Cost-effectiveness of a Pharmacogenomic Test for Stratified Isoniazid Dosing in Treatment of Active Tuberculosis.

BACKGROUND: There is marked interindividual variability in metabolism and resulting toxicity and effectiveness of drugs used for tuberculosis treatment. For isoniazid, mutations in the N-acetyltransferase 2 (NAT2) gene explain >88% of pharmacokinetic variability. However, weight-based dosing remains the norm globally. The potential clinical impact and cost-effectiveness of pharmacogenomic-guided therapy (PGT) are unknown. METHODS: We constructed a decision tree model to project lifetime costs and benefits of isoniazid PGT for drug-susceptible tuberculosis in Brazil, South Africa, and India. PGT was modeled to reduce isoniazid toxicity among slow NAT2 acetylators and reduce treatment failure among rapid acetylators. The genotyping test was assumed to cost the same as the GeneXpert test. The main outcomes were costs (2018 US dollars), quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios. RESULTS: In Brazil, PGT gained 19 discounted life-years (23 QALYs) and cost $11 064 per 1000 patients, a value of $476 per QALY gained. In South Africa, PGT gained 15 life-years (19 QALYs) and cost $33 182 per 1000 patients, a value of $1780 per QALY gained. In India, PGT gained 20 life-years (24 QALYs) and cost $13 195 per 1000 patients, a value of $546 per QALY gained. One-way sensitivity analyses showed the cost-effectiveness to be robust to all input parameters. Probabilistic sensitivity analyses were below per capita gross domestic product in all 3 countries in 99% of simulations. CONCLUSIONS: Isoniazid PGT improves health outcomes and would be cost-effective in the treatment of drug-susceptible tuberculosis in Brazil, South Africa, and India.

National assessment of availability, awareness, and utilization of supervised exercise therapy for peripheral artery disease patients with intermittent claudication.

BACKGROUND: Supervised exercise therapy (SET) is an inexpensive, low-risk, and effective option when compared with invasive therapies for the treatment of patients with peripheral artery disease (PAD) and intermittent claudication. Randomized, controlled trials have demonstrated the benefits of SET in improving maximum walking distance in intermittent claudication patients, and society guidelines recommend SET as first-line therapy. In 2017, the Centers for Medicare & Medicaid Services (CMS) added coverage of SET. We aimed to evaluate the availability and use of SET programs, determine the awareness of SET CMS coverage in the United States, and gauge the academic interest in SET in the vascular community. METHODS: An eight-question online survey regarding SET coverage, reimbursement, barriers to prescription, and SET use was sent to 900 vascular surgeons, cardiologists, and vascular medicine physicians across the United States. The most recent 2-year programs for the Vascular Annual Meeting, Midwestern Vascular Society, Eastern Vascular Society, and Western Vascular Society were reviewed to identify SET-related abstracts and gauge academic interest and awareness for SET within the vascular surgery community. RESULTS: We received 135 physician responses (15%) to the survey. All 50 states were represented. The majority of responders (54%) stated that there was no SET program at their facility, and 5% did not know if there was a SET program available. Of those who did have a SET program available, 81% were associated with cardiac rehabilitation and 19% had a PAD-specific program. A significant number of physicians (49%) had never referred a patient for SET. Twenty-six percent were not aware that CMS covered SET sessions. Of the physicians who were aware of CMS reimbursement, 36% had never referred a patient to a SET program. Of all surveyed, 98% indicated they would refer patients to a SET program if one was available. Top barriers to use of a SET program included (1) no SET center availability and (2) significant cost or travel expense to the patient. A review of major vascular surgery meeting programs for the last 2 years yielded no identification of a SET-related abstract. CONCLUSIONS: There is a lack of both availability and use of SET for patients with PAD with claudication, despite guideline recommendations and CMS reimbursement for SET sessions in the United States. When SET is offered, it is typically through cardiac rehabilitation programs which is not focused on PAD. Travel distance, lack of SET program availability, and low reimbursement rates are primary areas that could be addressed to improve use.

Factors associated with COVID-19 vaccine acceptance and hesitancy among residents of Northern California jails.

