Carolien Zeetsen

53 CHAPTER Validating the MoCA in addiction health care 3 At baseline, correlations between performance on the MoCA and NPA were significant for the MoCA–DS executive functioning ( r = 0.238, p = .032), abstract reasoning ( r = 0.300, p = .006), and memory ( r = 0.423, p < .001). At follow–up, there was an almost perfect correspondence between MoCA and NPA performance: all MoCA–DS were significantly correlated to the corresponding NPA domain (executive functioning: r = 0.328, p = .003; visuospatial abilities: r = 0.241, p = .029; attention: r = 0.396, p < .001; abstract reasoning: r = 0.542, p < .001; memory: r = 0.455, p < .001; orientation: r = 0.229, p = .043). Predictive validity at baseline An AUC value of 0.676 was found ( p = .006; Figure 3.1) and a cut–off score of 24 yielded the most optimal sensitivity (0.56), specificity (0.62), PPV (64.1%), and NPV (53.5%), using the NPA as gold standard. Applying this cut–off score, 39 out of 82 patients were classified as having NCD, while 45 out of 82 patients were classified as having NCD based on the NPA. The overall agreement with the NPA was 58.5% and the chance–adjusted agreement was 17.5% (Table 3.5). Concurrent validity at follow–up An AUC of 0.745 was found ( p < .001; Figure 3.1) and a cut–off score of 25 yielded the most optimal sensitivity (0.67), specificity (0.73), PPV (75.0%), and NPV (64.3%), using the NPA as gold standard. Applying this cut–off score, 40 out of 82 patients were classified as having NCD. The overall agreement with the NPA was 69.5% and the chance–adjusted agreement was 39.2% (Table 3.5). Figure 3.1. Receiver Operator Characteristic (ROC) curve for the Montreal Cognitive Assessment (MoCA) total score at baseline and follow–up, using several cut–off points in comparison with neurocognitive disorders (NCD versus no–NCD); AUC = Area Under the Curve.