Lecture 5: Disease in non-Western countries Flashcards
Double burden of disease
more non-communicable/chronic disease in high income countries, but still a lot of communicable diseases in low-income countries
Double burden of malnutrition
coexistence of undernutrition together with diet-related non-communicable diseases like overweight and obesity
SDI
socio-demographic index
Selection bias
bias resulting from selection of people into or out of the study
Ascertainment of detection bias
if an individual’s chance of being diagnosed is related to whether they have been exposed to the factor of interest
The healthy-worker effect
people who are working have to be healthy enough to do their jobs
Information bias
biased exposure or outcome relation resulting from errors in exposure and/or outcome
Confounding
effect of an extraneous factor is mistaken for/mixed with the actual exposure effect
3 criteria:
- Confounder is a risk factor
- Confounder is associated with exposure of interest
- Confounder is not an intermediate between exposure and outcome
Randomisation
allocate people to study groups at random
Restriction
restricting a study to a particular age or socioeconomic group
Matching
match subjects on the presence or absence of the confounding variable
Effect measure modification
association differs across levels of a third factor
Individual matching
same distribution in case and control group
Frequency matching
for each ‘smoking’ case, use a ‘smoking’ control
Prevalence ratio
prevalence in exposed / prevalence in unexposed
IRR
incidence rate ratio; incidence rate in exposed / incidence rate in unexposed
IPR
incidence proportion ratio; incidence proportion in exposed / incidence proportion in unexposed
Odds ratio
relative risk
Attributable risk
measures the actual amount of disease that can be attributed to a particular exposure; incidence rate exposed - incidence rate unexposed. Or: incidence proportion exposed - incidence proportion unexposed
AF
attributable fraction; attributable risk / incidence in exposed * 100%
PAR
population attributable risk; incidence rate population - incidence rate unexposed. Or: incidence proportion population - incidence proportion unexposed. Or: attributable risk * prevalence
PAF
population attributable fraction; PAR / incidence in total population * 100%
NNT
number needed to treat; 1 / AR
ARR
absolute risk reduction; same as attributable risk
