Midterm 1 Flashcards
What is Epidemiology?
Epidemiology is the study of the distribution, determinants, and deterrents of morbidity and mortality in human populations
What is Behavioral Epidemiology?
- Behavioral Epidemiology is a subset of epidemiology
- Focuses on health related behaviors in populations.
- Uses patterns and their influence on population wide disease prevention/health
What is the WHO definition of “health?”
Health is the state of complete physical, mental, and social well-being, and not merely the absence of disease or infirmity
Medical model
- Narrow understanding of health
- focuses on the absence of disease/disability
- looks at the body as an isolate (not outside factors)
- Heavily based on science/ Expert knowledge
- Puts the responsibility of health on the individual
What is Population Health?
Population health is an approach that aims to improve the health of the entire population and to reduce health inequities among population groups. It considers and acts upon the broad range of factors and conditions that have a strong influence on our health
What is a “population” in the context of population health?
A group of people or individuals with a common characteristic
Ex. Age, race, gender, Geography, life events…
What is a fixed population?
The population membership size cannot be changed because it is based on a permanent event.
Ex. your birthdate (this cannot be changed)
Ex. WW2 Survivors (you cannot become a WW2 Survivor cuz the war is over)
What is a dynamic population
A population that can increase or decrease (is changable)
what is a steady state in the context of a dynamic population
When the amount of people entering a population is equal to the amount of people leaving. There is a Net Change of ZERO
Components Investigated in Population Health
The field of population health investigates dererminants/factors (such as Health care, Individual behavious, Social environemnt, Physical enivronments and genetics) and their interactions with mean outcomes (Mortality & health related quality of life) and disparity (race/ethnicity, SES, geography & gender).
Different types of Health Research
- Basic Research: Studies cells, tissues, and animals in laboratory settings with the goal of understanding disease mechanisms and the effects of toxic substances. Examples include toxicology and immunology.
- Clinical Research: Studies sick patients who come to health care facilities with the goal of improving diagnosis and treatment of disease. Examples include internal medicine and pediatrics.
- Population Health Research: Studies populations or communities at large with the goal of preventing disease and promoting health. Examples include epidemiology and environmental health science.
Population health research aims at prevention of disease and promotion of health, whereas clinical research focuses on improving diagnosis and treatment and basic research focuses on understanding disease mechanisms
Why is the Ottawa Charter for Health Promotion important?
The Ottawa Charter for Health Promotion (1986) was developed at the first international conference on health promotion and focused on broader social, economic, and environmental factors
What five action areas of the ottawa charter for health promotion?
- Strengthen Community Action: Developing programs or networks (e.g., after-school physical activity program led by university students).
- Develop Personal Skills: Health literacy/education (e.g., media literacy initiative in a school).
- Build Healthy Public Policy: Implementing legislation or taxation (e.g., tax sugar-sweetened beverages).
- Create Supportive Environments: Changing natural or built environment (e.g., building new bike lanes).
- Reorient Health Services: Increasing infrastructure and resources (e.g., investment in city-wide health promotion campaign).
Which Ottawa Charter for Health Promotion are on the individual level and the population level
What is the difference between population health and public health?
- Population health and public health are subtly different. Public health involves activities (e.g., programs and services) organized and carried out typically by various levels of government to protect, promote, and restore the health of citizens (e.g., Public Health Agency of Canada, Alberta Health Services)
- Population health is an approach that aims to improve the health of the entire population and to reduce health inequities among population groups. It considers and acts upon the broad range of factors and conditions that have a strong influence on our health
What is the difference between disease and illness? which one does epidemology reasearch focus on and why?
- Disease is defined as abnormal, medically defined changes in the structure or functioning of the human body.
- Illness (or sickness) is the individual’s experience or subjective perception of lack of physical or mental well-being and consequent inability to function normally in social roles.
- Population health focuses on disease, although it may be hard to focus on due to its subjectivity
What are the two primary types of disease?
- Infectious or communicable disease
- Non-infectious, non-communicable, or chronic disease
Define infectious diseases and what is the differences between outbreak,
epidemic, and pandemic.
