Introduction to Public Health and Global Health PDF

Introduction to Public Health and Global Health Theodore Lytras, MD, PhD Assistant Professor of Public Health What is Health? What is Health? Is it the absence of disease? What is Health? Is it the absence of disease? Can you be healthy, if you are old? What is Health?...

Introduction to Public Health and Global Health Theodore Lytras, MD, PhD Assistant Professor of Public Health What is Health? What is Health? Is it the absence of disease? What is Health? Is it the absence of disease? Can you be healthy, if you are old? What is Health? Is it the absence of disease? Can you be healthy, if you are old? What if you have chronic low back pain? What is Health? Is it the absence of disease? Can you be healthy, if you are old? What if you have chronic low back pain? Can you be healthy, if you’re alone? What is Health? Is it the absence of disease? Can you be healthy, if you are old? What if you have chronic low back pain? Can you be healthy, if you’re alone? Can you be healthy, if you’re unemployed? What is Health? Is it the absence of disease? Can you be healthy, if you are old? What if you have chronic low back pain? Can you be healthy, if you’re alone? Can you be healthy, if you’re unemployed? Definition of health (WHO, 1949) A state of complete, physical, mental and social well-being and not merely the absence of disease or infirmity. – World Health Organization What is Medicine? A scientific specialty that is concerned with the health of individuals It provides: diagnostic services therapeutic services preventive services What is Medicine? A scientific specialty that is concerned with the health of individuals It provides: diagnostic services therapeutic services preventive services But what about the social context? Can you separate it from treatment? From prevention? From diagnosis? General practice to improve Public health (Definitions: RACGP 2013) General practice is that component of the health care system which provides initial, continuing, comprehensive and coordinated medical care for all individuals, families and communities and which integrates current biomedical, psychological and social understandings of health A general practitioner is a medical practitioner with recognised generalist training, experience and skills, who provides and co-ordinates comprehensive medical care for individuals, families and communities. Primary care is the point of first contact for the majority of people seeking health care. In the provision of primary care, much ill-defined illness is seen; the general/family practitioner often deals with problem complexes rather than with established diseases. General practice to improve Public health General Practice Focus on the medical specialty Family medicine Focus on the family as a target of care Primary care Focus on the context/level of healthcare delievery Definition of General practice / Family medicine An academic and scientific discipline, with its own educational content, research, evidence base and clinical activity, and a clinical specialty orientated to primary care. Primary care / general practice is a critical “mediator” to improve Public Health Characteristics of General Practice / Family medicine (EURACT 2005) 1. It is normally the point of first medical contact within the health care system, providing open and unlimited access to its users, dealing with all health problems regardless of the age, sex, or any other characteristic of the person concerned 2. It makes efficient use of health care resources through co-ordinating care, working with other professionals in the primary care setting and by managing the interface with other specialities, taking an advocacy role for the patient when needed. “Gatekeeping” =⇒ cost-effectiveness of care Advocacy −→ patient comes first Characteristics of General Practice / Family medicine (EURACT 2005) 3. It develops a person-centred approach, orientated to the individual, his/her family, and their community Focus on how the patient copes with disease (not just on the disease itelf) Understand person’s beliefs, fears, expectations and needs 4. It has a unique consultation process, which establishes a relationship over time, through effective communication between doctor and patient Personal continued relationship between patient and doctor Consultation benefits – therapeutic benefits 5. It is responsible for the provision of longitudinal continuity of care as determined by the needs of the patient Continuity of care – throughout illness, and throughout life Characteristics of General Practice / Family medicine (EURACT 2005) 6. It has a specific decision making process determined by the prevalence and incidence of illness in the community No prior selection of patients! Lower predictive value of signs / symptoms / diagnostic tests Often reassurance is required – but also vigilance −→ patient-doctor relationship 7. It manages simultaneously both acute and chronic health problems of individual patients. Doesn’t manage the presenting complaint alone... Multiple problems ⇒ hierarchical management (+ family/social context) 8. It manages illness which presents in an undifferentiated way at an early stage in its development, which may require urgent intervention “Risk management” – exclude serious outcomes first, than “watchful wait” Characteristics of General Practice / Family medicine (EURACT 2005) 9. It promotes health and well being both by appropriate and effective intervention = evidence-based interventions where possible No intervention where none is required (harmful / wasteful) Health promotion — preventive interventions 10. It has a specific