Diagnostic value of a simplified Pfeiffer questionnaire for polypathological patients. / Valor diagnóstico de un cuestionario de Pfeiffer simplificado en pacientes pluripatológicos.

OBJECTIVES: To analyse the correlation, sensitivity, specificity and positive predictive (PPV) and negative predictive (NPV) values of each question on the Pfeiffer questionnaire (SPMSQ) compared with the full questionnaire for polypathological patients (PPPs). METHODS: Multicentre cross-sectional study. An SPMSQ score is considered pathological if 3 or more errors are recorded. For each question and combination of 2 questions, we calculated the correlation (kappa index), sensitivity, specificity and predictive values compared with the full SPMSQ. RESULTS: Of the 1632 PPPs included (mean age, 77.9±9.8 years, 53% men), 1434 performed the SPMSQ (the remaining presented delirium); 39% of the PPPs were pathological. The question "What day is it today?" and the command "Count backwards by 3s from 20" obtained good correlation and NPV (85 and 89%, respectively); the combination of both increased the NPV to 97%. The question "When were you born?' achieved good correlation and greater PPV (93%). CONCLUSIONS: The combination of the question "What day is it today?" and the command "Count backwards by 3s from 20" achieved a high NPV. The question related to the date of birth achieved the highest PPV.