Guidelines cannot be so specific that they are suitable for every patient in your surgery. Certain aspects can, however, be accounted for such as age and sex. The recent guideline from the Dutch College of General Practitioners on diabetes differentiates between optimal HbA1c levels according to a patient's age and duration of diabetes. In cases where a patient has more than one disease, things get more problematic as personalised care has to be provided in collaboration with the patient. In these cases, a physician has to know how to search for relevant specific evidence and how to judge that evidence. These academic skills must be included in all medical training programmes and should be maintained throughout the physician's professional life.