Géraud Dautzenberg

Summary and general discussion

7.1.4 Main findings of Section C: The MoCA in clinical practice Chapters 5 and 6 discuss the outcomes of the use of the MoCA in clinical practice. In Chapter 5, we substantiate why and which two cut-off values can best be used, what the consequences could or should be, and why, when using the MoCA with two instead of one cut-off value. We compared different selection methods to determine who is and is not (yet) a candidate for a more extensive follow-up study for cognitive problems. The optimal strategy found among the compared strategies was to use the MoCA to select, after a history interview, those patients who were suspected of having cognitive impairment in whom an elaborate follow-up examination is promptly desirable (MoCA < 21) and in whom this comprehensive examination is very likely to show no cognitive decline (MoCA ≥ 26); therefore, a further referral is not desired. The use of one cut-off point also does injustice to the continuum of cognitive impairment where the two extremes, dementia on one side of the spectrum and no cognitive impairment on the other end, will result in a state that falls in between, namely, MCI. Using two cut-off points improved many parameters used to assess test efficiency compared to one cut-off point. The accuracy, PPV, and NPV improved, but more importantly, the number of false-positive referrals could be reduced by 65% without adding more false negatives. This is essential, especially in consideration of the future substantial increase in referrals with cognitive symptoms if the diagnostic pathways are not to be overcrowded. Thus, although people often intuitively use the MoCA with an uncertainty range surrounding the one cut-off in clinical practice, resembling, therefore, two cut-off points, our study has now added the scientific rationale and motivation for which two cut-offs are best used. The use of two cut-off points also adds to the value of the MoCA in terms of MCI versus mild dementia. Although both are entitled to good diagnostics, their priorities differ. Thus, especially in situations of scarcity, that is, when determining howmoney and time can best be spent, an MoCA with a double cut-off point can be helpful. It also provides the possibility to (quickly) categorise patients into three risk groups: -no indications of cognitive impairment, -possible MCI, -high risk of MD, and implementation of different policies. We discuss the suggested policy for MoCA scores that fall between these cut-off values. Instead of choosing between referral and no referral, with the in-between group (MCI) previously falling under one or the other policy, a double cut-off point can also be used to choose a third option: active follow-up without referral for a costly and burdensome examination of an elaborate neurocognitive assessment. As this activemonitoring could also be performed using the MoCA. The MoCA has been shown to be appropriate for monitoring cognitive development (Krishnan et al. , 2017). With this, not only flexibility and time but also money can be gained up to €1000 per avoided false positive referral.

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