Likelihood ratios - Revision history

Rossdonaldson1: Rossdonaldson1 moved page Likelihood Ratios to Likelihood ratios

2017-01-21T22:48:05Z

Rossdonaldson1 moved page Likelihood Ratios to Likelihood ratios

← Older revision	Revision as of 22:48, 21 January 2017
(No difference)

Rossdonaldson1: /* References */

2016-05-11T14:09:19Z

References

← Older revision		Revision as of 14:09, 11 May 2016
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	==References==		==References==
			<references/>

	[[Category:Misc/General]]		[[Category:Misc/General]]
	[[Category:EBQ]]		[[Category:EBQ]]

Rossdonaldson1: /* Comments */

2016-05-11T14:09:06Z

Comments

← Older revision		Revision as of 14:09, 11 May 2016
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	*Values >1 increase the probability of disease		*Values >1 increase the probability of disease

	==Comments==		==Comments<ref>J Gen Intern Med. 2002 August; 17(8): 647–650.</ref>==
	An easy way to recall at the bedside by simply remembering 3 specific LRs 2, 5, and 10—and the first 3 multiples of 15 (i.e., 15, 30, and 45). An LR of 2 increases probability 15%, one of 5 increases it 30%, and one of 10 increases it 45%. For those LRs between 0 and 1, the clinician simply inverts 2, 5, and 10 (i.e., 1/2 = 0.5, 1/5 = 0.2, 1/10 = 0.1). Just as the LR of 2.0 increases probability 15%, its inverse, 0.5, decreases probability 15%. Similarly, an LR of 0.2 (the inverse of 5) decreases probability 30%, and a LR of 0.1 (the inverse of 10) decreases it 45%. These benchmark LRs can be used to approximate the remainder of Table 1.		An easy way to recall at the bedside by simply remembering 3 specific LRs 2, 5, and 10—and the first 3 multiples of 15 (i.e., 15, 30, and 45). An LR of 2 increases probability 15%, one of 5 increases it 30%, and one of 10 increases it 45%. For those LRs between 0 and 1, the clinician simply inverts 2, 5, and 10 (i.e., 1/2 = 0.5, 1/5 = 0.2, 1/10 = 0.1). Just as the LR of 2.0 increases probability 15%, its inverse, 0.5, decreases probability 15%. Similarly, an LR of 0.2 (the inverse of 5) decreases probability 30%, and a LR of 0.1 (the inverse of 10) decreases it 45%. These benchmark LRs can be used to approximate the remainder of Table 1.

Rossdonaldson1: /* Source */

2016-05-11T14:08:46Z

Source

← Older revision		Revision as of 14:08, 11 May 2016
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	Although this method is inaccurate for pretest probabilities less than 10% or greater than 90%, this is not a disadvantage, because these polar extremes of probability indicate diagnostic certainty for most clinical problems, making it unnecessary to order further tests (and apply additional LRs).		Although this method is inaccurate for pretest probabilities less than 10% or greater than 90%, this is not a disadvantage, because these polar extremes of probability indicate diagnostic certainty for most clinical problems, making it unnecessary to order further tests (and apply additional LRs).

	==~~Source~~==		==References==
	~~J Gen Intern Med. 2002 August; 17(8): 647–650.~~

	[[Category:Misc/General]]		[[Category:Misc/General]]
	[[Category:EBQ]]		[[Category:EBQ]]

Rossdonaldson1: /* Likelihood Ratio Approximate Change in Probability (%) */

2016-05-11T14:08:25Z

Likelihood Ratio Approximate Change in Probability (%)

← Older revision		Revision as of 14:08, 11 May 2016
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	*Values >1 increase the probability of disease		*Values >1 increase the probability of disease

