<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>0212-1611</journal-id>
<journal-title><![CDATA[Nutrición Hospitalaria]]></journal-title>
<abbrev-journal-title><![CDATA[Nutr. Hosp.]]></abbrev-journal-title>
<issn>0212-1611</issn>
<publisher>
<publisher-name><![CDATA[Grupo Arán]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S0212-16112008000300011</article-id>
<title-group>
<article-title xml:lang="es"><![CDATA[Validación de un cuestionario de frecuencia de consumo alimentario corto: reproducibilidad y validez]]></article-title>
<article-title xml:lang="en"><![CDATA[Validation of a short questionnaire on frequency of dietary intake: reproducibility and validity]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Trinidad Rodríguez]]></surname>
<given-names><![CDATA[I.]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Fernández Ballart]]></surname>
<given-names><![CDATA[J.]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Cucó Pastor]]></surname>
<given-names><![CDATA[G.]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Biarnés Jordà]]></surname>
<given-names><![CDATA[E.]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Arija Val]]></surname>
<given-names><![CDATA[V.]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
</contrib-group>
<aff id="A01">
<institution><![CDATA[,Universidad Rovira i Virgili Facultad de Medicina y Ciencias de la Salud. Medicina Preventiva y Salud Pública ]]></institution>
<addr-line><![CDATA[Reus ]]></addr-line>
<country>España</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>06</month>
<year>2008</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>06</month>
<year>2008</year>
</pub-date>
<volume>23</volume>
<numero>3</numero>
<fpage>242</fpage>
<lpage>252</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://scielo.isciii.es/scielo.php?script=sci_arttext&amp;pid=S0212-16112008000300011&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://scielo.isciii.es/scielo.php?script=sci_abstract&amp;pid=S0212-16112008000300011&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://scielo.isciii.es/scielo.php?script=sci_pdf&amp;pid=S0212-16112008000300011&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="es"><p><![CDATA[Antecedentes: El conocimiento de la ingesta dietética de los individuos es una herramienta fundamental para conocer patrones alimentarios y explorar su asociación con el riesgo de enfermedad. Actualmente, uno de los métodos más utilizados son los cuestionarios de consumo alimentario. El principal inconveniente de su uso es la necesidad de ser validado previamente. Nuestro objetivo es validar un cuestionario de frecuencia de consumo alimentario corto. Ámbito: Reus (Cataluña), España. Sujetos: 71 adolescentes y adultos de ambos sexos, con niveles socioculturales y categorías profesionales diferentes. Intervenciones: El cuestionario fue administrado 2 veces en un periodo aproximado de un año para valorar la reproducibilidad. A lo largo de este mismo periodo se administraron 9 recordatorios de 24 horas (método de referencia) para determinar su validez. Resultados: Los coeficientes de correlación de Spearman para el estudio de reproducibilidad oscilaban entre 0,49 y 0,75 para los alimentos y entre 0,44 y 0,78 para la energía y los nutrientes. La mayoría de coeficientes de correlación intraclase oscilaron entre 0,53 y 0,96 para los alimentos y entre 0,49 y 0,78 para la energía y los nutrientes. En el estudio de validez las correlaciones oscilaron entre 0,27 y 0,59 para los alimentos y entre 0,30 y 0,49 para la energía y los nutrientes. Los coeficientes de correlación intraclase en el estudio de validez oscilaron entre 0,41 y 0,67 para los alimentos y entre 0,29 y 0,47 para la energía y nutrientes. Conclusión: El cuestionario permite valorar en general el consumo de grupos de alimentos, energía y macronutrientes con adecuada reproducibilidad y validez.]]></p></abstract>
<abstract abstract-type="short" xml:lang="en"><p><![CDATA[Background: Knowledge on dietary intake in individuals is an essential tool to know the dietary patterns and explore their association with the disease risk. One of the current methods most currently used are dietary intake questionnaires. The main drawback of their use is the need for previous validation. Our objective was to validate a short questionnaire on the frequency of dietary intake. Setting: Reus (Catalonia), Spain. Subjects: 71 adolescents and adults from both genders, with different socio-cultural levels and professional categories. Interventions: The questionnaire was administered two times within an approximated period of one year to assess the reproducibility. Through this time, 9 24-hour recalls (gold standard method) were administered to determine the validity. Results: Spearman's correlation coefficients for the reproducibility analysis varied 0.49-0.75 for foods and 0.44-0.78 for energy and nutrients. Most of intra-class correlation coefficients varied 0.53-0.96 for foods and 0.49-0.78 for energy and nutrients. In the validity analysis, the correlations varied 0.27-0.59 for foods, and 0.30-0.49 for energy and nutrients. The correlation coefficients in the validity study varied 0.41-0.67 for foods, and 0.29-0.47 for energy and nutrients. Conclusion: The questionnaire allows assessing the consumption of groups of foods, energy and macronutrients with adequate reproducibility and validity.]]></p></abstract>
