HSCI211 lec1 - Scott Lear PDF

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Scott Lear...

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Perspectives on Cancer, Cardiovascular and Metabolic Diseases Chronic: “prolonged, long-lasting, long term, often but not necessarily implying incurable”! Chronic Disease: “any disease that is long-lasting or permanent” ! -often refers to an illness episode greater than 6 weeks! Chronic Disease Control: Usually refers to conditions not caused by transmissible agents! -Something like HIV is communicable, it is a chronic disease. !

Incidence: “the number of new cases in a specific time period! Prevalence: “the number of existing cases at a given time” ! Cardiovascular Diseases is 30% of main causes of death worldwide! Cancer 13% Diabetes: 2% Total deaths In 2005: 58 million Factors -Where we live, policies, gender, access to care can all affect the rates, DALYs of diseases and diabetes! -the prevalence of CVDs tends to be higher in HIC but lower deaths compared to LIC.! … this is due to access to health care systems.! More deaths in LIC but in HIC you are more likely to be diagnosed with a condition. But you have more access to treatments and there is coverage in healthcare and medications, but in comparison to LIC you may be diagnosed but have little access or cannot afford treatment, there is higher rates of death.! WHERE YOU LIVE AND HEALTH:! Ted Talk: New insights on Poverty! -walks within the city can result with different health outcome you don’t just need to look at different countries! The causes of Chronic Diseases is Complex! • Simple! -Baking a cake! • Complicated! -sending a rocket to the moon ! • Complex (this is where chronic diseases is relevant)! -Raising a child! -many factors, where changing one affects another! Q: Which pattern of global mortality is correct? ! A DECREASE IN INFECTIOUS DISEASE AND AN INCREASE IN CHRONIC DISEASE.! Epidemiology: the study of the distribution of disease and its determinants! From “epidemic”!

Two levels of analysis: ! 1. Compare individuals: can learn about the disease and how to help these individuals! 2. Compare populations (groups of individuals): Can see if there are some underlying conditions (determinants) in the whole population that affect this “condition” Population Health ! -The health outcomes of a group of individuals, including the distribution of such outcomes within the group! Goals of Population Health! - to maintain and improve the health status of the entire population! • in order to due this you may need to reduce inequities! - To reduce inequities in health status between population groups ! Health Inequality and Health Inequity Health Inequality:! - a difference in health measurements between groups (distribution of a particular characteristic)! - Mobility in young vs. Old people ! Health Inequity: ! -A difference in measurements between groups that is not only unnecessary and avoidable, but, in addition, is considered unjust (unfair)! -Rural/urban access to services ! ** he mentioned the health care act.! POPULATION HEALTH! - how can we tell that Vancouver/Canada has health problem? How can we make that “diagnosis”?! - What should Vancouver/Canada do about it? How do we decide? ! - How is this improvement implemented? Who is involved? ! - How can we tell if Vancouver/Canada is getting better? (prevalence and incidence rates) ! Steps in Addressing a Health Problem -Examination! -Diagnosis! -Prescription (deciding on the intervention/treatment) or policy development! -communication of the decision! Epidemiological Transition: the Stages -Age of pestilence and famine! • High death rates and birth rates! -Receding pandemics! • Low death rates, but high birth rates! -Degenerative and chronic diseases! • Low death rates and low birth rates! Early Health improvements

-Significant reduction in mortality from infectious disease, particularly in young people (infants and children) ! -improvements in water and sanitation (England and Wales mid-19th century)! -immunization (early 20th century)! -antibiotics (mid 20th century) ! Disease Patterns Developed countries: ! -low birth rates, ! -rectangular population pyramid, ! -predominantly chronic diseases which are decreasing! Low Mortality developing countries: ! -lower death rates (low life expectancy)! -high birth rates! -population pyramid becoming rectangular! -double burden of disease (infectious and chronic) ! High mortality developing countries:! -High death rates ! -high birth rates ! -population pyramid is triangular! -high burden of infectious disease- particularly in children! What has fuelled the epidemic of Chronic Diseases? -The globalization of risk! -the transmission of unhealthy behaviours has proceeded with great rapidity to developing countries! -countermeasures are absent- both at a policy level and a sophisticated population/public health infrastructure! The globalization of Risk! -Governments have underdeveloped: ! • Policy responses ! • Health and public health systems! -Economic Development usually the priority even before people - uneven wealth distribution! -Political and geographic boundaries cannot cope with modern communications where ideas and culture rapidly transfer (governments are working to ban marketing on foods for kids, may work on TVs but not on social media.)! -demands and global response:! • Regulate international trade ! • Share and disseminate interventions ! • Policies on recruiting professionals! URBANIZATION: Canada is very urbanized. ! Changes in Dietary Patterns!! When looking at China: there is a shift from eating legumes to getting protein from animals instead of plant sources, they get more from animal sources over time. !

