Influence of random measurement error on estimated rates of headache chronification and remission

Timothy T. Houle, Dana P. Turner, Todd A. Smitherman, Donald B. Penzien, Richard B. Lipton

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Objective.- To examine the potential influence of random measurement error on estimated rates of chronification and remission. Background.- Studies of headache chronification and remission examine the proportion of headache sufferers that move across a boundary of 15 headache days per month between 2 points in time. At least part of that apparent movement may represent measurement error or random variation in headache activity over time. Methods.- A mathematical simulation was conducted to examine the influence of varying degrees of measurement error on rates of chronic migraine onset and remission. Using data from the American Migraine Prevalence and Prevention Study, we estimated a starting distribution of headache days from 0 to 30 in the migraine population. Assuming various levels of measurement error, we then simulated 2 sets of data for Time 1 and Time 2. The "individuals" in this study were assumed to have no real change in headache frequency from Time 1 to Time 2. The observed variations in headache frequency were those influenced by imputed random variance to resemble typical measurement error or natural variability. Using this simulation approach, we estimated the amount of chronification and remission rates that might be attributed simply to statistical artifacts such as unreliability or regression to the mean. Results.- As the degree of measurement error increased, the amounts of illusory chronification and remission increased substantially. For example, if the headache frequency of sufferers randomly varies by only 2 headache days each month due to chance alone, a substantial degree of illusory chronification (0.6% to 1.3%) and illusory remission (10.3% to 23.5%) rates are expected simply due to random variation. Conclusions.- Random variation, without real change, has the potential to influence estimated rates of progression and remission in longitudinal migraine studies. The magnitude of random variation needed to fully reproduce observed rates of progression and remission are implausibly large. Recommendations are offered to improve estimation of rates of progression and remission, reducing the influence of random variation.

Original languageEnglish (US)
Pages (from-to)920-929
Number of pages10
JournalHeadache
Volume53
Issue number6
DOIs
StatePublished - 2013

Fingerprint

Headache
Migraine Disorders
Artifacts
Longitudinal Studies
Cross-Sectional Studies
Population

Keywords

  • headache chronification
  • headache frequency
  • methodology
  • statistics

ASJC Scopus subject areas

  • Clinical Neurology
  • Neurology

Cite this

Influence of random measurement error on estimated rates of headache chronification and remission. / Houle, Timothy T.; Turner, Dana P.; Smitherman, Todd A.; Penzien, Donald B.; Lipton, Richard B.

In: Headache, Vol. 53, No. 6, 2013, p. 920-929.

Research output: Contribution to journalArticle

Houle, Timothy T. ; Turner, Dana P. ; Smitherman, Todd A. ; Penzien, Donald B. ; Lipton, Richard B. / Influence of random measurement error on estimated rates of headache chronification and remission. In: Headache. 2013 ; Vol. 53, No. 6. pp. 920-929.
@article{2443150b6e36450aa2529f6f38674e34,
title = "Influence of random measurement error on estimated rates of headache chronification and remission",
abstract = "Objective.- To examine the potential influence of random measurement error on estimated rates of chronification and remission. Background.- Studies of headache chronification and remission examine the proportion of headache sufferers that move across a boundary of 15 headache days per month between 2 points in time. At least part of that apparent movement may represent measurement error or random variation in headache activity over time. Methods.- A mathematical simulation was conducted to examine the influence of varying degrees of measurement error on rates of chronic migraine onset and remission. Using data from the American Migraine Prevalence and Prevention Study, we estimated a starting distribution of headache days from 0 to 30 in the migraine population. Assuming various levels of measurement error, we then simulated 2 sets of data for Time 1 and Time 2. The {"}individuals{"} in this study were assumed to have no real change in headache frequency from Time 1 to Time 2. The observed variations in headache frequency were those influenced by imputed random variance to resemble typical measurement error or natural variability. Using this simulation approach, we estimated the amount of chronification and remission rates that might be attributed simply to statistical artifacts such as unreliability or regression to the mean. Results.- As the degree of measurement error increased, the amounts of illusory chronification and remission increased substantially. For example, if the headache frequency of sufferers randomly varies by only 2 headache days each month due to chance alone, a substantial degree of illusory chronification (0.6{\%} to 1.3{\%}) and illusory remission (10.3{\%} to 23.5{\%}) rates are expected simply due to random variation. Conclusions.- Random variation, without real change, has the potential to influence estimated rates of progression and remission in longitudinal migraine studies. The magnitude of random variation needed to fully reproduce observed rates of progression and remission are implausibly large. Recommendations are offered to improve estimation of rates of progression and remission, reducing the influence of random variation.",
keywords = "headache chronification, headache frequency, methodology, statistics",
author = "Houle, {Timothy T.} and Turner, {Dana P.} and Smitherman, {Todd A.} and Penzien, {Donald B.} and Lipton, {Richard B.}",
year = "2013",
doi = "10.1111/head.12125",
language = "English (US)",
volume = "53",
pages = "920--929",
journal = "Headache",
issn = "0017-8748",
publisher = "Wiley-Blackwell",
number = "6",

