Quality of published research (March 14, 2005) Category: Systematic overviews

One of the big advantages of meta-analysis is that it allows you to review a series of publications in an area to see if there are any gaps or quality shortfalls. While I was doing a few PubMed searches, I found eight articles co-authored by LL Kjaergard that showed how this works in a variety of different areas.

• Association of funding and conclusions in randomized drug trials: a reflection of treatment effect or adverse events? Als-Nielsen B, Chen W, Gluud C, Kjaergard LL. Jama 2003: 290(7); 921-8. [Medline]
• Misuse of randomization: a review of Chinese randomized trials of herbal medicines for chronic hepatitis B. Liu J, Kjaergard LL, Gluud C. Am J Chin Med 2002: 30(1); 173-6. [Medline]
• Funding, disease area, and internal validity of hepatobiliary randomized clinical trials. Kjaergard LL, Gluud C. Am J Gastroenterol 2002: 97(11); 2708-13. [Medline]
• Citation bias of hepato-biliary randomized clinical trials. Kjaergard LL, Gluud C. J Clin Epidemiol 2002: 55(4); 407-10. [Medline]
• Validity of randomized clinical trials in gastroenterology from 1964-2000. Kjaergard LL, Frederiksen SL, Gluud C. Gastroenterology 2002: 122(4); 1157-60. [Medline]
• Association between competing interests and authors' conclusions: epidemiological study of randomised clinical trials published in the BMJ. Kjaergard LL, Als-Nielsen B. Bmj 2002: 325(7358); 249. [Medline]
• Reported methodologic quality and discrepancies between large and small randomized trials in meta-analyses. Kjaergard LL, Villumsen J, Gluud C. Ann Intern Med 2001: 135(11); 982-9. [Medline] [Abstract] [PDF]
• Randomized clinical trials in HEPATOLOGY: predictors of quality. Kjaergard LL, Nikolova D, Gluud C. Hepatology 1999: 30(5); 1134-8. [Medline]

The classic reference that I commonly cite in my training classes is

• Content and quality of 2000 controlled trials in schizophrenia over 50 years. Thornley B, Adams C. British Medical Journal 1998: 317(7167); 1181-1184. [Medline] [Abstract] [Full text] [PDF]

which documented problems with selecting the wrong patients, not studying enough of them, not studying them long  enough and not measuring them properly.

07/08/2008.