Lecture 9: Chronic Disease Epidemiology Flashcards
what is the primary focus for epidemiology?
Populations - how we study disease phenomenon to improve the health of a population
mortality patterns in the last century
- beginning of the 20th century, many cause of mortality was due to infectious diseases from factors such as human settlement and colonization
- decrease in infectious diseases due to improved sanitation, housing, nutrition, antibiotics, and immunizations
- increase in chronic disease in the last few decades due to overconsumption
- in 2030, we are about to see a 27% increase in chronic diseases
Most common types of chronic disease
- heart disease
- cancer
- chronic lung disease
- stroke
- Alzheimer’s disease
- diabetes
- chronic kidney disease
multi-morbidity
an individual is living with multiple conditions
Chronic Disease in Canada
44% of adults 20+ have at least 1 of these 10 common conditions:
Hypertension
Osteoarthritis
Mood and anxiety disorders
Osteoporosis
Cancer
Asthma
Diabetes
Ischemic heart disease
COPD
Dementia
Chronic Disease in Ontario
74.2% of deaths are from chronic disease. Within that, most are from cancer.
Reason for the trend from infectious to non-infectious diseases
advances in medicine, demography, and quality of life
How do we reduce disparities in chronic disease risk and burden?
look at the upstream factors which are those that are beyond the control of the individual.
Population health
aims to improve the health of the overall population and reduce disparities
Health Impact Pyramid
- Counseling and education
- Clinical interventions
- long-lasting protection interventions
- changing the context to make healthy decisions the default
- socioeconomic factors
Types of preventions
primordial, primary, secondary, tertiary
Phases of each of the preventions
primordial - underlying economic, social, and environmental conditions
primary - specific causal factors
secondary - early stages of disease
tertiary - late stage of disease
Primordial prevention
to avoid the emergence and establishment of the social, economic, and cultural patters of living that increase the risk of disease
primary prevention
limit the incidence of disease by controlling specific causes and risk factors
secondary prevention
reduce the more serious consequences of disease through early diagnosis and treatment
tertiary prevention
reduce the number and/or impact of complications
demographic transition
model to explain that population growth has been exponential and is looking to keep growing
explanation for the demographic transition
decrease in mortality rate
decrease in fertility rate (birth rate)
increase in population size
increase in age population
The 5 stages to the demographic transition
Stage 1:
high birth and death rate
natural increase: stable or slow increase
Stage 2:
high birth rate
death rate rapidly drops
natural increase: very rapid increase
Stage 3:
dropping birth rate
death rate drops slowly
natural increase: increase slows down
Stage 4:
low birth and death rate
natural increase: falling and then stable
Stage 5:
birth rate rising and low death rate
natural increase: stable or slow increase
Epidemiologic Transition
experienced high infectious disease and low non-communicable disease to low infectious disease to high non-communicable disease. Infectious diseases are lower than NCD now
Abdel Omran
- 1971, posited his theory of epidemiologic transition
- a stage of development characterized by a shift in population growth, life expectancy, and disease patterns
Stage 1: Pestilence and Famine
- first stage of the epidemiologic transition
- infectious and parasite disease were the main cause of death
- also accidents and attacks by animals and other humans
- Thomas Malthus called these deaths “natural checks”
- The Black Plague was the most violent stage 1 epidemic
Stage 2: Receding Pandemics
- improved sanitation, nutrition, and medicine during the industrial revolution reduced the spread of infectious diseases
- death rates did not improve universally or immediately though
- poor people who were crowded in industrial cities had high death rates from cholera
Stage 3: Degenerative disease
- chronic disease of aging
- physical and mental illness
Stage 4: Delayed Degenerative disease
- Life expectancy of older people
is extended through medical
advances. - Cancer medicines, bypass
surgery, better diet, reduced use
of tobacco, and alcohol - However, consumption of non-
nutritious food and sedentary
behavior have resulted in an
increase in obesity in this stage
Possible Stage 5
- Infectious Diseases
- Reemergence of infectious and
parasitic diseases; diseases
thought to have been eradicated
or controlled return, and new
ones emerge
Reasons for why there is a possible stage 5
- evolution
- poverty
- increased connections
- comordities
How does global climate change impact human health?
