<?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>0120-2448</journal-id>
<journal-title><![CDATA[Acta Medica Colombiana]]></journal-title>
<abbrev-journal-title><![CDATA[Acta Med Colomb]]></abbrev-journal-title>
<issn>0120-2448</issn>
<publisher>
<publisher-name><![CDATA[Asociacion Colombiana de Medicina Interna]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S0120-24482018000200100</article-id>
<title-group>
<article-title xml:lang="es"><![CDATA[Revisiones sistemáticas para la evaluación de intervenciones que incluyen estudios no aleatorizados. Consideraciones metodológicas]]></article-title>
<article-title xml:lang="en"><![CDATA[Systematic reviews for the evaluation of interventions that include non-randomized studies. Methodological considerations]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Muñoz]]></surname>
<given-names><![CDATA[Óscar Mauricio]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Ruiz Morales]]></surname>
<given-names><![CDATA[Álvaro J.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Pontificia Universidad Javeriana Departamento de Medicina Interna Hospital Universitario San Ignacio]]></institution>
<addr-line><![CDATA[Bogotá D.C.]]></addr-line>
<country>Colombia</country>
</aff>
<aff id="Af2">
<institution><![CDATA[,Pontificia Universidad Javeriana Departamento de Medicina Interna Departamento de Epidemiología Clínica y Bioestadística]]></institution>
<addr-line><![CDATA[Bogotá D.C.]]></addr-line>
<country>Colombia</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>06</month>
<year>2018</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>06</month>
<year>2018</year>
</pub-date>
<volume>43</volume>
<numero>2</numero>
<fpage>100</fpage>
<lpage>106</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.co/scielo.php?script=sci_arttext&amp;pid=S0120-24482018000200100&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.co/scielo.php?script=sci_abstract&amp;pid=S0120-24482018000200100&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.co/scielo.php?script=sci_pdf&amp;pid=S0120-24482018000200100&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="es"><p><![CDATA[Resumen Las revisiones sistemáticas para evaluar intervenciones que incluyan la evidencia aportada por los estudios no aleatorizados (ENA), pueden ser muy útiles para soportar decisiones clínicas en temas que no estén bien cubiertos por experimentos clínicos aleatorizados (ECA), como la evaluación de los efectos de un tratamiento a largo plazo, sus efectos adversos o la evaluación de intervenciones en salud pública u organizacionales. El desarrollo de estas RSL requiere una serie de ajustes metodológicos para la búsqueda y selección de los estudios primarios, la evaluación de la calidad de los mismos y la combinación de la evidencia. Especial cuidado debe tenerse para identificar y manejar adecuadamente el mayor riesgo de sesgos, en especial los derivados de un inadecuado control de los factores de confusión. El presente artículo presenta las particularidades a tener en cuenta a la hora de realizar RSL para evaluar intervenciones que incluyan ENA, las herramientas que se han desarrollado para facilitar su desarrollo, y las consideraciones importantes para reportar y discutir los hallazgos. El desarrollo de este tipo de RSL requiere un alto nivel de experiencia por parte del grupo desarrollador y una mayor cantidad de recursos económicos y de tiempo. Sin embargo, cuando han sido bien diseñadas, conducidas y analizadas, pueden ser de gran utilidad en la toma de decisiones clínicas, y pueden ser integradas en el desarrollo de las recomendaciones presentadas en las guías de práctica clínica. (Acta Med Colomb 2018; 43: 100-106).]]></p></abstract>
<abstract abstract-type="short" xml:lang="en"><p><![CDATA[Abstract Systematic reviews to evaluate interventions including the evidence provided by non-randomized studies (NRS), can be very useful to support clinical decisions in subjects that are not well covered by randomized clinical trials (RCTs), such as the evaluation of the effects of long-term treatment, its adverse effects or the evaluation of public health or organizational interventions. The development of these RSLs requires a series of methodological adjustments for the search and selection of the primary studies, the evaluation of their quality and the combination of the evidence. Special care must be taken to identify and appropriately manage the increased risk of bias, especially those derived from inadequate control of confounding factors. This article presents the particularities to take into account when performing RSL to evaluate interventions that include NRS, the tools that have been developed to facilitate their development, and the important considerations to report and discuss the findings. The development of this type of RSL requires a high level of experience by the developer group and a greater amount of economic resources and time. However, when they have been well designed, conducted and analyzed, they can be very useful in clinical decision-making, and can be integrated into the development of the recommendations presented in the clinical practice guidelines. (Acta Med Colomb 2018; 43: 100-106).]]></p></abstract>
<kwd-group>
<kwd lng="es"><![CDATA[revisiones sistemáticas]]></kwd>
