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Flashcards in Stats Deck (81)
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1

Bias

Any factor that moves the findings of a study away from the truth

2

Binary data

Data where there are only two possible values such as survived/died; also known as dichotomous data

3

Blinding in a randomized controlled trial

When the treatment allocation is concealed from either the subject or the assessor or both

4

Case-control studies

Observational study that starts with cases with a disease and compares them with controls without the disease to investigate possible risk factors

5

Chi-squared goodness of fit test

A statistical test used to investigate whether a frequency distribution follows a specific theoretical distribution

6

Chi-squared test

A statistical test used to investigate the association between two categorical variables

7

Cluster Analysis

A statistical method used to identify groups or clusters of individuals who have common features in terms of known variables

8

Cluster randomization

When groups of individuals are allocated to treatments so that all subjects in a group receive the same treatment

9

Cohort study

Observational study that starts with a sample of individuals who are disease-free and measures possible causal factors at baseline and over time. The cohort of subjects is followed and their disease status is observed to investigate which factors are linked to the disease

10

Confidence interval (CI)

A range of values that indicates the precision of an estimate; for a 95% CI we can be 95% confident that the interval contains the true value

11

Continuous data

Data that lie on a continuum and so can take any value between two limits

12

Cox proportional hazards regression

A multifactorial regression model used with a time-to-event outcome

13

Crossover trial

A single group study where each patient receives each of two or more treatments in turn so that they act as their own control

14

Degrees of freedom (DF or df)

A quantity used in statistical testing and modelling that is related to the size of the sample and the number of parameters that have been estimated

15

Dummy variables

Used in regression modelling to enable a categorical predictor variable to be included, by converting a variable with n categories into n–1 binary variables, where one category is the reference category

16

Equivalence trial

A trial that aims to see if a new treatment is no better or worse than an existing one

17

Fisher’s exact test

A statistical test that can be used to investigate the association between two categorical variables when the sample is small

18

Forest plot

A graph used to display individual study estimates and confidence intervals, and the pooled estimate and confidence interval in a meta-analysis

19

Gold standard test

A diagnostic test that is regarded as definitive, i.e. it gives the correct answer

20

Funnel plot

A simple graphical method for exploring the results from studies to see if publication bias might be present

21

Hazard ratio

Hazard ratio In survival analysis, the ratio of hazards or risks of outcome in two groups

22

Heterogeneity

Where there is statistical variability between estimates such as may be found in a meta-analysis

23

Incidence

The number of new cases of a given condition occurring within a specific time period

24

Indirect standardization

Gives the standardized mortality ratio (SMR), which is the ratio of the observed number of deaths in the comparison population and the number expected if that population had the same age-specific death rates as the standard population

25

Intention to treat analysis

Statistical analysis where patients are analysed in the treatment group to which they were originally randomly allocated even if they did not actually receive that treatment

26

Logistic regression

A multifactorial regression model used with a binary outcome

27

Logrank test

A statistical test used to compare time-to-event data in two or more groups

28

Meta-analysis

A statistical analysis which combines the results of several independent studies examining the same question

29

Multifactorial methods

Statistical models fitted to datasets with one outcome variable and several predictor variables; used to disentangle effects

30

Multiple regression

A multifactorial regression model used with a continuous outcome