- Infectious diseases are due to a specific infectious agent or its toxic products that arise through transmission of that agent or its products from an infected person, animal, or reservoir to a susceptible host. An example is Covid-19.
- Outbreak: Occurrence of new cases in excess of baseline in a localized area (e.g., institution, city).
- Epidemic: Occurrence of new cases in excess of baseline across a country or a number of countries.
- Pandemic: Crossing many international boundaries and affects a large number of people.
Are infectious diseases a major cause of mortality in developed countries? Why / why not?
Infectious diseases are not a major cause of mortality in developed countries over the last four to five decades. Mortality is typically restricted to the very young, the elderly, and the infirm. An exception to this was Covid-19 because those who were affected did not always fit into those three categories.
Define chronic diseases! What are the 4 main behavioral risk factors associated with them?
- Chronic diseases are non-communicable diseases (NCDs) that are not passed from person to person. They are of long duration and generally slow progression.
Four main behavioral risk factors:
* Tobacco Use
* Unhealthy Diet
* Insufficient physical activity
* Harmful use of alcohol
What is the life course approach to chronic diseases? Why is it
important?
Life-Course Approach: Ageing is an important marker of the accumulation of modifiable risk factors for chronic disease, and the impact of risk factors increases over the life course. Interventions early in life have the potential to substantially reduce chronic diseases
What are the points discussed in relation to the graphs about total deaths and chronic diseases in countries of different incomes
Chronic diseases are leading causes of death globally, killing more people each year than all other causes combined. A large percentage of deaths from chronic disease occur in low- and middle-income countries
What is risk transition? What does it mean in relation to the types of disease
that are more prevalent in a country?
As a country develops, the types of diseases that affect a population shift from primarily infectious to primarily chronic. This is due to improvements in medical care, public health interventions, and the ageing of the population
What are the 3 levels of prevention? What are the differences between them?
Which group (s) does each level of prevention target?
- Primary Prevention: Aims to prevent disease before it starts through maintenance of health via individual or community efforts. It targets the general population before a person gets the disease.
- Secondary Prevention: Focuses on early detection to reduce the expression and severity of disease. It identifies asymptomatic individuals, delaying the onset and duration of clinical disease. This level targets subgroups, such as those at risk for type II diabetes.
- Tertiary Prevention: Seeks to slow the progression of a disease, reduce impairments and disabilities, and prevent complications after a clinical diagnosis has been made. It targets diseased subgroups with symptoms.
Can you “fit” the different levels of prevention within the life-course
approach to chronic disease? For example, which one would be more
important earlier in life?
Primary prevention is more important earlier in life, as it aims to prevent the disease process from ever starting. Secondary prevention becomes relevant as individuals enter higher-risk subgroups or show early signs of disease. Tertiary prevention is implemented after a clinical diagnosis
Can you identify examples of different strategies that target each level
of prevention?
*Primary Prevention: Public health campaigns promoting healthy eating and exercise.
* Secondary Prevention: Screening programs for diseases like type II diabetes.
* Tertiary Prevention: Rehabilitation programs for individuals recovering from a stroke
What are the differences between population-level & indivdual-based approach?
- Population-Based Approach: Aims to control the causes of disease in the whole population and shift the entire risk distribution
- Individual-Based (High-Risk) Approach: Identifies high-risk susceptible individuals and offers individual protection
What is the outcome of the population-level and the individual-based
approach on risk distribution?
The population-based approach shifts the entire risk distribution, while the individual-based approach truncates the risk distribution.
What are the advantages and disadvantages of the population-level approach?
- Advantages: Radical; removes underlying causes of disease, has a large potential for the population; small individual changes can lead to a large effect at the population level, and is behaviorally appropriate, changing social norms and the environment.
- Disadvantages: Small benefit to the individual (“prevention paradox”), poor motivation of the individual due to no immediate reward, and poor motivation of physicians because of the small benefit to individual patients
What are the advantages and disadvantages of the individual-based approach?
