1. March 20121 POPULATION HEALTH: Health determinants, Prevention & Health promotion Ian McDowell Epidemiology & Community Medicine mcdowell@uottawa.ca mcdowell@uottawa.ca Other resources available on SIM web siteSIM web site Toronto Notes

2. March 20122 MCC Objectives: Population health 78-1 Concepts of health and its determinants As defined by Health Canada and the World Health Organization: 1. Discuss alternative definitions of health, wellness, illness, disease and sickness; 2. Describe the determinants of health (Health Canada list) 3.Explain how the differential distribution of health determinants influences health status, and 4.Explain the possible mechanisms by which determinants influence health status. 5.Discuss the concept of life course, natural history of disease, particularly with respect to possible public health and clinical interventions. 6.Describe the concept of illness behaviour and the way this affects access to health care and adherence to therapeutic recommendations. 7.Discuss how culture and spirituality influence health and health practices, and how they are related to other determinants of health.

3. March 20123 Objective 1: Definitions of HealthDefinitions of Health A state characterized by anatomic, physiologic and psychologic integrity; ability to perform personally valued family, work and community roles; ability to deal with physical, biologic, psychologic and social stress..." (Stokes J. J Community Health 1982;8:33-41) “Medical model;” absence of damage. Practical, but criticized as too narrow A state of complete physical, mental and social well-being and not merely the absence of disease or infirmity. (WHO, 1948) Classic; concerns over how to measure The ability to identify and to realize aspirations, to satisfy needs, and to change or cope with the environment. Health is therefore a resource for everyday life, not the objective of living. Health is a positive concept emphasizing social and personal resources, as well as physical capacities. (WHO Europe, 1986] Dynamic & holistic view; health = capacity rather than a state

4. March 20124 WHO (1980): International Classification of Impairments, Disabilities & Handicaps (ICIDH) Impairment = loss or abnormality of psychological, physiological, or anatomical structure or function (e.g., loss of visual acuity) Disability = resulting loss of ability to function, perform normal activities (can’t see well) Handicap = resulting disadvantage due to inability to perform social roles (loses driving license, so perhaps job) WHO (2001): Critique of negativity of above leads to International Classification of Function (ICF). Similar concepts, renamed impairments, activities & functions. Emphasizes ‘participation’ & importance of environment in which person lives.ICF Definitions of Disability, etc

5. March 20125 Disease Discussion over margins of what constitutes ‘disease’ Pathological process? Abnormal condition? Illness causing discomfort? Nosologies evolve over time: –what we have a treatment for (impotence) = a disease? –Syndrome & ill-defined conditions evolve into disease “Each civilization defines its own diseases…” (Illich) “Non-diseases” (Richard Smith): burnout, senility, baldness, jet lag, etc. Illness = what the patient complains of; sickness = society’s definition (what is allowable: ‘sick days’; the ‘sick role’)

6. March 20126 Disease onset signs & symptoms consequences (loss or abnormality of structure or function) Impairment (restriction in performing a function) Disability; Activity (disadvantage; loss of involvement) Handicap; Participation (something the doctor diagnoses and treats) Disease (the patient’s experience of being unwell) Illness (socially defined status of people who are ill) Sickness Time line Level of impact Cellular Social function Diagnosis (WHO terms in red) (Susser’s terms in green) Assembling these concepts

7. March 20127 Determinants seen as underlying social forces that affect large groups of people –‘Causes of the causes’ of disease E.g. poverty levels; policies; pricing of commodities Risk factors largely relevant at individual level (age, genetics, health behaviours, etc) –They often mediate the influence of determinants –Clarify determinants versus confounding factors Objective 2: DeterminantsDeterminants

8. March 20128 Income and Social Status Social Support Networks Education and Literacy Employment / Working Conditions Social Environments Physical Environments Personal Health Practices and Coping Skills Healthy Child Development Biology and Genetic Endowment Health Services Gender Culture Health Canada’s list of determinants Note that this list blends individual and societal factors. But it may be the basis for the exam!

