Table 1

Examples of journals at four research levels (RL), as categorised by CHI Research Inc.

RL Description Examples
1Clinical observation Am J Gastroenterol; BMJ;Endoscopy; Dis Colon Rectum; Gastrointest Endosc
2Clinical mix Cancer;Dig Dis Sci;Gastroenterology;Gut;Hepatology;Lancet; N Engl J Med
3Clinical investigation Cancer Res;Gastroenterol Clin North Am; Infect Immun; J Clin Invest
4Basic research Am J Physiol;J Biol Chem; J Physiol; Nature;Proc Nat Acad Sci USA