Carceral facilities are high-risk settings for COVID-19 transmission. Factors associated with COVID-19 vaccine acceptance and hesitancy among incarcerated individuals are poorly understood, especially among jail residents. Here, we conducted a retrospective review of electronic health record (EHR) data on COVID-19 vaccine uptake in custody and additionally administered a survey to assess reasons for vaccine hesitancy, sources of COVID-19 information, and medical mistrust among residents of four Northern California jails. We performed multivariate logistic regression to determine associations with vaccine acceptance. Of 2,564 jail residents offered a COVID-19 vaccine between March 19, 2021 and June 30, 2021, 1,441 (56.2%) accepted at least one dose. Among vaccinated residents, 497 (34.5%) had initially refused. Vaccine uptake was higher among older individuals, women, those with recent flu vaccination, and those living in shared housing. Among 509 survey respondents, leading reasons for vaccine hesitancy were concerns around side effects and suboptimal efficacy, with cost and the need for an annual booster being other hypothetical deterrents to vaccination. Vaccine hesitancy was also associated with mistrust of medical personnel in and out of jail, although this association varied by race/ethnicity. Television and friends/family were the most common and most trusted sources of COVID-19 information, respectively. Overall, vaccine acceptance was much lower among jail residents than the local and national general population. Interventions to increase vaccination rates in this setting should utilize accessible and trusted sources of information to address concerns about side effects and efficacy, while working to mitigate medical and institutional mistrust among residents.

Reliability and repeatability of a smartphone-based 6-min walk test as a patient-centred outcome measure.

Aims: The 6-min-walk test (6MWT) is a validated proxy for frailty and a predictor of clinical outcomes, yet is not widely used due to implementation challenges. This comparative effectiveness study assesses the reliability and repeatability of a home-based 6MWT compared to in-clinic 6MWTs in patients with cardiovascular disease. Methods and results: One hundred and ten (110) patients scheduled for cardiac or vascular surgery were enrolled during a study period from June 2018 to December 2019 at the Palo Alto VA Hospital. Subjects were provided with an Apple iPhone 7 and Apple Watch Series 3 loaded with the VascTrac research study application and performed a supervised in-clinic 6MWT during enrolment, at 2 weeks, 1, 3, and 6 months post-operatively. Subjects also received notifications to perform at-home smartphone-based 6MWTs once a week for a duration of 6 months. Test-retest reliability of in-clinic measurements and at-home measurements was assessed with an industry standard Cronbach's alpha reliability test. Test-retest reliability for in-clinic ground truth 6MWT steps vs. in-clinic iPhone 6MWT steps was 0·99, showing high reliability between the two tested measurements. When comparing for in-clinic ground truth 6MWT steps vs. neighbouring at-home iPhone 6MWT steps, reliability was 0·74. Conclusion: Running the test-reliability test on both measurements shows that an iPhone 6MWT test is reliable compared to an in-clinic ground truth measurement in patients with cardiovascular disease.

Activity data from wearables as an indicator of functional capacity in patients with cardiovascular disease.

BACKGROUND: Smartphone and wearable-based activity data provide an opportunity to remotely monitor functional capacity in patients. In this study, we assessed the ability of a home-based 6-minute walk test (6MWT) as well as passively collected activity data to supplement or even replace the in-clinic 6MWTs in patients with cardiovascular disease. METHODS: We enrolled 110 participants who were scheduled for vascular or cardiac procedures. Each participant was supplied with an iPhone and an Apple Watch running the VascTrac research app and was followed for 6 months. Supervised 6MWTs were performed during clinic visits at scheduled intervals. Weekly at-home 6MWTs were performed via the VascTrac app. The app passively collected activity data such as daily step counts. Logistic regression with forward feature selection was used to assess at-home 6MWT and passive data as predictors for "frailty" as measured by the gold-standard supervised 6MWT. Frailty was defined as walking <300m on an in-clinic 6MWT. RESULTS: Under a supervised in-clinic setting, the smartphone and Apple Watch with the VascTrac app were able to accurately assess 'frailty' with sensitivity of 90% and specificity of 85%. Outside the clinic in an unsupervised setting, the home-based 6MWT is 83% sensitive and 60% specific in assessing "frailty." Passive data collected at home were nearly as accurate at predicting frailty on a clinic-based 6MWT as was a home-based 6MWT, with area under curve (AUC) of 0.643 and 0.704, respectively. CONCLUSIONS: In this longitudinal observational study, passive activity data acquired by an iPhone and Apple Watch were an accurate predictor of in-clinic 6MWT performance. This finding suggests that frailty and functional capacity could be monitored and evaluated remotely in patients with cardiovascular disease, enabling safer and higher resolution monitoring of patients.