Validation of the Malay version of the Amsterdam Preoperative Anxiety and Information Scale (APAIS)

Background: Preoperative anxiety is a significant problem worldwide that may affect patients’ surgical outcome. By using a simple and reliable tool such as the Amsterdam Preoperative Anxiety and Information Scale (APAIS), anaesthesiologists would be able to assess preoperative anxiety adequately and accurately. Objective: The purpose of this study was to develop and validate the Malay version of APAIS (Malay-APAIS), and assess the factors associated with higher anxiety scores. Methods: The authors performed forward and backward translation of APAIS into Malay and then tested on 200 patients in the anaesthetic clinic of University Malaya Medical Centre. Psychometric analysis was performed with factor analysis, internal consistency and correlation with Spielberger’s State-Trait Anxiety Inventory (STAI-state). Results: A good correlation was shown with STAI-state (r = 0.59). Anxiety and need for information both emerged with high internal consistency (Cronbach’s alpha 0.93 and 0.90 respectively). Female gender, surgery with a higher risk and need for information were found to be associated with higher anxiety scores. On the other hand, previous experience with surgery had lower need for information. Conclusion: The Malay-APAIS is a valid and reliable tool for the assessment of patients’ preoperative anxiety and their need for information. By understanding and measuring patient’s concerns objectively, the perioperative management will improve to a much higher standard of care.

Usos del coeficiente alfa de Cronbach en el análisis de instrumentos escritos / The usage of the Cronbach Coefficient alpha in the Analysis of the Written Instruments

Se realizó un estudio de carácter evaluativo para determinar la precisión de un examen escrito mediante un análisis de fiabilidad. El examen, integrado por 30 preguntas que exploran cierto tipo de conocimiento profesional, se aplicó a 45 personas, y con los puntajes obtenidos se creó una base de datos en SPSS para Windows, versión 16. Se calculó el coeficiente alfa de Cronbach, para diferentes partes del examen y coeficientes de discriminación para determinar las variables más relevantes a los efectos de la confiabilidad del examen. Los resultados principales se presentaron en tablas. Se obtuvo un valor negativo para la confiabilidad del examen, y mediante eliminación de preguntas y cambio de escala de los puntajes, se obtuvo un examen de confiabilidad aceptable. Se concluyó que el análisis de fiabilidad es un procedimiento efectivo para incrementar la precisión de un examen

It was performed a study, to evaluate the precision of a written test by means of a reliability analysis. The test, with 30 questions exploring some kind of professional knowledge, was applied to a set of 45 persons. Using the SPSS for Windows Version 16 software, a data base was created with the scores obtained. We calculated the Cronbach alpha coefficients for different parts of the test and the corresponding indexes of discrimination in order to determine the most relevant variables related with the reliability of the test. The principal findings were presented in statistical tables. A negative value of the reliability coefficient was obtained for the initial test, but, by means of putting out some questions and making appropriate changes in the score scales of them, a new version of the test with a medium level of reliability was obtained. It was concluded that the reliability analysis is an effective tool to increase the precision of a test

Coeficientes de confiabilidad de instrumentos escritos en el marco de la teoría clásica de los tests / Reliability coefficient of written tools in the frame of the classical theory of tests

Evaluar la confiabilidad en el marco de la teoría clásica de los tests y precisar las condiciones bajo las cuales el coeficiente alfa de Cronbach constituye la mejor alternativa. El coeficiente alfa de Cronbach es el recurso numérico más utilizado para evaluar la confiabilidad de instrumentos escritos. Como prueba de esto, baste decir que desde su publicación en 1951 hasta la fecha, ha sido citado más de 5 590 veces. Sin embargo, se ha comprobado que en no pocas situaciones este coeficiente no es la mejor alternativa para evaluar la confiabilidad. Se discutieron varias alternativas para la evaluación de la confiabilidad y se precisaron las condiciones bajo las cuales el coeficiente alfa de Cronbach constituye la mejor alternativa. La teoría clásica de los tests constituye un modelo apropiado para desarrollar el concepto de confiabilidad y las diferentes fórmulas de cálculo de mayor utilidad en las aplicaciones, el coeficiente alfa de Cronbach es el indicador más utilizado para cuantificar la consistencia interna de los tests y es necesario tener en cuenta los supuestos que sustentan la correcta aplicación del coeficiente alfa para hacer una interpretación adecuada de su valor numérico.

To assess reliability in the frame of the classical theory of tests and to exactly specify the conditions under which Cronbach's alpha coefficient is the best option. Cronbach's alpha coefficient is the most used numerical resort to evaluate the reliability of written tools. As a proof, it is enough to say that from its publication in 1951 up to now, it has been cited more than 5 590 times. However, it has been proved that this coefficient is not always the best option to assess reliability. Various alternatives were discussed for the assessment of reliability, and the conditions under which Cronbach's alfa coefficient is the best choice were determined. The classical theory of tests is an appropriate model to develop the concept of reliability and the calculation formulae more useful for the applications. This coefficient is the most used indicator to quantify the internal consistency of tests, and it is necessary to bear in mind the suppositions that support the correct application of alpha coefficient to make a proper interpretation of its numerical value.