responsibility for the health of the community Interaction with public health 11. It deals with health problems in their physical, psychological, social, cultural and existential dimensions Give appropriate weight to each dimension Illness exist in a specific context, which must be addressed Additional reading WONCA Europe, The European Definition of General Practice / Family Medicine (2011) What is Public Health? Definition (1) “the science and art of preventing disease, prolonging life, and promoting health through the organized efforts and in- formed choices of society, organizations, public and private communities, and individuals” – Charles-Edwary Amory Winslow (1920) Definition (2) “Public health refers to all organized measures (whether public or private) to prevent disease, promote health, and prolong life among the population as a whole. Its activities aim to provide conditions in which people can be healthy and focus on entire populations, not on individual patients or diseases.” – World Health Organization (2011) A multifaceted, multidisciplinary domain American Public Health Association Public health is multidisciplinary Who works in Public Health? physicians public health nurses & midwives environmental health officers (public health inspectors) veterinarians epidemiologists biostatisticians / data managers medical microbiologists economists sociologists bioethicists... The goals of Public Health (in brief) Preventing deaths, illness and injuries Identifying and mitigating environmental hazards Promoting healthy behaviours Providing health education targeted to at-risk people Ensuring access to essential health services Its defining characteristic: the population perspective It is concerned with the health of entire populations rather than individuals only Medicine works with individuals, Public Health works with populations Public health services National/Supranational-level public health agencies and laboratories CDC (US), ECDC (Europe), Robert Koch-Institut (Germany), etc Special agencies, e.g. EMCDDA (drugs), EFSF (food safety) Regional-level public health departments Local public health services Often integrated into primary care services Three interacting approaches to Public Health Defined as the health of entire populations 1. Health care Treatment, but also preventive, rehabilitative, palliative services Examples: vaccinations, counseling, disease screening 2. Traditional Public Health Community-based interventions directed at health promotion and disease prevention Examples: communicable disease control, food safety, control of environmental hazards, reduction in risk factors for disease 3. Social interventions Interventions with secondary impacts on health Examples: improving built environment, education, reducing socioeconomic inequities, social mobility, regulation Adapted from: Riegelman R, Kirkwood B. Public Health 101: Improving Community Health (3rd edition). Jones & Bartlett, 2015. Burden of disease in the population Measuring disease burden in the population Burden of disease in the population WHO Global Health Estimates 2016 Disability-Adjusted Life Years lost (DALYs) Global Europe Africa Communicable, maternal, Communicable, maternal, perinatal and perinatal and nutritional conditions nutritional conditions Communicable, maternal, Noncommunicable perinatal and diseases nutritional conditions Injuries Injuries Injuries Noncommunicable diseases Noncommunicable diseases Burden of disease in the population WHO Global Health Estimates 2016 % of all DALYs, Global Cardiovascular diseases Infectious and parasitic diseases Malignant neoplasms Neonatal conditions Unintentional injuries Mental and substance use disorders Respiratory Infections Respiratory diseases Musculoskeletal diseases Sense organ diseases 0 5 10 15 % of all DALYs, Europe Cardiovascular diseases Malignant neoplasms Mental and substance use disorders Unintentional injuries Neurological conditions Musculoskeletal diseases Sense organ diseases Digestive diseases Respiratory diseases Intentional injuries 0 5 10 15 20 % of all DALYs, Africa Infectious and parasitic diseases Neonatal conditions Respiratory Infections Unintentional injuries Cardiovascular diseases Nutritional deficiencies Mental and substance use disorders Malignant neoplasms Congenital anomalies Digestive diseases 0 5 10 15 20 25 30 Health transitions Demographic transition Low-income countries Middle-income countries High-income countries High fertility rate Intermediate fertility rate Low fertility rate Very low child mortality High child mortality rate Low child mortality rate rate Intermediate life Low life expectancy High life expectancy expectancy Children a large propor- Intermediate aging Older adults a large pro- tion of the population profile portion of the population Health transitions Epidemiologic transition Low-income countries Middle-income countries High-income countries Lots of infectious disease Lots of chronic disease Both infectious & chronic (“diseases of poverty”) (“diseases of affluence”) Nutritional transition Low-income countries Middle-income countries High-income countries Malnourishment in some Overweight and obesity Malnourishment a major populations and obesity major public health public health threat in others threats (or subsets thereof) How to effect change? Health Impact Pyramid Health Impact Pyramid Examples, top-down Examples, top-down Can this really be effective? Disease risk forms a continuum LDL cholesterol vs Coronary Heart Disease (CHD) No increased risk threshold Fernandez-Friera et al. J Am Coll Cardiol 2017;70(24):2979 Exposures (risk factors) also form a continuum Population