9. March 20129 Causes, Determinants & Risk Factors Better health Average health in society Determinants Risk factors cause individual variability around mean Level of a risk factor

10. March 201210 Objectives 3 & 4: Differential socioeconomic impact of health determinants Individual Poverty associated with increased incidence of virtually all health problems, often working through known risk factors (smoking, obesity, etc). On a population level, Income inequality is a factor in many nations: the broader the spread, or disparity, in income the worse the average health. –Seems to operate through decreased social cohesion, greater conservatism, less community investment, less concern over supportive legislation, less caring society, etc. (Few Turnbulls!)

11. March 201211 Objective 5: Concept of Life Course Two hypotheses in understanding genesis of chronic disease 1.Biological programming: long term, cumulative health effects of early exposures at critical periods (during gestation, childhood, adolescence). 2.Learned lifestyle patterns (e.g., via culture, religion, SES, parenting). “Embodiment”: extrinsic factors inscribed into body functions or structures. Life course approach blends these 2 conceptions: both are important. Descriptive perspective: –0 – 45 = age of misadventure (morbidity from injuries) –45 – 75 = age of premature degenerative diseases –75+ = age of senescence Analytic perspective: Health is determined by cumulative impact of insults at critical developmental times + lifetime behaviors, exposures & compensating coping mechanisms (these are also determined by early experiences). “Accumulation of risk model” Child rearing & patterning of behaviours that become risk factors. Links to SES. –Bowlby: early child attachment determines susceptibility to later psychiatric disorders –Eepigenetic influences on neural development that establish set points for a range of physiological parameters –Barker hypothesis: under-nutrition in utero ‘programs’ the structure & function of body systems and affect later risk of CVD & diabetes

12. March 201212 Objective 5: Natural history & interventions Diagnosis Initial outcome Symptoms Biological onset of disease Preclinical Phase Clinical Phase Therapy Longer-term outcome: Impact on family work; economic impact, etc. Post-clinical Phase Social & Environmental Determinants Risk & Protective Factors Living environment ↑ Community circumstances (services available, etc.) ↑ Conditions in society (economic stability, etc.) Personal factors: Lifestyle; Genetics; Education; Occupation; Social supports, etc. HandicapImpairmentDisability Etiological Phase

13. March 201213 Objective 6: Illness Behavior Person’s response to illness. Several ingredients: 1.Behaviour in seeking care: may seek care promptly or may delay (fear, denial, $ cost) 2.Coping mechanisms; changes activities? 3.Factors affecting adherence to therapy (knowledge, attitudes, personality, $) Describe one or more models of behaviour change, including predisposing, enabling and re- enforcing factors a.Health Belief Model b.‘Stages of change model’ (aka trans-theoretical model)

14. March 201214 Perceived Susceptibility to Disease · Demographics · Personality, SES, peer pressures, etc. · Knowledge, prior experience, etc.) Perceived Threat of the Disease · Raised awareness (e.g., mass media campaign) · Personal advice (e.g., reminder from health professional) · Personal symptoms · Illness of family member or friend Perceived benefits of taking action, minus Perceived barriers to action Likelihood of Taking Recommended Health Action Modifying Factors Perceived Severity of Disease Cues to Action Health Belief Model

15. March 201215 Precontemplation Stable Lifestyle Contemplation Preparation Action Maintenance Relapse Stages of Change “Transtheoretical” model

16. March 201216 Objective 7: Culture & Spirituality Culture = shared knowledge, beliefs, and values that characterize a social group. Learned through socialization. Cultural sensitivity = understanding the values and perceptions of your culture and how this may shape your approach to patients from other cultures. Cultural competence = attitudes, knowledge, and skills of practitioners necessary to become effective health care providers for patients from diverse backgrounds. Cultural safety goes a step beyond accepting differences, to appreciating the power imbalances and possible discrimination that exist, & treating people with respect

17. March 201217 Cultural influences on health (Close connection to religion, morals, spirituality) Perceptions of disease (‘sickness’ = social perceptions of what is considered disease) May affect styles of treatment & care –Alternative therapies Health behaviours (diet, use of alcohol, etc) Decision-making (individual vs. collective) –End of life care, life support, etc. –Ethics & morality Social bonds & mutual obligations

18. March 201218 Self-test questions SIM web questions on concepts of health, etc: http://www.medicine.uottawa.ca/sim/data/Self- test_Qs_Pop_Health_e.htm

19. March 201219 MCC Objectives: Population health 78-3 Interventions at the population level 1.Define the concept of levels of prevention at individual (clinical) and population levels 2.Name and describe the common methods of health protection (such as agent-host-environment approach for communicable diseases, and source- path-receiver approach for occupational/environmental health). 3.Apply the principles of screening … discuss the potential for lead-time bias and length-prevalence bias. 4.Understand the importance of disease surveillance in maintaining population health and be aware of approaches to surveillance. 5.Identify ethical issues with the restricting of individual freedoms and rights for the benefit of the population as a whole..

