Additional file 1.
Table S1. Comparisons of anthropometrics (means) and percentages reporting symptoms and diseases between participants having answered questionnaire 1 (Q1) (23 049) or questionnaire 2 (Q2), and those having answered a shortened nonparticipation questionnaire (QNP) (n = 3677) among men stratified by age groups.
Format: DOC Size: 133KB Download file
This file can be viewed with: Microsoft Word Viewer
Langhammer et al. BMC Medical Research Methodology 2012 12:143 doi:10.1186/1471-2288-12-143