Design of Clinical Trials to Validate Cuffless Blood Pressure Monitors

Author(s):  
Willem J. Verberk
2011 ◽  
Vol 3 (1) ◽  
pp. 30
Author(s):  
Anding Xu ◽  
Zefeng Tan ◽  
◽  

Hypertension is the most important of the prevalent and modifiable risk factors for stroke. Based on evidence, blood pressure (BP) lowering is recommended in guidelines for the prevention of stroke. However, there are still some uncertainties in the guidelines for controlling BP and preventing stroke in patients with previous cerebrovascular events, such as the goal BP, who to treat and which class of BP-lowering drugs to use. This article discusses these questions by reviewing guidelines and corresponding clinical trials, with the aim of reducing the gap between guidelines and clinical practice.


2020 ◽  
Author(s):  
Lida Feyz ◽  
Yale Wang ◽  
Atul Pathak ◽  
Manish Saxena ◽  
Felix Mahfoud ◽  
...  

BACKGROUND Great and costly efforts are required to recruit potential participants into clinical trials. Using social media may make the recruitment process more efficient. Merely 20% of clinical trials are completed on time, a finding mostly linked to challenges in patient recruitment [1]. Recruitment through social media is increasingly being recognized as a tool to efficiently identify eligible subjects at lower costs [2, 3]. One of the key reasons for its success is the strong adherence of users to specific social media platforms. Facebook for instance has over 2.38 billion active monthly users of which about 75% access the network on a daily basis [4]. As such, the platform and other like it offer great potential to quickly and affordably enroll patients into clinical trials and surveys [3, 5-7]. At present, little evidence is available on the efficacy of using social media to recruit patients into cardiovascular and hypertension trials [8]. The aim of the present study was to evaluate the efficacy of social media as an approach to recruit hypertensive patients into the RADIANCE-HTN SOLO trial. OBJECTIVE The aim of the present study was to evaluate the efficacy of social media as an approach to recruit hypertensive patients into the RADIANCE-HTN SOLO trial. METHODS The RADIANCE-HTN SOLO (NCT02649426) is a multicenter, randomised study that was designed to demonstrate the efficacy and safety of endovascular ultrasound renal denervation (RDN) to reduce ambulatory blood pressure at 2 months in patients with combined systolic–diastolic hypertension in the absence of medications. Between March 28, 2016, and Dec 28, 2017, 803 patients were screened for eligibility and 146 were randomised to undergo RDN (n=74) or a sham procedure (n=72) [9]. Key entry criteria included: age 18-75 years with essential hypertension using 0-2 antihypertensive drugs. Patients were recruited from 21 hospitals in the USA and 18 hospitals in Europe. The study was approved by local ethics committees or institutional review boards and was performed in accordance with the declaration of Helsinki. All participants provided written informed consent. All recruitment materials including social media campaigns was approved by local ethics committees of the involved sites. Recruitment strategies included social media (Facebook), conventional advertisements (ads) (magazine, brochure/poster, radio, newspaper), web search (the clinical website, craigslist and web-browsing), and physician referral. Both newspaper ads and posters contained brief information about study entry criteria. Newspapers were distributed at public transport places and posters were displayed in outpatient cardiology and hypertension clinics. Radio ads were run for 30 or 60 seconds providing a short summary of the study, entry criteria and contact information. Ads were run in major metropolitan areas on radio stations with large adult listener bases during popular days and times. Facebook ads were targeted towards subjects >45 years old within a certain distance from a recruitment site (range 20-50 miles). Criteria were modified over time in order to increase response rates [i.e. distance was increased or decreased, age was increased to >55 year]. Facebook ads referred to a dedicated study website translated into country specific languages. If interested, subjects could complete an anonymous online screening questionnaire which provided direct automatic feedback on study eligibility. Eligible subjects were asked to provide contact details (name and telephone number) to receive additional information, a process coordinated via a secure online portal (Galen Gateway Patient Recruitment Portal, Galen Patient Recruitment, Inc., Cumberland, RI). Study site were only able to contact potential candidates within their area. The study sponsor was not able to access any personal data. Trained local site personnel or contracted secondary screeners contacted candidates by phone to verify eligibility and answer potential questions. A subsequent outpatient clinic visit was scheduled during which the study was explained in greater detail and the informed consent form could be signed. Statistical analysis Categorical variables were expressed as percentages and counts. Continuous variables were described as mean  standard deviation (SD) when normally distributed, data was compared using an Independent-Samples or Paired-Samples T test to analyze the difference between recruitment methods. In case of non-normal distribution, median data was presented with the interquartile range [IQR]. All statistical tests are 2-tailed. A P-value <0.05 was considered statistically significant. Statistical analysis was performed using SPSS statistical analysis (version 24.0).   RESULTS Results Facebook ads were active during a 115-day recruitment period between August and November 2017. A total of 285 potential candidates were recruited by different recruitment strategies in this specific time period, of which 184 (65%) were consented through Facebook (Table 1). The average age of the subjects consented through Facebook was 59 ± 8 years and 51% were male (Table 2). Facebook reached 5.3 million people in 168 separate campaigns run in proximity to 19 sites in the US and 14 sites in Europe. The number of candidates per site was variable with a median of 23 [17 – 26] candidates per site that passed the questionnaire (Figure 1). A total of 27/184 subjects were eventually randomised. Total cost for the Facebook ads was $152,412; costing $907/campaign and $0.83/click. This resulted in a total cost of $828/consent. During the same recruitment period, 7-day radio spots were launched with a total cost of $2,870; resulting in 9 inquiries with eventually 5 potential candidates and 2 consents ($1,435/consent).   CONCLUSIONS Conclusion Targeted social media was a successful and efficient strategy to find potential candidates for a multicenter blood pressure clinical trial. Whether this approach can be replicated across other disease states or demographics remains to be studied.


