<?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>1139-7632</journal-id>
<journal-title><![CDATA[Pediatría Atención Primaria]]></journal-title>
<abbrev-journal-title><![CDATA[Rev Pediatr Aten Primaria]]></abbrev-journal-title>
<issn>1139-7632</issn>
<publisher>
<publisher-name><![CDATA[Asociación Española de Pediatría de Atención Primaria]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S1139-76322017000100016</article-id>
<title-group>
<article-title xml:lang="es"><![CDATA[Diseños secuenciales: interrupción precoz del ensayo clínico]]></article-title>
<article-title xml:lang="en"><![CDATA[Sequential designs: early interruption of clinical trial]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Molina Arias]]></surname>
<given-names><![CDATA[M]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
<xref ref-type="aff" rid="Aaf"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Hospital Infantil Universitario La Paz Servicio de Gastroenterología ]]></institution>
<addr-line><![CDATA[ Madrid]]></addr-line>
<country>España</country>
</aff>
<aff id="Af2">
<institution><![CDATA[,AEP/AEPap Grupo de Trabajo de Pediatría Basada en la Evidencia ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>España</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>03</month>
<year>2017</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>03</month>
<year>2017</year>
</pub-date>
<volume>19</volume>
<numero>73</numero>
<fpage>87</fpage>
<lpage>90</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://scielo.isciii.es/scielo.php?script=sci_arttext&amp;pid=S1139-76322017000100016&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://scielo.isciii.es/scielo.php?script=sci_abstract&amp;pid=S1139-76322017000100016&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://scielo.isciii.es/scielo.php?script=sci_pdf&amp;pid=S1139-76322017000100016&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="es"><p><![CDATA[Resumen: Al contrario que en el ensayo en paralelo habitual, en los diseños secuenciales el tamaño muestral no es fijo, sino que depende de los resultados de análisis intermedios que se realizarán a lo largo del estudio. Son los resultados de estos análisis intermedios los que determinarán si el ensayo puede finalizar o debe continuar hasta alcanzar un tamaño muestral máximo previamente fijado.]]></p></abstract>
<abstract abstract-type="short" xml:lang="en"><p><![CDATA[Abstract: Unlike in the usual parallel clinical trials, in sequential designs the sample size is not fixed, but depends on the results of interim analysis that will be carried out throughout the study. The results of these interim analyzes will determine if the trial can be interrupted or must continue until reaching a previously set maximum sample size.]]></p></abstract>
<kwd-group>
<kwd lng="es"><![CDATA[Análisis intermedios]]></kwd>
<kwd lng="es"><![CDATA[Ensayos secuenciales]]></kwd>
<kwd lng="en"><![CDATA[Interim analysis]]></kwd>
<kwd lng="en"><![CDATA[Sequential trials]]></kwd>
</kwd-group>
</article-meta>
</front><back>
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