Tuesday 27 November 2012

Why bother testing?

Neuropsychologists hopefully agree that formal testing of cognition is the best way to know if cognitive impairment is present. We also hopefully agree that intuitive speculations based on interview alone aren't very reliable, especially in cases of subtle impairment. I imagine that we have all, on one occasion or another, assumed someone was reasonably okay on the basis of the interview, only to find the opposite on testing. 

I've recently been disturbed to hear that some neuropsychologists think formal testing of mood isn't necessary, that the sensitivity and specificity of our tests aren't as important as our intuitions, that the best way to determine mood is simply by asking the patient how they feel, and not worrying about complicated tests of mood.

The following article from Medscape shows that neurologists aren't very good at detecting depression and cognitive impairment compared to how well it is detected by using formal measures of mood and cognition. By inference, that probably applies to our profession as well. This shouldn't be news to anyone.

Medscape from WebMD - Email This
A link to the following Medscape article was sent to you by: Fiona Bardenhagen
Neurologists' Diagnostic Accuracy of Depression and Cognitive Problems in Patients With Parkinsonism
BMC Neurology, 2012-06-15
I'm sad that this article needs to be shared, it's probably not the best reference to remind us of the science behind psychology. 

However, I'm posting it because it came today, after an uplifting conference, and because it's important to remember that we are psychologists, and that the thing that distinguishes us from neurologists, psychiatrists, and all other professions who deal with the brain is our training in psychological assessment, test theory, psychometrics, biases, validity, reliability, sensitivity, specificity, and our knowledge that behaviour can be measured in a meaningful way. That we can measure states and traits that people deny or are unaware of through our techniques. And that we can combine this scientific study of mood, behaviour, and cognition with a holistic appreciation of the individual patient that we have gained through our careful interviews and history-taking with the patient and informants. 

As someone who appreciates the science of our profession, I don't say that we should discount our clinical skills and intuitions. I believe we should be aware of where they come from - are they based on biases, hunches, hermeneutics, clinician's illusions, or are they based on careful the study and application of  evidence over time? If we come to an intuitive conclusion about someone, it's probably a good idea to examine the reasons for and against that conclusion, so that we're not led astray by unscientific assumptions. (See Kahneman's book on decision-making, mentioned on this blog, for the evidence behind my belief.) And it's probably a good idea to include some brief, formal measure of mood for every patient you see, just to be more sure that they are not minimising how they feel when you ask them. 

yours in patient-centered care (sounds cheesy, but that's what this is about)
Fiona