Study designs in epidemiology

  • Created by: Sophie
  • Created on: 24-10-18 12:57
View mindmap
  • Research studies used in cancer epidemiology
    • Cohort study
      • a cohort is a group of people that share a common experience
      • follows a cohort of people over a period of time to see how exposure influences the outcome
      • all of the people that are recruited at the start of the study don't have the disease of interest
      • the group is split into a group of exposure or non-exposure and then are monitored over a period of time to see who develops the outcome of interest
      • it is one of the most common forms of study that is chosen in cancer epidemiology
      • take place over a long period of time so there can be loss to follow up - non participation bias
    • Case - Control study
      • cases are selected from  a group of individuals that have the disease of interest
      • a group of suitable controls are then selected to compare the cases to
        • looks at the  relationships between outcome and exposure
          • cases are selected from  a group of individuals that have the disease of interest
      • controls can only be selected if they would have been included in the study if they had had the disease
      • it is one of the most common forms of study that is chosen in cancer epidemiology
      • it is retrospective so it is worked back to find out the exposure that had caused the disease
        • but cases can be added prospectively, as new cases are diagnosed they are added into the cases group
      • directionality can be determined as you know that the exposure must have happened before the disease
      • timing can be determined
      • matching can be used to control for confounding variables
    • environmentalstudy
      • observational study that looks at population data rather than individual data
      • used when there is no individual data available or there is too little for the data to remain anonymous as individual data
      • care needs to be taken when applying group findings to an individual as ecological fallacy can be introduced
      • can be used to make large  scale comparisons between countries
      • longitudinal study will follow a population over a period of time and assess the changes
      • there may be unknown confounding factors that may display the same pattern of disease
      • ecological fallacy is only seen in ecological studies and occurs when relationships found for groups are assumed to be true for individuals
    • Cross sectional study
      • observational studies that look at the prevalence of  disease at one point in time
        • provides a indication of the risk factors and associated outcomes at that time
      • there is no loss to follow  as it is only looked at at one point in time
      • used when the purpose of the study is descriptive
      • there is usually no prior hypothesis for this type of study but can be used to generate hypothesis
      • helps with public health interventions
      • can't infer causal associations
        • no indication of the sequence of events
      • some people may be more likely to respond than  others so might be biased responses

Comments

No comments have yet been made

Similar Other resources:

See all Other resources »See all Epidemiology resources »