- Advantages: Intervention appropriate to the individual, individual already has a problem, individual and physician motivation, and cost-effective use of resources.
- Disadvantages: Difficulties and costs of screening, palliative and temporary (not radical), limited potential for the individual and population, poor ability to predict the future of disease, and behaviorally inappropriate, constrained by social norms/built environment
According to Rose, which approach is needed? Which one should be
emphasized?
According to Rose, many diseases require both approaches. However, the priority should always be discovering and controlling the causes of incidence
What are the benefits of a small shift in physical inactivity and sedentary
behavior levels to the incidence of chronic diseases? What is the desired
outcome for changes in sedentary behavior and physical activity according
to the Conference board of Canada? Does the increase in PA has to be of
MVPA?
The Conference Board of Canada (CBC) explored potential benefits from a small shift/improvement in physical inactivity and sedentary behavior levels of Canadians from 2015 to 2040.
* Reduced incidence rates for major chronic diseases (222,000 fewer hypertension cases, 120,000 fewer diabetes cases, 170,000 fewer heart disease cases, 31,000 fewer cancer cases).
* Increase in GDP by a cumulative $75 billion by 2040 due to Canadians living longer and healthier lives.
* Potential reduction in health care spending on hypertension, diabetes, heart disease, and cancer by a cumulative $2.6 billion over this time frame
What is epidemiology?
Epidemiology is the study of the distribution, determinants, and deterrents of morbidity and mortality in human populations
What is the difference between descriptive and analytic
epidemiology? What kind of information can each provide?
- Descriptive epidemiology describes the distribution of determinants, morbidity, or mortality by person, place, or time variables. It is useful for assessing the health status of a population, generating hypotheses, and examining patterns to establish public health programs.
- Analytic epidemiology studies the associations or causes of disease
Types of Descriptive Studies
- Case series: Describes characteristics of a group of individuals with the same exposure or disease/outcome.
- Cross-sectional: Examines a group of people at one point in time, describing the prevalence of an exposure or disease/outcome.
Types of Analytical Studies
- Experimental: Investigator intentionally alters one or more factors to study the effects. Randomized Controlled Trials (RCTs) fall under this category.
- Observational: Investigator observes without intervention. This includes cohort studies and case-control studies
What is a cohort study?
Cohort studies are a type of analytical and observational study.
* Involve a forward directionality where exposure is ascertained prior to the ascertainment of an outcome.
* Individuals are followed over an extended period of time.
* An example is comparing smokers vs. non-smokers.
What is a case-control study?
Case-control studies are a type of analytical and observational study.
* Involve a backward directionality where outcome is ascertained prior to ascertainment of exposure.
* An example is studying lung cancer.
Steps of a Randomized Controlled Trial (RCT)
- Selection of appropriate study sample and baseline assessment.
- Randomly assign participants into an Experimental Group(s) and a Control Group.
- Application of intervention.
- Follow-up assessment(s)
Not all relationships can be examined with RCTs. A famous example is the link between cigarette smoking and lung cancer.
The the hierarchy of evidence
The hierarchy of evidence indicates that some study designs provide stronger evidence than others. In general, RCTs are considered to provide a higher quality of evidence compared to observational studies like cohort studies, assuming both have good quality
What are measures of Disease Frequency (Descriptive Studies)
Prevalence rate & incidence rate
Prevalence rate and Incidence rate – what’s the difference
between them?
- Prevalence Rate: is the proportion of a population with a given disease or condition at a specified time.
- Incidence Rate: The proportion of the population at risk that develops a given disease or condition during a specified time period
How do we calculate prevalance rate?
- remember to multiply by 100
How do we calculate incidence rate
Remember the sink analogy for the relationship between prevalence and incidence
What are measures of Association (Analytical Studies)
relative risk ratio and odd ratios
Relative risk (risk ratio - RR) – what is it? How’s it calculated?
- The ratio of the risk of the outcome in the exposed group to the risk of the outcome in the unexposed group (referent group).
- Estimates the increased or decreased risk of an outcome due to a particular exposure.
