Diagnostic accuracy and predictive validity of combined use of Fototest and Mini-Cog in cognitive impairment.

INTRODUCTION: The Fototest and Mini-Cog include all the domains that are necessary in a cognitive assessment. This study aims to evaluate the diagnostic accuracy of the combined use of both instruments for detecting cognitive impairment. METHODS: We performed a phase III diagnostic accuracy study with 2 independent samples: STUDY, which included 448 participants randomly allocated to 2 datasets (BASE [80%] and TEST [20%]); and EXTERNAL, which included 61 participants. The index test was consecutive administration of the Fototest and Mini-Cog, and the reference test was formal cognitive assessment. We evaluated the diagnostic accuracy of two-step vs consecutive application of the tests and simple (Comb-Simple), logistic regression (Comb-LR), and random decision tree (Comb-RDT) models of their combined use for detecting cognitive impairment (Global Deterioration Scale score ≥ 3). We performed an exploratory analysis of the BASE dataset, selecting criteria that maximise accuracy; a pre-specified analysis was used to evaluate the selected criteria in the TEST and EXTERNAL datasets. RESULTS: The diagnostic accuracy (95% confidence interval) of the combined models in the BASE dataset (Comb-Simple: 88.3 [88.5-91.4]; Comb-LR: 91.6 [88.2-94.3]; Comb-RDT 95.2 [92.5-97.2]) was significantly higher than the individual values observed for the Mini-Cog and Fototest (81.6 [77.1-85.4] and 84.9 [80.8-88.5], respectively). These results were replicated in the TEST (Comb-Simple: 88.9; Comb-LR: 95.6; Comb-RDT: 92.2) and EXTERNAL datasets (Comb-Simple: 91.8; Comb-LR: 90.2; Comb-RDT: 88.5). Two-step application had the same diagnostic accuracy than consecutive application but required less time (mean [SD] of 197.3 s [56.7] vs 233.9 s [45.2]; P < .0001). CONCLUSIONS: Combined application of the Fototest and Mini-Cog takes less than 4 minutes and improves the diagnostic accuracy of both instruments. Two-step application is more efficient as it requires less time while maintaining the same diagnostic accuracy.

Diagnostic performance of brief cognitive tests in cognitive impairment screening.

INTRODUCTION AND OBJECTIVES: This study aims to assess and compare the diagnostic performance of brief cognitive tests for cognitive impairment (CI) screening recommended by the Spanish guidelines for the integral care of people with Alzheimer's disease and other dementias. MATERIAL AND METHODS: We performed a phase iii study into the accuracy of diagnostic tests, including patients with suspected CI in a primary care setting. All patients completed the Mini-Mental State Examination (MMSE), the Mini Examen Cognoscitivo (MEC), the Short Portable Mental Status Questionnaire (SPMSQ), the Memory Impairment Screen (MIS), the Clock Drawing Test (CDT), the Eurotest, the Fototest, and the Memory Alteration Test (M@T). CI was diagnosed independently by researchers blinded to scores on these tests. Diagnostic performance was evaluated by calculating the area under the receiver operating characteristic curve (AUC). RESULTS: The study included 141 individuals (86 with CI). The Eurotest and M@T (AUC±SE: 0.91±0.02 and 0.90±0.02, respectively) took longer to administer (mean [SD]: 7.1 [1.8] and 6.8 [2.2]min, respectively) and have significantly better diagnostic performance compared to the MMSE, MEC, SPMSQ, and CDT, but not compared to MIS or Fototest (both with an AUC of 0.87±0.03), with the latter taking less than half as long to administer (2.8 [0.8]min). The M@T and MIS only evaluate memory, and the latter cannot be administered to illiterate people. CONCLUSION: The most advisable tests for CI screening in primary care are the Eurotest, M@T, and Fototest, with the latter being the most efficient as it takes half as long to administer.

Assessment of the diagnostic accuracy and discriminative validity of the Clock Drawing and Mini-Cog tests in detecting cognitive impairment.

