Published 8 July 2009, doi:10.1136/bmj.b2702
Cite this as: BMJ 2009;339:b2702

Endgames

Statistical question

Choosing a statistic

John Fletcher, clinical epidemiologist

1 BMJ, BMA House, Tavistock Square, London WC1H 9JR

jfletcher@bmj.com

The first 150 words of the full text of this article appear below.

Which statistical test is best for each outcome measure?

a) Comparing improvement in pain scores over 4 weeks using a visual analogue scale in a trial of 100 people with back pain.
b) Comparing the effect of two drugs on time to reduce fever below 38ºC in two groups of 100 febrile infants.
c) Comparing for 100 countries the number of doctors trained per million population with the infant mortality rate of that country.
d) Comparing death rates at 30 days after discharge from hospital of 100 patients having hip surgery and 100 patients having eye surgery.

e) Chi square test ({chi}2)
f) Fisher’s test of exact probability
g) Cox regression
h) Correlation coefficient (r)
i) Student’s t test

a) i: Student’s t test
b) g: Cox regression
c) h: Correlation coefficient
d) f: Fisher’s test of exact probability

A visual analogue scale . . . [Full text of this article]


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to StumbleUpon StumbleUpon   Add to Technorati Technorati    What's this?

Access jobs at BMJ Careers
Whats new online at Student BMJ