}

TY - JOUR

T1 - Influence of random measurement error on estimated rates of headache chronification and remission

AU - Houle, Timothy T.

AU - Turner, Dana P.

AU - Smitherman, Todd A.

AU - Penzien, Donald B.

AU - Lipton, Richard B.

PY - 2013

Y1 - 2013

N2 - Objective.- To examine the potential influence of random measurement error on estimated rates of chronification and remission. Background.- Studies of headache chronification and remission examine the proportion of headache sufferers that move across a boundary of 15 headache days per month between 2 points in time. At least part of that apparent movement may represent measurement error or random variation in headache activity over time. Methods.- A mathematical simulation was conducted to examine the influence of varying degrees of measurement error on rates of chronic migraine onset and remission. Using data from the American Migraine Prevalence and Prevention Study, we estimated a starting distribution of headache days from 0 to 30 in the migraine population. Assuming various levels of measurement error, we then simulated 2 sets of data for Time 1 and Time 2. The "individuals" in this study were assumed to have no real change in headache frequency from Time 1 to Time 2. The observed variations in headache frequency were those influenced by imputed random variance to resemble typical measurement error or natural variability. Using this simulation approach, we estimated the amount of chronification and remission rates that might be attributed simply to statistical artifacts such as unreliability or regression to the mean. Results.- As the degree of measurement error increased, the amounts of illusory chronification and remission increased substantially. For example, if the headache frequency of sufferers randomly varies by only 2 headache days each month due to chance alone, a substantial degree of illusory chronification (0.6% to 1.3%) and illusory remission (10.3% to 23.5%) rates are expected simply due to random variation. Conclusions.- Random variation, without real change, has the potential to influence estimated rates of progression and remission in longitudinal migraine studies. The magnitude of random variation needed to fully reproduce observed rates of progression and remission are implausibly large. Recommendations are offered to improve estimation of rates of progression and remission, reducing the influence of random variation.

AB - Objective.- To examine the potential influence of random measurement error on estimated rates of chronification and remission. Background.- Studies of headache chronification and remission examine the proportion of headache sufferers that move across a boundary of 15 headache days per month between 2 points in time. At least part of that apparent movement may represent measurement error or random variation in headache activity over time. Methods.- A mathematical simulation was conducted to examine the influence of varying degrees of measurement error on rates of chronic migraine onset and remission. Using data from the American Migraine Prevalence and Prevention Study, we estimated a starting distribution of headache days from 0 to 30 in the migraine population. Assuming various levels of measurement error, we then simulated 2 sets of data for Time 1 and Time 2. The "individuals" in this study were assumed to have no real change in headache frequency from Time 1 to Time 2. The observed variations in headache frequency were those influenced by imputed random variance to resemble typical measurement error or natural variability. Using this simulation approach, we estimated the amount of chronification and remission rates that might be attributed simply to statistical artifacts such as unreliability or regression to the mean. Results.- As the degree of measurement error increased, the amounts of illusory chronification and remission increased substantially. For example, if the headache frequency of sufferers randomly varies by only 2 headache days each month due to chance alone, a substantial degree of illusory chronification (0.6% to 1.3%) and illusory remission (10.3% to 23.5%) rates are expected simply due to random variation. Conclusions.- Random variation, without real change, has the potential to influence estimated rates of progression and remission in longitudinal migraine studies. The magnitude of random variation needed to fully reproduce observed rates of progression and remission are implausibly large. Recommendations are offered to improve estimation of rates of progression and remission, reducing the influence of random variation.

KW - headache chronification

KW - headache frequency

KW - methodology

KW - statistics

UR - http://www.scopus.com/inward/record.url?scp=84878509261&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84878509261&partnerID=8YFLogxK

U2 - 10.1111/head.12125

DO - 10.1111/head.12125

M3 - Article

C2 - 23721239

AN - SCOPUS:84878509261

VL - 53

SP - 920

EP - 929

JO - Headache

JF - Headache

SN - 0017-8748

IS - 6

ER -