<kwd-group>
<kwd lng="es"><![CDATA[Cuestionario de frecuencia de consumo alimentario]]></kwd>
<kwd lng="es"><![CDATA[Validez]]></kwd>
<kwd lng="es"><![CDATA[Reproducibilidad]]></kwd>
<kwd lng="en"><![CDATA[Questionnaire on frequency of food consumption]]></kwd>
<kwd lng="en"><![CDATA[Validity]]></kwd>
<kwd lng="en"><![CDATA[Reproducibility]]></kwd>
</kwd-group>
</article-meta>
</front><body><![CDATA[ <p align="right"><b><font face="Verdana" size="2"><a name="top"></a>ORIGINAL</font></b></p>     <p align="right">&nbsp;</p>     <p><font face="Verdana"><b> <font size="4">Validaci&oacute;n de un cuestionario de frecuencia de consumo alimentario corto: reproducibilidad y validez</font></b></font></p>     <p><b><font face="Verdana" size="4">Validation of a short questionnaire on frequency of dietary intake: reproducibility and validity</font></b></p>     <p>&nbsp;</p>     <p>&nbsp;</p>     <p><b><font size="2" face="Verdana">I. Trinidad Rodr&iacute;guez, J. Fern&aacute;ndez Ballart, G. Cuc&oacute; Pastor, E. Biarn&eacute;s Jord&agrave; y V. Arija Val</font></b></p>     <p><font size="2" face="Verdana">Facultad de Medicina y Ciencias de la Salud. Medicina Preventiva y Salud P&uacute;blica. Universidad Rovira i Virgili. Reus. Tarragona. Espa&ntilde;a.</font></p>     <p><a href="#bajo"><font size="2" face="Verdana">Direcci&oacute;n para correspondencia</font></a></p>     <p>&nbsp;</p>     ]]></body>
<body><![CDATA[<p>&nbsp;</p> <hr size="1">     <p><b><font size="2" face="Verdana">RESUMEN</font></b></p>     <p><font face="Verdana" size="2"><B>Antecedentes:</B> El conocimiento de la ingesta diet&eacute;tica de los individuos es una herramienta fundamental para conocer patrones alimentarios y explorar su asociaci&oacute;n con el riesgo de enfermedad. Actualmente, uno de los m&eacute;todos m&aacute;s utilizados son los cuestionarios de consumo alimentario. El principal inconveniente de su uso es la necesidad de ser validado previamente. Nuestro objetivo es validar un cuestionario de frecuencia de consumo alimentario corto.    <BR><B>&Aacute;mbito:</B> Reus (Catalu&ntilde;a), Espa&ntilde;a.    <BR><B>Sujetos:</B> 71 adolescentes y adultos de ambos sexos, con niveles socioculturales y categor&iacute;as profesionales diferentes.    <BR><B>Intervenciones:</B> El cuestionario fue administrado 2 veces en un periodo aproximado de un a&ntilde;o para valorar la reproducibilidad. A lo largo de este mismo periodo se administraron 9 recordatorios de 24 horas (m&eacute;todo de referencia) para determinar su validez.    <BR><B>Resultados:</B> Los coeficientes de correlaci&oacute;n de Spearman para el estudio de reproducibilidad oscilaban entre 0,49 y 0,75 para los alimentos y entre 0,44 y 0,78 para la energ&iacute;a y los nutrientes. La mayor&iacute;a de coeficientes de correlaci&oacute;n intraclase oscilaron entre 0,53 y 0,96 para los alimentos y entre 0,49 y 0,78 para la energ&iacute;a y los nutrientes.    <BR>En el estudio de validez las correlaciones oscilaron entre 0,27 y 0,59 para los alimentos y entre 0,30 y 0,49 para la energ&iacute;a y los nutrientes. Los coeficientes de correlaci&oacute;n intraclase en el estudio de validez oscilaron entre 0,41 y 0,67 para los alimentos y entre 0,29 y 0,47 para la energ&iacute;a y nutrientes.    <BR><B>Conclusi&oacute;n:</B> El cuestionario permite valorar en general el consumo de grupos de alimentos, energ&iacute;a y macronutrientes con adecuada reproducibilidad y validez.</b></font></p>     <p><font face="Verdana" size="2"><b>Palabras clave:</b> Cuestionario de frecuencia de consumo alimentario. Validez. Reproducibilidad.</font></p> <hr size="1">     ]]></body>
<body><![CDATA[<p><b><font size="2" face="Verdana">ABSTRACT</font></b></p>     <p><font face="Verdana" size="2"><B>Background:</B> Knowledge on dietary intake in individuals is an essential tool to know the dietary patterns and explore their association with the disease risk. One of the current methods most currently used are dietary intake questionnaires. The main drawback of their use is the need for previous validation. Our objective was to validate a short questionnaire on the frequency of dietary intake.    <BR><B>Setting:</B> Reus (Catalonia), Spain.    <BR><B>Subjects:</B> 71 adolescents and adults from both genders, with different socio-cultural levels and professional categories.    <BR><B>Interventions:</B> The questionnaire was administered two times within an approximated period of one year to assess the reproducibility. Through this time, 9 24-hour recalls (gold standard method) were administered to determine the validity.    <BR><B>Results:</B> Spearman's correlation coefficients for the reproducibility analysis varied 0.49-0.75 for foods and 0.44-0.78 for energy and nutrients. Most of intra-class correlation coefficients varied 0.53-0.96 for foods and 0.49-0.78 for energy and nutrients.    <BR>In the validity analysis, the correlations varied 0.27-0.59 for foods, and 0.30-0.49 for energy and nutrients. The correlation coefficients in the validity study varied 0.41-0.67 for foods, and 0.29-0.47 for energy and nutrients.    <BR><B>Conclusion:</B> The questionnaire allows assessing the consumption of groups of foods, energy and macronutrients with adequate reproducibility and validity.</b></font></p>     <p><font face="Verdana" size="2"><b>Key words:</b> Questionnaire on frequency of food consumption.Validity. Reproducibility.</font></font></p> <hr size="1">     <p>&nbsp;</p>     ]]></body>
<body><![CDATA[<p><b><font face="Verdana">Introducci&oacute;n</font></b></p>     <p><font size="2" face="Verdana">Debido a la influencia que ejerce la alimentaci&oacute;n sobre el desarrollo y evoluci&oacute;n de las enfermedades<sup>1-3</sup>, as&iacute; como para su prevenci&oacute;n y tratamiento, resulta de vital importancia el poder disponer de un buen conocimiento de los h&aacute;bitos alimentarios de la poblaci&oacute;n. La medici&oacute;n de la ingesta en cualquier poblaci&oacute;n es dif&iacute;cil de realizar y est&aacute; considerada como uno de los mayores problemas metodol&oacute;gicos de la epidemiolog&iacute;a nutricional<sup>4-7</sup>. Por este motivo es imprescindible el disponer de instrumentos capaces de valorar la ingesta alimentaria para poder explorar asociaciones entre dieta y enfermedad<sup>6,8-10</sup>.</font></p>     <p><font size="2" face="Verdana">Uno de los m&eacute;todos m&aacute;s com&uacute;nmente utilizados es el Cuestionario de Frecuencia de Consumo de Alimentos (CFCA)<sup>6, 11-16</sup> debido a que permite obtener informaci&oacute;n del modelo de consumo habitual a largo plazo en poblaciones grandes. Adem&aacute;s de tratarse de un m&eacute;todo relativamente barato, r&aacute;pido y f&aacute;cil de aplicar<sup>6, 17-19</sup>.</font></p>     <p><font size="2" face="Verdana">Exige un menor esfuerzo por parte del entrevistado que otros m&eacute;todos, no altera el patr&oacute;n de consumo habitual y permite extraer informaci&oacute;n sobre la influencia de la variabilidad estacional o incluso intersemanal<sup>6</sup>. Finalmente, los CFCA son capaces de clasificar a los individuos de una poblaci&oacute;n seg&uacute;n su consumo lo que permite realizar comparaciones e identificar conductas de alto riesgo. No obstante, es necesario validar cualquier CFCA antes de su uso en la poblaci&oacute;n espec&iacute;fica para la que ha sido dise&ntilde;ado<sup>5, 6, 18, 20</sup>.</font></p>     <p><font size="2" face="Verdana">En la poblaci&oacute;n espa&ntilde;ola se han realizado pocos estudios de este tipo<sup>2, 21</sup> y ser&iacute;a de gran utilidad disponer de instrumentos adaptados a regiones geogr&aacute;ficas espec&iacute;ficas<sup>22</sup> o los h&aacute;bitos alimentarios de subgrupos poblacionales con especial riesgo nutricional como son los ni&ntilde;os y adolescentes<sup>14, 23-25</sup>, los ancianos o las mujeres embarazadas y en edad f&eacute;rtil<sup>20, 26, 27</sup>.</font></p>     <p><font size="2" face="Verdana">Para validar un CFCA se debe verificar la reproducibilidad y la validez de sus mediciones. Para valorar la reproducibilidad de un cuestionario o la capacidad para medir lo mismo en diferentes momentos es necesario comprobar que existe similitud entre los resultados obtenidos en dos momentos diferentes. La validez del cuestionario o habilidad para estimar ingestas similares a otros m&eacute;todos se estudia comparando sus resultados con los obtenidos por otros m&eacute;todos considerados como referencia, como son los registros diet&eacute;ticos y los recordatorios de 24 horas (R-24h)<sup>6, 16, 17, 28</sup>.</font></p>     <p><font size="2" face="Verdana">Este estudio tiene como objetivo la validaci&oacute;n de un CFCA con 45 &iacute;tems elaborado para evaluar los h&aacute;bitos alimentarios en la poblaci&oacute;n general.</font></p>     <p>&nbsp;</p>     <p><b><font face="Verdana">Material y m&eacute;todos</font></b></p>     <p><i><font size="2" face="Verdana">Sujetos</font></i></p>     ]]></body>
