Practising sound medicine in the absence of evidence

We agree with Fiona Kouyoumdjian and Vanessa Cardy that in the face of uncertain evidence, clinical context and clinician experience will ultimately determine the course of care. Unfortunately, Kouyoumdjian and Cardy seem to have misunderstood a key point of our commentary1 and the accompanying recommendations of the Canadian Task Force on Preventive Health Care.2 We do not recommend that clinicians “screen people with signs and symptoms of ‘potential abuse’”; rather, good clinical care demands accurate diagnosis and appropriate treatment when a woman presents with injuries or other manifestations consistent with abuse. The difficulty in recommending universal screening — that is, routine assessment of all women presenting for any medical concern — is the lack of evidence regarding appropriate treatment interventions.3

Kouyoumdjian and Cardy further state that there is an “apparent lack of harm in screening patients for abuse” and that the act of disclosing abuse “may be a positive outcome in and of itself.” In fact, a range of potential harms may result from screening, including the possibility of psychological distress (as opposed to the benefit assumed by Kouyoumdjian and Cardy) when a woman is asked to disclose abuse when she is not ready to do so;4 the raising of false hope that screening can help, when in fact it may not; and the potential of exposing the woman to further violence. The lack of evaluation of the potential harms of screening is a major problem in this field. No intervention is completely without harm or cost, whether it be opportunity cost (e.g., the clinical time required for screening that could be spent on other problems) or a specific risk associated with the intervention or its sequelae (e.g., adverse reaction to a vaccine). It is essential that screening be evaluated to determine whether it does more good than harm, rather than simply assuming that it has benefit. As outlined in our commentary,1 we are fortunate that various organizations, including the US Centers for Disease Control and Prevention and the Ontario Women's Health Council, have recognized this gap in scientific evidence and that studies to address this question are under way.

Harriet L. MacMillan Departments of Psychiatry and Behavioural Neurosciences and of Pediatrics C. Nadine Wathen Offord Centre for Child Studies McMaster University Hamilton, Ont.