Estimated analytical model. We assumed that every variable on a “lower” level could be explained by variables higher in the hierarchy (i.e., variables at Level 4 could be explained by all variables at Levels 1 – 3). BMI = body mass index, AChEI = acetylcholine-esterase inhibitor.
Elsais et al. BMC Neurology 2013 13:132 doi:10.1186/1471-2377-13-132