RT Journal
A1 Runhaar J, van der Wouden JC
T1 EFfect of oral glucosamine on pain-related disability in patients with chronic low back pain
JF JAMA
JO JAMA
YR 2010
FD October 20
VO 304
IS 15
SP 1673
OP 1673
DO 10.1001/jama.2010.1466
UL http://dx.doi.org/10.1001/jama.2010.1466
AB 
However, based on the information given in the article, we find it hard to assess the generalizability of the study findings. The authors described that recruitment occurred via general practitioners, physiotherapists, chiropractors, and self-referrals through a newspaper advertisement. It would be helpful to know the distribution of included participants among these 4 methods of recruitment. Self-referred participants had to meet the additional requirement of a recent magnetic resonance imaging (MRI) scan, but it would be helpful to have more information about the Norwegian health care system to understand the implications of this route. A more precise description of the way the investigators recruited the participants would also result in a clearer description of the study population.