- pesticide use
- chemical pollution
- water contamination
- antimicrobial resistance
- intensive agriculture
- biodiversity loss
Global type 2 diabetes patterns
Rising rates of prediabetes and type 2 diabetes prevalence, globally
Type 2 Diabetes among Immigrant Populations
Risk Factors:
- genetics
- ethnicity
- environment
- SES, age, sex
- migration
Theories and Policies
- thrifty genotype/phenotype hypothesis
- acculturation
- immigration policies
- healthy migrant effect
Immigration trends
Between 2006 and 2011, recent immigrants made up 17.2% of foreign-born populations
diabetes prevalence stats among immigrants
Between 1985 and 2005, about 12% of immigrants were
diagnosed with diabetes in Ontario
Prediabetes and Conversion to Diabetes
There is a critical window of opportunity to prevent
diabetes, especially among high risk populations.
Intensive lifestyle, physical activity, dietary changes, decrease in fat. Prevents diabetes in nearly 60%.
The Built Environment
- population interventions
- “Built environment”
encompasses all the physical
structures and elements of the
human made environments in
which we live, work, travel, and
play - Research shown health risks
and benefits of the built
environment shape health
outcomes such as obesity and
diabetes = health impacts at a
population level - compact communities are better than urban sprawl
- low walkability among ethnic groups
How do we address chronic diseases moving forward
21 Recommendations tackling (PHO and CCO report)
- tobacco use
- alcohol consumption
- physical activity
- healthy eating
- capacity-building of public health systems
- promoting health equity
Recommendations for Smoking
- increase tobacco tax
- integrated tobacco
cessation system - social marketing campaign
- Ban smoking on bar and restaurant patios
Recommendations for Alcohol consumption
- socially responsible pricing
- controls on alcohol availability
- control alcohol marketing and promotion
- access to counselling interventions
Recommendations for Physical Activity
- Physical education credit
- Daily physical activity
- Active Transportation
- Workplace physical activity policy
Recommendations for Healthy Eating
- Food and nutrition strategy
- Food skills in curricula
- Healthy eating in publicly funded institutions
- Mandatory menu labelling
Recommendations for Capacity-Building
- Whole-of-government approach
- Improve measurement, and increase accountability
- Connect knowledge with practice
- Communications campaigns
Recommendations for Health Equity
- Reduce health inequities
- Address First Nations, Inuit, and Metis Health
Clinical Medicine Vs. Epidemiology
Clinical Medicine:
- patients
- diagnosis
- treatment
- prognosis
Epidemiology:
- populations/group
- prevention/health promotion
- risk assessment
Clinical Epidemiology (Clinical Part)
seeks to answer questions and to guide clinical decisions making with the best available evidence
Clinical Epidemiology (Epidemiology Part)
used to answer the questions have been developed
by epidemiologists
Clinical Epidemiology
- Clinical epidemiology is the application of epidemiology principles and methods to the clinical setting.
- studying patients
- improve patient-level outcomes
Purpose of clinical epidemiology
develop and apply methods of clinical observation that will lead to valid conclusions
Questions for clinical epidemiology
Abnormality - is the patient sick or well?
Diagnosis - How accurate are the diagnosis tests?
Frequency - How often does the disease occur?
Risk - What are the associated risk factors?
Prognosis - Consequences of having the disease?
Treatment - How treatment changes course of disease.
Prevention - Is the intervention effective in preventing?
Cause - what conditions lead to the disease?
Cost - How much will care for an illness cost?
Evidence of Causality
RCT
Cohort
Case-Control
Cross sectional
Ecological Study
