Análisis psicométrico del cuestionario de memoria prospectiva y retrospectiva

Abstract

Para poder cuantificar e investigar científicamente las quejas mnésicas de los pacientes, se hace necesario contar con un instrumento adaptado y que presente análisis psicométricos adecuados. El objetivo del presente trabajo fue estudiar propiedades psicométricas de una versión argentina del Cuestionario de Memoria Prospectiva y Retrospectiva. Para ello se administró el Cuestionario de Memoria Prospectiva y Retrospectiva de forma individual a 192 participantes sanos con más de 27 puntos en el Mini Mental State Examination. La media de edad fue de 39.67 años (DE = 12.3). La media de escolaridad fue de 14.5 años (DE = 2.72). A un subgrupo de participantes (n = 45) denominado Subgrupo A, también se les administraron pruebas de memoria prospectiva y retrospectiva. El Índice Global del Cuestionario presentó una distribución normal. Según el análisis factorial exploratorio se estableció la extracción de un factor que explicó el 35.19 % de la varianza. El coeficiente α de Cronbach fue de .87. La confiabilidad estimada por el método de la división por mitades fue de .73 y de .84 luego de la corrección con la fórmula de Spearman-Brown. No hubo correlación significativa entre las respuestas del cuestionario y los test de memoria retro y prospectiva en el subgrupo A. Estos resultados permiten concluir que el Cuestionario de Memoria Prospectiva y Retrospectiva presenta adecuados índices de confiabilidad y una estructura de un solo factor. Si bien no se asocia con el rendimiento objetivo en pruebas de memoria, muestra ser apropiado para el registro de las quejas subjetivas de los pacientes en la región de estudio.

Memory complaints are the reason for consultation in many cases of neurological injuries and in the majority of aged people who attend the neurological clinic. The presence of memory complaints is a diagnostic criterion for mild cognitive impairment, for which it is necessary to have an appropriate and specific instrument, which would allow us to quantify and scientifically investigate it. The aim of the present study is to analyze the psychometric properties of an Argentine version of the Prospective and Retrospective Memory Questionnaire: the factorial structure of the test; its internal consistency; correlations of the questionnaire with an objective measurement of retro and prospective memory; and correlations of the questionnaire with affective-emotional variables. The Mexican version of the Prospective and Retrospective Memory Questionnaire was administered individually to 192 healthy participants who achieved more than 27 point in the Mini Mental State Examination. A modification was made to the syntax of two sentences in order to increase the comprehensibility. A Global, Prospective and a Retrospective Index of the questionnaire was calculated for each participant. Anxiety (the State-Trait Anxiety Inventory: STAI) and depression (the Beck’s Depression Inventory-II) scales were also administered. The mean age was 39.67 years (SD = 12.3). The average of schooling was 14.5 years (SD = 2.72). We also selected a subgroup of participants (n = 45) with a mean age of 37.58 years (SD = 11.4), and an average schooling in years of 14.36 (SD = 3). In addition to the memory questionnaire, this subgroup, called the A Subgroup, was administered prospective (El Cóndor test) and retrospective (The Selective Memory Test) objective memory tests. The mean in the Global Index was 32.25 (SD = 8.49), in the Prospective Index it was 17.3 (SD = 5.01) and in the Retrospective Index it was 14.95 (SD = 4.07). The test for normality of the distribution of the Global Index Kolmogorov-Smirnov (K-S) was Z = 1.031, p = .238. In the same way, the other two scores of the questionnaire show a normal curve, K-S of the Prospective Index Z = 1.109, p = .171; K-S of the Retrospective Index Z = 1.264, p = .082. According to the exploratory factor analysis through the Maximum Likelihood extraction method, a single factor explained 35.19 % of the variance. The Cronbach’s α coefficient was .87. The reliability estimated by the split-half method was .73 and .84 after correction with the Spearman-Brown formula. There was a significant positive correlation of mild degree between the Global Questionnaire Index and the STAI Trait, r = .33, p = .013, and with the IDB-II, r = .23, p = .127. There was no significant correlation between the questionnaire responses and the retro and prospective memory objective tests in the A Subgroup. The Prospective and Retrospective Memory Questionnaire presents adequate reliability indexes and a single factor structure. The results indicate that the questionnaire associates with anxiety and depression in a positive way, but not with the objective measures of retro and prospective memory, in coincidence with the literature about the relationship between cognitive complaints and cognitive tests performance. In sum, this study shows that the questionnaire is an appropriate instrument to quantify patient’s memory complaints and particularly for its use in the study region. This study is the first in the country to investigate the psychometric properties of the Prospective and Retrospective Memory Questionnaire, widely used in neuropsychological clinic and research around the world. Efforts should be made to obtain normative data and validation in the pathological population of interest.