Epidemiology Flashcards

1
Q

What is exercise?

A

A subset of physical activity that is planned, structured and repetitive bodily movement, done to improve or maintain one more more components of fitness, performance or health

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2
Q

What is physical activity?

A

Bodily movement that is produced by the contraction of skeletal muscle and that substantially increases energy expenditure

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3
Q

What is most ill health in Australia attributed to?

A

Non-communicable diseases (chronic)

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4
Q

What is prevalence?

A

Quantifies the proportion of the population who have a particular health problem (eg diabetes) at a specified time

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5
Q

What is incidence?

A

Quantifies the number of new occurrences that develop during a specified time (person-time incidence rate)

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6
Q

How to calculate prevalence?

A

Number of people with disease/illness etc at a particular point in time / number of people in the sample

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7
Q

How to calculate incidence?

A

Number of new cases of disease/risk factor in a specified period / number who were initially disease-free

Must involve a period of time!

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8
Q

Two main types of research design

A

Observational studies and experimental studies

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9
Q

What are the observational studies?

A

Case reports/series
Cross-sectional
Case-control
Cohort

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10
Q

What are the experimental studies?

A

Single group intervention
Quasi-experimental intervention
Randomised controlled intervention

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11
Q

What is primary prevention?

A

Preventing the disease before any symptoms appear (i.e. in a largely healthy population)

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12
Q

What is secondary prevention?

A

Preventing a biological risk factor (usually detected from screening) from worsening, once it is evident. Requires action to delay progression and reduce severity

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13
Q

What is tertiary prevention?

A

Managing an established problem to prevent it from getting worse

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14
Q

Where does almost all primary prevention evidence on physical activity come from?

A

Cohort studies

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15
Q

Who is the father of epidemiology who studied bus drivers?

A

Jeremy Morris

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16
Q

Who continued Jeremy Morris’ work in his studies of heavy work?

A

Ralph Paffenbarger

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17
Q

What are cross-sectional studies designed to do?

A

Used to assess at one point in time:

Prevalence of a health problem or behaviour and the associations between ‘exposure’ and ‘risk’

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18
Q

What does it mean by “Cohort studies are prospective”

A

They measure physical (in)activity and then compare risks of developing health problems with people in different “levels of exposure” to that risk factor

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19
Q

Characteristics of cohort studies

A

Select an identified cohort
Should be representative of the population
Follow over time for many years
Collect data on both exposures and outcomes
Expensive
Needs right questions at beginning

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20
Q

What seperates epidemiologists from other researchers?

A

They count and compare data from the population, not the laboratory.

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21
Q

What is a risk ratio?

A

Relative risk - compare risk in two or more groups

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22
Q

What is an odds ratio?

A

Comparison of odds in two or more groups

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23
Q

What is a prevalence ratio?

A

Comparison of prevalence in two or more groups

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24
Q

What does RR > 1.00 mean?

