Clinical v. actuarial: need we choose?

Mental health professionals should use what works best. Research in evidence-based medicine tells us that we do well to use actuarial methods, since using the evidence there is improves patient outcomes. But to understand the patient, such external evidence should be complemented with individual clinical experience and judgement, and the patient’s unique story is quite important (Reference GreenhalghGreenhalgh, 2002). In Greenhalgh’s view, no one ever needs to choose between evidence-based practice and clinical expertise. Clinical expertise generates the hypotheses that may then be tested scientifically against the available evidence; and the evidence figures in the hypotheses.

Introducing narratives in the clinical encounter has clear advantages. The clinician could use the available evidence, in the form of an illness-script or a DSM classification or a nosological or other model, as a skeleton explanation. They could then flesh out this skeleton with individual patient data, thereby creating a well-founded yet personalised narrative or story. The patient could also present their narrative, and the clinician would match this story to actuarial evidence about the hypothesised illness. The result is a healthy mix of statistical and clinical input: a story that facilitates communication between clinician and patient, and that at the same time incorporates the available evidence. Like Greenhalgh, I see no need to choose between the clinical and the statistical. On the contrary: why not have the best of both? Incorporating statistics would keep clinicians from being drawn into the patient’s narrative, which is the most available and vivid explanation of their behaviour, but possibly not the best one. Adding clinical insights to statistical explanations would give meaning to the figures. It improves our understanding of why this individual would, for example, perform violent acts and how to manage it.

Understanding violent patients through a narrative-based approach is just as insufficient for predicting violence as understanding the meaning of violent behaviour through a psychodynamic approach. If narrative-based medicine, or the psychodynamic approach, is to make a difference, common key elements in patients’ narratives should be taken up in the cues that are used in prediction. It remains to be tested whether the predictive value of actuarial methods using these cues is then really improved, over just using the single cue of past violence. Until that time, it seems irresponsible to trade in actuarial methods for clinical methods in the prediction of the risk of violence.

Conclusions

Mental health professionals can use whatever suits their professional expertise in trying to understand their violent patients: psychodynamic psychotherapy, the patient’s narrative, or their own stories based on their experience and training. But their methods ought not to be used in predictions without validation. The effectiveness of the different approaches in predicting violence needs to be established through well-designed comparative studies. That is, the evidence-base of the chosen approach should be uncovered. Meanwhile, for the sake of the safety of the general public and the patients themselves, actuarial methods cannot be discarded. Indeed, clinicians should ‘[retreat] emotionally into … a scientific attitude’ (Reference DoctorDoctor, 2004, this issue) not to blind them to what happens, but to add to the scientific value of their predictions. Clinical psychology and psychiatry are sciences, not arts. The bottom line is, as Reference HollowayHolloway (2004, this issue) puts it, that ‘we all need to learn how to combine clinical wisdom with reliable evidence’.