Return on investment of self-measured blood pressure is associated with its use in preventing false diagnoses, not monitoring hypertension.

Previous research indicates that patient self-measured blood pressure (SMBP) is a cost-effective strategy for improving hypertension (HTN) diagnosis and control. However, it is unknown which specific uses of SMBP produce the most value. Our goal is to estimate, from an insurance perspective, the return-on-investment (ROI) and net present value associated with coverage of SMBP devices when used (a) only to diagnose HTN, (b) only to select and titrate medication, (c) only to monitor HTN treatment, or (d) as a bundle with all three uses combined. We employed national sample of claims data, Framingham risk predictions, and published sensitivity-specificity values of SMBP and clinic blood-pressure measurement to extend a previously-developed local decision-analytic simulation model. We then used the extended model to determine which uses of SMBP produce the most economic value when scaled to the U.S. adult population. We found that coverage of SMBP devices yielded positive ROIs for insurers in the short-run and at lifetime horizon when the three uses of SMBP were considered together. When each use was evaluated separately, positive returns were seen when SMBP was used for diagnosis or for medication selection and titration. However, returns were negative when SMBP was used exclusively to monitor HTN treatment. When scaled to the U.S. population, adoption of SMBP would prevent nearly 16.5 million false positive HTN diagnoses, thereby improving quality of care while saving insurance plans $254 per member. A strong economic case exists for insurers to cover the cost of SMBP devices, but it matters how devices are used.

Human Errors in Automated Office Blood Pressure Measurement: Still Room for Improvement.

In this review of the literature and commentary, we examine the literature on automated blood pressure (BP) measurements in the office and clinic. Our purpose is to revisit issues as to the pros and cons of automated BP measurement published in Hypertension in June 2020 and to identify areas needing additional research. Despite initial reservations about automated BP, it is here to stay. A number of experts suggest that human error will be reduced when we move from the more complex skills required by aneroid sphygmomanometer measurement to the fewer skills and steps required by automated BP measurement. Our review indicates there is still need for reduction in errors in automated BP assessment, for example, retraining programs and monitoring of assessment procedures. We need more research on the following questions: (1) which classes of health care providers are least likely to measure BP accurately, usually by ignoring necessary steps; (2) how accurate is BP assessment by affiliated health care providers for example the dental office, the optometrist; and (3) why do some dedicated and well-informed health care professionals fail to follow simple directions for automated BP measurement? We offer additional solutions for improving automated BP assessment in the office and clinic.

Mixed-methods feasibility study of blood pressure self-screening for hypertension detection.

OBJECTIVE: To assess the feasibility of using a blood pressure (BP) self-measurement kiosk-a solid-cuff sphygmomanometer combined with technology to integrate the BP readings into patient electronic medical records- to improve hypertension detection. DESIGN: A concurrent mixed-methods feasibility study incorporating observational and qualitative interview components. SETTING: Two English general practitioner (GP) surgeries. PARTICIPANTS: Adult patients registered at participating surgeries. Staff working at these sites. INTERVENTIONS: BP self-measurement kiosks were placed in the waiting rooms for a 12-month period between 2015 and 2016 and compared with a 12-month control period prior to installation. OUTCOME MEASURES: (1) The number of patients using the kiosk and agreeing to transfer of their data into their electronic medical records; (2) the cost of using a kiosk compared with GP/practice nurse BP screening; (3) qualitative themes regarding use of the equipment. RESULTS: Out of 15 624 eligible patients, only 186 (1.2%, 95% CI 1.0% to 1.4%) successfully used the kiosk to directly transfer a BP reading into their medical record. For a considerable portion of the intervention period, no readings were transferred, possibly indicating technical problems with the transfer link. A comparison of costs suggests that at least 52.6% of eligible patients would need to self-screen in order to bring costs below that of screening by GPs and practice nurses. Qualitative interviews confirmed that both patients and staff experienced technical difficulties, and used alternative methods to enter BP results into the medical record. CONCLUSIONS: While interviewees were generally positive about checking BP in the waiting room, the electronic transfer system as tested was neither robust, effective nor likely to be a cost-effective approach, thus may not be appropriate for a primary care environment. Since most of the cost of a kiosk system lies in the transfer mechanism, a solid-cuff sphygmomanometer and manual entry of results may be a suitable alternative.