2021 ◽  
pp. 0271678X2110043
Author(s):  
Thompson G Robinson ◽  
Jatinder S Minhas ◽  
Joseph Miller

Over the last two decades, there have been a number of major landmark clinical trials, classified as “major” as they sought to address clear clinical practice driven questions, in a pragmatic yet robust trial design, using a large powered sample size (n > 1000), in order to help improve patient outcome through informing guidelines. A commonality across all stroke sub-types included in these trials is the tendency to acute hypertensive crises within the acute stroke period. This phenomenon is associated with greater stroke complications and worsened overall prognosis. Multiple trials have attempted to address the issue of acute blood pressure management during the acute stroke period, with consideration for timing, magnitude of lowering, agent and relationship to other interventions. This review will consider the major clinical trials performed in ischaemic and haemorrhagic stroke that test the hypothesis that acute BP reduction improves clinical outcomes.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Thenral Socrates ◽  
Philipp Krisai ◽  
Annina S. Vischer ◽  
Andrea Meienberg ◽  
Michael Mayr ◽  
...  

AbstractA cuffless blood pressure (BP) device (TestBP) using pulse transit time is in clinical use, but leads to higher BP values compared to a cuff-based 24 h-BP reference device (RefBP). We evaluated the impact of a recent software update on BP results and TestBP’s ability to differentiate between normo- and hypertension. 71 individuals had TestBP (Somnotouch-NIBP) and RefBP measurements simultaneously performed on either arm. TestBP results with software version V1.5 were compared to V1.4 and RefBP. Mean 24 h (± SD) BP for the RefBP, TestBP-V1.4 and TestBP-V1.5 were systolic 134.0 (± 17.3), 140.8 (± 20) and 139.1 (± 20) mmHg, and diastolic 79.3 (± 11.7), 85.8 (± 14.1) and 83.5 (± 13.0) mmHg, respectively (p-values < 0.001). TestBP-V1.5 area under the curve (95% confidence interval) versus RefBP for hypertension detection was 0.92 (0.86; 0.99), 0.94 (0.88; 0.99) and 0.77 (0.66; 0.88) for systolic and 0.92 (0.86; 0.99), 0.92 (0.85; 0.99) and 0.84 (0.74; 0.94) for diastolic 24 h, awake and asleep BP respectively. TestBP-V1.5 detected elevated systolic/diastolic mean 24 h-BP with a 95%/90% sensitivity and 65%/70% specificity. Highest Youden’s Index was systolic 133 (sensitivity 95%/specificity 80%) and diastolic 87 mmHg (sensitivity 81%/specificity 98%). The update improved the agreement to RefBP. TestBP was excellent for detecting 24 h and awake hypertensive BP values but not for asleep BP values.


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