Comment with regard to “Outcomes of decompression surgery for lumbar spinal stenosis in elderly diabetic patients” (Z. Arinzon et al.)

This is a sort of epidemiological study for which a correct methodology is, of course, very important. However, not only do we have to deal with a retrospective analysis, but also with the fact that the way the control group was selected probably leads to important bias. In order to exclude this bias, it would have been necessary to examine a third group of patients: namely all the non-diabetic patients (n=195). Since this was not done, the conclusions of this study should be interpreted with the utmost caution.