LifeVest ‘Wearable Defibrillator’ a Cost-Effective Bridge After ICD Removal for Infection

For patients who have undergone the successful removal of their implantable cardioverter defibrillator (ICD) because of an infection, the use of a wearable cardioverter defibrillator (LifeVest, Zoll) is a cost-effective treatment strategy for preventing sudden cardiac arrest (SCA) while patients wait for another device, according to a new analysis[1].

“The decision regarding when to reimplant must be individualized to each patient and clinical situation,” state Drs Christopher Healy and Roger Carrillo (University of Miami Miller School of Medicine, FL). “For many patients, continuous inpatient monitoring may be impossible or at least highly undesirable. The wearable cardioverter defibrillator is likely a cost-effective treatment modality for the prevention of SCA in a significant number of these at-risk patients.”
Writing in Heart Rhythm March 31, they note that a patient is typically given antibiotics for several weeks following the extraction of an infected device. If a second device is put in too soon, there is a risk of repeat infection. While the device is out, however, there is a risk of SCA. For the patient, continuous monitoring is impractical and, for the hospital, expensive.

In the present analysis, outpatient use of the wearable defibrillator cost $1805 more but resulted in better clinical outcomes compared with a strategy of discharging the patient home without a wearable or implanted defibrillator. Based on a 5.6% risk of sudden cardiac death within the first 2 months (4.0% risk within the first month), 0.089 life-years were gained with the wearable defibrillator, yielding an incremental cost-effectiveness ratio (ICER) of $26 436 per quality-adjusted life-year (QALY) gained.

As with all economic analyses, the researchers made some assumptions. Their base-case scenario assumed the wearable defibrillator was 84.5% effective in terminating potentially fatal ventricular tachyarrhythmias. If the efficacy of the defibrillator increased to 95%, the ICER was as low as $15 392/QALY. If efficacy declined below 69%, the wearable defibrillator would no longer be considered cost-effective as it would exceed $50 000/QALY.
The wearable defibrillator was also cost-effective as long as the time to reimplantation of the replacement ICD was at least 2 weeks.

In addition, researchers report the wearable device was cheaper than discharging patients to a nursing facility or leaving them in the hospital and also had better clinical outcomes. As a result, the wearable defibrillator was considered a “dominant” strategy against these two treatment options.

Global Burden of Sickle Cell Anaemia in Children under Five, 2010–2050: Modelling Based on Demographics, Excess Mortality, and Interventions.



The global burden of sickle cell anaemia (SCA) is set to rise as a consequence of improved survival in high-prevalence low- and middle-income countries and population migration to higher-income countries. The host of quantitative evidence documenting these changes has not been assembled at the global level. The purpose of this study is to estimate trends in the future number of newborns with SCA and the number of lives that could be saved in under-five children with SCA by the implementation of different levels of health interventions.

Methods and Findings

First, we calculated projected numbers of newborns with SCA for each 5-y interval between 2010 and 2050 by combining estimates of national SCA frequencies with projected demographic data. We then accounted for under-five mortality (U5m) projections and tested different levels of excess mortality for children with SCA, reflecting the benefits of implementing specific health interventions for under-five patients in 2015, to assess the number of lives that could be saved with appropriate health care services. The estimated number of newborns with SCA globally will increase from 305,800 (confidence interval [CI]: 238,400–398,800) in 2010 to 404,200 (CI: 242,500–657,600) in 2050. It is likely that Nigeria (2010: 91,000 newborns with SCA [CI: 77,900–106,100]; 2050: 140,800 [CI: 95,500–200,600]) and the Democratic Republic of the Congo (2010: 39,700 [CI: 32,600–48,800]; 2050: 44,700 [CI: 27,100–70,500]) will remain the countries most in need of policies for the prevention and management of SCA. We predict a decrease in the annual number of newborns with SCA in India (2010: 44,400 [CI: 33,700–59,100]; 2050: 33,900 [CI: 15,900–64,700]). The implementation of basic health interventions (e.g., prenatal diagnosis, penicillin prophylaxis, and vaccination) for SCA in 2015, leading to significant reductions in excess mortality among under-five children with SCA, could, by 2050, prolong the lives of 5,302,900 [CI: 3,174,800–6,699,100] newborns with SCA. Similarly, large-scale universal screening could save the lives of up to 9,806,000 (CI: 6,745,800–14,232,700) newborns with SCA globally, 85% (CI: 81%–88%) of whom will be born in sub-Saharan Africa. The study findings are limited by the uncertainty in the estimates and the assumptions around mortality reductions associated with interventions.


Our quantitative approach confirms that the global burden of SCA is increasing, and highlights the need to develop specific national policies for appropriate public health planning, particularly in low- and middle-income countries. Further empirical collaborative epidemiological studies are vital to assess current and future health care needs, especially in Nigeria, the Democratic Republic of the Congo, and India.

Multiple warnings regarding the effect of epidemiological and demographic transitions in low-income countries and their consequences for SCA burden have been published . By quantifying this increase from 2010 to 2050 using evidence-based data and identifying potential changes in the distribution of areas the most affected, we hope (i) to highlight further the need for greater awareness of SCA, appropriate public health policies, and funding; (ii) to guide the implementation of appropriate policies; and (iii) to provide a framework that could be applied to other birth defects. In most countries, the burden of SCA has so far not been recognised. Its long-term toll is nevertheless significant. These results highlight once more the need for further epidemiological collaborative studies, particularly in Nigeria, the DRC, and India, to define more accurately the current and future health burden of SCA.

