Mark Emmanuel Engel

Dr. Mark Emmanuel Engel

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Research Focus & Metrics

Academic Career Length

30Years (1997-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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24 July 2007 in PLOS Medicine
Verified
Journal Article
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SMSalla A Munro
Salla A Munro
SLSimon A Lewin
Simon A Lewin
HSHelen J Smith
Helen J Smith
MEMark Emmanuel Engel
Mark Emmanuel Engel
AFAtle Fretheim
Atle Fretheim
JVJimmy Volmink
Jimmy Volmink
Tuberculosis (TB) is a major contributor to the global burden of disease and has received considerable attention in recent years, particularly in low- and middle-income countries where it is closely associated with HIV/AIDS. Poor adherence to treatment is common despite various interventions aimed at improving treatment completion. Lack of a comprehensive and holistic understanding of barriers to and facilitators of, treatment adherence is currently a major obstacle to finding effective solutions. The aim of this systematic review of qualitative studies was to understand the factors considered important by patients, caregivers and health care providers in contributing to TB medication adherence. We searched 19 electronic databases (1966–February 2005) for qualitative studies on patients', caregivers', or health care providers' perceptions of adherence to preventive or curative TB treatment with the free text terms “Tuberculosis AND (adherence OR compliance OR concordance)”. We supplemented our search with citation searches and by consulting experts. For included studies, study quality was assessed using a predetermined checklist and data were extracted independently onto a standard form. We then followed Noblit and Hare's method of meta-ethnography to synthesize the findings, using both reciprocal translation and line-of-argument synthesis. We screened 7,814 citations and selected 44 articles that met the prespecified inclusion criteria. The synthesis offers an overview of qualitative evidence derived from these multiple international studies. We identified eight major themes across the studies: organisation of treatment and care; interpretations of illness and wellness; the financial burden of treatment; knowledge, attitudes, and beliefs about treatment; law and immigration; personal characteristics and adherence behaviour; side effects; and family, community, and household support. Our interpretation of the themes across all studies produced a line-of-argument synthesis describing how four major factors interact to affect adherence to TB treatment: structural factors, including poverty and gender discrimination; the social context; health service factors; and personal factors. The findings of this study are limited by the quality and foci of the included studies. Adherence to the long course of TB treatment is a complex, dynamic phenomenon with a wide range of factors impacting on treatment-taking behaviour. Patients' adherence to their medication regimens was influenced by the interaction of a number of these factors. The findings of our review could help inform the development of patient-centred interventions and of interventions to address structural barriers to treatment adherence.

16 April 2008 in BMC Medical Research Methodology
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Journal Article
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SASalla Atkins
Salla Atkins
SLSimon Lewin
Simon Lewin
HSHelen Smith
Helen Smith
MEMark Emmanuel Engel
Mark Emmanuel Engel
AFAtle Fretheim
Atle Fretheim
JVJimmy Volmink
Jimmy Volmink
Qualitative synthesis has become more commonplace in recent years. Meta-ethnography is one of several methods for synthesising qualitative research and is being used increasingly within health care research. However, many aspects of the steps in the process remain ill-defined. We utilized the seven stages of the synthesis process to synthesise qualitative research on adherence to tuberculosis treatment. In this paper we discuss the methodological and practical challenges faced; of particular note are the methods used in our synthesis, the additional steps that we found useful in clarifying the process, and the key methodological challenges encountered in implementing the meta-ethnographic approach. The challenges included shaping an appropriate question for the synthesis; identifying relevant studies; assessing the quality of the studies; and synthesising findings across a very large number of primary studies from different contexts and research traditions. We offer suggestions that may assist in undertaking meta-ethnographies in the future. Meta-ethnography is a useful method for synthesising qualitative research and for developing models that interpret findings across multiple studies. Despite its growing use in health research, further research is needed to address the wide range of methodological and epistemological questions raised by the approach.

26 November 2014 in European Heart Journal
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LZLiesl Zühlke
Liesl Zühlke
MEMark Emmanuel Engel
Mark Emmanuel Engel
GKGanesan Karthikeyan
Ganesan Karthikeyan
SRSumathy Rangarajan
Sumathy Rangarajan
PMPam Mackie
Pam Mackie
BMBongani M. Mayosi
Bongani M. Mayosi
Rheumatic heart disease (RHD) accounts for over a million premature deaths annually; however, there is little contemporary information on presentation, complications, and treatment. This prospective registry enrolled 3343 patients (median age 28 years, 66.2% female) presenting with RHD at 25 hospitals in 12 African countries, India, and Yemen between January 2010 and November 2012. The majority (63.9%) had moderate-to-severe multivalvular disease complicated by congestive heart failure (33.4%), pulmonary hypertension (28.8%), atrial fibrillation (AF) (21.8%), stroke (7.1%), infective endocarditis (4%), and major bleeding (2.7%). One-quarter of adults and 5.3% of children had decreased left ventricular (LV) systolic function; 23% of adults and 14.1% of children had dilated LVs. Fifty-five percent (n = 1761) of patients were on secondary antibiotic prophylaxis. Oral anti-coagulants were prescribed in 69.5% (n = 946) of patients with mechanical valves (n = 501), AF (n = 397), and high-risk mitral stenosis in sinus rhythm (n = 48). However, only 28.3% (n = 269) had a therapeutic international normalized ratio. Among 1825 women of childbearing age (12–51 years), only 3.6% (n = 65) were on contraception. The utilization of valvuloplasty and valve surgery was higher in upper-middle compared with lower-income countries. Rheumatic heart disease patients were young, predominantly female, and had high prevalence of major cardiovascular complications. There is suboptimal utilization of secondary antibiotic prophylaxis, oral anti-coagulation, and contraception, and variations in the use of percutaneous and surgical interventions by country income level.

