PSY306 Health Psychology Morrison Ch 3 & 4

Question 1

Define etiology

Answer 1

The scientific study of causes or origins of specific diseases.

Question 2

Describe epidemiological research studies

Answer 2

• Usually conducted in the field
• Use statistical comparison between groups exposed to different risk factors
• Are useful in determining disease etiology
• Often are easily replicated; good generalisability
• Use some variables that may be controlled by selection rather than direct manipulation
• Are often time-consuming and expensive

Question 3

Define Morbidity (disease)

Answer 3

Number of cases of a specific illness, injury, or disability in a given group of people at a given time

Question 4

Define Mortality (death)

Answer 4

Number of deaths due to a specific cause in a given group at a given time

Question 5

Define Incidence

Answer 5

Number of new cases of a disease or condition that occur in a specific population within a defined time interval.

Question 6

Define Prevalence

Answer 6

Total number of diagnosed cases of a disease or condition that exist at a given time

Question 7

What are the three fundamental objectives of epidemiological research?

Answer 7

• Pinpoint the etiology of a particular disease in order to generate hypotheses
• Evaluate the hypotheses
• Assess the effectiveness of intervention programs created to test the researchers’ hypotheses

Question 8

What is a correlational study?

Answer 8

• Descriptive studies.
• Correlational Designs study the association between variables.
• Causality cannot be inferred (other variables may be involved).
• Mistaking statements of association for statements of causation is a common error in the interpretation of research results.

Question 9

What are two types of correlational designs?

Answer 9

Cross-Sectional Correlational Designs

• Measures taken at the same point in time.
• Temporal sequence (directionality) cannot be inferred.

Longitudinal (Prospective) Correlational Designs

• Measures taken at more than one point in time.
• Some indication of temporal sequence (directionality) can be inferred. E.g., Intention to exercise (measured today) may predict exercise behaviour measured in 2 weeks.
• Even when temporal sequence is inferred, it is not a causal effect as there is not control of other potentially confounding variables.

Question 10

What is a qualitative design?

Answer 10

• Descriptive study
• Focuses on qualities instead of quantities
• Often uses participants’ expressed ideas as part of qualitative studies
• May be combined with experimental methods to make investigations more comprehensive (mixed methods research)
• A method of ascertaining a rich understanding of peoples’ experiences

Question 11

What is a quasi-experimental study?

Answer 11

• Intervention study design
• Use two or more comparison groups that differ naturally on the variables of interest at the outset of the study (not a true experiment)
• Cannot draw cause-and-effect conclusions
• Commonly use age, gender, ethnicity, and SES variables
• Can be incidental exposure to an intervention/campaign (or not)

Question 12

What is a Pre-Test Post-Test Repeated Measures Design?

Answer 12

• Intervention study design
• Take measures of an outcome variable pre and post delivering an intervention/manipulating a variable.
• No control group and no randomisation.

Question 13

What are four possible explanations for patient improvement in intervention study?

Answer 13

1. The treatment was actually effective
2. The illness improved on its own after time; cyclical conditions (compare to control group)
3. The patient was misdiagnosed and didn’t have an illness to begin with (i.e., they didn’t belong to the population we are studying) (sufficient sample size and random assignment to groups)
4. A nonspecific effect, such as the belief the treatment will be beneficial (placebo) (placebo control group/sham treatment also double blind design)

Question 14

What are experimental studies within health psychology?

Answer 14

• Intervention study
• Randomly assign participants (or a cluster) to groups
• Usually measure all groups pre and post intervention (mixed design)
• Statistical comparisons of pre and post measures and measures between groups
• The only thing that should differ between groups is the IV – the treatment
• This may suggest that the IV causes the change in the DV (outcome)

Question 15

What are systematic reviews?

Answer 15

• Combines many research studies examining the same effect or phenomenon
• Collects no new data; includes qualitative combination of many study results
• Aids in making sense of conflicting reports
• Is replicable, so has greater validity
• Has potential bias due to which studies are selected for inclusion
• Involves quality appraisal of included studies
• Provides qualitative summaries of findings

Question 16

What is a meta-analyses?

Answer 16

• Combines many research studies examining the same effect or phenomenon
• Collects no new data; includes statistical combination of many study results
• Aids in making sense of conflicting reports
• Is replicable, so has greater validity
• Has potential bias due to which studies are selected for inclusion
• Involves quality appraisal of included studies
• Provides an overall quantitative effect size

Question 17

List the study designs in order of levels of strength of evidence. (weak to strongest)

Answer 17

• Cross-sectional correlational study: Are self-efficacy and exercise behaviour correlated at a single point in time?
• Longitudinal correlational study: Is a measure of self-efficacy today correlated with exercise behaviour over the next 2 weeks?
• Pre-test post-test repeated measures intervention studies: Take a measure of exercise behaviour before and after a self-efficacy intervention and examine whether they differ.
• Quasi-experimental intervention study: Two gyms have different posters to promote self-efficacy. Compare exercise behaviour between people at the two gyms. Not randomised.
• Experimental intervention study: Take a measure of exercise behaviour before and after a self-efficacy intervention. Take measures from a control group at the same time points. Compare all measures. Randomised into groups.
• Systematic review or meta analysis of experimental studies: Systematic search for all self-efficacy interventions for exercise. Synthesise findings and/or meta-analyse data.