Cost-Effectiveness of Telemonitoring and Self-Monitoring of Blood Pressure for Antihypertensive Titration in Primary Care (TASMINH4).

The use of self-monitoring of blood pressure, with or without telemonitoring, to guide therapy decisions by physicians for patients with hypertension has been recently demonstrated to reduce blood pressure compared with using clinic monitoring (usual care). However, both the cost-effectiveness of these strategies compared with usual care, and whether the additional benefit of telemonitoring compared with self-monitoring alone could be considered value for money, are unknown. This study assessed the cost-effectiveness of physician titration of antihypertensive medication using self-monitored blood pressure, with or without telemonitoring, to make hypertension treatment decisions in primary care compared with usual care. A Markov patient-level simulation model was developed taking a UK Health Service/Personal Social Services perspective. The model adopted a lifetime time horizon with 6-month time cycles. At a willingness to pay of £20 000 per quality-adjusted life year, self-monitoring plus telemonitoring was the most cost-effective strategy (£17 424 per quality-adjusted life year gained) compared with usual care or self-monitoring alone (posting the results to the physician). However, deterministic sensitivity analysis showed that self-monitoring alone became the most cost-effective option when changing key assumptions around long-term effectiveness and time horizon. Overall, probabilistic sensitivity analysis suggested that self-monitoring regardless of transmission modality was likely to be cost-effective compared with usual care (89% probability of cost-effectiveness at £20 000/quality-adjusted life year), with high uncertainty as to whether telemonitoring or self-monitoring alone was the most cost-effective option. Self-monitoring in clinical practice is cost-effective and likely to lead to reduced cardiovascular mortality and morbidity.

Cost-effectiveness of home blood pressure telemonitoring and case management in the secondary prevention of cerebrovascular disease in Canada.

Home blood pressure (BP) telemonitoring and pharmacist case management reduce BP, but cost-effectiveness assessments are mixed. We examined the incremental cost-effectiveness of this intervention vs usual care in Canadians with cerebrovascular disease. A Markov decision model cost-utility analysis examining community-residing, high-risk patients with a recent nondisabling cerebrovascular event was created. A lifetime time horizon and health care payer perspective were used. Achieved BP, future cardiovascular risks, and attendant consequences on quality-adjusted life years and Canadian dollar costs were modeled. BP telemonitoring was assumed to occur for 3 months, then quarterly. Life tables were used to determine overall mortality, adjusted by cardiovascular disease mortality. Relative efficacies of intervention-associated BP lowering, resource use, and costs were obtained from Canadian published literature. Reduction in systolic BP of 9.7 mmHg was used in the base case; subsequently, robust sensitivity analyses were conducted. The results showed that, over the lifetime horizon, telemonitoring with case management led to net health care savings of $1929 Canadian and increased per-patient QALYs by 0.83. These findings were robust to sensitivity analysis, with the intervention remaining dominant or highly cost-effective. Increasing telemonitoring costs by 50% still resulted in the intervention being dominant; if the costs of telemonitoring plus case management were 2-3 times base case cost, incremental cost-effectiveness was $1200-$4700 per quality-adjusted life year gained. In conclusion, home BP telemonitoring and pharmacist case management poststroke lowered costs and improved QALYs. Strategies and funding for broad implementation of this dominant strategy should be implemented.

Is Screening for Atrial Fibrillation in Canadian Family Practices Cost-Effective in Patients 65 Years and Older?

