Slides #2 Flashcards
(21 cards)
Epidemiology
The study of how often diseases occur in different groups of people and why.
Used to plan and evaluate strategies to prevent illness and as a guide to the management of patients in whom disease has already developed.
PA epidemiology
Studies the causal relationship between PA, or lack of PA, and health. Also, studies the distribution and determines of PA/inactivity.
How active Are Canadians
As few of 15% of adults are meeting the minimum recommend 150 minutes of moderate to vigorous PA per week.
Observational study design
The development of disease or health outcome is observed and compared between those that participate in different levels of PA. Collect record, analyze data, on participants as they naturally divide themselves
Pros: researchers do not control/ manipulate PA levels of subjects, better for patients.
Cons: Subjects can lie on the questionairs when asked about PA
Experimental Study Design
Random assignment of PA levels to individuals with out the disease or health outcome of interest.
Pros: study is very detailed constructs great information.
Cons: study takes along time over several months. Researchers control PA levels.
Cross-sectional Study
A cross-sectional study provides and instant picture of the relationship between the disease or the condition of interest and physical activity levels at the same point in time.
Pros: cheap to perform
Cons: lack of temporal sequences and lack of evidence in some cases.
Case-control Study
Identifies the cases (group known to have the outcome) and the controls (group free of the outcome). then look back (retrospective) in time to learn which subjects in group had the exposures comparing the frequency of the exposure in the case group to the control group.
Pros: cheap and not as time consuming
Cons: participants could lie on the questionnaire when asked about PA
Prospective Cohort Study ( Aka longitudinal cohort study)
Follows overtime a group of similar individuals (cohorts) who differ with respect to certain factors understudy, to determine how these factors affect rates of certain outcome.( follows groups for several years one that does PA and one that does not and indicates if PA had a factor in and illness like diabetes)
Pros: large sample size
Cons: takes several years. Lie on questionnaire
Randomized Clinical Trial
Participants are randomly assigned to receive either an intervention or no intervention (control) and two groups are followed for a period of time to determine if they differ.
Pros: No bias and less costly
Cons: random participants don’t get to choose. Can take long time.
Incidence
Rate at which new case occur in a population during a specified period.
Prevalence
Proportion of a population who have disease or attribute to a specified point of time.
Mortality rate
Incidence of death from a disease
Morbidity
Any departure, subjective or objective, from a state of psychological or physiological well-being
PA and fitness levels of Canadian adults
Body mass is over weight, waist circumference has increased and grip strength is getting weaker, but adults are getting more flexible.
Odds ratio
Prevalence (or incidence) rate in 1 group divided by the prevalence (or incidence)rate and another referent group (odds ratio is always 1.0 in the referent group)
An odds ratio > than 1.0 in the comparison group indicates a higher risk that in the referent groups, while an odds ratio of < 1.0 = lower risk.
95% Confidence interval
Indicates with 95% certainty that the true ratio score would fall within that interval; wider confidence intervals = less reliability
Confounding variables
Related to both the intervention and outcome of interest; thus, may skew findings
In class study
Hypothesis: Men in physically active jobs have a lower incidence of coronary heart disease disease than have men in physically in active jobs
Conductors and drivers: conductors had 30% lower incidence rate of coronary heart disease (CHD). They were also older when they developed CHD, had less severe disease, experienced lower case fatalities rate.
Conclusion: Employees in the position that required high physical activity had lower rates of CHD
In class study strengthens and weaknesses
Strength: wide age range, same company, large sample size thousands of people.
Weaknesses: only males, don’t know what done after working hours, did not do a proper statistic analysis, stress of a driver did not include.
PA Epidemiological research
Investigating association of recreational, nonrecreational and house of physical activity with disease risk.
Recognizing short bouts of Moderat PA greater or equally than 10 minutes in improving fitness and cardiovascular risk factors.
Incorporating objective measures to assess fitness, energy expenditure, and physical activity levels
Exploring which results in lower disease incidence in those that live with being overweight or obese: low or high fitness
Key epidemiological finding
Those who are physically active 75mins a day do not have to worry about how much time they are spending being sedentary/ sitting.
Cdn PA guidelines: 30 PA a day and sitting 4-8 hour’s a day is ok.
