Introduction to EBM and critical appraisal Flashcards Preview

Block 1 - Evidence-based medicine > Introduction to EBM and critical appraisal > Flashcards

Flashcards in Introduction to EBM and critical appraisal Deck (16)
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1
Q

Primary sources of clinical evidence

A
  • peer reviewed journals
  • magazines
  • newspapers
2
Q

Secondary sources of clinical evidence

A
  • NHS evidence
  • medicines and prescribing from NICE
  • guidance from major bodies eg. CKS, SIGN
  • published systematic reviews eg Cochrane Library
  • MTRAC
3
Q

Types of studies

A
  • Observational (no intervention)
  • cross sectional (survey at one point in time)
  • cohort and case control studies

-Experimental (with intervention)

  • Controlled trial (parallel, cross over, clusters) RCT, blinding (open single, double blind)
  • Systematic review
4
Q

PICO

A

Population
intervention
comparator/control
outcomes

5
Q

p <0.05 =

A

statistically significant

6
Q

power

A

the ability of the study to detect an effect if in truth there is an effect

7
Q

An RCT may be underpowered if:

A
  • the duration is too short
  • it included too few people
  • the wrong outcome was used
  • expecting a higher level of statistical proof than is realistic for the condition and the intervention being tested
8
Q

confidence intervals, CI

A
  • the range within which the true value of a population mean lies with a given degree of certainty usually 95%
9
Q

RRR

A

the RRR stays constant in different populations

10
Q

ARR

A

the ARR alters in different populations - it will be much more impressive if the population has a lot of events

11
Q

relative risk =

A

EER/CER

12
Q

CER =

A

control event rate, number of events in the control group/total participants in control group [b/ b+d]

13
Q

EER=

A

experimental event rate, number of events in the experimental or intervention group/total participants in experimental or intervention group [a/a+c]

14
Q

Absolute risk difference =

A

EER - CER

15
Q

relative risk difference =

A

(CER - EER)/ CER

16
Q

NNT =

A

1/ARR or 100/ARR