- calculation:
Prevalence ratio and odds ratio? Why do they have to be used in place of RR in case control and cross-sectional studies?
Risk ratio cannot be used in case-control and cross-sectional studies because there is no forward time component that determines relative risk. In case-control studies, the outcome is ascertained before exposure. In cross-sectional studies, exposure and outcome are measured at the same time.
Prevalence ratio what is it and how do we calculate it?
- Indicates the proportion of individuals that have the outcome in the exposed versus unexposed groups
formula:
Odds ratio what is it and how do we calculate it?
- Indicates the odds of that outcome occurring in the exposed group compared to the unexposed group
Formula:
Define CAUSE!
A cause is an event, condition, or characteristic that precedes a disease event; without the cause, the disease event would not have occurred until some other time.
Why can’t we assess causal relationship with a descriptive cross-
sectional study?
Causal relationships cannot be assessed using a descriptive cross-sectional study because this type of study only provides a snapshot in time.
What is the germ theory? Why is the germ theory no longer dominant in explaining mortality in high income countries?
The germ theory, which was dominant in clinical medicine and public health in the mid-to-late 1800s and early 1900s, posits that diseases have a single causative agent. It worked well for infectious diseases that dominated much of the world at the time. The germ theory is no longer dominant in explaining mortality in high income countries because the disease pattern shifted to one dominated by chronic disease by the 1950s
What is the black box of causation?
The black box of causation refers to understanding risk factors and diseases without necessarily understanding the biological mechanisms. Studies on smoking and lung cancer are examples of the black box, where a causal relationship was determined without understanding the biological mechanism
What is the “Web of Causation” in the history of cause and effect?
The web of causation, conceptualized in the 1960s, explains that the occurrence of a disease can be explained by a complex web of interconnected factors. Pathways in the web of causation can differ from person to person
What is a confounder? What are common confounders in behavioral
epidemiology?
A confounder is a third variable that, when present, distorts the association between the exposure and the outcome. Common confounders in behavioral epidemiology research include diet, age, sex, race and socioeconomic status
when it comes to cause and effect, an experimental study (RCT) would be ideal. However, not all relationships can be assessed via RCT
Hill’s criteria for causal association
In 1965, Sir Austin Bradford Hill suggested a set of nine criteria to help determine if associations are causal. These criteria are often used by epidemiologists today and involve some subjectivity and rely on the judgment of the researcher.
Hill’s criteria for causal association (9):
- Temporality: The exposure occurred before the disease. This is considered the most important criteria.
- Strength of association: There is a strong measure of association (i.e., OR, RR).
- Consistency: The same results occur for different people, places, and times. This is related to the repeatability of the study.
- Specificity: More commonly related to infectious disease and a single cause leading to an effect (i.e., germ theory).
- Dose-Response Relationship (Biological Gradient): As the dose of the exposure increases, the risk for the outcome also increases or decreases in a gradient fashion.
- Biological Plausibility: There is an existing biological or social model to explain the association.
- Coherence: The association does not conflict with known facts about the history and biology of disease.
- Experiment: The association has been tested using an experimental design.
- Analogy: There are similarities between the observed association and other associations
Which of Hill’s causal associations are not used?
Specificity, coherence & analogy
What is physical activity and how do we measure?
Physical activity: Any bodily movement produced by skeletal muscles that expends energy beyond resting levels.
- Measurement: Physical activity can be measured subjectively through self-reports like questionnaires or objectively using devices like accelerometers and pedometers. The definition relates to measurement because the focus is on quantifying movement and energy expenditure
What is sedentary behaviour and how do we measure?
Sedentary behavior: Any waking behavior characterized by an energy expenditure ≤ 1.5 metabolic equivalents while in a sitting, reclining, or lying posture. Standing is not considered sedentary behavior because it typically involves a higher energy expenditure than sitting or lying down.
* Measurement: Sedentary behavior can be measured subjectively through self-reports or objectively using accelerometers or inclinometers, which can measure posture and time spent sitting or lying down
What is sleep and how do we measure it?
Sleep: Loss of conscious awareness.