distribution of cholesterol levels Large overlap in exposure between diseased and healthy Castelli. Atherosclerosis 1996;124 Suppl:S1 Exposures (risk factors) also form a continuum Population distribution of cholesterol levels Large overlap in exposure between diseased and healthy Castelli. Atherosclerosis 1996;124 Suppl:S1 The individual approach: targeting high-risk people A population approach to prevention LDL cholesterol distribution in the population Before intervention After intervention Density 50 100 150 200 250 LDL cholesterol Even a small shift in the risk factor distribution, can result in a large reduction of “high-risk” individuals The prevention paradox (Rose 1981) A large number of people exposed to a small risk may generate many more cases than a small number exposed to a high risk =⇒ “A preventive measure that brings large benefit to the community offers little to each participating individual” Harder to motivate individuals (or societies / governments) to effectuate meaningful change Results also much less visible compared to clinical medicine (in terms of disease prevented) Population-based vs individual-based perspective Complementary (and not competitive) approaches to disease prevention Preventive measures for high-risk individuals e.g. a statin for CHD Preventive measures for the entire population e.g. healthier food, physical excercise, clean air Microenvironmental vs macroenvironmental exposures Macro-: e.g. air pollution, green spaces, bicycle lanes Easier to control, via regulation & legislation Micro-: individual habits and lifestyle, e.g. tobacco, alcohol, occupation, diet, etc Much harder to target! The context: Social determinants of health Social determinants of health: the example of TB Tuberculosis deaths in England and Wales, 1900-1970 Lönnroth et al. Soc Sci Med 2009;68(12):2240-6 Improvements in living conditions and hygiene standards (rather than drugs) account for most of the progress in controlling tuberculosis Social determinants of health: the example of TB Tuberculosis cases in the US, 1980-2015 CDC, 2018 Poverty, social exclusion and the AIDS epidemic have slowed (or even on occasion reversed) progress in controlling tuberculosis Poverty and infectious diseases Epidemics in marginalized groups Measles epidemic among Roma, Greece, 2017-2018 Georgakopoulou et al. Epidemiol Infect 2018;146(13):1692 Vaccination and herd immunity – a social benefit Maintaining high vaccine coverage protects even unvaccinated people from infectious disease epidemics McIntyre and Leask. BMJ 2008;336:729 Social determinants of chronic diseases Chronic Obstructive Pulmonary Disease (COPD) Attributable to tobacco smoking: 50–80% of all COPD cases Lower in less developed countries Eisner et al. Am J Respir Crit Care Med 2010;182:693 The remainder: environmental exposures Air pollution, secondhand tobacco smoking, biomass smoke, etc Occupational exposures = 14% of all cases Blanc et al. Am J Respir Crit Care Med 2019;199(11):1312 Social determinants of chronic diseases Income level and green spaces, association with all-cause and cardiovascular deaths Mitchell and Popham. Lancet 2008;372(9650):1655 Income level and life expectancy Marmot and Bell. Public health 126 (2012):S4 So, how does Public Health work? Partners in Public Health (1) Partners in Public Health (2) Ten Essential Public Health Operations (EPHOS) (WHO Euro 2012) Intelligence EPHOs 1. Surveillance of population health and well-being 2. Monitoring and response to health hazards and emergencies Core services delivery EPHOs 3. Health protection including environmental, occupational, food safety and others 4. Health promotion including action to address social determinants and health inequity 5. Disease prevention, including early detection of illness Enabler EPHOs 6. Assuring governance for health and well-being 7. Assuring a sufficient and competent public health workforce 8. Assuring sustainable organizational structures and financing 9. Advocacy, communication and social mobilization for health 10. Advancing public health research to inform policy and practice 1. Surveillance of population health Public Health Surveillance “the continuous, systematic collection, analysis and interpretation of health-related data needed for the planning, implementation, and evaluation of public health practice” Vital statistics, Communicable/Non-communicable disease, Injuries, Healthcare-associated infections, Environmental health, Laboratories, Disease registries, etc. Analysis and reporting of findings to multiple audiences – especially those that need to take action 2. Monitoring and response to health hazards and emergencies Monitoring and response to health hazards Biological (incl. infectious disease outbreaks) / Chemical / Radiological / Nuclear e.g. outbreak investigations (multidisciplinary!) Control of environmental health hazards Identification of hazardous exposures, risk assessment Environmental monitoring, clean air, water quality, food safety, consumer goods, etc Laboratory support for investigation of health threats Diagnostic & surveillance needs; ensure quality, accuracy and timeliness; ability to scale-up Preparedness and response to public health emergencies e.g. pandemics, bioterrorism, other threats Plans/protocols for rapid investigation and response; defined organizational responsibilities, and communication channels; coordination with other sectors (whole-of-government / whole-of-society approach) 3. Health protection Risk assessment → Regulatory standards and enforcement Environmental safety Chemicals, air pollution, ambient heat, climate change, etc Occupational health and safety Other