INTRODUCTION AND OBJECTIVES: The Mini-Cog is a very brief, widely used cognitive test that includes a memory task and a simplified assessment of the Clock Drawing Test (CDT). There is not a formal evaluation of the Mini-Cog test in Spanish. This study aims to analyse the diagnostic usefulness of the Mini-Cog and CDT for detecting cognitive impairment (CI). METHODS: We performed a cross-sectional study, systematically including all patients who consulted at our neurology clinic over a 6-month period. We assessed diagnostic usefulness for detecting CI (defined according to the National Institute on Aging-Alzheimer's Association criteria for mild cognitive impairment and dementia) according to the area under the receiver operating characteristic curve (AUC). Sensitivity, specificity, and positive and negative likelihood ratios were calculated for each cut-off point. RESULTS: The study included 581 individuals (315 with CI); 55.1% were women and 27.7% had not completed primary studies. The Mini-Cog showed greater diagnostic usefulness than the CDT (AUC ±â€¯sensitivity: 0.88 ±â€¯0.01 vs 0.84 ±â€¯0.01; P < .01). Both instruments were less useful for screening in individuals with a low education level (0.74 ±â€¯0.05 vs 0.75 ±â€¯0.05, respectively). A cut-off point of 2/3 in the Mini-Cog achieved a sensitivity of 0.90 (95% CI, 0.87-0.93) and a specificity of 0.71 (95% CI, 0.65-0.76); a cut-off point of 5/6 in the CDT achieved a sensitivity of 0.77 (95% CI, 0.72-0.81) and a specificity of 0.80 (95% CI, 0.75-0.85). CONCLUSION: In our neurology clinic, the Mini-Cog showed acceptable diagnostic usefulness for detecting CI, greater than that of the CDT; neither test is an appropriate instrument for individuals with a low level of education.

Diagnostic accuracy and predictive validity of associated use of Fototest and Mini-Cog in cognitive impairment. / Utilidad diagnóstica y validez predictiva del uso conjunto de Fototest y Mini-Cog en deterioro cognitivo.

INTRODUCTION: The Fototest and Mini-Cog include all the domains that are necessary in a cognitive assessment. This study aims to evaluate the diagnostic accuracy of the combined use of both instruments for detecting cognitive impairment. METHODS: We performed a phase iii diagnostic accuracy study with 2 independent samples: STUDY, which included 448 participants randomly allocated to 2 datasets (BASE [80%] and TEST [20%]); and EXTERNAL, which included 61 participants. The index test was consecutive administration of the Fototest and Mini-Cog, and the reference test was formal cognitive assessment. We evaluated the diagnostic accuracy of two-step vs. consecutive application of the tests and simple (Comb-Simple), logistic regression (Comb-LR), and random decision tree (Comb-RDT) models of their combined use for detecting cognitive impairment (Global Deterioration Scale score ≥ 3). We performed an exploratory analysis of the BASE dataset, selecting criteria that maximise accuracy; a pre-specified analysis was used to evaluate the selected criteria in the TEST and EXTERNAL datasets. RESULTS: The diagnostic accuracy (95% confidence interval) of the combined models in the BASE dataset (Comb-Simple: 88.3 [88.5-91.4]; Comb-LR: 91.6 [88.2-94.3]; Comb-RDT 95.2 [92.5-97.2]) was significantly higher than the individual values observed for the Mini-Cog and Fototest (81.6 [77.1-85.4] and 84.9 [80.8-88.5], respectively). These results were replicated in the TEST (Comb-Simple: 88.9; Comb-LR: 95.6; Comb-RDT: 92.2) and EXTERNAL datasets (Comb-Simple: 91.8; Comb-LR: 90.2; Comb-RDT: 88.5). Two-step application had the same diagnostic accuracy than consecutive application but required less time (mean [SD] of 197.3 s [56.7] vs. 233.9 s [45.2]; P<.0001). CONCLUSIONS: Combined application of the Fototest and Mini-Cog takes less than 4minutes and improves the diagnostic accuracy of both instruments. Two-step application is more efficient as it requires less time while maintaining the same diagnostic accuracy.

Ischaemic stroke and SARS-CoV-2 infection: A causal or incidental association? / Ictus isquémico e infección por SARS-CoV-2, ¿asociación casual o causal?

INTRODUCTION: Ischaemic stroke has been reported in patients with COVID-19, particularly in more severe cases. However, it is unclear to what extent this is linked to systemic inflammation and hypercoagulability secondary to the infection. METHODS: We describe the cases of 4 patients with ischaemic stroke and COVID-19 who were attended at our hospital. Patients are classified according to the likelihood of a causal relationship between the hypercoagulable state and ischaemic stroke. We also conducted a review of studies addressing the possible mechanisms involved in the aetiopathogenesis of ischaemic stroke in these patients. RESULTS: The association between COVID-19 and stroke was probably causal in 2 patients, who presented cortical infarcts and had no relevant arterial or cardioembolic disease, but did show signs of hypercoagulability and systemic inflammation in laboratory analyses. The other 2 patients were of advanced age and presented cardioembolic ischaemic stroke; the association in these patients was probably incidental. CONCLUSIONS: Systemic inflammation and the potential direct action of the virus may cause endothelial dysfunction, resulting in a hypercoagulable state that could be considered a potential cause of ischaemic stroke. However, stroke involves multiple pathophysiological mechanisms; studies with larger samples are therefore needed to confirm our hypothesis. The management protocol for patients with stroke and COVID-19 should include a complete aetiological study, with the appropriate safety precautions always being observed.

