Limits...
Principles for high-quality, high-value testing.

Power M, Fell G, Wright M - Evid Based Med (2012)

Bottom Line: A survey of doctors working in two large NHS hospitals identified over 120 laboratory tests, imaging investigations and investigational procedures that they considered not to be overused.A common suggestion in this survey was that more training was required.The core principles are: (1) Base testing practices on the best available evidence. (2) Apply the evidence on test performance with careful judgement. (3) Test efficiently. (4) Consider the value (and affordability) of a test before requesting it. (5) Be aware of the downsides and drivers of overdiagnosis. (6) Confront uncertainties. (7) Be patient-centred in your approach. (8) Consider ethical issues. (9) Be aware of normal cognitive limitations and biases when testing. (10) Follow the 'knowledge journey' when teaching and learning these core principles.

View Article: PubMed Central - PubMed

Affiliation: Pharmacy Department, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK. Michael.Power@NUTH.NHS.UK

ABSTRACT
A survey of doctors working in two large NHS hospitals identified over 120 laboratory tests, imaging investigations and investigational procedures that they considered not to be overused. A common suggestion in this survey was that more training was required. And, this prompted the development of a list of core principles for high-quality, high-value testing. The list can be used as a framework for training and as a reference source. The core principles are: (1) Base testing practices on the best available evidence. (2) Apply the evidence on test performance with careful judgement. (3) Test efficiently. (4) Consider the value (and affordability) of a test before requesting it. (5) Be aware of the downsides and drivers of overdiagnosis. (6) Confront uncertainties. (7) Be patient-centred in your approach. (8) Consider ethical issues. (9) Be aware of normal cognitive limitations and biases when testing. (10) Follow the 'knowledge journey' when teaching and learning these core principles.

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Related in: MedlinePlus

SnOut—rule of thumb for using a test with high sensitivity and low specificity. For example genetic typing for coeliac disease has 99% sensitivity and 54% specificity, and positive and negative likelihood ratios 2.2 and 0.02.7 The horizontal line shows the threshold for action. Upward-sloping lines point to positive predictive values. Downward-sloping lines point to negative predictive values. The angles of the prediction lines reflect the likelihood ratios. Thick prediction lines show results that change management. Thin prediction lines show results that will not change management. The steep downward and gentle upward slopes of the prediction lines reflect the combination of high sensitivity and low specificity. This figure is only reproduced in colour in the online version.
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EBMED2012100645F5: SnOut—rule of thumb for using a test with high sensitivity and low specificity. For example genetic typing for coeliac disease has 99% sensitivity and 54% specificity, and positive and negative likelihood ratios 2.2 and 0.02.7 The horizontal line shows the threshold for action. Upward-sloping lines point to positive predictive values. Downward-sloping lines point to negative predictive values. The angles of the prediction lines reflect the likelihood ratios. Thick prediction lines show results that change management. Thin prediction lines show results that will not change management. The steep downward and gentle upward slopes of the prediction lines reflect the combination of high sensitivity and low specificity. This figure is only reproduced in colour in the online version.

Mentions: Figure 3 is representative of tests with moderately high sensitivity and specificity, and is the appropriate model to use when test performance is unknown but thought to be acceptable. Figure 4 illustrates how tests with high specificity and low sensitivity are useful in ruling diagnoses in—SPin. If the prevalence of the condition is very low (as it is with screening), a test has to be very highly specific to reduce the number of false-positive results to an acceptable level. Figure 5 illustrates that the more sensitive a test, the better it is at ruling out a diagnosis—SNout. Figure 6 illustrates how post-test probability changes with a series of tests (including items from the history and examination). The logarithmic axis enables the graph to show the discriminatory power of the tests at the ends of the spectrum.


Principles for high-quality, high-value testing.

Power M, Fell G, Wright M - Evid Based Med (2012)

SnOut—rule of thumb for using a test with high sensitivity and low specificity. For example genetic typing for coeliac disease has 99% sensitivity and 54% specificity, and positive and negative likelihood ratios 2.2 and 0.02.7 The horizontal line shows the threshold for action. Upward-sloping lines point to positive predictive values. Downward-sloping lines point to negative predictive values. The angles of the prediction lines reflect the likelihood ratios. Thick prediction lines show results that change management. Thin prediction lines show results that will not change management. The steep downward and gentle upward slopes of the prediction lines reflect the combination of high sensitivity and low specificity. This figure is only reproduced in colour in the online version.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3585491&req=5

EBMED2012100645F5: SnOut—rule of thumb for using a test with high sensitivity and low specificity. For example genetic typing for coeliac disease has 99% sensitivity and 54% specificity, and positive and negative likelihood ratios 2.2 and 0.02.7 The horizontal line shows the threshold for action. Upward-sloping lines point to positive predictive values. Downward-sloping lines point to negative predictive values. The angles of the prediction lines reflect the likelihood ratios. Thick prediction lines show results that change management. Thin prediction lines show results that will not change management. The steep downward and gentle upward slopes of the prediction lines reflect the combination of high sensitivity and low specificity. This figure is only reproduced in colour in the online version.
Mentions: Figure 3 is representative of tests with moderately high sensitivity and specificity, and is the appropriate model to use when test performance is unknown but thought to be acceptable. Figure 4 illustrates how tests with high specificity and low sensitivity are useful in ruling diagnoses in—SPin. If the prevalence of the condition is very low (as it is with screening), a test has to be very highly specific to reduce the number of false-positive results to an acceptable level. Figure 5 illustrates that the more sensitive a test, the better it is at ruling out a diagnosis—SNout. Figure 6 illustrates how post-test probability changes with a series of tests (including items from the history and examination). The logarithmic axis enables the graph to show the discriminatory power of the tests at the ends of the spectrum.

Bottom Line: A survey of doctors working in two large NHS hospitals identified over 120 laboratory tests, imaging investigations and investigational procedures that they considered not to be overused.A common suggestion in this survey was that more training was required.The core principles are: (1) Base testing practices on the best available evidence. (2) Apply the evidence on test performance with careful judgement. (3) Test efficiently. (4) Consider the value (and affordability) of a test before requesting it. (5) Be aware of the downsides and drivers of overdiagnosis. (6) Confront uncertainties. (7) Be patient-centred in your approach. (8) Consider ethical issues. (9) Be aware of normal cognitive limitations and biases when testing. (10) Follow the 'knowledge journey' when teaching and learning these core principles.

View Article: PubMed Central - PubMed

Affiliation: Pharmacy Department, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK. Michael.Power@NUTH.NHS.UK

ABSTRACT
A survey of doctors working in two large NHS hospitals identified over 120 laboratory tests, imaging investigations and investigational procedures that they considered not to be overused. A common suggestion in this survey was that more training was required. And, this prompted the development of a list of core principles for high-quality, high-value testing. The list can be used as a framework for training and as a reference source. The core principles are: (1) Base testing practices on the best available evidence. (2) Apply the evidence on test performance with careful judgement. (3) Test efficiently. (4) Consider the value (and affordability) of a test before requesting it. (5) Be aware of the downsides and drivers of overdiagnosis. (6) Confront uncertainties. (7) Be patient-centred in your approach. (8) Consider ethical issues. (9) Be aware of normal cognitive limitations and biases when testing. (10) Follow the 'knowledge journey' when teaching and learning these core principles.

Show MeSH
Related in: MedlinePlus