Models in nutrition/study design Flashcards
What is in vivo?
Within the living, whole animal
What is ex vivo?
Outside the living. Could be perfused organs, tissue segments..
What is in vitro?
In glass, isolated cells or cell components
What is in situ?
Situated in the original place, natural tissue within an organism
What does intention-to-treat approach mean?
All participants randomized in a trial, regardless of whether they completed it, are included in the analysis
What are typical kinds of observational studies?
- Cohort study
- Longitudinal study
- Case-control
- Cross-sectional
What kind of study lets you determine between correlation or causality?
Intervention studies
What are the characteristics of an observational study?
That the study only observe the participants without intefering
What are the characteristics of an intervention study?
That the participants follows guidelines and the study have intervened
Describe a cohort study
A cohort study is large, longitudinal, observational study, where a lot of data is obtained and later you study correlations.
Eksempel: sundhed i generationer, hvor mange mennesker giver data på mange parametre. Dette kan senere bruges til at se sammenhænge i f.eks. sygdomme og livstil.
Describe a case-control study
A study where people are not randomised, but grouped according to what you are studying, without interfering.
Eksempel: Studie om lungekræft. Man undersøger rygere, og bruger ikke-rygere som kontrol. Man ændre ikke nogens vaner, men observere, hvad de gør
Describe a cross-sectional study
A study where people are observed, with no specific characteristic. Descriptive study, no interfering.
Eksempel: Kunne være man kigge på en population og ville beregne gennemsnitshøjde eller mængden af vitamin i kroppen.
Describe a randomised controlled trial
An intervention study, where the participants are randomly put in the treatment or no treatment categories. There have to be control group without treatment
Describe a blinded and double blinded study
Blinded: The subjects involved in the study do not know which study treatment they receive
Double blinded: The subjects involved in the study do not know which study treatment they receive AND researchers also do not know which treatment is being given to any given sub
What is the difference between a randomised controlled study and a randomised placebo-controlled study?
A placebo control study is specifically designed to test if the non-treatment group have an effect. The placebo group will think they get a treatment, which might effect the results, compared to the no-treatment group who know there will be no effect