20. 78-3 (continued) 6.Describe the advantages and disadvantages of identifying and treating individuals versus implementing population-level approaches to prevention. 7.Describe the five strategies of health promotion as defined in the Ottawa Charter and apply them to relevant situations. 8.Describe one or more models of behaviour change, including predisposing, enabling and re-enforcing factors (covered above). 9.Identify community factors that might promote healthy behaviours & ways to assist communities in addressing these factors. March 201220

21. March 201221March 201221 Objective 1: Levels of Prevention Interventions to arrest disease development 1°, 2°, 3° categories are not black and white Primary prevention: –Strategies applied BEFORE disease starts. E.g., Immunization Secondary prevention: –Early identification of disease in order to intervene to prevent its progression E.g., Cancer screening –Some people suggest secondary prevention relates to reducing the severity of disease. Tertiary prevention: –Treatment and rehabilitation of disease

22. March 201222 Preclinical phase Clinical phase Post-clinical phase Social & environmental determinants Risk & protective factors Etiological Phase Primordial prevention: Alter societal structures & thereby underlying determinants Primary prevention: Alter exposures that lead to disease Secondary prevention: Detect & treat pathological process at an earlier stage when treatment can be more effective Tertiary prevention: Prevent relapses & further deterioration via follow-up care & rehabilitation

23. March 201223 Linking Health Promotion and Disease Prevention Prevention strategy Population addressed Goals Health Promotion 1° Prevention2° Prevention3° Prevention Healthy population Prevent development of risk factors; reduce average population risk Those with risk factors Prevent development of disease: reduce incidence Limited disease Prevent disease progression Symptomatic or advanced disease Reduce recurrence, complications or disability

24. March 201224 Objective 2: Health Protection Activities undertaken by public health departments & government agencies such as the Public Health Agency of Canada (PHAC) to: Reduce threats to the health of the population (environmental & occupational health; terrorism) Includes primordial and primary prevention: –ensuring safe food and water supplies; restaurant inspections; –protecting people from environmental threats; –regulatory framework for controlling infectious disease. –smoke-free bylaws. Legislation covers identified threats, often detected via surveillance systems –Public health policies & healthy public policies.

25. Agent Host Environment (virulence; infectivity; addictive qualities, etc.) (genetic susceptibility; resiliency; nutritional status; motivation, etc.) (rural/urban; sanitation; social environment; access to health care, etc) The idea can also be represented more dynamically, suggesting that disease results from imbalance between agent virulence and host resistance, mediated by the environment in which they interact: HostAgent Environment Oleckno WA: Essential epidemiology. Waveland Press, Long Grove, IL, 2002 The ‘epidemiologic triad’: Disease arises when a susceptible host encounters an agent in a supportive environment March 201225

26. March 201226 Source Path(s) Receiver Modify Redesign Substitute Relocate Enclose Absorb Block Dilute Ventilate Enclose Protect Relocate Potential approaches to risk control Source-Path-Receiver model for Occupational / Environmental health protection

27. March 201227 Objective 3: Screening Can either: –Detect pre-disease states (e.g. dysplasia) –Detect the disease at an early stage Criteria for when screening is useful –Disease criteria Serious: Disease causes significant morbidity, mortality Early detection can lead to an intervention that will arrest or slow the course of the disease –Criteria related to the screening test Valid test: high sensitivity (and specificity if possible) Safe, rapid, cheap, acceptable –Health care System criteria Adequate capacity for follow-up & providing treatment

28. March 201228 Apparent increase in life expectancy or lead time Evaluating a screening program: the hazard of Lead Time bias No screening Survival after diagnosis Death Disease onset Appearance of 1 st symptoms Detectable by screening Time Survival after screening Screening

