Revision Q Flashcards
because of the epidemiological transition, the burden of infectious disease in developing countries is set to worsen
False
infectious diseases are the leading cause of death in Sub-Saharan Africa
True
chicken pox is one of the six most common causes of death from infectious disease worldwide
False
Malaria is one of the six most common causes of death from infectious disease worldwide
True
the best indicator of the burden of an infectious disease is the number of deaths
False
If an exposure and disease are statistically associated this means that the exposure causes the disease
False
evidence-based medicine has replaced clinical decision making over the last 30 years
False
systematic reviews and meta-analyses are at the top of the hierarchy of evidence
True
in the hierarchy of evidence, case-control studies provide stronger evidence than that from cohort studies
False
What is the hierarchy of studies
Systematic review and meta analyses RCT Cohort study Case control study Ecological study descriptive/cross sectional study case report/series
Definition of bias
A systematic error in design, conduct or analysis of a study which produces a mistaken estimate of an exposure on the risk of disease
What are the critical features of a clinical trial?
Objectives Patient selection Controls Study size Unbiased data collection Specific design Ethics Analysis
What are the advantages to randomisation?
Validates statistics
excludes biased allocation
equally distributes prognostic factors of known and unknown
Why use controls?
Placebo effect regression to the mean acclimatisation seasonal effect basis of study question
What is a regression to the mean?
Any intervention at bad times will be followed by an improvement
Bias in RCTs
Sponsorship study patient allocation/selection prejudice of patient prejudice of observer faulty method faulty analysis faulty interpretation
The 95% confidence intervals provide information that helps us determine whether a statistical association between an exposure and disease (expressed as a relative risk or odds ratio) could have occurred by chance
True
if increasing levels of an exposure lead to increasing risk of disease i.e. a dose-response relationship is found, this provides further evidence of causality
True
The association being assessed is less likely to be causal if it is consistent with evidence from animal experiments and known biological mechanisms
False
A lack of consistency between results from a number of studies using different study designs in different populations excludes a causal association
False
A strong association, as measured by the magnitude of the relative risk, is more likely to be causal than a weak association
True
for a putative risk factor to be the cause of a disease, it has to precede the disease
True
there is a systematic difference between the observed association between exposure and disease and the true association between exposure and disease
True
The presence of bias in an observational study of the effect of an exposure on disease risk implies: there are missing values in the response (disease outcome) measurements
False
The presence of bias in an observational study of the effect of an exposure on disease risk implies: there is a systematic difference between the observed association between exposure and disease and the hypothesized association between exposure and disease
False
The presence of bias in an observational study of the effect of an exposure on disease risk implies: the estimated relative risk of disease associated with the exposure is inaccurate
True
The presence of bias in an observational study of the effect of an exposure on disease risk implies: there are missing values in the exposure measurements
False
a study to assess the effect of regular exercise on the risk of coronary heart disease, by collecting information on exercise via a questionnaire as part of a health and lifestyle survey
Experimental?
False. Observational