Comparing Smoothing Techniques in Cox Models for Exposure-Response Relationships

Details

• Personal Author:
  Eisen EA ; Ganguli B ; Govindarajulu US ; Spiegelman D ; Thurston SW
• Description:
  To allow for non-linear exposure-response relationships, we applied flexible non-parametric smoothing techniques to models of time to lung cancer mortality in two occupational cohorts with skewed exposure distributions. We focused on three different smoothing techniques in Cox models: penalized splines, restricted cubic splines, and fractional polynomials. We compared standard software implementations of these three methods based on their visual representation and criterion for model selection. We propose a measure of the difference between a pair of curves based on the area between them, standardized by the average of the areas under the pair of curves. To capture the variation in the difference over the range of exposure, the area between curves was also calculated at percentiles of exposure and expressed as a percentage of the total difference. The dose-response curves from the three methods were similar in both studies over the denser portion of the exposure range, with the difference between curves up to the 50th percentile less than 1 per cent of the total difference. A comparison of inverse variance weighted areas applied to the data set with a more skewed exposure distribution allowed us to estimate area differences with more precision by reducing the proportion attributed to the upper 1 percent tail region. Overall, the penalized spline and the restricted cubic spline were closer to each other than either was to the fractional polynomial. [Description provided by NIOSH]
• Subjects:
  Chemistry Coal Coal Mining Environment Mining Occupational Health Safety Waste Management
• Keywords:
  Author Keywords: Penalized Spline Bootstrapping Cancer Dose-response Environmental Epidemiology Environmental Exposure Epidemiology Exposure Levels Fractional Polynomial Lung Lung Cancer Models Morbidity Rates Mortality Rates Restricted Cubic Spline Smoothing

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• ISSN:
  0277-6715
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Connecticut ; Massachusetts ; OSHA Region 1
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  26
• Issue:
  20
• NIOSHTIC Number:
  nn:20055826
• Citation:
  Stat Med 2007 May; 26(20):3735-3752
• Contact Point Address:
  Usha S. Govindarajulu, 2, Church St South, Yale Center for Clinical Investigation, Yale School of Medicine, New Haven, CT 06510
• Email:
  usha.govindarajulu@yale.edu
• Federal Fiscal Year:
  2007
• Performing Organization:
  Harvard School of Public Health
• Peer Reviewed:
  True
• Start Date:
  20050701
• Source Full Name:
  Statistics in Medicine
• End Date:
  20280630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:6b6d0de25fed4ad90467218571f7421e1e670cb98d54b0d7da0442781f62a95ad2ada331c29857fa95ac3bb96131445ae6bb79aa5410e506edd7e8b5c06528e7
• Download URL:
  https://stacks.cdc.gov/view/cdc/213593/cdc_213593_DS1.pdf
• File Type:
  [PDF - 211.33 KB ]