29. March 201229 Screening identifies 2 cases of rapidly progressive disease and 5 cases of slowly progressive disease Screening Slowly progressive disease Rapidly progressive disease death Disease onset Legend Note: The incidence of rapidly progressive disease is equal to that of slowly progressive disease Length bias

30. March 201230 Objective 4: Surveillance = the systematic collection, analysis and timely dissemination of information on population health… Can be: –Passive: system for collecting information sent in by MDs (e.g. notifiable disease reports). Long term. –Active: hunt for cases of a disease of concern. Short term. Sources: –Notifiable disease reportsNotifiable –Vital statistics –Hospital data & OHIP billing reports

31. March 201231 Objective 5: Public health ethics Underlying principles of –Respect for autonomy (dignity & making one’s own choices) –Beneficence (do good) –Nonmaleficence (do more good than harm) –Justice (distribute benefits fairly & impartially) Four virtues: Prudence, Compassion, Trustworthiness, Integrity Conflicts: –Beneficence for majority may conflict with autonomy –Justice in funding prevention vs. high-tech cure –Between values in different cultures (e.g. reproduction)

32. March 201232 Common ethical issues in public health Social beneficence versus individual autonomy: Isolation & quarantine restrict freedom but are acceptable in communicable disease control. However, maintain confidentiality & avoid stigma. Authority to search for contagious cases is acceptable. Mass medication (beneficence vs. nonmaleficence): –Harm : benefit ratios for immunizations have to accept some individual harm (should we stop immunization against measles after it is eradicated, thereby risking returning epidemics?) Risks of not immunizing usually greater; everyone must be informed. –Opposition to fluoridation: political or evidence-based? Privacy & health statistics (individual autonomy vs. social beneficence) –Surveillance systems can use anonymous, unlinked data (e.g. from blood test results) –Subsequent analyses of medical records for research purposes –Computerized record linkage –Issue of research discoveries that damage commercial interests (e.g. industrial pollution; cigarette companies & lawsuits) Informed consent is required for testing (e.g. HIV) (autonomy) –Debate, however, over anonymity vs. linking to allow for counseling.

33. March 201233 Occupational health code of ethics guides balance between protecting company which employs you and worker.code of ethics –Put the health of the worker first; must inform workers of health threats –MD to remain fully informed of the working conditions –Advise management of health threats; workers can inform unions –Apply precautions –Must not reveal commercial secrets, but must protect workers’ health –Only inform management of worker’s fitness to work, not the diagnosis “Crimes against the environment” (pollution, etc) conflict with economic interests & jobs (which harm health also) Legally subpoenaing research records in order to discredit the data or pursue legal action (e.g. toxic shock case; breast implant study) not allowed, but variations in ruling. Common ethical issues in public health

34. March 201234 Objective 6: Strategies for Prevention: High Risk Approach Identify individuals at high risk and attempt to reduce their risk, by changing behaviour, etc. Logical: high risk people should be motivated to change But it may require testing larger population (costs, false positives) Asks targeted people to act differently from their peers It may also miss many cases depending on how you define ‘high risk.’ (Most cases typically occur in medium-risk people: see next slide)

35. March 201235 BMI ≥ 35 30 to 34.9 25 to 29.9 23 to 24.9 < 23 X 32 % = 129,280 cases X 21 % = 274,700 cases X 10 % = 418,500 cases X 7 % = 157,800 cases X 3 % = 61,400 cases BMI distribution in the Canadian population (2007) Individual risk of diabetes over 10 years Population burden: new cases of diabetes 2007–2017 X Data source: ICES report, June 2010: How many Canadians will be diagnosed with diabetes between 2007 and 2017? = 13 % 41 % 22 % 20 % 12 % of total 26 % 40 % 15 % 6 % of total

36. March 201236 Strategies for Prevention: Population Approach Attempts to shift distribution of risk factor in whole population Gets to root of the problem Shades into health promotion Benefits everyone

37. March 201237 Objective 7: Health PromotionHealth Promotion Distinguishable from prevention: Non-specific: Focuses on enhancing health (e.g., resiliency, coping skills) rather than preventing specific pathology. Tackle ‘upstream’ factors. Uses a participatory approach: active community involvement; often grass roots groups. –Partnerships with community agencies: community mobilization. –Public health physician roles = advocacy, support.

