Brief cognitive tests as a decision-making tool in primary care. A population and validation study

Brief cognitive tests (BCT) are used in primary care (PC) for the detection of cognitive impairment (CI). Still, there are little data on their diagnostic utility (DU) in a community setting. This work evaluates the DU at the population level of Fototest, T@M, AD8 questionnaire and MMSE. It provides new cut-off points (CoP) validated in a CI early detection program.

In the population and validation samples, the evaluation was carried out in two phases, a first of screening and administration of BCT and a second of clinical diagnosis, blinded to the results of the BCT, applying the current NIA-AA criteria. The DU of BCT in the population sample was evaluated with the area under the ROC curve (aROC). Youden index and the CoP with the best specificity that ensured a sensitivity of 80% were used to decide on the most appropriate CoP. The sensitivity, specificity, and predictive values for these CoP were calculated in the validation sample.

260 participants (23.1% with CI) from the population sample and 177 (42.4% with CI) from the validation sample were included. The Fototest has the best UD at the population level (aROC 0.851), which improves with the combination of Fototest and AD8 (aROC 0.875). The proposed CoP are AD8 ≥ 1, Fototest ≤ 35, T@M ≤ 40, and MMSE ≤ 26.

BCT are helpful in detecting CI in PC. This work supports the use of more demanding PoC.