From Tuberculosis Patients

Successful TB treatment is hampered by increasing resistance to the two most effective first-line anti-TB drugs, namely isoniazid and rifampicin, thus innovative therapies focused on host processes, termed host-directed therapies (HDTs), are promising novel approaches for increasing treatment efficacy without inducing drug resistance. We assessed the ability of Sildenafil, a type-5 phosphodiesterase inhibitor, as a repurposed compound, to serve as HDT target, by counteracting the suppressive effects of myeloid-derived suppressor cells (MDSC) obtained from active TB cases on T-cell responsiveness. We confirm that MDSC suppress non-specific T-cell activation. We also show that Sildenafil treatment fails to reverse the MDSC-mediated suppression of T-cell functions measured here, namely activation and proliferation. The impact of Sildenafil treatment on improved immunity, using the concentration tested here, is likely to be minimal, but further identification and development of MDSC-targeting TB host-directed therapies are warranted.

Clinical standards for drug-susceptible pulmonary TB

BACKGROUND: The aim of these clinical standards is to provide guidance on 'best practice´ for diagnosis, treatment and management of drug-susceptible pulmonary TB (PTB).METHODS: A panel of 54 global experts in the field of TB care, public health, microbiology, and pharmacology were identified; 46 participated in a Delphi process. A 5-point Likert scale was used to score draft standards. The final document represents the broad consensus and was approved by all 46 participants.RESULTS: Seven clinical standards were defined: Standard 1, all patients (adult or child) who have symptoms and signs compatible with PTB should undergo investigations to reach a diagnosis; Standard 2, adequate bacteriological tests should be conducted to exclude drug-resistant TB; Standard 3, an appropriate regimen recommended by WHO and national guidelines for the treatment of PTB should be identified; Standard 4, health education and counselling should be provided for each patient starting treatment; Standard 5, treatment monitoring should be conducted to assess adherence, follow patient progress, identify and manage adverse events, and detect development of resistance; Standard 6, a recommended series of patient examinations should be performed at the end of treatment; Standard 7, necessary public health actions should be conducted for each patient. We also identified priorities for future research into PTB.CONCLUSION: These consensus-based clinical standards will help to improve patient care by guiding clinicians and programme managers in planning and implementation of locally appropriate measures for optimal person-centred treatment for PTB.