@article{ref1,
title="Cell phone use and crash risk: evidence for positive bias",
journal="Epidemiology",
year="2012",
author="Young, Richard A.",
volume="23",
number="1",
pages="116-118",
abstract="BACKGROUND: Recent epidemiologic studies have estimated little or no increased risk of automotive crashes related to cell phone conversations by the driver, whereas earlier case-crossover studies estimated the relative risk as close to 4. Did earlier studies introduce a positive bias in relative risk estimates by overestimating driving exposure in control windows? METHODS: Driving exposures in a &quot;control&quot; window and a corresponding &quot;case&quot; window on the subsequent day were tabulated across 100 days for 439 GPS-instrumented vehicles in the Puget Sound area during 2005-2006. RESULTS: For control windows containing at least some driving, driving exposure was about one-fourth that of case windows. Adjusting for this imbalance reduces relative risk estimates in the earlier case-crossover studies from 4 to 1. CONCLUSION: Earlier case-crossover studies likely overestimated the relative risk for cell phone conversations while driving by implicitly assuming that driving during a control window was full-time when it may have been only part-time.  Erratum:   On page 118, left column, line 8, the sentence should say “with >0% consistency,” not “with 70% consistency.” (Epidemiology. 23(2):358, March 2012.)   See also comments and rebuttals: Mittleman MA, Maclure M, Mostofsky E. Epidemiology. 2012 Jul;23(4):647-8; author reply 649-50. doi: 10.1097/EDE.0b013e3182583cdf.  Walsh MC, Trentham-Dietz A, Newcomb PA, Gangnon R, Palta M. Epidemiology. 2012 Sep;23(5):772-3. Using propensity scores to reduce case-control selection bias.  Young RA. Epidemiology. 2013 May;24(3):469. doi: 10.1097/EDE.0b013e31828abbea. Cell phone use and crash risk.  Kidd DG, McCartt AT. Epidemiology. 2013 May;24(3):468-9. doi: 10.1097/EDE.0b013e31828c4663. Cell phone use and crash risk.  McEvoy SP, Stevenson MR, Woodward M. Epidemiology. 2012 Jul;23(4):648; author reply 649-50. doi: 10.1097/EDE.0b013e3182594053. Cell phone use and crash risk.  Kidd DG, McCartt AT. Epidemiology. 2012 Sep;23(5):773-4;author reply 774-5. doi: 10.1097/EDE.0b013e318262247e. More on cell phone use and crash risk.      <p /> <p>Language: en</p>",
language="en",
issn="1044-3983",
doi="10.1097/EDE.0b013e31823b5efc",
url="http://dx.doi.org/10.1097/EDE.0b013e31823b5efc"
}