<body><![CDATA[<p><font size="2" face="Verdana">Participaron 71 voluntarios adolescentes y adultos. Los adolescentes fueron reclutados de un instituto p&uacute;blico de ense&ntilde;anza secundaria y los adultos, de 3 centros distintos (hospital, facultad de medicina e instituto de educaci&oacute;n secundaria). La muestra inicial fue de 48 adolescentes (41,7% varones y 58,3% mujeres) de edades comprendidas entre 13-16 a&ntilde;os y de 35 adultos (48,6% varones y 51,4% mujeres). Un 65,7% de los adultos ten&iacute;an entre 25-45 a&ntilde;os y un 34,3% entre 46-65 a&ntilde;os. La muestra de adultos representaba los 3 niveles socioculturales: bajo (37,1%), medio (28,6%) y alto (34,3%). Abandonaron el estudio 7 adolescentes y 4 adultos. Un adulto var&oacute;n fue excluido del an&aacute;lisis por estar realizando dieta hipocal&oacute;rica.</font></p>     <p><i><font size="2" face="Verdana">Dise&ntilde;o del estudio</font></i></p>     <p><font size="2" face="Verdana">El estudio comprendi&oacute; el periodo de tiempo de un a&ntilde;o. Al inicio y al final de este periodo los participantes cumplimentaron el mismo CFCA (CFCA1 y CFCA2 respectivamente). A lo largo de este a&ntilde;o entrevistadores entrenados estimaron el consumo alimentario de 9 d&iacute;as mediante el m&eacute;todo de R-24 h en 3 periodos distanciados equitativamente a lo largo del a&ntilde;o. En cada periodo se estimaron 3 d&iacute;as de 2 semanas consecutivas que inclu&iacute;an un festivo<sup>23, 29, 30</sup>  (<a href="/img/revistas/nh/v23n3/original7_f1.gif" target="_blank">fig. 1</a>).</font></p>     <p><i><font size="2" face="Verdana">Confecci&oacute;n del CFCA</font></i></p>     <p><font size="2" face="Verdana">Se dise&ntilde;&oacute; un CFCA corto, de 45 &iacute;tems, auto-administrado que preguntaba sobre el n&uacute;mero de veces a la semana o al mes con que habitualmente se consum&iacute;an determinados grupos de alimentos (<a href="/img/revistas/nh/v23n3/original7_anexo1.gif" target="_blank">anexo I</a>). El listado de alimentos incluidos en el CFCA fue creado partiendo de datos del mismo grupo de edad de un estudio de Estimaci&oacute;n del Consumo Alimentario que se us&oacute; como referencia (ECA-REF)<sup>31, 32</sup>. En este estudio se identificaron los grupos de alimentos que m&aacute;s contribu&iacute;an a la ingesta de energ&iacute;a y macronutrientes. Posteriormente, se agruparon todos los alimentos de consumo habitual en 45 &iacute;tems.</font></p>     <p><font size="2" face="Verdana">El aceite no fue incluido en el listado a pesar de ser un alimento habitualmente consumido y con importante contribuci&oacute;n a la ingesta de energ&iacute;a y l&iacute;pidos. Esto fue debido a que su consumo en varios platos y varias veces al d&iacute;a dificultaba la estimaci&oacute;n de su frecuencia. Por lo tanto se opt&oacute; por aplicar a todos los sujetos 46 g/d&iacute;a, cantidad media obtenida del estudio ECA-REF.</font></p>     <p><font size="2" face="Verdana">Para comprobar la comprensi&oacute;n del CFCA se administr&oacute; a 3 adolescentes y 3 adultos previamente al inicio del estudio.</font></p>     <p><i><font size="2" face="Verdana">Generaci&oacute;n de tablas</font></i>     <p><font size="2" face="Verdana">Se generaron tablas para obtener datos cuantitativos partiendo del <a href="/img/revistas/nh/v23n3/original7_f2.gif" target="_blank">CFCA</a>.</font></p>     <p><font size="2" face="Verdana">Tabla del Peso de la Raci&oacute;n de los &Iacute;tems (PRI) </font></p>     ]]></body>
<body><![CDATA[<p><font size="2" face="Verdana">El peso de la raci&oacute;n de consumo habitual de cada&iacute;tem se obtuvo a partir de los valores del estudio ECA-REF redondeados por expertos en nutrici&oacute;n (<a href="/img/revistas/nh/v23n3/original7_t1.gif" target="_blank">tabla I</a>).</font></p>     <p><font size="2" face="Verdana">Tabla de Composici&oacute;n de Alimentos Adaptada (CAA)</font>     <p><font size="2" face="Verdana">Se utiliz&oacute; la tabla de composici&oacute;n de alimentos francesa REGAL<sup>33</sup> para crear la nueva tabla de CAA.</font></p>     <p><font size="2" face="Verdana">A partir de los datos del estudio ECA-REF, primero se sum&oacute; el consumo en la poblaci&oacute;n de todos los alimentos incluidos en cada &iacute;tem; posteriormente, se calcul&oacute; la proporci&oacute;n de este total aportado por cada uno de estos alimentos. Por ejemplo, el consumo del &iacute;tem"leche" estaba constituido en un 45,2% de leche entera, un 36,3% de leche semidesnatada y un 38,5% de leche desnatada, en total 100%. Estos porcentajes se utilizaron como factores de ponderaci&oacute;n. Finalmente, se calcul&oacute; el contenido energ&eacute;tico y nutricional de cada &iacute;tem (tabla CAA) aplicando los factores de ponderaci&oacute;n a la tabla REGAL original.</font></p>     <p><i><font size="2" face="Verdana">An&aacute;lisis de la informaci&oacute;n del CFCA</font></i></p>     <p><font size="2" face="Verdana">Las respuestas obtenidas del CFCA sobre el de n&uacute;mero de veces que era consumido cada &iacute;tem a la semana o al mes se transformaron en n&uacute;mero de veces que eran consumidos al d&iacute;a.</font></p>     <p><font size="2" face="Verdana">Posteriormente se calcularon los g/d&iacute;a multiplicando las frecuencias de consumo de cada &iacute;tem por el peso de la raci&oacute;n de consumo habitual de cada &iacute;tem (tabla de PRI).</font></p>     <p><font size="2" face="Verdana">Por &uacute;ltimo, el valor energ&eacute;tico y nutricional fue calculado aplicando la tabla de CAA.</font></p>     <p><font size="2" face="Verdana">Los 45 &iacute;tems del CFCA se reagruparon en 16 grupos de alimentos: 1.- carne (carne picada, carne roja, pollo y pavo), 2.- embutidos, 3.- huevos, 4.- pescado (pescado y marisco), 5.- leche, 6.- derivados l&aacute;cteos (yogur, queso, resto de productos l&aacute;cteos), 7.- cereales (cereales de desayuno, galletas, boller&iacute;a, pan, pasta y arroz), 8.- patatas (patata, legumbres y frutos secos, 9.- verdura (ensaladas y verduras), 10.- fruta (fruta, fruta en conserva), 11.- az&uacute;cares (az&uacute;car y chocolates), 12.-bebidas azucaradas, 13.- vino, 14.- bebidas destiladas, 15.- cerveza y 16.- bebidas light.</font></p>     <p><i><font size="2" face="Verdana">An&aacute;lisis de la informaci&oacute;n del m&eacute;todo de referencia: R-24 h</font></i>     ]]></body>