38. March 201238 TimeBirth Health, Quality of life Death Disability-free survival The red line represents a survival curve for a population. The blue lines represent varying levels of disability among survivors. Squaring the curve implies shifting these lines up and to the right, towards the green line, which represents the hypothetical population health limit. HP Goals: “Squaring the survival curve”

39. March 2012 HEALTH PROMOTION Ottawa Charter for Health Promotion (1987)Ottawa Charter Five key pillars to action: –Build healthy public policy Smoking-free areas; mandatory bike helmets, etc –Re-orient health services Alter physician fees to encourage prevention –Create supportive environments Needle drop-off locations; safe jogging trails –Strengthen community action Neighbourhood Watch; increase walkability –Develop personal skills CHC community cooking skills program Policy  services  env’t  community  individual

40. 40 Objective 9: Social marketing Applies commercial marketing approaches to the analysis, planning, execution and evaluation of programmes to influence voluntary behaviour in order to improve their personal welfare and that of society –Draws on many other models –Studies what consumer thinks & tailors approach to that –Uses marketing approaches –Can apply to changing behaviour of professionals 1. Plan overall strategy 2. Select materials & channels 3. Develop intervention and pretest 4. Implement the program 5. Assess effectiveness (process & outcomes) 6. Use results to refine program March 2012

41. 41 Identify the administrative & financial policies needed Identify education, skills & ecology required Identify desirable outcomes: Behavioural, Environmental, Epidemiological, Social Predisposing factors Enabling factors Reinforcing factors Lifestyle Environment Planning phase What can be achieved? What needs to be changed to achieve it? What can be learned? What can be adjusted? Evaluation phase Adapted from: Green L. http://www.lgreen.net/precede.htmhttp://www.lgreen.net/precede.htm Policies Resources Organisation Service or programme components Health status Quality of life Implementation: What is the programme intended to be? What is delivered in reality? What are the gaps between what was planned and what is occurring? Process: Why are there gaps between what was planned and what is occurring? What are the relations between the components of the programme? Impact: What are the programme’s intended and unintended consequences? What are its positive and negative effects? Outcome: Did the programme achieve its targets? Start Finish

42. March 201242 Population health 78-7 Health of Special Populations Enabling objectives Aboriginal health Describe the diversity amongst First Nations, Inuit, and/or Métis communities Describe the connection between historical and current government practices towards FNIM… and the intergenerational health outcomes that have resulted. Describe medical, social and spiritual determinants of health and well-being for First Nations, Inuit, Métis peoples Describe the health care services that are delivered to FNIM peoples Global health and immigration. Identify the travel histories and exposures in different parts of the world as risk factors for illness and disease. Appreciate the challenges faced by new immigrants in accessing health and social services in Canada. Appreciate the unique cultural perspective of immigrants with respect to health and their frequent reliance on alternative health practices. Discuss the impact of globalization on health and how changes in one part of the world (e.g. increased rates of drug-resistant Tuberculosis in one country) can affect the provision of health services in Canada.

43. March 201243 (Objectives, continued) Persons with disabilities. Identify the challenges of persons with disabilities in accessing health and social services in Canada. Discuss the issues of stigma and social challenges of persons with disabilities in functioning as members of society Discuss the unique health and social services available to some persons with disabilities (e.g. persons with Down’s syndrome) and how these supports can work collaboratively with practicing physicians. Homeless persons. Identify the challenges of providing preventive and curative services to homeless persons. Discuss the major health risks associated with homelessness as well as the associated conditions such as mental illness. Challenges at the extremes of the age continuum Identify the challenges of providing preventive and curative services to isolated seniors and children living in poverty. Discuss the major health risks associated with isolated seniors and children living in poverty. Discuss potential solutions to these concerns.