			==Comments==
	An easy way to recall at the bedside by simply remembering 3 specific LRs 2, 5, and 10—and the first 3 multiples of 15 (i.e., 15, 30, and 45). An LR of 2 increases probability 15%, one of 5 increases it 30%, and one of 10 increases it 45%. For those LRs between 0 and 1, the clinician simply inverts 2, 5, and 10 (i.e., 1/2 = 0.5, 1/5 = 0.2, 1/10 = 0.1). Just as the LR of 2.0 increases probability 15%, its inverse, 0.5, decreases probability 15%. Similarly, an LR of 0.2 (the inverse of 5) decreases probability 30%, and a LR of 0.1 (the inverse of 10) decreases it 45%. These benchmark LRs can be used to approximate the remainder of Table 1.		An easy way to recall at the bedside by simply remembering 3 specific LRs 2, 5, and 10—and the first 3 multiples of 15 (i.e., 15, 30, and 45). An LR of 2 increases probability 15%, one of 5 increases it 30%, and one of 10 increases it 45%. For those LRs between 0 and 1, the clinician simply inverts 2, 5, and 10 (i.e., 1/2 = 0.5, 1/5 = 0.2, 1/10 = 0.1). Just as the LR of 2.0 increases probability 15%, its inverse, 0.5, decreases probability 15%. Similarly, an LR of 0.2 (the inverse of 5) decreases probability 30%, and a LR of 0.1 (the inverse of 10) decreases it 45%. These benchmark LRs can be used to approximate the remainder of Table 1.

Rossdonaldson1: /* Likelihood Ratio Approximate Change in Probability (%) */

2016-05-11T14:08:12Z

Likelihood Ratio Approximate Change in Probability (%)

← Older revision		Revision as of 14:08, 11 May 2016
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	\| 2\|\|15%		\| 2\|\|15%
	\|-		\|-
	\| 1\|\|0%		\| '''1'''\|\|'''0%'''
	\|-		\|-
	\| 0.5\|\|-15%		\| 0.5\|\|-15%

Rossdonaldson1: /* Likelihood Ratio Approximate Change in Probability (%) */

2016-05-11T14:07:48Z

Likelihood Ratio Approximate Change in Probability (%)

← Older revision		Revision as of 14:07, 11 May 2016
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	==Likelihood Ratio Approximate Change in Probability (%)==		==Likelihood Ratio Approximate Change in Probability (%)==

	~~Values between 0 and 1 decrease the probability of disease~~		{\| {{table}}
	*0.1 −45%		\| align="center" style="background:#f0f0f0;"\|'''LR'''
	*0.2 −30%		\| align="center" style="background:#f0f0f0;"\|'''Post-Test Probablility Change'''
	*0.3 −25%		\|-
	*0.4 ~~−20~~%		\| 9-10\|\|45%
	*0.5 −15%		\|-
	*1 - 0%		\| 7-8\|\|40%
			\|-
	~~Values greater than~~ 1 ~~increase the probability of disease~~		\| 6\|\|35%
	*2 +15%		\|-
	*3 +20%		\| 5\|\|30%
	*4 +25%		\|-
	*5 +30%		\| 4\|\|25%
	*6 +35%		\|-
	*~~7 8 +40%~~		\| 3\|\|20%
	*~~9 10 +45%~~		\|-
			\| 2\|\|15%
			\|-
			\| 1\|\|0%
			\|-
			\| 0.5\|\|-15%
			\|-
			\| 0.4\|\|-20%
			\|-
			\| 0.3\|\|-25%
			\|-
			\| 0.2\|\|-30%
			\|-
			\| 0.1\|\|-45%
			\|}
			*Values <1 decrease the probability of disease
			*Values >1 increase the probability of disease


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	Although this method is inaccurate for pretest probabilities less than 10% or greater than 90%, this is not a disadvantage, because these polar extremes of probability indicate diagnostic certainty for most clinical problems, making it unnecessary to order further tests (and apply additional LRs).		Although this method is inaccurate for pretest probabilities less than 10% or greater than 90%, this is not a disadvantage, because these polar extremes of probability indicate diagnostic certainty for most clinical problems, making it unnecessary to order further tests (and apply additional LRs).

	~~<br>~~

	==Source==		==Source==

Rossdonaldson1: moved Likelyhood Ratios to Likelihood Ratios

2013-08-22T17:36:56Z

moved Likelyhood Ratios to Likelihood Ratios

← Older revision	Revision as of 17:36, 22 August 2013
(No difference)

Rossdonaldson1 at 01:29, 19 August 2013

2013-08-19T01:29:58Z

← Older revision		Revision as of 01:29, 19 August 2013
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	[[Category:Misc/General]]		[[Category:Misc/General]]
			[[Category:EBQ]]

Rossdonaldson1: /* Source */

2012-11-21T21:37:09Z

Source

← Older revision		Revision as of 21:37, 21 November 2012
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	==Source==		==Source==
	J Gen Intern Med. 2002 August; 17(8): 647–650.		J Gen Intern Med. 2002 August; 17(8): 647–650.

			[[Category:Misc/General]]