<body><![CDATA[<p><font size="2" face="Verdana">La ingesta de alimentos/d&iacute;a se calcul&oacute; mediante la media de consumo de alimentos de los 9 d&iacute;as valorados de cada sujeto con el R-24 h<sup>30</sup>.</font></p>     <p><font size="2" face="Verdana">Para realizar una mejor evaluaci&oacute;n de la cantidad ingerida de los alimentos las entrevistas fueron realizadas por una dietista entrenada. Adem&aacute;s, para valorar correctamente el tama&ntilde;o de las raciones de los alimentos se utiliz&oacute; un archivo fotogr&aacute;fico y se utiliz&oacute; una tabla estandarizada para calcular la parte comestible de los alimentos, creada por la unidad de investigaci&oacute;n<sup>31, 32</sup>.</font></p>     <p><font size="2" face="Verdana">Los alimentos fueron agrupados en los mismos 16 grupos finales que el CFCA para comparar los resultados obtenidos por ambos m&eacute;todos.</font></p>     <p><font size="2" face="Verdana">Para el c&aacute;lculo de la ingesta de energ&iacute;a y nutrientes se utiliz&oacute; la tabla REGAL.</font></p>     <p><i><font size="2" face="Verdana">Depuraci&oacute;n de los datos</font></i></p>     <p><font size="2" face="Verdana">Se consideraron valores extremos de consumo alimentario las ingestas de aquellos &iacute;tems que se alejaban m&aacute;s de 1,5 veces de la amplitud intercuartil de consumo de aquel alimento. En la aplicaci&oacute;n de este &uacute;ltimo criterio se elimin&oacute; del an&aacute;lisis a un sujeto adulto que cumpliment&oacute; un CFCA con valores extremos.</font></p>     <p><i><font size="2" face="Verdana">M&eacute;todos estad&iacute;sticos</font></i></p>     <p><font size="2" face="Verdana">Los datos fueron analizados mediante el programa SPSS (versi&oacute;n 13.0 para Windows). Para conocer la distribuci&oacute;n de la ingesta se calcularon los percentiles 25, 50 y 75. Cuando no se cumpl&iacute;an las condiciones de aplicaci&oacute;n de las pruebas param&eacute;tricas se utilizaron las correspondientes pruebas no param&eacute;tricas. Se calcularon los coeficientes de correlaciones de Spearman con los datos sin ajustar y ajustados por la energ&iacute;a mediante regresi&oacute;n lineal y los coeficientes de correlaci&oacute;n intraclase (CCI). Se realiz&oacute; un an&aacute;lisis para datos apareados mediante la prueba de Wilcoxon para valorar la significaci&oacute;n de las medias de las diferencias de consumo alimentario, energ&eacute;tico y nutricional entre los cuestionarios.</font></p>     <p><font size="2" face="Verdana">En todas las pruebas estad&iacute;sticas se utiliz&oacute; el nivel de significaci&oacute;n p &lt; 0,05 para contrastes bilaterales.</font></p>     <p>&nbsp;</p>     ]]></body>
<body><![CDATA[<p><b><font face="Verdana">Resultados</font></b></p>     <p><i><font size="2" face="Verdana">Reproducibilidad</font></i>     <p><font size="2" face="Verdana">Las <a href="/img/revistas/nh/v23n3/original7_t2.gif" target="_blank"> tablas II</a> y <a href="/img/revistas/nh/v23n3/original7_t3.gif" target="_blank"> III</a> muestran los percentiles 25, 50 y 75 de ingesta en las dos ocasiones evaluadas con el CFCA (CFCA1 y CFCA2). Con la finalidad de conocer la reproducibilidad del CFCA, se calculan los coeficientes de correlaci&oacute;n de Spearman  para los grupos de alimentos, que son &gt; 0,50 para la carne, las verduras y frutas, las bebidas azucaradas, el vino y las bebidas destiladas; y en los nutrientes fueron &gt; 0,60, siendo especialmente elevados (&gt; 0,70) para la energía, el alcohol y los ß-carotenos. Para el 81% de los grupos de alimentos y el 79% de los nutrientes, el coeficiente de correlación es &#8805; 0,50, y para el 12,5% de alimentos y 15,8% de los nutrientes la correlación es &#8805; 0,70.</font></p>     <p><font size="2" face="Verdana">Cuando se calculan los coeficientes de correlaci&oacute;n de Spearman con la ingesta ajustada por la energ&iacute;a se obtiene una disminuci&oacute;n general de las correlaciones, respecto a los valores no ajustados. Esta disminuci&oacute;n es m&aacute;s ostensible para las bebidas destiladas, cerveza, hierro, tiamina y piridoxina. Sin embargo, ocurre lo contrario con el pescado, la leche, las verduras y el vino, as&iacute; como con el alcohol, los &szlig;-carotenos y la vitamina D, cuyos valores se incrementan.