Prevention(1) Primordial: ! -actions or measures that inhibit the emergence and establishment of environmental, economic, social and behavioural conditions, cultural patterns of living etc. Known to increase the risk of disease. ! Primary:! -protection of health by personal or communal efforts, such as enhancing nutritional status, immunizing against communicable diseases and eliminating environmental risks! -alteration of susceptibility or reduction of exposure of susceptible individuals! Prevention (2) Secondary:! – “a set of measures available to individuals and communities for the early detection and prompt intervention to control disease and minimize disability” ! – Early detection and treatment of disease ! Tertiary: ! – $“Measures aimed at softening the impact of long-term disease and disability by eliminating or reducing impairment, disability and handicap; minimizing suffering and maximizing potential years of useful life” ! – $Alleviation of disability resulting from disease and attempts to restore normal functioning ! What is a Risk Factor? ! -Presence of behaviour or physiological parameter that increases the chances of having heart disease.! -No single factor causes heart disease! -A risk factor must be: associated with a disease- greater exposure, greater risk ! … make sense in a biological way ! …. reducing risk factor reduces disease! Cardiovascular Disease Risk Factors:! Non-modifiable: -Age! -Sex! -Family history! -a learned behaviour (kids with parents who smoke are likely to smoke) ! Modifiable -Cholesterol (blood lipids) ! -blood pressure! -diabetes! -smoking! -sedentary behaviour! -poor nutrition! -obesity! -stress/depression!

Sick Individuals and Sick populations Sir Geoffrey Rose: The strategy in Rose’s time! -a clinical strategy - physician strategy! -people were sick and became patients ! -intervention usually when the disease was entrenched and often well advanced ! -prevention was not as important a concept! -sometimes patients are created (eg: high blood pressure)! -Public health strategies were educational and addressed those at risk ! The concept of Normal -looking at a population we consider ‘normal’ for what population as those that fall below an action level and make up most who fall within distribution curve for the population.! -normal also represents what is common for that population - and common therefore must be okay. ! -normal is common, but we tend to think of its ideal… when it is not ideal! The Concept of Risk -high risk (HR) - the relative risk of death is high due to the presence of the risk factor or the disease process ! -there are far fewer people in the HR group - the majority are not in the HR group! -the absolute risk - while the actual # of deaths is high in the HR group it accounts for very few of the population death due to this disease or risk factor ! -a large number of people exposed to a lesser or moderate risk leads to the majority of cases in population. ! -risk is continuous!! ! Cont. of RIsk: view graphs in the lecture slides! POPULATION PREVENTION STRATEGY! -control the determinants of incidence ! -lower mean levels of risk factors (shifting people the the left on those graphs is an example of this… altering social norms is a way to doing this)! -shift the distribution of exposure in a more favourable direction! -the mechanisms- mass environmental controls alter social norms of behaviour! Advantages of population strategies! -behaviourally appropriate (influence physical activity in people, changing the environment) ! -large potential for the population! Limitations:! -as an individual you will not notice much of a change in health! -poor subject motivation ! -poor physician motivation! -benefit-risk ratio problematic to demonstrate- potentially costly !

“an intervention which brings much benefit to the population offers little benefit to each participating individual”! The population Approach: ! -both populations and high risk groups! -generally exist outside the health care system! -efforts for smoking taxation not paid for by health care system, no power to make this change! -NORMAL IS NOT NECESSARILY OKAY ! -MOST CASES DO NOT ARISE FROM THE HIGH RISK GROUP! -POPULATION TYPE RISK PREVENTION STRATEGIES TO IMPROVE/COMPLEMENT A HIGH RISK STRATEGY! WE CAN CONCLUDE: -since most cases arise in the muddle of the curve! -since population curves potentially shift! -since small changes which occur over an entire population produce great population benefits (though small individuals benefits)! -… a population health approach is essential if risk is to be reduced and consequently morbidity and mortality!...