44. March 201244 Aboriginal groups Historical threats: colonization; Indian Act; residential schools; move to urban living; disruption of traditional economies; poverty, inadequate housing & facilities;Historical threats Elevated rates of –Trauma, poisoning, SIDS, suicide, substance use –Circulatory diseases (incl rheumatic fever) –Neoplasms –Respiratory diseases (TB…) –Infection (gastroenteritis, otitis media, infectious hepatitis) –Diabetes Life expectancy rising, but still 9 years lower than ROC; high birth rate; IMR has fallen dramatically;

45. March 201245 Special populations: Seniors Risk of –Musculoskeletal injuries includes falls & injuries –Hypertension/heart diseases –Respiratory diseases –Dementia –Polypharmacy

46. March 201246 Special populations: Children in Poverty Note life course approach (above) –Low birth weight –Trauma/poisoning –Oral problems (abnormalities in teeth and jaws) –Fever/infectious diseases –Psychiatric problems

47. March 201247 Special populations: People with Disabilities Increased risk of –Emotional & psychological problems –Job insecurity (hence low income & poverty)

48. March 201248 Some MCQs.

49. March 201249 28) In describing the leading causes of death in Canada, two very different lists emerge, depending on whether proportional mortality rates or person- years of life lost (PYLL) are used. This is because: a) one measure uses a calendar year and the other a fiscal year to calculate annual experience b) one measure includes morbidity as well as mortality experience c) both rates exclude deaths occurring over the age of 70 d) different definitions of “cause of death” are used e) one measure gives greater weight to deaths occurring in younger age groups

50. March 201250 Which of the following statements concerning cross- cultural care is true? a) It has proven very hard to change physicians’ attitudes and make them more culturally aware. b) There still is no formal accreditation requirement to train physicians in cross-cultural skills. c) There is considerable literature comparing the effectiveness of different techniques of cross-cultural communication d) Lower quality care results when clinicians fail to acknowledge cultural differences. e) The CMA and Royal College have collaborated to produce clear guidelines on developing cultural competency.

51. March 201251 26) All of the following statements are true EXCEPT: a) one indirect measure of a population’s health status is the percentage of low birth weight neonates b) accidents are the largest cause of potential years of life lost for men in Canada c) the Canadian population is steadily undergoing rectangularization of mortality d) morbidity is defined as all health outcomes excluding death e) the neonatal mortality rate is the number of infant deaths divided by the number of live births multiplied by 1000

52. March 201252 44) Of the five items listed below, the one which provides the strongest evidence for causality in an observed association between exposure and disease is: a) a large attributable risk b) a large relative risk c) a small p-value d) a positive result from a cohort study e) a case report

53. March 201253 Which of the following test characteristics are typical of a screening test? A. High sensitivity and high specificity. B. High sensitivity and low specificity. C. Low sensitivity and high specificity. D. Low sensitivity and low specificity. E. Low sensitivity and low accuracy.

54. March 201254 23) Which of the following is the most important justification for mounting a population screening program for a specific disease? a) early detection of the disease of interest is achieved b) the specificity of the screening test is high c) the natural history of the disease is favorably altered by early detection d) effective treatment is available e) the screening technology is available

55. March 201255 40) The effectiveness of a preventative measure is assessed in terms of: a) the effect in people to whom the measure is offered b) the effect in people who comply with the measure c) availability and the optimal use of resources d) the cost in dollars versus the benefits in improved health status e) all of the above

56. March 201256 42) Each of the following is an example of primary prevention EXCEPT: a) genetic counselling of parents with one retarded child b) nutritional supplements in pregnancy c) immunization against tetanus d) chemoprophylaxis in a recent tuberculin converter e) speed limits on highways

57. March 201257 12) The following indicate the results of screening test “Q” in screening for disease “Z”: The specificity of test “Q” would be: a) 40 / 70 b) 120 / 130 c) 40 / 50 d) 120 / 150 e) 40 / 130

58. March 201258 13) The positive predictive value would be: a) 40/70 b) 120/130 c) 40/50 d) 120/150 e) 70/200

59. March 201259 43) Which of the following describes the factors in the classic “epidemiological triad” of disease causation? a) host, reservoir, environment b) host, vector, environment c) reservoir, agent, vector d) host, agent, environment e) host, age, environment

60. March 201260 23) Which of the following is the most important justification for population screening programs for a specific disease? a) early detection of the disease of interest is achieved b) the specificity of the screening test is high c) the natural history of the disease is favourably altered by early detection d) effective treatment is available e) the screening technology is available

61. March 201261 More MCQs Here are some more questions that students can use to test their own knowledge: http://www.medicine.uottawa.ca/sim/data/Self -test_Qs_Pop_Interventions_e.htm (The questions contain comments on the answers, to illustrate why a given response is not correct)