</font></p>     <p><font size="2" face="Verdana">Los coeficientes de correlaci&oacute;n intraclase (CCI) que se obtienen con los grupos de alimentos son todos&gt; 0,50. Huevos, pescado, leche, verduras y la mayor&iacute;a de bebidas son &gt; 0,70. Para la energ&iacute;a y nutrientes, la mayor&iacute;a de los CCI mejoran respecto al coeficiente de correlaci&oacute;n de Spearman con y sin ajustar por la energ&iacute;a, coincidiendo los valores m&aacute;s bajos para aquellos nutrientes que ya presentan un coeficiente de correlaci&oacute;n de Spearman m&aacute;s bajos.</font></p>     <p><i><font size="2" face="Verdana">Validez</font></i>     <p><font size="2" face="Verdana">En las <a href="/img/revistas/nh/v23n3/original7_t4.gif" target="_blank"> tablas IV</a> y <a href="/img/revistas/nh/v23n3/original7_t5.gif" target="_blank"> V</a> se presentan los percentiles 25, 50 y 75 de la ingesta media de alimentos, energ&iacute;a y nutrientes de los nueve d&iacute;as recogidos por el R-24 h y los del CFCA-2 para analizar la validez del CFCA.</font></p>     <p><font size="2" face="Verdana">Analizando los coeficientes de correlaci&oacute;n de Spearman de los resultados de los R-24 h y el CFCA-2 hemos observado que las mayores correlaciones se aprecian para la energ&iacute;a y los macronutrientes en general, y valores similares se obtienen para las vitaminas C y piridoxina y los &szlig;-carotenos; y el mejor de todos corresponde al alcohol. Los coeficientes m&aacute;s bajos son los correspondientes a la vitamina E y el retinol. Entre los grupos de alimentos, el pescado, los cereales, las verduras, las frutas y el vino obtienen correlaciones&gt; 0,50. La correlaci&oacute;n no es significativa para el grupo que engloba patatas, frutos secos y legumbres.</font></p>     <p><font size="2" face="Verdana">Cuando ajustamos por la energ&iacute;a, los coeficientes de correlaci&oacute;n de Spearman se mantienen en valores similares para la mayor&iacute;a de alimentos y nutrientes. En los alimentos, las mejores correlaciones (&gt; 0,50) corresponden al pescado, las verduras y frutas, el vino y la cerveza. Entre los nutrientes aumentan las correlaciones ajustadas respecto a las no ajustadas para el alcohol, el calcio, los &szlig;-carotenos, la vitamina C, la riboflavina y los folatos; y disminuyen para los cereales, las patatas y las bebidas destiladas; as&iacute; como para los l&iacute;pidos, el hierro y algunas vitaminas.</font></p>     <p><font size="2" face="Verdana">Los CCI para los grupos de alimentos son &gt; 0,60 para el pescado, las frutas y verduras, el vino, las bebidas destiladas y la cerveza. Y en los nutrientes los CCI&gt; 0,50 son para las prote&iacute;nas, la fibra, el alcohol, y los &szlig;-carotenos, la vitamina C y los folatos. Las correlaciones m&aacute;s bajas corresponden al grupo de las patatas, el az&uacute;car y l&iacute;pidos, hierro, retinol y vitaminas E, piridoxina y vitamina B<sub>12</sub>.</font></p>     ]]></body>
<body><![CDATA[<p>&nbsp;</p>     <p><b><font face="Verdana">Discusi&oacute;n</font></b>     <p><font size="2" face="Verdana">En el presente estudio se plante&oacute; la validaci&oacute;n de un CFCA corto y auto-administrable para determinar el consumo habitual alimentario, energ&eacute;tico y nutricional de la poblaci&oacute;n general.</font></p>     <p><font size="2" face="Verdana">La muestra de individuos que particip&oacute; comprend&iacute;a la mayor&iacute;a de las edades de la poblaci&oacute;n (13 a 65 a&ntilde;os), ambos sexos y representaba los diferentes estratos sociales, culturales y laborales de la poblaci&oacute;n.</font></p>     <p><font size="2" face="Verdana">La participaci&oacute;n de 71 individuos es suficiente para identificar como significativas diferencias relevantes en la estimaci&oacute;n de la ingesta. Otros muchos estudios han validado cuestionarios con un n&uacute;mero similar<sup>19, 34-40</sup>o inferior de individuos<sup>18, 24, 41-44</sup> obteni&eacute;ndose resultados aceptables.</font></p>     <p><font size="2" face="Verdana">El dise&ntilde;o aplicado es el propuesto por Willett WC y cols., 1985, aceptado y utilizado habitualmente<sup>4,14,21,23,27,29,45,46</sup>.</font></p>     <p><font size="2" face="Verdana">El m&eacute;todo de referencia de R-24 h utilizado en nuestro estudio difiere en el tipo de errores que se cometen en el CFCA y esto evita la obtenci&oacute;n de &iacute;ndices de validez falsamente elevados<sup>27, 28, 47</sup>. Otros m&eacute;todos como son el registro diet&eacute;tico<sup>11, 39, 42, 43, 48, 49</sup> o el registro diet&eacute;tico por pesada<sup>26, 50</sup> aportan una exactitud similar al R-24 h, pero pueden modificar la ingesta del participante, adem&aacute;s de requerir una mayor implicaci&oacute;n por parte de los sujetos, con la consecuente p&eacute;rdida de participaci&oacute;n<sup>17</sup>. Las determinaciones bioqu&iacute;micas<sup>4, 46, 51</sup> o urinarias<sup>1, 4, 38, 40, 52</sup>, aunque aportan una mayor precisi&oacute;n que las encuestas alimentarias, tienen un mayor