We present an economic evaluation of a recently completed cohort study in which 2054 seniors were screened for atrial fibrillation (AF) in 22 Canadian family practices. Using a Markov model, trial and literature data were used to project long-term outcomes and costs associated with 4 AF screening strategies for individuals aged 65 years or older: no screening, screen with 30-second radial manual pulse check (pulse check), screen with a blood pressure machine with AF detection (BP-AF), and screen with a single-lead electrocardiogram (SL-ECG). Costs and outcomes were discounted at 1.5% and the model used a lifetime horizon from a public payer perspective. Compared with no screening, screening for AF in Canadian family practice offices using pulse check or screen with a blood pressure machine with AF detection is the dominant strategy whereas screening with SL-ECG is a highly cost-effective strategy with an incremental cost per quality-adjusted life-year (QALY) gained of CAD$4788. When different screening strategies were compared, screening with pulse check had the lowest expected costs ($202) and screening with SL-ECG had the highest expected costs ($222). The no-screening arm resulted in the lowest number of QALYs (8.74195) whereas pulse check and SL-ECG resulted in the highest expected QALYs (8.74362). Probabilistic analysis confirmed that pulse check had the highest probability of being cost-effective (63%) assuming a willingness to pay of $50,000 per QALY gained. Screening for AF in seniors during routine appointments with Canadian family physicians is a cost-effective strategy compared with no screening. Screening with a pulse check is likely to be the most cost-effective strategy.

Home blood pressure monitoring in the 21st century.

Home blood pressure monitoring provides multiple measurements in the usual environment of each individual, allows the detection of intermediate hypertension phenotypes (white-coat and masked hypertension), and appears to have superior prognostic value compared to the conventional office blood pressure measurements. Accumulating evidence suggests that home blood pressure monitoring improves long-term hypertension control rates. Moreover, it is widely available, relatively inexpensive, and well accepted by patients. Thus, current guidelines recommend home blood pressure monitoring as an essential method for the evaluation of almost all untreated and treated patients with suspected or treated hypertension. Validated automated upper-arm cuff devices with automated storage and averaging of readings should be used. The home blood pressure monitoring schedule for 4 to 7 days with exclusion of the first day (12-24 readings) should be averaged to provide values for decision making.

Evaluation of a novel device for the management of high blood pressure and shock in pregnancy in low-resource settings: study protocol for a stepped-wedge cluster-randomised controlled trial (CRADLE-3 trial).

BACKGROUND: Obstetric haemorrhage, sepsis and pregnancy hypertension account for more than 50% of maternal deaths worldwide. Early detection and effective management of these conditions relies on vital signs. The Microlife® CRADLE Vital Sign Alert (VSA) is an easy-to-use, accurate device that measures blood pressure and pulse. It incorporates a traffic-light early warning system that alerts all levels of healthcare provider to the need for escalation of care in women with obstetric haemorrhage, sepsis or pregnancy hypertension, thereby aiding early recognition of haemodynamic instability and preventing maternal mortality and morbidity. The aim of the trial was to determine whether implementation of the CRADLE intervention (the Microlife® CRADLE VSA device and CRADLE training package) into routine maternity care in place of existing equipment will reduce a composite outcome of maternal mortality and morbidity in low- and middle-income country populations. METHODS: The CRADLE-3 trial was a stepped-wedge cluster-randomised controlled trial of the CRADLE intervention compared to routine maternity care. Each cluster crossed from routine maternity care to the intervention at 2-monthly intervals over the course of 20 months (April 2016 to November 2017). All women identified as pregnant or within 6 weeks postpartum, presenting for maternity care in cluster catchment areas were eligible to participate. Primary outcome data (composite of maternal death, eclampsia and emergency hysterectomy per 10,000 deliveries) were collected at 10 clusters (Gokak, Belgaum, India; Harare, Zimbabwe; Ndola, Zambia; Lusaka, Zambia; Free Town, Sierra Leone; Mbale, Uganda; Kampala, Uganda; Cap Haitien, Haiti; South West, Malawi; Addis Ababa, Ethiopia). This trial was informed by the Medical Research Council guidance for complex interventions. A process evaluation was undertaken to evaluate implementation in each site and a cost-effectiveness evaluation will be undertaken. DISCUSSION: All aspects of this protocol have been evaluated in a feasibility study, with subsequent optimisation of the intervention. This trial will demonstrate the potential impact of the CRADLE intervention on reducing maternal mortality and morbidity in low-resource settings. It is anticipated that the relatively low cost of the intervention and ease of integration into existing health systems will be of significant interest to local, national and international health policy-makers. TRIAL REGISTRATION: ISCRTN41244132. Registered on 2 February 2016. Prospective protocol modifications have been recorded and were communicated to the Ethics Committees and Trials Committees. The adapted Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) Checklist and the SPIRIT Checklist are attached as Additional file 1.