Source: PLOS

Sickle Cell Anaemia in a Changing World.

Populations and their health are dynamic. Societal, environmental, and economic changes lead to changes in rates of birth, death, and disease, often described as transitions in mortality, demography, and epidemiology. The notion of epidemiologic transition provides an insight into the relationship between levels of overall mortality and the distribution of its causes [1][3], in which the greatest changes arise from the survival of children and young women. Recent falls in global child mortality are good news [4], but will lead to increases in the relative burdens of morbidity and disability in children who would previously have died, and of congenital malformations and inherited disorders. The work of Frédéric Piel and colleagues on sickle cell anaemia (SCA), published in this week’s PLOS Medicine [5], speaks strongly to this point: SCA is an inherited disease whose global importance will increase in terms of absolute numbers and relative population burden. SCA occurs when individuals are homozygous for sickle haemoglobin (HbS) in place of normal adult haemoglobin, and is the most common form of sickle cell disorder (SCD) [6]. Piel and colleagues have collated HbS allele frequency surveys and used them in models to generate a global distribution map and estimate the numbers of infants born heterozygotic and homozygotic for HbS. Using population and mortality projections, they predict an increase in the numbers of newborns with SCA to over 400,000 in 2050. They also estimate the potential mortality effects of four care-provision scenarios, with a best-case scenario that between 7.5 and 15.5 million newborn lives could be saved, most of them in Africa.

Modelled estimates are a growth area in global health. Whilst useful at supra-national and national levels, their emergence highlights the lack of reliable data on populations, disease, and mortality across most of the world: precisely the sort of information that policy makers and health planners need. The utility of estimates for planning screening programmes, infrastructural and human resource requirements, and clinical care protocols at sub-national levels is likely to be limited where the generalisability of assumptions is challenged by diversity at the local level. Even at a global level, estimates can cause confusion. Research teams using different models may, for example, come to different conclusions [7]. Piel et al. have combined available data, statistical methods, and assumptions to predict current burdens and future trends. Their uncertainties are described clearly, and a preoccupation with methodological critiques can easily distract us from the public health concerns that estimates raise.

The epidemiologic transition has been reframed as a health transition that involves sociocultural, behavioural, and health service factors [8], and policy and health services must respond to changing disease burdens. Unfortunately, the notion of transitions is general. Parallel transitions are happening in different groups within one nation, the best example being differences between socioeconomic groups. Rates of transition vary with local environment, and counter-transition is even possible [9]. Policy makers must set priorities in an environment of multiple burdens, unfinished agendas, competing discourses, and the voices of interest groups[10], a process that has been described as a chaos of purposes and accidents [11]. In an environment of Realpolitik, the generation of estimates of burden is important for advocacy. Characteristically, investigators working in an important public health field that has not received global attention lay down the strategic epidemiology [7],[12], as Piel and colleagues are doing, demonstrating that lack of progress will hinder efforts to attain targets such as those of the Millennium Development Goals.

Quantifying the problem is important, but not sufficient. In a consideration of issue attention for newborn health, Jeremy Shiffman considered four elements: the power of the actors involved, new ideas that can be brought to the table, the characteristics of the issue in terms of attractiveness and tractability, and political context [13]. The kind of strategic epidemiology that the SCA figures exemplify needs to be linked with granular understanding of local epidemiology and service provision [7]. SCA poses a particular challenge in terms of tractability. Haematopoietic stem cell transplantation, an emerging cure, is currently too costly a technology for the countries on which the burden predominantly falls, as is hydroxyurea therapy for children at high risk of illness. Survival, health, and well-being can all be improved substantially, but rely on health care systems with a certain level of functionality. Piel and colleagues suggest that the priority is to identify births of infants with SCA, but that such births could be avoided through genetic counselling and prenatal diagnosis. Termination of pregnancy is one of several options, which include preconception genetic screening and strategic reproductive choices, education for carrier parents, and holistic management from infancy. Quite apart from the logistic and financial challenges, these approaches raise substantial ethical questions summarised in recent work from Ghana [14].

Several interventions would be enormously helpful. Routine newborn screening remains costly—but is likely to become less so—and may miss infants born at home. Penicillin prophylaxis and pneumococcal immunisation are possible in most health care systems. The most beneficial approach involves comprehensive care [15]: family education, routine immunisation, malaria prevention, nutrition and hydration, prophylactic antibiotics, folic acid supplements, transfusion when required, support groups for children and their families, protocols for the management of acute events by health workers and—most importantly—regular follow-up. Human resources for health need to be well trained, and the medicines required need to be affordable and available, including the pain relief required by many people with SCD [16].

Steps towards a systematic approach are being taken [17]. A 2006 World Health Assembly resolution on SCA recommends increased awareness in the international community and emphasises collaboration between countries, including technical support, development of practice models, and coordination [18]. The World Health Organization has published a strategy for the African Region, with targets that include development and implementation of national control programmes in member states with high SCD prevalence, adoption of comprehensive health care management, and establishment of surveillance systems [19]. The estimates from Piel and colleagues underscore the need for both collaborative responses and better data for planning and monitoring.

Source: PLOS