Finlay McAlister and colleagues made use of the Canadian Hypertension Education Program (CHEP) grading scheme. They conclude that most recommendations are based on the results of well-conducted clinical trials. However, less than a third of the recommendations were found to be based on high-quality evidence applicable to the populations, treatments and outcomes specified in guideline recommendations.
The researchers say that physicians should be aware that official guidelines are not necessarily based on high-quality evidence. They emphasize the need to make the evidence underlying guideline recommendations more transparent by using an extended grading system, like the CHEP scheme.
If this were done, the researchers suggest, it would help clinicians to apply guideline recommendations appropriately to their individual patients.