Diagnostic performance of brief cognitive tests in cognitive impairment screening. / Utilidad diagnóstica de test cognitivos breves en el cribado de deterioro cognitivo.

INTRODUCTION AND OBJECTIVES: This study aims to assess and compare the diagnostic performance of brief cognitive tests for cognitive impairment (CI) screening recommended by the Spanish guidelines for the integral care of people with Alzheimer's disease and other dementias. MATERIAL AND METHODS: We performed a phase iii study into the accuracy of diagnostic tests, including patients with suspected CI in a primary care setting. All patients completed the Mini-Mental State Examination (MMSE), the Mini Examen Cognoscitivo (MEC), the Short Portable Mental Status Questionnaire (SPMSQ), the Memory Impairment Screen (MIS), the Clock Drawing Test (CDT), the Eurotest, the Fototest, and the Memory Alteration Test (M@T). CI was diagnosed independently by researchers blinded to scores on these tests. Diagnostic performance was evaluated by calculating the area under the receiver operating characteristic curve (AUC). RESULTS: The study included 141 individuals (86 with CI). The Eurotest and M@T (AUC ± SE: 0.91 ± 0.02 and 0.90 ± 0.02, respectively) took longer to administer (mean [SD]: 7.1 [1.8] and 6.8 [2.2] min, respectively) and have significantly better diagnostic performance compared to the MMSE, MEC, SPMSQ, and CDT, but not compared to MIS or Fototest (both with an AUC of 0.87 ± 0.03), with the latter taking less than half as long to administer (2.8 [0.8] min). The M@T and MIS only evaluate memory, and the latter cannot be administered to illiterate people. CONCLUSION: The most advisable tests for CI screening in primary care are the Eurotest, M@T, and Fototest, with the latter being the most efficient as it takes half as long to administer.

Assessment of the diagnostic accuracy and discriminative validity of the Clock Drawing and Mini-Cog tests in detecting cognitive impairment. / Evaluación de la utilidad diagnóstica y validez discriminativa del Test del Reloj y del Mini-Cog en la detección del deterioro cognitivo.

INTRODUCTION AND OBJECTIVES: The Mini-Cog is a very brief, widely used cognitive test that includes a memory task and a simplified assessment of the Clock Drawing Test (CDT). There is not a formal evaluation of the Mini-Cog test in Spanish. This study aims to analyse the diagnostic usefulness of the Mini-Cog and CDT for detecting cognitive impairment (CI). METHODS: We performed a cross-sectional study, systematically including all patients who consulted at our neurology clinic over a 6-month period. We assessed diagnostic usefulness for detecting CI (defined according to the National Institute on Aging-Alzheimer's Association criteria for mild cognitive impairment and dementia) according to the area under the receiver operating characteristic curve (AUC). Sensitivity, specificity, and positive and negative likelihood ratios were calculated for each cut-off point. RESULTS: The study included 581 individuals (315 with CI); 55.1% were women and 27.7% had not completed primary studies. The Mini-Cog showed greater diagnostic usefulness than the CDT (AUC±sensitivity: 0.88±0.01 vs 0.84±0.01; P<.01). Both instruments were less useful for screening in individuals with a low education level (0.74±0.05 vs 0.75±0.05, respectively). A cut-off point of 2/3 in the Mini-Cog achieved a sensitivity of 0.90 (95%CI, 0.87-0.93) and a specificity of 0.71 (95%CI, 0.65-0.76); a cut-off point of 5/6 in the CDT achieved a sensitivity of 0.77 (95%CI, 0.72-0.81) and a specificity of 0.80 (95%CI, 0.75-0.85). CONCLUSION: In our neurology clinic, the Mini-Cog showed acceptable diagnostic usefulness for detecting CI, greater than that of the CDT; neither test is an appropriate instrument for individuals with a low level of education.