NUTR UNIT 1 Case Studies

• Observational

  An observational study is when the researcher observes the effect of a specific variable as it occurs naturally, without making any attempt to intervene. Cannot claim cause and effect.

  • Cohort studies
  • Case control
  • Cross sectional
• Cohort Study

  (type of observational study)

  Observes a group of individuals overtime

  1. Retrospective/Historical: Looking backwards, you already have the data, so data is collected from records. LOOKING AT OLDER
  2. Prospective: Looking into the future. Follow individuals and see who develops the disease and who does not. Seek data as the study goes on. PROSPER=FUTURE
• Case Control 


  Individuals that have the condition (case) compared to those who don't (control). A strong study will compare groups that are similar in multiple factors. Exposed and unexposed group.

  CANNOT CLAIM CAUSE/EFFECT
• Causation


  One variable changes another.
• Randomized Controlled Trials


  Gives more definitive testing of a hypothesis. Experimental group receives intervention while control group receives placebo. Can directly modify independent variable.

  • Single Blind: Participant does not know who is receiving placebo or treatment.
• To help reduce bias

  1. Neither study participants nor researchers know who is in control/experimental group.
  2. Expected outcomes of protocol are not discussed reducing the chance of placebo effect.
• Systematic Reviews-Meta Analyses


  Helps determine which clinical methods are likely to help patients.

  Come from trusted sources/organizations.

  STRONGEST EVIDENCE