8 November 2016 in Circulation
Verified
Journal Article
Closed access
LZLiesl Zühlke
Liesl Zühlke
GKGanesan Karthikeyan
Ganesan Karthikeyan
MEMark Emmanuel Engel
Mark Emmanuel Engel
SRSumathy Rangarajan
Sumathy Rangarajan
PMPam Mackie
Pam Mackie
BMBongani M. Mayosi
Bongani M. Mayosi
Background: There are few contemporary data on the mortality and morbidity associated with rheumatic heart disease or information on their predictors. We report the 2-year follow-up of individuals with rheumatic heart disease from 14 low- and middle-income countries in Africa and Asia. Methods: Between January 2010 and November 2012, we enrolled 3343 patients from 25 centers in 14 countries and followed them for 2 years to assess mortality, congestive heart failure, stroke or transient ischemic attack, recurrent acute rheumatic fever, and infective endocarditis. Results: Vital status at 24 months was known for 2960 (88.5%) patients. Two-thirds were female. Although patients were young (median age, 28 years; interquartile range, 18–40), the 2-year case fatality rate was high (500 deaths, 16.9%). Mortality rate was 116.3/1000 patient-years in the first year and 65.4/1000 patient-years in the second year. Median age at death was 28.7 years. Independent predictors of death were severe valve disease (hazard ratio [HR], 2.36; 95% confidence interval [CI], 1.80–3.11), congestive heart failure (HR, 2.16; 95% CI, 1.70–2.72), New York Heart Association functional class III/IV (HR, 1.67; 95% CI, 1.32–2.10), atrial fibrillation (HR, 1.40; 95% CI, 1.10–1.78), and older age (HR, 1.02; 95% CI, 1.01–1.02 per year increase) at enrollment. Postprimary education (HR, 0.67; 95% CI, 0.54–0.85) and female sex (HR, 0.65; 95% CI, 0.52–0.80) were associated with lower risk of death. Two hundred and four (6.9%) patients had new congestive heart failure (incidence, 38.42/1000 patient-years), 46 (1.6%) had a stroke or transient ischemic attack (8.45/1000 patient-years), 19 (0.6%) had recurrent acute rheumatic fever (3.49/1000 patient-years), and 20 (0.7%) had infective endocarditis (3.65/1000 patient-years). Previous stroke and older age were independent predictors of stroke/transient ischemic attack or systemic embolism. Patients from low- and lower-middle–income countries had significantly higher age- and sex-adjusted mortality than patients from upper-middle–income countries. Valve surgery was significantly more common in upper-middle–income than in lower-middle– or low-income countries. Conclusions: Patients with clinical rheumatic heart disease have high mortality and morbidity despite being young; those from low- and lower-middle–income countries had a poorer prognosis associated with advanced disease and low education. Programs focused on early detection and the treatment of clinical rheumatic heart disease are required to improve outcomes.

9 November 2016 in Heart
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Journal Article
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TATarek Alsaied
Tarek Alsaied
JBJouke P Bokma
Jouke P Bokma
MEMark Emmanuel Engel
Mark Emmanuel Engel
JKJoey M Kuijpers
Joey M Kuijpers
SHSamuel P Hanke
Samuel P Hanke
GVGruschen R Veldtman
Gruschen R Veldtman
Background Despite an ageing Fontan population, data on late outcomes are still scarce. Reported outcome measures and determinants vary greatly between studies making comprehensive appraisal of mortality hazard challenging. Methods We conducted a systematic review to evaluate causes and factors associated with late mortality in patients with Fontan circulation. Late mortality was defined as mortality beyond the first postoperative year. Studies were included if they had ≥90 patients or ≥20 late mortalities and/or transplants. Studies with overlapping patients were rationalised to include only the most recent studies to avoid duplication. Results From 28 studies, a total of 6707 patients with an average follow-up time of 8.23±5.42 years was identified. There were 1000 deaths. Causes of late death were reported in 697 cases. The five most common causes were heart/Fontan failure (22%), arrhythmia (16%), respiratory failure (15%), renal disease (12%) and thrombosis/bleeding (10%). Factors associated with late mortality were evaluated and classified into 9 categories. Conclusions Causes and factors associated with late mortality after the Fontan operation are summarised in this study. The presented information will aid in identifying patients at highest risk for mortality and guide our risk stratification efforts in this patient population.

1 February 2017 in Current Treatment Options in Cardiovascular Medicine
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Journal Article
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LZLiesl J. Zühlke
Liesl J. Zühlke
ABAndrea Beaton
Andrea Beaton
MEMark Emmanuel Engel
Mark Emmanuel Engel
CHChristopher T. Hugo-Hamman
Christopher T. Hugo-Hamman
GKGanesan Karthikeyan
Ganesan Karthikeyan
JCJonathan Carapetis
Jonathan Carapetis
Opinion statement Early recognition of group A streptococcal pharyngitis and appropriate management with benzathine penicillin using local clinical prediction rules together with validated rapi-strep testing when available should be incorporated in primary health care. A directed approach to the differential diagnosis of acute rheumatic fever now includes the concept of low-risk versus medium-to-high risk populations. Initiation of secondary prophylaxis and the establishment of early medium to long-term care plans is a key aspect of the management of ARF. It is a requirement to identify high-risk individuals with RHD such as those with heart failure, pregnant women, and those with severe disease and multiple valve involvement. As penicillin is the mainstay of primary and secondary prevention, further research into penicillin supply chains, alternate preparations and modes of delivery is required.