Sociální epidemiologie Úvodní přednáška Martin Bobák 2021 Social epidemiology = branch of epidemiology focusing on: • Influences of societal, social and psychosocial factors on health • Differences in health between socioeconomic groups • Pathways linking social factors and health • Using epidemiological methods and concepts Objectives At the end of the course students should be able to: • Describe differences in health between populations, groups and individuals • Understand most important indicators of population health • Describe the concept of social determinants o health • Discuss main features of demographic and epidemiological transition • Understand the concept and measurement of socioeconomic status • Describe the main pathways linking socioeconomic factors with health, chains of causes (“causes of the causes”) • Understand the concept of life course influences on health • Discuss the main aspects of the societal transformation in Central and Eastern Europe Why are some people healthier than others? • Epidemiology: – Biological factors – Health behaviours – Environment (climate, contamination, pollution) • Social epidemiology – Societal / social structure – Psychosocial / psychological factors Outline of introductory session • Part 1 – Basic measures of population health – How to study influences on health – Large differences in health between groups of people • Part 2 – Factors influencing health of individuals (risk factors) • Part 3 – Chains of causes Part 1 Introduction to population health Measures of population health • Mortality: rates (deaths / total number of people, per 100,000 persons) • Life expectancy: average number of subsequent years of life for someone now aged x if current mortality rates apply (years) • Morbidity: rates or proportions (number with disease / total number of people, per 100 persons, %) – Incidence (risk of new disease) – Prevalence (proportion with existing disease) How long people live Era Life Expectancy at Birth (years) Upper Paleolithic 33 Neolithic 20 Bronze Age and Iron Age 26 Classical Greece 28 Classical Rome 28 Pre-Columbian North America 25–30 Medieval Islamic Caliphate 35+ Medieval Britain 30 Early Modern Britain 25–40 Early 20th Century 31 2010 world average 67 Causes of death, E&W 2011, men Ischaemic heart diseases 28% Malignant neoplasm of trachea, bronchus and lung 13% Stroke 11% Chronic lower respiratory diseases 10% Dementia 9% Influenza and Pneumonia 8% Prostate cancer 7% Malignant neoplasm of colon, sigmoid, rectum and anus (C18-C21) 6% Malignant neoplasms of lymphoid, haematopoietic and related tissue (C81-C96) 5% Diseases of the liver (K70-K77) 3% Leading causes of death by age group, England &Wales 2009 Distribution of deaths by leading cause groups, males and females, world, 2004 Child mortality rates by cause and region, 2004 Adult mortality rates by major cause group and region, 2004 0 2 4 6 8 10 12 Africa Europe South East Asia Eastern Mediterranean Americas Western Pacific High income Death rate per 1000 adults aged 15–59 years Cardiovascular diseases Cancers Other noncommunicable diseases Injuries HIVAIDS Other infectious and parasitic diseases Maternal and nutritional conditions Life expectancy in Sub-Saharan Africa Death rates in Russia 1980-2007 both genders, per 100,000 800 1000 1200 1400 1600 1800 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 SDR Crude DR Gorbatchev elected Coup against Gorbatchev, breakup of USSR Rouble crisis 3M extra deaths Why does health differ so much between people, places, times…? Part 2 Factors influencing health Differences between groups of people Differences between countries Glasgow men (Calton) 54 Glasgow men(Lenzie) 82* National data WHO 2009, Glasgow data: Hanlon et al. 2006 Life expectancy at birth and income Life expectancy at birth and percentage of income received by least well off 70% of families, 1981 (Wilkinson, BMJ 1992) 72 73 74 75 76 77 78 43 44 45 46 47 48 49 50 51 % of income received Lifeexpectancy W Germany USA Australia Canada UK Switzerland Netherlands Sweden Norway r=0.86, p<0.001 Life expectancy and disability-free life expectancy at birth by neighbourhood income deprivation, 1999-2003 Under-5 mortality rate Probability of dying (per 1000) under age five years by wealth quintile in India, Bangladesh, Pakistan, Kenya and Uganda 0 20 40 60 80 100 120 140 160 180 India 2005/6 Bangladesh 2007 Pakistan 2006/7 Kenya 2008/9 Uganda 2006 Lowest 2nd 3rd 4th Highest Source: Bell 2012 using DHS data Influences on health of individuals Risk factors for major diseases Risk factors for major diseases • Age • Gender • Genetic factors • Smoking • Excessive alcohol consumption • Obesity • High blood pressure • High cholesterol • Poor diet • Low physical activity • Poor access to medical care • Drug misuse • Poor hygiene • … and many other factors Not modifiable WHO (2002). Leading causes of DALYs, GBD 2017, Lancet 2018 Smoking • Compared to never-smokers, smokers have – About twice higher mortality from all causes – About twice higher mortality from CVD – About 20 times higher mortality from lung cancer • The more and the longer you smoke, the higher the risk • It takes several years for the risk to get down after quitting smoking • Strong social gradient in smoking Risk of heart diseases by alcohol consumption in 28 high quality cohort studies (Corrao et al 2000) Part 3 Chains of causes Chains of causes • Temporal • Psychosocial pathways • Behavioural mechanisms • Biological mechanisms • Social causation (“causes of the causes”) Education Adult SEP Tracking of causes of the life course: social position and cognition in later life 34 Childhood SEP Health & Lifestyle Life course Cognitive development Cognition Critical periods (foetal programming) Impaired foetal growth Low Birth weight Obesity High blood pressure CVD In utero Birth Adolescence Midlife Psychosocial and behavioural pathways • Direct effects: – mental health (depression, anxiety, quality of life etc) – Suicides, violence • Indirect effects – Behaviours (smoking, drinking, substance misuse) – Diet and nutrition (leading to obesity, dislipidemias, diabetes) “causes of the causes” Poor health Smoking Drinking a lot Obesity Physical inactivity High blood pressure High cholesterol Unhealthy diet Risk taking Drugs Not seeking medical care Chain of causes (“causes of the causes”) Poor health Smoking Drinking a lot Obesity Physical inactivity High blood pressure High cholesterol Unhealthy diet Risk taking Drugs Not seeking medical care Low education Bad job Unemployment Poverty Deprivation Bad housing Got divorced / single parents Bad parenting “Stress” Chain of causes (“causes of the causes”) Poor health Smoking Drinking a lot Obesity Physical inactivity High blood pressure High cholesterol Unhealthy diet Risk taking Drugs Not seeking medical care Low education Bad job Unemployment Poverty Deprivation Bad housing Got divorced / single parents “Stress” Economy Sanitation Water supply Educational system Health care system Employment policy Social benefits Public transport Energy supply Chain of causes (“causes of the causes”) Poor health Smoking Drinking a lot Obesity Physical inactivity High blood pressure High cholesterol Unhealthy diet Risk taking Drugs Bad hygiene Not seeking medical care Low education Bad job Unemployment Poverty Deprivation Bad housing Got divorced / single parents “Stress” Economy Sanitation Water supply Educational system Health care system Employment policy Social benefits Public transport Energy supply Personal levelGroup levelNational International Economy & development Trade War & conflict History Conclusions • Mortality and morbidity are distributed unequally between countries, groups and people • Health is best in high income countries and high income groups and worst in low income countries and low income groups • Proximal risk factors are important (prevention!) • But proximal factors are powerfully influenced by more distant forces (social position, national and international environment)