coste y s&oacute;lo permiten valorar la ingesta de uno o pocos nutrientes<sup>6, 23, 53</sup>. Existen estudios que han utilizado una triple comparaci&oacute;n (CFCA, m&eacute;todo de referencia y determinaciones bioqu&iacute;micas) denominada m&eacute;todo de tr&iacute;adas, con el cual se aumenta la exactitud de los resultados pero se suman los inconvenientes de los 3 m&eacute;todos<sup>1, 4, 6, 12, 37, 38, 40, 46, 51-53</sup>. Al igual que nosotros, gran n&uacute;mero de estudios han utilizado el m&eacute;todo de R-24 h<sup>1, 17, 40, 44, 52, 54, 55</sup>, ya que lo podemos considerar un m&eacute;todo de referencia adecuado para validar un CFCA, sobre todo cuando se estiman varios d&iacute;as durante el periodo que eval&uacute;a el CFCA y se realiza con un entrevistador entrenado, obteniendo un elevado grado de exactitud en la estimaci&oacute;n de la ingesta habitual<sup>6, 17, 19, 30, 55, 56</sup>. La administraci&oacute;n del R-24 h en diferentes momentos del a&ntilde;o y en distintos d&iacute;as de la semana permiti&oacute; estimar las posibles influencias de las variabilidades estacionales y semanales.</font></p>     <p><font size="2" face="Verdana">Respecto a la duraci&oacute;n del estudio se conoce que estudios demasiado cortos no permiten incluir variaciones estacionales y facilitan el hecho de que los participantes respondan en funci&oacute;n a las respuestas recordadas en la primera administraci&oacute;n del cuestionario. Estudios demasiado largos conllevan a una mayor p&eacute;rdida de participaci&oacute;n y desinter&eacute;s, a una p&eacute;rdida de memoria en lo referente al consumo realizado y, por&uacute;ltimo, aumenta la posibilidad de haberse producido un verdadero cambio en el patr&oacute;n alimentario. Muchos estudios han utilizado tambi&eacute;n un a&ntilde;o entre el primero y el segundo CFCA<sup>1, 4, 6, 11, 21, 23, 28, 29, 40, 45-47, 49,52</sup>.</font></p>     <p><font size="2" face="Verdana">Para la elaboraci&oacute;n de un CFCA es necesario determinar previamente cu&aacute;l es el tipo de informaci&oacute;n que se desea obtener, como por ejemplo si el inter&eacute;s recae en un nutriente concreto (calcio, hierro,...) o en la dieta completa de una poblaci&oacute;n o grupo de poblaci&oacute;n espec&iacute;fico y si el objetivo es la obtenci&oacute;n de informaci&oacute;n cualitativa o cuantitativa.</font></p>     <p><font size="2" face="Verdana">Para confeccionar un CFCA de f&aacute;cil y r&aacute;pida aplicaci&oacute;n y suficientemente inteligible para ser auto-administrado, del mismo modo que han realizado la mayor&iacute;a de estudios semejantes, se elabor&oacute; un CFCA con 45&iacute;tems de forma de cada &iacute;tem inclu&iacute;a alimentos con una composici&oacute;n nutricional similar<sup>9, 14</sup>.</font></p>     ]]></body>
<body><![CDATA[<p><font size="2" face="Verdana">Una reciente revisi&oacute;n de estudios de validaci&oacute;n de CFCA estim&oacute; en 79 la media del n&uacute;mero de &iacute;tems incluidos en los cuestionarios<sup>17</sup>. Existen estudios que demuestran la posibilidad de obtener buenas correlaciones con cuestionarios sencillos y cortos obteniendo buena reproducibilidad y validez para clasificar a los sujetos seg&uacute;n el rango de consumo<sup>2, 8, 20, 24, 28, 29, 34, 35, 42, 49, 57-59</sup>.</font></p>     <p><font size="2" face="Verdana">Un inconveniente de los CFCA es la valoraci&oacute;n del consumo de aceite. Aunque el aceite contribuye de forma importante al aporte energ&eacute;tico y lip&iacute;dico no se incluy&oacute; como un &iacute;tem m&aacute;s del CFCA debido a la dificultad de indicar su frecuencia de consumo. Para solucionar este inconveniente se opt&oacute; por adjudicar a todos los sujetos una cantidad constante de 46 g/d&iacute;a, seg&uacute;n el estudio ECA-REF. Esta aproximaci&oacute;n puede en parte explicar los bajos coeficientes de correlaci&oacute;n de los l&iacute;pidos y de la mayor&iacute;a de micronutrientes relacionados. Otros CFCA validados han encontrado a&uacute;n menores coeficientes de correlaciones en estos mismos nutrientes<sup>60, 61</sup>. Varios autores han descrito que el CFCA sobreestima las grasas como porcentajes de la energ&iacute;a<sup>59</sup>.</font></p>     <p><font size="2" face="Verdana">El dise&ntilde;o del CFCA solicitaba informaci&oacute;n cualitativa, lo cual facilitaba su cumplimentaci&oacute;n, pero no se obten&iacute;an resultados cuantitativos. Para superar esta limitaci&oacute;n se utiliz&oacute; la tabla PRI (tabla I) y la tabla de CAA. Ambos instrumentos podr&aacute;n ser de utilidad en futuros estudios en la misma poblaci&oacute;n o en aquellas con caracter&iacute;sticas similares.