Research Design (wk2) Flashcards
Why is research design important?
-To provide a framework of methods and techniques
-Enables research to be conducted in a structured way
-Research design tells us ‘how’ a study is conducted
Descriptive and experimental research
-Descriptive -> What is going on?
-Experimental (analytical) -> Why is it going on?
Observational v Experimental designs
-Observational
-There is no intervention
-Provides information on ‘associations’ between an ‘exposure’ and an ‘event’ or ‘characteristics’ of the population
Observational v Experimental studies
-Experimental
-Involves an intervention (if the measurement is effected by the intervention put in place)
-Allows for the determination of cause and effect (if the study is designed appropriately)
Cross-sectional v Longitudinal designs
Cross-sectional;
-Assesses a phenomenon at one point in time
-Measures different samples/populations
-Provides a snapshot of a given point in time
-Examines trends and changes at a societal/national/international level
-Example: Health survey for England
Longitudinal;
-Assesses a phenomenon at several points in time
-Measures the same sample/pop over time
-Provides information on change at the individual level
-Provides insight into cause-effect relationships
-Example: Lothian birth cohort study
Common study designs - Cross-sectional design (single group)
-One sample of ppt’s recruited from target population
-Information is collected from these people once
-Type of research Q -> What are the associations between energy/nutrient intakes and frailty in older migrant women in the UK
-Can provide a quick look at correlations that may exist at a particular point
Common study designs - Cross-sectional design (multiple groups)
-Different groups of defined ppt’s are recruited
-Information is collected from these people once
-Type of research Q -> Are athletes different from non-athletes?
Common study designs - Retrospective data
-Backward looking -> examine data that already exists
-Tries to identify factors that predict whether something will happen e.g. disease, sports performance
-Type of research Q -> Does meeting the UK physical activity recommendations over a lifetime have a protective effect against falling in older people
-This design is the strongest among the observational studies
-Can suggest associations between an exposure and a health outcome
Common study designs - Prospective design
-Forward looking -> collects new data, then sometimes, watch/wait
-Waits for outcomes e.g. development of disease, or sporting performance and relates this to suspected influencing factors
-Type of research Q -> What is the relationship between premature mortality and red meat consumption
-This design is the strongest among the observational studies
Common study designs - Case control study
-Usually retrospective (but not exclusively)
-‘Cases’ have the outcome e.g. heart disease
-‘Controls’ do not have the outcome
-Type of research Q ->What is the association between allotment gardening and mental well-being
-Can assess whether exposure is disproportionately distributed between the cases and controls
Common study designs - Randomised controlled trial
-Forward looking -> prospective
-Can identify a cause and effect relationship
-Participants are randomized into a ‘control’ or ‘intervention’ group
-Follows groups over time to determine a difference in outcomes
-Type of research Q -> What is the effect of exercise on cognitive impairment in older adults with mild to moderate dementia
Common study designs - Quasi-experimental design
-An intervention study that does not -> randomise ppt’s and/or have a control group
-Not as robust as a randomised trial
-Example -> Testing the impact of physical activity intervention on risk for type 2 diabetes in South Asian adults
-Only one group
-Without a control group we cannot say with confidence that the intervention is/is not effective (it could be due to time/season)
-It draws statistical conclusions from quantitative data
Feasibility and pilot studies
Feasibility:
-Research done before a main study to determine whether the methods are feasible and acceptable
-Can this study be done? Can we recruit patients?
Pilot studies:
-A small-scale study conducted prior to a large-scale experiment to test and refine procedures
-Does initial data suggest our method/intervention could work
-Both are used to inform the design and implementation of large, definitive randomized controlled trials
Draw diagram of how a theory is derived using study designs
-The continuum of increasing evidence
