Sir, I wish to add to the views expressed by Geddis (Systemic health screening; BDJ 2012; 213: 146). The mindset of screening of medical conditions at dental clinics is intriguing, but it also raises important ethical and methodological questions that should not be overlooked.

For example, as dental professionals have traditionally focused on oral conditions, often not regarded by the patients as medical, dental patients are not primarily focused on general health issues when visiting a dental practice. However, the same patients may consent to participate in a general health screening if one is offered in conjunction with the dental visit.

If the screening test turns out to be negative for a certain marker that might indicate a general health problem (eg a certain blood sugar level for diabetes), the patient will probably leave the dental clinic without further thoughts, believing everything is all right. But, if the screening test result turns out to be positive, the patient will leave the practice with a tentative diagnosis. Although feeling perfectly well a moment ago when entering the dental practice, the patient is now probably worried about his or her health.

To this it should be added that screening tests are generally limited in their accuracies by imperfect sensitivities and specificities. Therefore, the interpretation of the test result may lead to wrong conclusions in both directions. Thus, if the test is falsely negative, the patients will consider themselves healthy, when being ill. And vice versa, if the test result is falsely positive, a healthy patient will leave the practice with a false diagnosis that may take some time to prove wrong. This may of course have a negative effect on the individual's quality of life.

Considering both the ethical issues and the limitations of the screening test methods, one might ask: is it justified to screen individuals for medical conditions at dental practices when the individuals do not feel unwell and do not ask for medical care?

1. Göteborg