Minimally important change determined by a visual method integrating an anchor-based and a distribution-based approach

Henrica C.W. De Vet, Raymond W.J.G. Ostelo, Caroline B. Terwee, Nicole Van Der Roer, Dirk L. Knol, Heleen Beckerman, Maarten Boers, Lex M. Bouter

Research output: Contribution to journalReview articleAcademicpeer-review

Abstract

Background: Minimally important changes (MIC) in scores help interpret results from health status instruments. Various distribution-based and anchor-based approaches have been proposed to assess MIC. Objectives: To describe and apply a visual method, called the anchor-based MIC distribution method, which integrates both approaches. Method: Using an anchor, patients are categorized as persons with an important improvement, an important deterioration, or without important change. For these three groups the distribution of the change scores on the health status instrument are depicted in a graph. We present two cut-off points for an MIC: the ROC cut-off point and the 95% limit cut-off point. Results: We illustrate our anchor-based MIC distribution method determining the MIC for the Pain Intensity Numerical Rating Scale in patients with low back pain, using two conceivable definitions of minimal important change on the anchor. The graph shows the distribution of the scores of the health status instrument for the relevant categories on the anchor, and also the consequences of choosing the ROC cut-off point or the 95% limit cut-off point. Discussion: The anchor-based MIC distribution method provides a general framework, applicable to all kind of anchors. This method forces researchers to choose and justify their choice of an appropriate anchor and to define minimal importance on that anchor. The MIC is not an invariable characteristic of a measurement instrument, but may depend, among other things, on the perspective from which minimal importance is considered and the baseline values on the measurement instrument under study. A balance needs to be struck between the practicality of a single MIC value and the validity of a range of MIC values.

LanguageEnglish
Pages131-142
Number of pages12
JournalQuality of Life Research
Volume16
Issue number1
DOIs
Publication statusPublished - 1 Feb 2007

Cite this

@article{f5035c6c39af44dd8811ab15bfa7e493,
title = "Minimally important change determined by a visual method integrating an anchor-based and a distribution-based approach",
abstract = "Background: Minimally important changes (MIC) in scores help interpret results from health status instruments. Various distribution-based and anchor-based approaches have been proposed to assess MIC. Objectives: To describe and apply a visual method, called the anchor-based MIC distribution method, which integrates both approaches. Method: Using an anchor, patients are categorized as persons with an important improvement, an important deterioration, or without important change. For these three groups the distribution of the change scores on the health status instrument are depicted in a graph. We present two cut-off points for an MIC: the ROC cut-off point and the 95{\%} limit cut-off point. Results: We illustrate our anchor-based MIC distribution method determining the MIC for the Pain Intensity Numerical Rating Scale in patients with low back pain, using two conceivable definitions of minimal important change on the anchor. The graph shows the distribution of the scores of the health status instrument for the relevant categories on the anchor, and also the consequences of choosing the ROC cut-off point or the 95{\%} limit cut-off point. Discussion: The anchor-based MIC distribution method provides a general framework, applicable to all kind of anchors. This method forces researchers to choose and justify their choice of an appropriate anchor and to define minimal importance on that anchor. The MIC is not an invariable characteristic of a measurement instrument, but may depend, among other things, on the perspective from which minimal importance is considered and the baseline values on the measurement instrument under study. A balance needs to be struck between the practicality of a single MIC value and the validity of a range of MIC values.",
keywords = "Health status questionnaires, Interpretation, Measurement error, Minimally important change, ROC analysis",
author = "{De Vet}, {Henrica C.W.} and Ostelo, {Raymond W.J.G.} and Terwee, {Caroline B.} and {Van Der Roer}, Nicole and Knol, {Dirk L.} and Heleen Beckerman and Maarten Boers and Bouter, {Lex M.}",
year = "2007",
month = "2",
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doi = "10.1007/s11136-006-9109-9",
language = "English",
volume = "16",
pages = "131--142",
journal = "Quality of Life Research",
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Minimally important change determined by a visual method integrating an anchor-based and a distribution-based approach. / De Vet, Henrica C.W.; Ostelo, Raymond W.J.G.; Terwee, Caroline B.; Van Der Roer, Nicole; Knol, Dirk L.; Beckerman, Heleen; Boers, Maarten; Bouter, Lex M.

