About the Authors
- Peter Tinnemann, Jonas Özbay, Victoria A. Saint, Stefan N. Willich
- Institute for Social Medicine, Epidemiology and Health Economics, Charité University Medical Center, Berlin, Germany
The authors have declared that no competing interests exist.
Analyzed the data: PT JÖ. Wrote the paper: PT JÖ VAS. Data acquisition and refinement: JÖ. Designed method: PT JÖ. Critical revision of manuscript: SNW.