A Universal Noninvasive Continuous Blood Pressure Measurement System for Remote Healthcare Monitoring.

BACKGROUND: The effectiveness of any remote healthcare monitoring system depends on how much accurate, patient-friendly, versatile, and cost-effective measurement it is delivering. There has always been a huge demand for such a long-term noninvasive remote blood pressure (BP) measurement system, which could be used worldwide in the remote healthcare industry. Thus, noninvasive continuous BP measurement and remote monitoring have become an emerging area in the remote healthcare industry. INTRODUCTION: Photoplethysmography-based (PPG) BP measurement is a continuous, unobtrusive, patient-friendly, and cost-effective solution. However, BP measurements through PPG sensors are not much reliable and accurate due to some major limitations like pressure disturbance, motion artifacts, and variations in human skin tone. MATERIALS AND METHODS: A novel reflective PPG sensor has been developed to eliminate the abovementioned pressure disturbance and motion artifacts during the BP measurement. Considering the variations of the human skin tone across demography, a novel algorithm has been developed to make the BP measurement accurate and reliable. The training dataset captured 186 subjects' data and the trial dataset captured another new 102 subjects' data. RESULTS AND DISCUSSION: The overall accuracy achieved by using the proposed method is nearly 98%. Thus, demonstrating the efficacy of the proposed method. CONCLUSIONS: The developed BP monitoring system is quite accurate, reliable, cost-effective, handy, and user friendly. It is also expected that this system would be quite useful to monitor the BP of infants, elderly people, patients having wounds, burn injury, or in the intensive care unit environment.

A Literature Review on Current and Proposed Technologies of Noninvasive Blood Pressure Measurement.

BACKGROUND: Noninvasive continuous blood pressure (BP) measurement has become an evolving topic in the field of remote healthcare. The classical noninvasive BP measurement techniques provide spontaneous values of systolic and diastolic BP. On the other hand, intrusive type BP measurement techniques provide continuous values of systolic and diastolic BP. However, these techniques are very painful, cannot be used for long-term monitoring, and are obtainable only in an intensive care unit environment. With the advancement of the remote healthcare industry, there is a growing demand for noninvasive continuous BP monitoring. OBJECTIVE: The objective of this research was to present a compact literature review on the various prospective approaches of noninvasive continuous BP measurement techniques. MATERIALS & METHODS: The most contemporary and advanced technologies on noninvasive continuous BP measurement are Tactile Sensing, Vascular Unloading Technique, Pulse Transit Time, Photoplethysmography, Ultrasound-based BP measurement, BP measurement from image processing, etc. The literature search based on these technologies was conducted in EMBASE, Web of Science, IEEE, PubMed, and Ovid MEDLINE databases. In this study, each selected approach was evaluated and characterized using the following criteria: (1) accuracy; (2) cost; (3) portability; (4) comfort and convenience of use; (5) clinical health and safety; and (6) ability to integrate with the remote healthcare system. RESULTS: A detailed technical analysis was done to determine the advantages and limitations of each technique in the context of the abovementioned parameters. It was observed that BP measurement, using photoplethysmography (using camera or sensor or both), perhaps was the most promising technique among all. CONCLUSION: The study emphasized the fact that the noninvasive, continuous BP measurement technique needs to evolve further to make it reliable, accurate, and user-friendly. Lastly, a possible direction toward a more reliable and comfortable noninvasive continuous BP measurement technique has been discussed.

The cost-effectiveness of real-time pulmonary artery pressure monitoring in heart failure patients: a European perspective.

