Changes in clinical research in anaesthesia and intensive care from 1974-2004

The purpose was to identify how the quality of anaesthesia research has improved from articles published in Anaesthesia and Intensive Care over 25 years. Original papers were included during the periods 1974-1978 and 2000-2004. Each article was classified according to principal research designs and the two five-year periods were compared. All interventional trials were evaluated according to the following a priori criteria: author number; ethics approval; informed consent; competing financial interest; eligibility criteria; sample size calculation; method of randomization; patients accounted for, blind assessment of outcome; adverse outcomes; statistical method stated; type I error; type II error; and anaesthetic department of origin. Comparisons of above criteria were made between the two groups rising chi-square test or Fischer's exact test. Two-hundred-and-ninety-two articles were reviewed in 1974-1978 and 529 articles were reviewed in 2000-2004. Animal/laboratory articles decreased from 17.47% to 12.28% (P = 0.05). Review articles decreased from 34.35% to 10.4% (P < 0.0001). Descriptive trials increased from 28.4% to 52.72% (P < 0.0001). Interventional trials increased from 18.84% to 22.31% (P = 0.269). Uncontrolled clinical trials decreased from 27.27% to 12.71%, non-randomized controlled trials decreased from 50.91% to 7.63%, and randomized controlled trials increased from 21.82% to 79.66% (P < 0.0001). All interventional trials criteria improved and were statistically significant except competing financial interest, method of randomization, patients accounted for, and type II error: The quality of anaesthetic research has improved in Anaesthesia and Intensive Care over the past 30 years. However, there is still room for improvement.