* Measurement: Sleep can be measured subjectively through self-reports or objectively using accelerometers or polysomnography. Polysomnography involves electrodes that record various parameters of sleep, but it is not typically used in population-based studies
What is nutrition and how do we measure it?
Nutrition: The kinds of food that a person, animal, or community habitually eats.
* Measurement: Nutrition can be measured subjectively through methods like 24-hour food recalls, food records, and food frequency questionnaires. Biomarkers can also be used to validate these tools
What is the importance of measuring health behaviors? What is the role of
measurements in the behavioral epidemiology framework?
- Measuring health behaviors is important because it has a ripple effect throughout the Behavioral Epidemiology Framework.
- Measurements play a crucial role in understanding health outcomes, determinants, and the effectiveness of interventions, as well as translating research into practice.
Measurement properties!
Measurement properties and their definitions
- Validity: Refers to the accuracy of an instrument in measuring what it seeks or claims to measure. It addresses whether we are measuring what we want to measure.
- Reliability: Refers to the stability and consistency of the instrument.
- Objectivity: Refers to being free of bias and uncontaminated by personal assessment. High objectivity implies being both reliable and valid and free from bias.
- Responsiveness: The ability of an instrument to detect important change from an individual perspective.
- Patient Acceptable Symptom State (PASS): The value beyond which individuals consider themselves well or consider their health state as acceptable
What are the advantages and disadvantages of using subjective measures to measure behaviors?
- Subjective Measures (e.g., self-reports, questionnaires, interviews):
◦ Advantages: Low cost, quick and efficient, can gather information on context or setting, and reliable.
◦ Disadvantages: Potential for biases such as social desirability and recall bias, and may have validity issues
What are the advantages and disadvantages of using objective measures to measure behaviors?
- Objective Measures (e.g., accelerometers, pedometers, observation):
◦ Advantages: Less bias.
◦ Disadvantages: Can be costly, may increase participant burden, may lack information on context, and might induce bias (reduce sedentary behavior when wearing a device).
When it comes to measuring nutrition, know what the gold standard is! Can you identify some of the bias that may happen with the measures?
- Gold Standard: 24-hour food recall.
- Potential Biases: Social desirability bias, recall bias, and reactivity bias (altering behavior to look better in the eyes of the researcher). Portion sizes can also be difficult to measure accurately
What is the gold standard for measuring sedentary behaviour and sleep and what are the biases that can occur?
- Sedentary Behavior: Inclinometers may be more precise but are costly.
- Sleep: Polysomnography is not used in population-based studies.
- Bias: Bias might occur with objective measures; for example, individuals might reduce sedentary behavior when wearing a device
Which component of TDEE has the most variability? Which one can we
influence the most?
The physical activity component has the most variability. This component can be influenced the most
FITT Principle
- FITT stands for Frequency, Intensity, Time (duration), and Type
Physical activity domains for children and youth?
The four domains are active play, active transportation, organized sport, and physical education
What is active play?
Active play is unstructured physical activity that is volitional, spontaneous, self-directed, and fun. Leisure activities apply to youth
What is active transportation?
Active transportation is physical activity performed to get to and from places, like cycling and walking
What is organized sport?
Organized sport includes individual or team sports or physical activity programs that typically have rules, coaches, and specialized equipment
What is physical education?
Physical education is a curricular subject within the school setting designed for students to develop motor skills, movement-related concepts and strategies, personal and social responsibility, personal fitness, and knowledge about the value of physical activity
Guidelines! What are the benefits / criticisms of having them?
◦ Benefits include standardization for fitness professionals so everyone gets the same information.
◦ Criticisms include that they do not take into account adapted populations, can be a “one size fits all” approach, and may form causal relationships
For ALL behaviors, “critical health outcomes” are more important than “important health outcomes”. So, which one “dictate” the guidelines?
◦ Critical health outcomes dictate the guidelines.
◦ For physical activity and health outcomes for those aged 5-17, the critical health outcomes are adiposity, cardiometabolic health, fitness, prosocial behavior, cognition/academic performance, quality of life, and risks/harms
What is the summary of recommendations for children / youth (5 – 17 years old)?