AIMS: Heart failure (HF) treatment guided by physicians with access to real-time pressure measurement from a wireless implantable pulmonary artery pressure (PAP) sensor (CardioMEMS), has previously been shown to reduce HF-related hospital admissions in the CHAMPION trial. However, uncertainty remains regarding the value of CardioMEMS in European health systems where healthcare costs are significantly lower than in the USA. METHODS AND RESULTS: A Markov model was developed to estimate the cost-effectiveness of PAP-guided treatment of HF using the CardioMEMS™ HF system compared with usual care. Cost-effectiveness was measured as the incremental cost per quality-adjusted life year (QALY) gained. In the base case analysis over a time horizon of 10 years, PAP-guided HF therapy increased cost compared with usual care by £10 916 (€14 030). QALYs per patient for usual care and PAP-guided patients were 2.57 and 3.14, respectively, reflecting an increase of 0.57 QALYs with PAP-guided treatment. The resultant incremental cost-effectiveness ratio (ICER) is £19 274 (€24 772) per QALY gained. The base case analysis did not include staff time, due to a lack of data concerning this variable. Running the model with estimated staff time included resulted in an increased ICER of between £22 342 and £25 464 per QALY gained (€28 709-32 721). CONCLUSION: The analysis indicates that integrating wireless PAP monitoring into the management of UK HF patients is likely to be a cost-effective addition to the HF treatment pathway for appropriate patients.

Screening and Treatment for Subclinical Hypertensive Heart Disease in Emergency Department Patients With Uncontrolled Blood Pressure: A Cost-effectiveness Analysis.

OBJECTIVES: Poorly controlled hypertension (HTN) is extremely prevalent and, if left unchecked, subclinical hypertensive heart disease (SHHD) may ensue leading to conditions such as heart failure. To address this, we designed a multidisciplinary program to detect and treat SHHD in a high-risk, predominantly African American community. The primary objective of this study was to determine the cost-effectiveness of our program. METHODS: Study costs associated with identifying and treating patients with SHHD were calculated and a sensitivity analysis was performed comparing the effect of four parameters on cost estimates. These included prevalence of disease, effectiveness of treatment (regression of SHHD, reversal of left ventricular hypertrophy [LVH], or blood pressure [BP] control as separate measures), echocardiogram costs, and participant time/travel costs. The parent study for this analysis was a single-center, randomized controlled trial comparing cardiac effects of standard and intense (<120/80 mm Hg) BP goals at 1 year in patients with uncontrolled HTN and SHHD. A total of 149 patients (94% African American) were enrolled, 133 (89%) had SHHD, 123 (93%) of whom were randomized, with 88 (72%) completing the study. Patients were clinically evaluated and medically managed over the course of 1 year with repeated echocardiograms. Costs of these interventions were analyzed and, following standard practices, a cost per quality-adjusted life-year (QALY) less than $50,000 was defined as cost-effective. RESULTS: Total costs estimates for the program ranged from $117,044 to $119,319. Cost per QALY was dependent on SHHD prevalence and the measure of effectiveness but not input costs. Cost-effectiveness (cost per QALY less than $50,000) was achieved when SHHD prevalence exceeded 11.1% for regression of SHHD, 4.7% for reversal of LVH, and 2.9% for achievement of BP control. CONCLUSIONS: In this cohort of predominantly African American patients with uncontrolled HTN, SHHD prevalence was high and screening with treatment was cost-effective across a range of assumptions. These data suggest that multidisciplinary programs such as this can be a cost-effective mechanism to mitigate the cardiovascular consequences of HTN in emergency department patients with uncontrolled BP.

Unfounded concerns about the use of automated office blood pressure measurement in SPRINT.

SPRINT reported significantly fewer cardiovascular events when patients with a higher cardiovascular risk were treated to a target systolic blood pressure (BP) of <120 versus <140 mm Hg. In SPRINT, BP was recorded using the automated office BP (AOBP) method, with multiple readings being taken automatically with the patient resting alone. This technique for BP measurement eliminates the white-coat effect and gives lower BP readings than conventional manual office BP. Critics have questioned if the readings were actually taken with the subject alone and have expressed concerns about the time taken to obtain the readings and the cost of automated sphygmomanometers. Others have suggested that the findings in SPRINT can be applied to current clinical practice if a correction factor is used to convert conventional BP readings to AOBP. This article responds to these criticisms and explains why current methods for recording BP in clinical practice should be changed to AOBP, the technique for BP measurement used in SPRINT.

Telemedicine and M-Health in Hypertension Management: Technologies, Applications and Clinical Evidence.