Pharmaceuticals, healthcare quality / patient safety, consumer goods, etc 4. Health promotion (incl. social determinants and health inequity) Building resilience of communities Community organizing / partnerships Address social determinants of health Health promotion activities e.g. obesity prevention (healthy diet / physical activity), prevention and control of tobacco / alcohol / drug abuse, sexual & reproductive health, dental hygiene, mental health, etc Intersectoral action 5. Disease prevention, including early detection of illness Primary prevention Vaccinations (children / adult) Post-exposure prophylaxis Consultations to minimize health risks and modify behaviours Secondary prevention Screening programmes Maternal and child health screening Tertiary prevention Rehabilitation of patients with established disease Patient support groups 6. Assuring governance for health and well-being Health policy planning and implementation Whole-of-government / whole-of-society approach Health impact assessments Evaluation of public health services / healthcare services Health technology assessments 7. Assuring a sufficient and competent public health workforce Human resources planning, public health workforce standards Education and accreditation Training of other actors public health “angle” – e.g. in economics, sociology, psychology, etc 8. Assuring sustainable organizational structures and financing Public health is not a one-off activity... Needs to be sustained — and funded appropriately. Example: the COVID-19 pandemic in certain settings Unable to “surge” when needed! Lacking contact tracing capacity and lab capacity 9. Advocacy, communication and social mobilization for health Make society a participant in public health initiatives Risk communication Countering hazardous messages (from tobacco... to conspiracy theories) Listen, in order to tailor messages and increase effectiveness 10. Advancing public health research to inform policy+practice Research on effectiveness of interventions / policies Implementation research (on effective implemenation of interventions) Core competencies for Public Health Professionals (ASPHER 2018) 1. methods in public health 2. population health and its social and economic determinants 3. population health and its material – physical, radiological, chemical and biological – environmental determinants 4. health policy, economics, organizational theory and management 5. health promotion: health education, health protection and disease prevention 6. ethics Do YOU want to be a Public Health specialist? Additional reading Rose GA, Khaw K-T, Marmot M. Rose’s strategy of preventive medicine: the complete original text. Oxford University Press, USA, 2008. WHO Regional office for Europe, European Action Plan for Strengthening Public Health Capacities and Services (2012) Frieden, TR. Framework for public health action: the health impact pyramid. Am J Public Health 2010;100:590–5 What is Global Health? Health determinants are often globally interlinked Health concerns that transcend national borders...it’s not just about the health of people in lower income countries! Example: pandemics! What happens in China does not stay there Example: multidrug-resistant tuberculosis % MDR/RR-TB in new TB cases Figures are based on the most recent year for which data have been reported, which varies among countries. Data reported before 2002 are not shown Example: emerging pathogens Example: emerging pathogens Example: migration Example: migration The “Calais jungle”, 2016 Example: migration Moria camp, Lesvos, Greece, September 2019 Example: migration Moria camp, Lesvos, Greece, January 2020 11 Urgent health challenges for the next decade (WHO, Jan 2020) WHO = World Health Organization 1. Elevating health in the climate debate Air pollution also has health effects Changes in ecology and food supply, “climate refugees”, etc Emerging pathogens in temperate countries (e.g. Dengue, West Nile Virus) 2. Delivering health in conflict and crisis Refugees −→ limited access to essential healthcare Disease outbreaks in conflict areas (e.g. Ebola in the DRC, cholera in Yemen) 3. Making health care fairer Increased socioeconomic and health divides Primary care a major focus to reduce health inequalities! 11 Urgent health challenges for the next decade (WHO, Jan 2020) 4. Expand access to medicines Availability for poorer countries – but also for some within rich countries Ever increasing costs!! (e.g. biologics) 5. Stopping infectious diseases HIV, tuberculosis, malaria, neglected tropical diseases, etc Also vaccine-preventable diseases (polio is still not gone!) 6. Preparing for epidemics Not just pandemics... (But that’s when lack of epidemic preparedness shows most) 7. Protecting people from dangerous products e.g. tobacco, e-cigarettes, unhealthy/unsafe food, dangerous chemicals, etc 11 Urgent health challenges for the next decade (WHO, Jan 2020) 8. Investing in people who defend our health Healthcare worker shortages – and not only in poorer countries! 9. Keeping adolescents safe Major health risks: road injury, HIV, suicide, sexually-transmitted infections, alcohol & tobacco, interpersonal violence, mental health Health education 10. Earning public trust e.g. anti-vaxxers, conspiracy theorists 11. Antimicrobial resistance unregulated use of antimicrobials, lack of infection prevention and control Additional reading World Health Organization, “Urgent health challenges for the next decade”, https://www.who.int/news-room/photo-story/photo-story-detail/ urgent-health-challenges-for-the-next-decade Taylor S. ’Global health’: meaning what? BMJ Glob Health. 2018;3(2):e000843 Thank you!