This group needs at least 60 minutes of moderate- to vigorous-intensity physical activity (MVPA) per day.
◦ More physical activity (duration, frequency, and/or intensity) was associated with better health
What can the graph below tell us about MVPA in this group (5-17 years)?
What’s the difference between PA and exercise?
◦ Physical activity is any bodily movement produced by skeletal muscles that results in energy expenditure.
◦ Exercise is a subset of physical activity that is planned, structured, and done regularly to improve or maintain physical fitness or health
What is NEAT? Why is it important?
NEAT is the energy expended for everything that is not sleeping, eating, or exercise. It includes activities like walking to work, typing, fidgeting, and doing chores.
◦ NEAT explains a large part of an individual’s non-resting energy needs and accounts for the majority of daily energy expenditure.
◦ The difference between the pie chart in this set of slides and the one you saw previously may be that this one highlights the significance of NEAT. NEAT can cause individuals to expend a lot more energy during the day
What are the domains of active living for adults?
The domains include household activities, occupation activities, active transportation, and active recreation/leisure activities.
◦ Household activities consist of housework, yard work, child care, chores, and self-care.
◦ Occupation activities include work-related physical labor tasks, walking, carrying, or lifting objects.
◦ Active transportation includes walking, rolling, or standing while riding transportation with the purpose of going somewhere.
◦ Active recreation/leisure activities include discretionary or recreation activities, sports, hobbies, exercise, and volunteer work
What is the summary of findings from the two systematic reviews added
about resistance training and balance?
- Resistance training improved health outcomes in adults, and the benefits outweighed the harms. More resistance training is associated with less mortality; physical functioning; health-related quality of life; cardiovascular disease; type 2 diabetes; mental health; brain health; cognitive function; cancer; fall-related injuries; and bone health.
- Balance and functional training participation was associated with reduced falls and improved health outcomes in adults 65 years of age and older. More balance/functional training was associated with physical functioning; health-related quality of life; physical activity; and sedentary behavior
What are the guidelines for PA in adults (18-64 years old)? What is different
for adults aged 65+?
The source mentions that the Canadian Physical Activity Guidelines for adults (18-64 years) and older adults (65 and over) were released in January 2011 and November 2020
What important information / trends can you get
from the graph below?
- Based on the CHMS (Canadian Health Measures Survey) data, males are generally more active than females.
- Moderate to vigorous physical activity (MVPA) decreases as age increases
What important information / trends can you get
from the graph below?
- 45% of adults accumulated ≥150 minutes of MVPA per week.
- Canadian adults maintained their physical activity levels, and adults 50+ years increased their physical activity. This increase was statistically significant among non-immigrant, non-Indigenous individuals, those not designated as a visible minority, those living in urban areas, and those with a postsecondary degree
Definition of sedentary behavior! What’s the MET value associated with it?
Sedentary behavior is defined as any waking behavior characterized by an energy expenditure ≤ 1.5 metabolic equivalents (METs), while in a sitting, reclining, or lying posture. Sleep does not count as sedentary behavior.
Is there a difference between being physically inactive and sedentary?
- Yes, there is a difference between being physically inactive and sedentary.
- Physically inactive refers to not meeting physical activity guidelines.
- Sedentary refers to not meeting sedentary behavior guidelines.
- It’s possible to be physically active but still engage in a lot of sedentary behavior, and vice versa
the aim is to increase daily PA and reduce SB!
What are the components of the SITT principle? Why would you prefer to be a breaker and not a prolonger?
The SITT principle includes:
▪ Sedentary behavior frequency (bouts) – number of bouts of a certain duration.
▪ Interruptions (breaks) – how often one interrupts sedentary behavior.
▪ Time – duration of sedentary behavior.
▪ Type (mode) – screen time, reading, etc
interrupting sedentary behavior is beneficial. Therefore, it’s preferable to be a “breaker” (someone who takes frequent breaks) rather than a “prolonger” (someone who engages in prolonged periods of sedentary behavior)
Is all SB created the same? I.e., are some types of sedentary behavior
more detrimental than others?