Electronic processes and communication technologies are more and more often employed to provide healthcare services to caregivers and their patients. Such solutions are currently referred as e-health, the most popular and widely distributed being those based on telemedicine and mobile health (m-health). A specific application of telemedicine for hypertension management is blood pressure telemonitoring (BPT), which allows remote data transmission of BP and additional information on patients' health status from their living site or from a community setting to the doctor's office or the hospital. Several randomized studies have documented a significant BP reduction with regular BPT compared to usual care, particularly in high risk hypertensive patients. Additional benefits are observed when BPT is offered under the supervision of a team of healthcare professionals, including a community pharmacist. BPT may also be provided in the context of m-health solutions, which commonly include wireless diagnostic and clinical decision support tools. M-health has the potential to promote patient's self-management, as a complement to the doctor's intervention, and encourage greater participation in medical decision making. Current statistics show that half of smartphone owners gather health information through their phone and 19 % use a health app. In case of hypertensive patients the most popular apps are those with tracking function, including BPT. Thus, e-health, and in particular BPT and m-health, are progressively gaining a key role in the management of hypertensive patients, having the potential to improve the quality of the delivered care and to more effectively prevent cardiovascular consequences of high BP.

Blood pressure profile in pregnancy: The impact of its duration on results and patients' well-being.

BACKGROUND: A blood pressure profile (BPP) is often used to diagnose and manage hypertension in pregnancy. However, there is no consensus on the number and interval of blood pressure (BP) readings required. AIMS: To ascertain whether BP readings at 15-min interval over one hour yields clinically equivalent results to readings at 60-min interval over three hours. MATERIALS AND METHODS: Eighty unique women were recruited to this prospective study. Automated BP machines were used to take readings at 15-min interval over one hour and at 60-min interval over three hours. The mean systolic and diastolic BPs obtained using each regimen were calculated and compared. Women also completed a questionnaire to evaluate the psychosocial and financial impact of a prolonged outpatient investigation. RESULTS: BP readings from 67 patients were included for analysis. Clinical equivalence was assessed using the British Hypertension Society (BHS) validation criteria for comparing nonmercury devices to the gold-standard calibrated mercury device. Mean SBP readings for 54% (36/67), 90% (60/67) and 97% (65/67) and mean DBP readings for 73% (49/67), 94% (63/67) and 100% (67/67) were within 5, 10 and 15 mmHg agreement across the two time regimens which achieved grade B and grade A validation, respectively. A BPP was costly and stressful for women and affected their ability to attend work and look after other children. CONCLUSIONS: A BPP performed over one hour compared to over three hours yields clinically equivalent results, yet has psychosocial and financial advantages.

Sustained effect of health insurance and facility quality improvement on blood pressure in adults with hypertension in Nigeria: A population-based study.

BACKGROUND: Hypertension is a leading risk factor for death in sub-Saharan Africa. Quality treatment is often not available nor affordable. We assessed the effect of a voluntary health insurance program, including quality improvement of healthcare facilities, on blood pressure (BP) in hypertensive adults in rural Nigeria. METHODS: We compared changes in outcomes from baseline (2009) to midline (2011) and endline (2013) between non-pregnant hypertensive adults in the insurance program area (PA) and a control area (CA), through household surveys. The primary outcome was the difference between the PA and CA in change in BP, using difference-in-differences analysis. RESULTS: Of 1500 eligible households, 1450 (96.7%) participated, including 559 (20.8%) hypertensive individuals, of which 332 (59.4%) had follow-up data. Insurance coverage increased from 0% at baseline to 41.8% at endline in the PA and remained under 1% in the CA. The PA showed a 4.97 mm Hg (95% CI: -0.76 to +10.71 mm Hg) greater decrease in systolic BP and a 1.81 mm Hg (-1.06 to +4.68 mm Hg) greater decrease in diastolic BP from baseline to endline compared to the CA. Respondents with stage 2 hypertension showed an 11.43 mm Hg (95% CI: 1.62 to 21.23 mm Hg) greater reduction in systolic BP and 3.15 mm Hg (-1.22 to +7.53 mm Hg) greater reduction in diastolic BP in the PA compared to the CA. Attrition did not affect the results. CONCLUSION: Access to improved quality healthcare through an insurance program in rural Nigeria was associated with a significant longer-term reduction in systolic BP in subjects with moderate or severe hypertension.

Goal-Directed Fluid Therapy Guided by Cardiac Monitoring During High-Risk Abdominal Surgery in Adult Patients: Cost-Effectiveness Analysis of Esophageal Doppler and Arterial Pulse Pressure Waveform Analysis.

