Rounding Behavior in the Reporting of Headache Frequency Complicates Headache Chronification Research
- 30 May 2013
- journal article
- research article
- Published by Wiley in Headache: The Journal of Head and Face Pain
- Vol. 53 (6), 908-919
- https://doi.org/10.1111/head.12126
Abstract
Objectives To characterize the extent of measurement error arising from rounding in headache frequency reporting (days per month) in a population sample of headache sufferers. Background When reporting numerical health information, individuals tend to round their estimates. The tendency to round to the nearest 5 days when reporting headache frequency can distort distributions and engender unreliability in frequency estimates in both clinical and research contexts. Methods This secondary analysis of the 2005 American Migraine Prevalence and Prevention study survey characterized the population distribution of 30‐day headache frequency among community headache sufferers and determined the extent of numerical rounding (“heaping”) in self‐reported data. Headache frequency distributions (days per month) were examined using a simplified version of Wang and Heitjan's approach to heaping to estimate the probability that headache sufferers round to a multiple of 5 when providing frequency reports. Multiple imputation was used to estimate a theoretical “true” headache frequency. Results Of the 24,000 surveys, headache frequency data were available for 15,976 respondents diagnosed with migraine (68.6%), probable migraine (8.3%), or episodic tension‐type headache (10.0%); the remainder had other headache types. The mean number of headaches days/month was 3.7 (standard deviation = 5.6). Examination of the distribution of headache frequency reports revealed a disproportionate number of responses centered on multiples of 5 days. The odds that headache frequency was rounded to 5 increased by 24% with each 1‐day increase in headache frequency (odds ratio: 1.24, 95% confidence interval: 1.23 to 1.25), indicating that heaping occurs most commonly at higher headache frequencies. Women were more likely to round than men, and rounding decreased with increasing age and increased with symptoms of depression. Conclusions Because of the coarsening induced by rounding, caution should be used when distinguishing between episodic and chronic headache sufferers using self‐reported estimates of headache frequency. Unreliability in frequency estimates is of particular concern among individuals with high‐frequency (chronic) headache. Employing shorter recall intervals when assessing headache frequency, preferably using daily diaries, may improve accuracy and allow more precise estimation of chronic migraine onset and remission.Keywords
This publication has 19 references indexed in Scilit:
- Rethinking Headache ChronificationHeadache: The Journal of Head and Face Pain, 2013
- Sociodemographic and comorbidity profiles of chronic migraine and episodic migraine sufferersJournal of Neurology, Neurosurgery & Psychiatry, 2010
- Cumulative Lifetime Migraine Incidence in Women and MenCephalalgia, 2008
- In-office Discussions of Migraine: Results from the American Migraine Communication StudyJournal of General Internal Medicine, 2008
- Prevalence and characteristics of allodynia in headache sufferersNeurology, 2008
- Healthcare provider–patient communication and migraine assessment: results of the American Migraine Communication Study, phase IICurrent Medical Research and Opinion, 2008
- Modeling heaping in self‐reported cigarette countsStatistics in Medicine, 2008
- Probable Migraine in the United States: Results Of The American Migraine Prevalence and Prevention (AMPP) StudyCephalalgia, 2007
- The PHQ-9Journal of General Internal Medicine, 2001
- Inference from Coarse Data via Multiple Imputation with Application to Age HeapingJournal of the American Statistical Association, 1990