Géraud Dautzenberg

Chapter 7

MoCA should not be usedwithout clinical judgment. It is clear that the reason for assessing the MoCA influences the outcome and interpretation of the outcome. Examiners need to be aware of this issue. There are motivations for using the MoCA in both situations. Clearly, the advantages of using the MoCA as a triaging instrument, meaning after clinical judgment, are proven: fewer (false positive) referrals. When used with a double cut-off, some of the disadvantages will even be solved (fewer misclassifications) and more advantages will even appear (intermediate state policy). This seems to lead to the conclusion that MoCA should be used on indication only, but it actually underlines that the clinical view should be in the lead. The MoCA should never be used ‘blind’, it is a tool, not a doctor. Given the nature of the population in old age psychiatry, there is a strong case for screening all referred patients for cognitive impairment. Maybe we should not consider it only screening but also getting their baseline as this population is not only at a higher risk of having cognitive impairment but also of developing it in the near future than the general population. The case report seems to be an isolated example, but in my experience, there have been many examples in which having a baseline MoCA was very important. As our studies have shown, screening can create many false positives, especially when applying the original cut-off score. However, using the double threshold substantially reduces the false positives on one side and gathers baseline scores on the other side, which can be very helpful. In addition, as explained earlier, the cohort design of the study introduces more false positives, as it is ‘blind’, by not being able to correct for low MoCA scores due to obvious non-cognitive aetiology. In clinical practice normally a correction of these false positives, for example a low MoCA score due to intoxication, would take place. Again, when the MoCA is used as a screener, the examiner should not, and hopefully will not, only look at the MoCA score itself, but also take all elements into consideration. This will, together with the double cut-off, further enhance the MoCA’s accuracy in clinical practice. The MoCA should not only be used on indication but also to get an indication. Another example where study and clinical reality do not (or cannot) match is the scientific confirmation of a third cut-off point, meaning that below a very lowMoCA score, no referral to a memory clinic is needed to confirm dementia. As mentioned in Chapter 5, this is not feasible on theMoCA score (alone), as the PPV is never high enough to be sure of a dementia diagnosis. However, PPV considers only the MoCA score in this study. In clinical practice, when there is a patient with a clear course (including advanced age) suggestive of dementia, and there are no other signs or symptoms suggestive of other (psychiatric) aetiology with a very low MoCA score, further follow-up investigations are often not initiated.

172