Background: Guidelines serve the purpose assisting the clinicians in clinical decision-making and practice. Guidelines ideally state the level of evidence for their commendations:

A: a meta-analysis of randomised controlled trials (RCTs) or at least one RCT among several good investigations.
B: Good non-randomised clinical trials
C: Expert Committee or well estimated authorities - no good investigations

Objective: To study whether the level of evidence varied from one country to another and if the evidence improved over time by comparing the two latest Guidelines from the same country within the area of colorectal cancer.

Methods: The guidelines were collected (Australia, Denmark, Scotland, UK and USA) the level of evidence for a given treatment recommendation and the total number of treatment recommendations in each guideline were registered and compared over time and/or from one country to another.

Results: When comparing the evidence level from the three latest guidelines Scotland, USA and Denmark using chi-squared we did not find any significant difference between countries (p>0.5). The guidelines from Scotland showed a significant increase in the number of level A recommendations over time (p<0,05) chi-squared test. Due to large difference in the number of recommendations the Danish guidelines was judged non-comparable over time with a significance test, but the overall trend seems to be a rise in level A evidence. The UK-guidelines showed no increase in level A recommendations over time. No update was found for the Australian guideline.

Conclusion: The guidelines examined in this study showed a dismal low level of good evidence to back their recommendations across the continents. None of the investigated guidelines managed back even a third of their recommendations by level A evidence. More effort needs to be put into updating the guidelines.