- Not all sedentary behavior is created equal; some types are more detrimental than others
- The type of sedentary behavior matters; some can be beneficial, while others are harmful. For example, screen-based sedentary behavior is likely to have no benefit and potential for harm
What is the summary of findings for those 5-17 years old?
Different types of sedentary behavior have different impacts on health indicators. Higher durations of TV viewing and/or screen time were associated with unfavorable health outcomes. Less sedentary behavior, especially screen time, is associated with better health
What are the guidelines for 5-17 years old? (think of SITT)
◦ Sedentary behavior frequency - no recommendation given.
◦ Interruptions (breaks) - no recommendation given.
◦ Time (duration of sedentary behavior) – limit to 2 hours.
◦ Type (mode) – screen time
What is the summary of findings for 0 – 4 years old? What types of sedentary behaviors can have a benefit in this
age group?
S- not restrained for one hour at a time
I- no recommendation yet
T- NO screen time
T- restrained time, screen time, reading/story telling
Interactive non-screen-based activities such as reading/storytelling benefit 0-4 yeard
What can we infer from the graph below?
◦ Based on the surveillance data, the percentage of infants (2, 4, and 6 months) meeting guidelines is 27%. For toddlers (1-2 years), it’s 15%, and for preschoolers (3-4 years), it’s 24%.
What were the important points we discussed about this one? I.e.,
can you think of the relationships between sedentary time, PA, and
risk of all-cause mortality?
- Very high levels of MVPA remove the excess risk of all-cause mortality associated with high volumes of sitting
- Very low time spent sitting reduces, but does not eliminate the risk of no moderate-to-vigorous PA
- Given the high levels of sitting and low levels of PA in the population, ,ost people will benefit from both increasing MVPA and reduce time spent sitting
What are the high-level recommendations for SB for adults?
- Adults should avoid high levels of sedentary behavior and break up periods of prolonged sitting.
- Given the high levels of sitting and low levels of physical activity in the population, most people would benefit from both increasing moderate-to-vigorous physical activity and reducing time spent sitting
Is there
emphasis on one or more types of SB?
- Recreational screen time is mentioned as a type of sedentary behavior.
- Higher levels of sedentary behavior and TV viewing were associated with unfavorable health
What does the 24-hour movement guidelines say about adults and
SB?
- The Canadian 24-Hour Movement Behaviour Guidelines include recommendations for adults aged 18-64 years and adults 65 and over, released in November 2020.
- There were no sedentary behavior guidelines for adults prior to 2020
Which SITT aspect does it address (24 hr movement guidelines)?
SITT Aspects Addressed:
* Time (duration of sedentary behavior) is addressed with a recommendation of 8 hours of sitting or less, and 3 hours of recreational screen time per day.
* Interruptions (breaks) are mentioned, recommending breaking up prolonged periods of sitting as often as possible.
* Sedentary behavior frequency (bouts) is mentioned, but there is no specific recommendation to minimize prolonged periods.
* Type (mode) is addressed by specifying recreational screen time
What is this graph telling us? What were the 3 key pieces of info / trends it tells us?
- Females engage in more sedentary behavior than males.
- Sedentary behavior tends to increase with age (this is also why we gain weight as we age)
- Everyone is exceeding the 8-hour recommendation.
Based on the CHMS (Canadian Health Measures Survey), only 6% of the population meets the sedentary behavior recommendations
What are the 5 dimensions of sleep?
- Sleep duration: The total amount of sleep obtained per 24 hours.
- Sleep continuity or efficiency: The ease of falling asleep and returning to sleep.
- Timing: The placement of sleep within the 24-hour day or the time of day that sleep occurs.
- Alertness/sleepiness: The ability to maintain attentive wakefulness.
- Satisfaction/Quality: The subjective assessment of “good” or “poor” sleep
What is sleep hygiene?
Habits and practices conducive to sleeping well on a regular basis.