A

Higher risk

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25
What does RR < 1.00 mean?
Protective
26
What does RR = 1.00 mean?
Neither risk nor protective
27
Calculation for risk ratio?
Occurrence [risk, prevalence, odds] in EXPOSED GROUP / Occurrence [risk, prevalence, odds] in UNEXPOSED GROUP
28
John Stewarts criteria for causation?
Temporal sequence Strength of the association Is the association consistent across studies? Is there a dose-response relationship? Is the association biologically plausible?
29
What is a meta-analysis?
A statistical procedure for combing data from multiple studies (usually of the same design). Based on systematic review of all publications
30
What does the Australian guideline say for PA?
Doing some activity is better than doing none. If you currently do no PA< start by doing some and gradually building up to the recommended amount And Be active on most, preferably all, days of the week
31
How much time does the Australian guideline recommend for adults 18-65?
Accumulate 150-300 minutes of moderate intensity PA, or 75-150 mins of vigorous activity, or an equivalent combination of moderate and vigorous activities each week
32
How many days a week should adults do muscle strengthening?
Two days
33
What does the Australian guideline say about sitting?
Minimise the amount of time in prolonged sitting and break up the periods of sitting as much as possible
34
What is sedentary behaviour characterised as in accordance with the Australian guidelines?
Any waking behaviour with an energy expenditure of <1.5 METs while sitting, lying or reclining.
35
Components of PA?
``` Frequency Intensity Time Type Domain ```
36
Subjective measures of recording?
Diaries and log books (use of time) Interviews Surveys/questionnaires
37
What is 1 MET equal to?
Rest (oxygen uptake of 3.5ml O2Kg^-1 * min^-1
38
What is the MET of sleeping?
1
39
What is the MET of moving about slowly (shopping etc)
1-<3
40
What is the MET of brisk walking?
3-5 METs
41
What is the MET for vigorous activity?
>6
42
What is sedentary behaviour?
Sedentary behavior is any waking behavior characterized by an energy expenditure ≤1.5 metabolic equivalents (METs), while in a sitting, reclining or lying posture.
43
How to calculate for METs?
Intensity (METs) * Time (mins) = MET.mins
44
PA guideline for MET minutes per week?
500-1000 MET minutes
45
Advantages of questionnaires?
Extremely useful for large scale data collection–cost effective Good for structured activity (exercise) and for people with regular PA habits Can collect quantitative and qualitative information e.g. on type and domain Provide an estimate of FITTD
46
Disadvantages of questionnaires?
Subject to recall problems, reporting bias (social desirability) Questions could be misinterpreted Sometimes too difficult to estimate total time spent eg walking Not good with young children (under 10); older people may have memory problems Physical activity is a complex behavior –it does not come in handy and easy to measure packages (e.g. packets of cigarettes/day)
47
Surveys used are VALIDATED against objective measures
* Active Australia (AA) * National Health Survey (NHS) * International Physical Activity Questionnaire (IPAQ) * Global Physical Activity Questionnaire (WHO) * Behavioural Risk Factor Surveillance System (BRFSS)
48
What are cross-sectional studies?
measure PA at one point in time interview, telephone or mail or objective measures determine prevalence of risk factors, disease, knowledge and attitudes do not show temporal relationships serial surveys can track changes over time –but not in the same people (eg National Health Survey)
49
Positives and benefits of pedometers?
+Cost-effective +Useful for detecting change (in steps) +Some have indirect measures of energy expenditure -No data on frequency, intensity, duration PA -Insensitive to some forms of PA -Step counts influenced by body size and speed of locomotion
50
Best way to measure data?
Direct observation
51
Two types of accelerometers?
Actigraph and ActiPAL
52
What do accelerometers do?
Monitor intensity of movement in a specific plane
53
What does an activPAL do?
Measures posture Good estimate for sedentary behaviours Based on 'not moving' and 'moving' with posture Expensive and a burden
54
Conclusions of fitness watches?
Measure heart rate accurately, but estimates of energy expenditure are poor and implications for weight loss are not great
55
What is a higher number of breaks from sitting associated with?
Lower average waist, BMI, triglycerides and 2-hr plasma glucose
56
Different stages of elderly?
Young-old 65-74yrs Mid-old 75-84yrs Old af - 85+ years
57
What percentages of adults over 65 years have at least one chronic health condition?
88%
58
What percentage of people >65 years living in the community fall ever year?
30-40%
59
What percentage of people over 70 years of age have arthritis?
60%
60
What percentage of women ages 70-80 have difficulty walking a fair bit or doing housework?
50%
61
What percentage of those aged over 85 years have moderate or severe cognitive impairment?
A third
62
2009 PA recommendations for elderly?
Do some form of physical activity, no matter your age, weight, health problems or abilities Be active every day in as many ways as possible, doing a range of physical activities that incorporate fitness, strength, balance and flexibility Accumulate at least 30 minutes of moderate-intensity physical activity on most, preferably all, days.
63
Life events associated with decreasing physical activity in YOUNGER women?
In order of strongest evidence ``` Getting married Birth of first child Birth of second child Decreased income Divorce ```
64
Life events associated with decreasing physical activity in MID-AGED women?
In order of strongest evidence Retirement Decreased income Death of spouse/partner Child or other family member leaving home (p=0.051) - debatable
65
Life events associated with decreasing physical activity in OLDER women?
Diagnosis with chronic illness Injury - fall/fracture Hospitalisation - major surgery Move to institutional care
66
What is a correlate?
A variable that is statistically associated with physical activity usually from cross-sectional surveys no causal relationship can be implied
67
What is a determinant?
evidence of statistical association in a longitudinal study (ie a observational (cohort) or experimental (randomised intervention trial) relationship MAY be causal
68
Challenges facing older adults?
Disability - inability to perform Functional limitations - restriction in performing generic tasks
69
Demographic determinants of PA in older adults?
Gender Retirement Ethnicity Marital Status
70
Psychological determinants of PA in older adults?
Knowledge Lack of interest Self-efficacy
71
PA guidelines for infants under 1 year of age?
Being physically active several times a day -if not mobile, 30 minutes of tummy time Not being restrained for more than one hour at a time
72
Sleep recommendations for infants under 1 year of age?
14-17 hours of sleep for 0-3 months, 12-26 hours for 4-11 months
73
PA guidelines for infants 1-2 years of age?
At least 180 minutes of physical activity Not being restrained for more than one hour at a time
74
Sleep recommendations for infants 1-2 years of age?
11-14 hours of good quality sleep, including naps, and consistent times of the day
75
PA guidelines for infants 3-5 years of age?
At least 180 minutes of PA with at least 60 minutes of energetic play
76
Sleep recommendations for infants 3-5 years of age?
10-13 hours of good quality sleep, including naps, and consistent times of the day
77
Screen time recommendations for children?
If under 2 years of age, screen time not recommended No more than an hour for 2-5 year olds Less than 2 hours for 5-17 year olds
78
PA guidelines for infants 5-17 years of age?
60 minutes or more of moderate to vigorous PA including mainly aerobic activities Several hours during a day of light PA Breaking up long periods of sitting as often as possible
79
Sleep recommendations for children 3-5 years of age?
9 to 1 1 hours for 5-13 year olds, and 8 to 10 for 14-17 years
80
Do active children become active adults?
It is weakly related
81
Demographic determinants of PA in older adults?
Gender Retirement Ethnicity Marital Status