In: Quality of Life Research, Vol. 16, No. 1, 01.02.2007, p. 131-142.

Research output: Contribution to journalReview articleAcademicpeer-review

TY - JOUR

T1 - Minimally important change determined by a visual method integrating an anchor-based and a distribution-based approach

AU - De Vet, Henrica C.W.

AU - Ostelo, Raymond W.J.G.

AU - Terwee, Caroline B.

AU - Van Der Roer, Nicole

AU - Knol, Dirk L.

AU - Beckerman, Heleen

AU - Boers, Maarten

AU - Bouter, Lex M.

PY - 2007/2/1

Y1 - 2007/2/1

N2 - Background: Minimally important changes (MIC) in scores help interpret results from health status instruments. Various distribution-based and anchor-based approaches have been proposed to assess MIC. Objectives: To describe and apply a visual method, called the anchor-based MIC distribution method, which integrates both approaches. Method: Using an anchor, patients are categorized as persons with an important improvement, an important deterioration, or without important change. For these three groups the distribution of the change scores on the health status instrument are depicted in a graph. We present two cut-off points for an MIC: the ROC cut-off point and the 95% limit cut-off point. Results: We illustrate our anchor-based MIC distribution method determining the MIC for the Pain Intensity Numerical Rating Scale in patients with low back pain, using two conceivable definitions of minimal important change on the anchor. The graph shows the distribution of the scores of the health status instrument for the relevant categories on the anchor, and also the consequences of choosing the ROC cut-off point or the 95% limit cut-off point. Discussion: The anchor-based MIC distribution method provides a general framework, applicable to all kind of anchors. This method forces researchers to choose and justify their choice of an appropriate anchor and to define minimal importance on that anchor. The MIC is not an invariable characteristic of a measurement instrument, but may depend, among other things, on the perspective from which minimal importance is considered and the baseline values on the measurement instrument under study. A balance needs to be struck between the practicality of a single MIC value and the validity of a range of MIC values.

AB - Background: Minimally important changes (MIC) in scores help interpret results from health status instruments. Various distribution-based and anchor-based approaches have been proposed to assess MIC. Objectives: To describe and apply a visual method, called the anchor-based MIC distribution method, which integrates both approaches. Method: Using an anchor, patients are categorized as persons with an important improvement, an important deterioration, or without important change. For these three groups the distribution of the change scores on the health status instrument are depicted in a graph. We present two cut-off points for an MIC: the ROC cut-off point and the 95% limit cut-off point. Results: We illustrate our anchor-based MIC distribution method determining the MIC for the Pain Intensity Numerical Rating Scale in patients with low back pain, using two conceivable definitions of minimal important change on the anchor. The graph shows the distribution of the scores of the health status instrument for the relevant categories on the anchor, and also the consequences of choosing the ROC cut-off point or the 95% limit cut-off point. Discussion: The anchor-based MIC distribution method provides a general framework, applicable to all kind of anchors. This method forces researchers to choose and justify their choice of an appropriate anchor and to define minimal importance on that anchor. The MIC is not an invariable characteristic of a measurement instrument, but may depend, among other things, on the perspective from which minimal importance is considered and the baseline values on the measurement instrument under study. A balance needs to be struck between the practicality of a single MIC value and the validity of a range of MIC values.

KW - Health status questionnaires

KW - Interpretation

KW - Measurement error

KW - Minimally important change

KW - ROC analysis

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U2 - 10.1007/s11136-006-9109-9

DO - 10.1007/s11136-006-9109-9

M3 - Review article

VL - 16

SP - 131

EP - 142

JO - Quality of Life Research

T2 - Quality of Life Research

JF - Quality of Life Research

SN - 0962-9343

IS - 1

ER -