Sir, we read with interest the opinion piece on endocarditis.1 Dentists are faced with a number of diverse medical problems that can influence the oral healthcare that they provide for their patients, but the evidence for healthcare recommendations very often does not have a reliably solid evidence base.2 Nevertheless, clinical guidance has been developing in many areas.3,4

The changes in the NICE (National Institute for Health and Care Excellence) endocarditis guidelines have not been without consequences, not only in clinical outcomes,5 but in our experience and opinion, contribute to a lack of clarity for both patients and healthcare providers. We consider that clear unambiguous guidance rather than several variants in guidance such as have appeared in the UK (eg NICE, SIGN) would be more welcome for practitioners and patients; variances between international guidelines hardly help.

Adherence to guidance, though not mandatory,6 may well in practice be seen as such, because failure to adhere needs justification by the clinician7 to resist challenge. Non-adherence may arise, amongst other reasons, due to guidelines being based on low-level evidence with weak recommendations and the notion that using such guidance could result in more harm to the patient.8

Clinical guidelines are just that, they offer guidance, which is not necessarily applicable to each and every situation and patient. In this respect, it should be stressed that fundamental to sound patient care is good clinical judgment, which involves more than simply the consideration of best current evidence, it requires consideration of patients' expectations, values and preferences to permit patients and clinicians to make informed choices.7