Health Psychology CLP 4314 lecture notes PDF

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Prof. Sharpe - Health Psychology CLP 4314 lecture notes 5...

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Cross-sectional Determining the possible effects of age on a particular dependent variable across a range of individuals

Participants should be similar across most other variables

Longitudinal Follow a group on individuals over a long period of time (20 years)

Upsides: - control for cohort effects - allows for investigation of change over time

Downsides: - attrition - people who stay in your study may be different on a certain characteristic - expensive!

Heritability/Genetics Twin Studies: comparing identical to fraternal twins or twins separated at birth

- Linking specific genes with diseases - Epigenetic effects

Epidemiology The study of patterns, causes and effects of health and disease conditions in defined populations

Morbidity Number of cases among a group of people during a given time

Mortality Number of deaths from a specific cause in a given time (e.g., heart disease, lung cancer)

Incidence Number of new cases of a disease, infection, or disability within a defined period of time

Prevalence The total number of diagnosed cases of a disease or condition that exists at a specific time

Epidemic Situation in which incidence, generally of infectious disease, has increased rapidly

Pandemic Epidemic that has increased to international/worldwide proportions

Absolute vs Relative Risk Absolute: 200% more likely to get X disease if you do X behaviour

Relative: risk of getting disease is 0.0001, you are 0.0002 more likely to get X disease if you do X behaviour

Objectives in Epidemiological Research Pinpoint etiology of particular disease to generate hypotheses Evaluate the hypotheses Test effectiveness of specific preventive health interventions

Epidemiological Studies... Can look back in time: Retrospective - usually accomplished by review of records - can be used to compare a group of people with a disease or condition to a group without

Can look forward in time: Prospective

- follows individuals over a long period of time to determine how the relationship between two or more variables change

Randomized Clinical Trial Gold standard of biomedical research

Many variations - usually include a baseline measure, followed by one or more measures of treatment effectiveness

Most common - baseline measures; participants are randomized into a treatment condition or control group; outcome measures

Meta-Analysis Systematic review with accompanying meta-analysis Summarizes existing evidence Uses an effect size to compare results Advantages: - pooling results tends to reveal significant results because of the increased sample size - findings that hold across study populations, researchers, and environments increases the confidence in the validity of findings - replication - any researcher should be able to follow the statistical steps and reach the same conclusions

The ORBIT Model For Behavioural Intervention Development International Behavioural Trials Network (IBTN)

Changing unhealthy behaviours is the "single greatest opportunity to reduce premature deaths..."

Behavioural patterns - 40% Genetic predisposition - 30%

Social circumstances - 15% Health care - 10% Environmental exposure - 5%

Even when behaviour change is successful, maintenance of health behaviours across time is challenging - Trials of Hypertension Prevention: weight loss over 36 months in 2382 overweight pre-hypertensives - 6 months of intervention: -4 kg from baseline - 36 months, return to baseline

- Behaviour powerfully affects health - Changing behaviour can improve health outcomes - The Challenge: to develop new & more effective approaches to changing health-related behaviours

Challenges to conducting "Translation 1" research in the behavioural sciences 1) There is no standardized, widely accepted "paradigm" or framework - to describe & guide the behavioural intervention development process (as is true for drug development research) 2) There is no real consensus on the types of study designs and methods - most useful and appropriate for early-phase behavioural intervention development research 3) Lack of industry support - for health behaviour intervention development (no equivalent to the pharmaceutical industry) 4) Few NIH funding opportunities, - no training opportunities, review groups not set up to review translation 1/behavioural intervention development 5) Few incentives to create & maintain interdisciplinary teams - required to conduct translational research 6) Lack of academic recognition - for bridging basic-clinical fields of study & for developing behavioural interventions 7) High-risk nature - of translational and intervention development research

Orbit Model - phases Significant Clinical Question

> Phase 1 Design a) define b) refine

(feedback between these and Basic Behavioural and Social Sciences Research)

> Phase 2 Preliminary Testing a) proof-of-concept b) pilots

> Phase 3 Efficacy

> Phase 4 Effectiveness

*start -> phase 2 take a lot of time to perform, are very valuable if done properly

Significant Clinical Question - disease Disease: - affects many - affects a subgroup - increasing rates - increasing in subgroups - not decreasing - costly

Significant Clinical Question - current treatment Current Treatment:

- not very effective - uncertain effectiveness (equipoise) - effective but not adhered to

Significant Clinical Question - new treatment New Treatment: - shows promise - targets novel risk factors - more cost-effective than standard

Significant Clinical Question (3) Disease Current Treatment New Treatment

Basic Behavioural and Social Sciences Research (example) Mesolimbic Reward Pathway - Impulsivity (immediate gratification) - "pleasure center" - *Overrides the homeostatic energy system

Prefrontal Cortex - executive function - High-level decision-making - Planning - Self-Monitoring - Pursuing goals - Delaying gratification - Behavioural inhibition

Implications for components of weight loss intervention

1) Avoid triggering the Limbic Reward Circuit: - remove temptations from the home - stimulus control^; putting pissing obstacles in the way 2) Enhance Executive Function Inhibitory Control: - self-management skills training: planning! -> meal prep, exercise shoes near the door, etc.

Phase 1(a) Early Definition of Essential Features - behavioural risk factor target - clinically significant milestones - candidate components - hypothesized pathway

Phase 1(a) - Define the Hypothesized Pathway: 1) Multi-component Intervention - reduce triggers - mobilize executive function 2) Treatment Targets - increase environmental rearrangement - increase goal setting skills - increase planning skills 3) Behavioural Risk Factor - increase physical activity (150 min/week) 4) Clinical Endpoint - decrease weight (≥ 7%)...