- Examples include sleep consistency (going to bed and rising at the same time each day), a quiet, dark, and relaxing sleep environment that is not too hot or too cold, and avoiding large meals before bedtime. Removing TVs, computers, and other “gadgets” from the bedroom is also an example of sleep hygiene
which one of these aspects (5 dimensions + hygiene) is frequently mentioned in the guidelines for all age groups?
Sleep duration and consistent bedtimes are frequently mentioned in the guidelines for all age groups
In adults…what type of relationship exists between sleep duration and all-
cause mortality? I.e., is more sleep better?
- There is a U-shaped association between sleep duration and health outcomes.
- Optimal sleep duration appears to be 7-8 hours
What is the summary of findings for 5-17 years old? Is there an optimal
sleep threshold in this group? Are all sleep dimensions addressed?
- Shorter sleep duration was associated with unfavorable physical and mental health indicators.
- Optimal sleep thresholds for health benefits were unclear.
- The sources only specifically mention the sleep duration dimension in relation to health outcomes
What is the summary of findings for 0-4 years old? Are all sleep dimensions
addressed?
- Shorter sleep duration was associated with unfavorable physical and emotional health indicators, along with unfavorable health behaviors.
- Better-quality studies with stronger research designs that can provide information on dose-response relationships are needed to inform contemporary sleep duration recommendations.
- The sources only specifically mention the sleep duration dimension in relation to health outcomes
What is the summary of findings for adults? Is there a difference between
adults 18-64 years old and 65+ years old? Remember that are two: one of
sleep duration and one for sleep timing / consistency. Are all sleep
dimensions addressed?
- Sleep Duration Review:
▪ U-shaped association between sleep duration and health outcomes.
▪ Optimal sleep duration appears to be 7-8 hours.
▪ No age-group differences existed. - Sleep Timing/Consistency Review:
▪ Inconsistent and/or late sleep timing is associated with several critical and important health outcomes.
▪ Later sleep timing & more sleep variability associated with adverse health outcomes.
▪ Cannot define clear thresholds.
▪ The sources address the sleep duration and timing/consistency dimensions in relation to health outcomes.
▪ There is no difference cited in the source between adults 18-64 years old and 65+ years old
What is the effect of social jetlag and catch-up sleep on the weekend on
adults’ health?
- Social jetlag was associated with adverse health outcomes.
- Weekend catch-up sleep was associated with better health outcomes
There were some interesting points about sleep from the image below. What were they?
- The proportion of those meeting the guidelines decreases as age increases.
- Sleep is the “best score” of all the behaviors.
- Sleeping for too long becomes more common as we age
Why is focusing mostly on MVPA a short-sighted approach?
All behaviors, including sleep duration, sedentary time, and physical activity, exist on a movement intensity continuum.
- Therefore, focusing primarily on MVPA is short-sighted because MVPA only makes up a small portion of a 24-hour period, and people cannot spend all their waking hours engaged in MVPA
What is the role of sleep in this integrated pattern?
Short sleep duration is associated with many adverse health outcomes and interacts with physical activity and sedentary behavior
What effect can an unhealthy behavior have on others? Can you meet
guidelines for one and not for others? What would happen to your
overall health
An “unhealthy” behavior can cancel out the benefits of others, having a larger impact on health. You can meet guidelines for one behavior (e.g., physical activity) and not for others (e.g., sedentary behavior or sleep)
What is the summary of findings for 0-4 years old?
- Ideal combinations of physical activity and sedentary behavior lead to better motor development and fitness (preschoolers) and lower adiposity (toddlers and preschoolers).
- Ideal combinations of sleep duration and sedentary behavior lead to lower adiposity (infants and toddlers).
- The most optimal health benefits were observed when replacing any movement behaviour with MVPA
What is the summary of findings for 5-17 years old?
- Ideal combinations of all movement behaviors are favorable for many health outcomes.
- The most optimal health benefits were observed when replacing sedentary behaviour with MVPA
What is the summary of findings for adults?
Replacing sedentary behavior with any other movement behavior was associated with a lower risk of all-cause mortality