</font></p>     <p><font size="2" face="Verdana">La reproducibilidad de nuestro cuestionario ha obtenido correlaciones de Spearman entre 0,49 y 0,75 (0,60 de media) para alimentos y entre 0,44 y 0,78 (0,63 de media) para nutrientes, correspondiendo las m&aacute;s altas a carne, verduras y frutas, bebidas azucaradas, vino y bebidas destiladas y las peores para huevos y pescado. Estos valores de reproducibilidad son comparables con el de otros estudios que han examinado la reproducibilidad de los CFCA dise&ntilde;ados para poblaciones espec&iacute;ficas, donde los coeficientes de correlaci&oacute;n estaban comprendidos entre 0,40 y 0,70<sup>1, 6, 17, 47, 51, 54, 62</sup>, o superiores (&gt; 0,80)<sup>1, 21, 37, 46, 61, 63</sup>. Los buenos resultados en la reproducibilidad del CFCA eran de esperar, ya que con cuestionarios simples, corto y cuantitativos se obtiene mejor reproducibilidad.</font></p>     <p><font size="2" face="Verdana">Los coeficientes de correlaci&oacute;n fueron tambi&eacute;n calculados con datos ajustados por la energ&iacute;a con el objetivo de controlar el efecto de confusi&oacute;n de las calor&iacute;as<sup>9</sup>. Este proceso de ajuste por la energ&iacute;a deber&iacute;a tender a incrementar las correlaciones por la reducci&oacute;n de las variaciones interpersonales<sup>27, 28, 64</sup>, sin embargo, no se observ&oacute; este aumento en nuestro estudio ni tampoco en otros<sup>4, 5, 8, 21, 62</sup>. Aunque el ajuste por la energ&iacute;a se realiza para aumentar el grado de concordancia<sup>5</sup>, en nuestro estudio no lo observamos para todos los nutrientes. Con el CCI mejoran los valores para los grupos de alimentos de 0,53 a 0,96 (0,70 de media) y de energ&iacute;a y nutrientes de 0,49 a 0,78 (0,56 de media).</font></p>     <p><font size="2" face="Verdana">Las correlaciones observadas, en el rango de 0,27 a 0,59 (0,43 de media) para grupos de alimentos y de 0,30 a 0,49 (0,39 de media) para nutrientes sugieren una razonable validez del cuestionario para determinar la exactitud de la ingesta alimentaria. Como suced&iacute;a con la reproducibilidad, cuando ajust&aacute;bamos por la energ&iacute;a, los coeficientes de correlaci&oacute;n de Spearman, en general, tend&iacute;an a disminuir hasta rangos de 0,23 a 0,58 (0,38 de media) para la mayor&iacute;a de grupos de alimentos y de 0,21 a 0,44 (0,30 de media) para la mayor&iacute;a de nutrientes. Otros autores han observado un aumento de los coeficientes de correlaci&oacute;n al ajustar la dieta por la energ&iacute;a ingerida52, pero no para todos los nutrientes; mientras que otros estudios no apreciaban pr&aacute;cticamente diferencia entre los valores ajustados y sin ajustar<sup>8, 65</sup>. La mayor&iacute;a de los CCI oscilaban entre rangos comprendidos entre 0,41 y 0,67 (0,53 de media) para alimentos y entre 0,29 y 0,47 (0,34 de media) para nutrientes.</font></p>     <p><font size="2" face="Verdana">En resumen, las mayores correlaciones obtenidas fueron para la reproducibilidad y buenas para la validez del CFCA. En relaci&oacute;n a la reproducibilidad, los mayores coeficientes de correlaci&oacute;n de Spearman se obtuvieron para verduras, las bebidas azucaradas y especialmente el vino, cuyos coeficientes de correlaci&oacute;n continuaron siendo mayores incluso tras el ajuste por la energ&iacute;a. Los mayores coeficientes de correlaci&oacute;n fueron para los macronutrientes en general, el alcohol y los &szlig;-carotenos.</font></p>     <p><font size="2" face="Verdana">Para la validez, los mayores coeficientes de correlaci&oacute;n corresponden al pescado, las frutas, las verduras y el vino; y entre los nutrientes, continuaban teniendo los mayores coeficientes de correlaci&oacute;n las prote&iacute;nas, los hidratos de carbono, el alcohol, los &szlig;-carotenos y la vitamina C.</font></p>     <p><font size="2" face="Verdana">En conclusi&oacute;n, el CFCA es m&aacute;s v&aacute;lido cuando lo que pretende valorar es la ingesta habitual de grupos de alimentos en general, la energ&iacute;a y los macronutrientes; y es menos v&aacute;lido para la valoraci&oacute;n de la ingesta de micronutrientes, principalmente vitaminas y en especial si &eacute;stas son liposolubles (retinol y vitamina E).</font></p>     <p>&nbsp;</p>     ]]></body>
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Acta Med Port 2003; 16:412-20.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=3522400&pid=S0212-1611200800030001100065&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><P>&nbsp;</p>     <P>&nbsp;</p>     <P><a name="bajo"><font size="2"></font></a><b><font face="Verdana" size="2"><a name="top"></a></font></b><font size="2" face="Verdana"><a href="#top"><img border="0" src="/img/revistas/nh/v23n3/seta.gif" width="15" height="17"></a><b>Dirección para correspondencia:</b>    <BR>Victoria Arija Val.    ]]></body>
<body><![CDATA[<BR>Facultad de Medicina y Ciencias de la Salud.    <BR>Medicina Preventiva y Salud P&uacute;blica.    <BR>Universidad Rovira i Virgili.    <BR>C/ San Lloren&ccedil;, 21    <BR>43201 Reus (Tarragona)    <BR>E-mail: <a href="mailto:mariavictoria.arija@irv.cat">mariavictoria.arija@irv.cat</a> </font></p>     <p><font size="2" face="Verdana">Recibido: 4-VI-2007.    <BR>Aceptado: 5-XI-2007.</font></p>      ]]></body><back>
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