BACKGROUND: Several minimally invasive techniques for cardiac output monitoring such as the esophageal Doppler (ED) and arterial pulse pressure waveform analysis (APPWA) have been shown to improve surgical outcomes compared with conventional clinical assessment (CCA). OBJECTIVE: To evaluate the cost-effectiveness of these techniques in high-risk abdominal surgery from the perspective of the French public health insurance fund. METHODS: An analytical decision model was constructed to compare the cost-effectiveness of ED, APPWA, and CCA. Effectiveness data were defined from meta-analyses of randomized clinical trials. The clinical end points were avoidance of hospital mortality and avoidance of major complications. Hospital costs were estimated by the cost of corresponding diagnosis-related groups. RESULTS: Both goal-directed therapy strategies evaluated were more effective and less costly than CCA. Perioperative mortality and the rate of major complications were reduced by the use of ED and APPWA. Cost reduction was mainly due to the decrease in the rate of major complications. APPWA was dominant compared with ED in 71.6% and 27.6% and dominated in 23.8% and 20.8% of the cases when the end point considered was "major complications avoided" and "death avoided," respectively. Regarding cost per death avoided, APPWA was more likely to be cost-effective than ED in a wide range of willingness to pay. CONCLUSIONS: Cardiac output monitoring during high-risk abdominal surgery is cost-effective and is associated with a reduced rate of hospital mortality and major complications, whatever the device used. The two devices evaluated had negligible costs compared with the observed reduction in hospital costs. Our comparative studies suggest a larger effect with APPWA that needs to be confirmed by further studies.

Accuracy validation of the Microlife 3AS1-2 blood pressure device in a pregnant population with low blood pressure.

OBJECTIVE: To assess the accuracy of the Microlife 3AS1-2 blood pressure (BP) device in pregnant women with low BP to investigate suitability for hypotensive detection in low-income and middle-income countries. METHODS: A prospective observational study was carried out evaluating the Microlife 3AS1-2, a hand-held, upper-arm, semiautomated BP device, according to British Hypertension Society (BHS) protocol methods. Thirty (stable) pregnant women with a clinical systolic BP less than 100 mmHg and/or diastolic BP less than 60 mmHg were recruited from antenatal wards and clinics and their BP was measured by three trained observers at a district-level hospital in South Africa. Accuracy was assessed according to the BHS grading criteria (A/B=pass) and the ANSI/AAMI/ISO standard for mean difference and SD (≤5±8 mmHg). RESULTS: The device achieved an A/A grade according to the BHS grading criteria. The mean difference±SD between the observer and the test device was 0.5±6.2 and 1.3±5.4 mmHg for systolic and diastolic BP, respectively, fulfilling the standard required by the ANSI/AAMI/ISO protocol. All observer differences were within 4 mmHg. CONCLUSION: According to the BHS protocol, the Microlife 3AS1-2 BP device is accurate in pregnant women with low BP. The device has been validated previously in pregnancy and pre-eclampsia and also fulfils the criteria of the WHO for use in a low-resource setting. Although unstable women were not included in this validation (for safety and pragmatic reasons), this device could potentially improve the detection of shock secondary to obstetric haemorrhage or sepsis, as well as being used in pre-eclampsia, particularly in low-income and middle-income countries.

The Search for High-Impact Diagnostic and Management Tools for Low- and Middle-Income Countries: A Self-Powered Low-Cost Blood Pressure Measurement Device Powered by a Solid-State Vibration Energy Harvester.

The World Health Organization has established recommendations for blood pressure measurement devices for use in low-resource venues, setting the "triple A" expectations of Accuracy, Affordability, and Availability. Because of issues related to training and assessment of proficiency, the pendulum has swung away from manual blood pressure devices and auscultatory techniques towards automatic oscillometric devices. As a result of power challenges in the developing world, there has also been a push towards semiautomatic devices that are not dependent on external power sources or batteries. Beyond solar solutions, disruptive technology related to solid-state vibrational energy harvesting may be the next iterative solution to attain the ultimate goal of a self-powered low-cost validated device that is simple to use and reliable.