<kwd lng="es"><![CDATA[estudios no aleatorizados]]></kwd>
<kwd lng="es"><![CDATA[estudios observacionales]]></kwd>
<kwd lng="es"><![CDATA[sesgo]]></kwd>
<kwd lng="en"><![CDATA[systematic reviews]]></kwd>
<kwd lng="en"><![CDATA[non-randomized studies]]></kwd>
<kwd lng="en"><![CDATA[observational studies]]></kwd>
<kwd lng="en"><![CDATA[bias]]></kwd>
</kwd-group>
</article-meta>
</front><back>
<ref-list>
<ref id="B1">
<label>1</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Reeves]]></surname>
<given-names><![CDATA[BC]]></given-names>
</name>
<name>
<surname><![CDATA[Higgins]]></surname>
<given-names><![CDATA[JPT]]></given-names>
</name>
<name>
<surname><![CDATA[Ramsay]]></surname>
<given-names><![CDATA[C]]></given-names>
</name>
<name>
<surname><![CDATA[Shea]]></surname>
<given-names><![CDATA[B]]></given-names>
</name>
<name>
<surname><![CDATA[Tugwell]]></surname>
<given-names><![CDATA[P]]></given-names>
</name>
<name>
<surname><![CDATA[Wells]]></surname>
<given-names><![CDATA[GA]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[An introduction to methodological issues when including non-randomised studies in systematic reviews on the effects of interventions]]></article-title>
<source><![CDATA[Res Synth Meth]]></source>
<year>2013</year>
<volume>4</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>1-11</page-range></nlm-citation>
</ref>
<ref id="B2">
<label>2</label><nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Reeves]]></surname>
<given-names><![CDATA[B]]></given-names>
</name>
<name>
<surname><![CDATA[Deeks]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
<name>
<surname><![CDATA[Higgins]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
<name>
<surname><![CDATA[Wells]]></surname>
<given-names><![CDATA[G]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Chapter 13: Including non-randomized studies]]></article-title>
<person-group person-group-type="editor">
<name>
<surname><![CDATA[Higgins]]></surname>
<given-names><![CDATA[JPT]]></given-names>
</name>
<name>
<surname><![CDATA[Green]]></surname>
<given-names><![CDATA[S]]></given-names>
</name>
</person-group>
<collab>Collaboration TC</collab>
<source><![CDATA[Cochrane Handbook Syst Rev Interv]]></source>
<year>2011</year>
</nlm-citation>
</ref>
<ref id="B3">
<label>3</label><nlm-citation citation-type="">
<collab>GRADE working group</collab>
<source><![CDATA[Grade handbook]]></source>
<year>2016</year>
</nlm-citation>
</ref>
<ref id="B4">
<label>4</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Higgins]]></surname>
<given-names><![CDATA[JPT]]></given-names>
</name>
<name>
<surname><![CDATA[Ramsay]]></surname>
<given-names><![CDATA[C]]></given-names>
</name>
<name>
<surname><![CDATA[Reeves]]></surname>
<given-names><![CDATA[B]]></given-names>
</name>
<name>
<surname><![CDATA[Deeks]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
<name>
<surname><![CDATA[Shea]]></surname>
<given-names><![CDATA[B]]></given-names>
</name>
<name>
<surname><![CDATA[Valentine]]></surname>
<given-names><![CDATA[JC]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Issues relating to study design and risk of bias when including non-randomized studies in systematic reviews on the effects of interventions]]></article-title>
<source><![CDATA[Res Synth Meth]]></source>
<year>2013</year>
<volume>4</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>12-25</page-range></nlm-citation>
</ref>
<ref id="B5">
<label>5</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Silverman]]></surname>
<given-names><![CDATA[SL]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[From randomized controlled trials to observational studies]]></article-title>
<source><![CDATA[Am J Med]]></source>
<year>2009</year>
<volume>122</volume>
<numero>2</numero>
<issue>2</issue>
<page-range>114-20</page-range></nlm-citation>
</ref>
<ref id="B6">
<label>6</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Goulart]]></surname>
<given-names><![CDATA[BHL]]></given-names>
</name>
<name>
<surname><![CDATA[Ramsey]]></surname>
<given-names><![CDATA[SD]]></given-names>
</name>
<name>
<surname><![CDATA[Parvathaneni]]></surname>
<given-names><![CDATA[U]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Observational study designs for comparative effectiveness research an alternative approach to close evidence gaps in head-and-neck cancer]]></article-title>
<source><![CDATA[Int J Radiat Oncol Biol Phys]]></source>
<year>2014</year>
<volume>88</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>106-14</page-range></nlm-citation>
</ref>
<ref id="B7">
<label>7</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Alemayehu]]></surname>
<given-names><![CDATA[D]]></given-names>
</name>
<name>
<surname><![CDATA[Cappelleri]]></surname>
<given-names><![CDATA[JC]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Revisiting issues, drawbacks and opportunities with observational studies in comparative effectiveness research]]></article-title>
<source><![CDATA[J Eval Clin Pract]]></source>
<year>2013</year>
<volume>19</volume>
<numero>4</numero>
<issue>4</issue>
<page-range>579-83</page-range></nlm-citation>
</ref>
<ref id="B8">
<label>8</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Garabedian]]></surname>
<given-names><![CDATA[LF]]></given-names>
</name>
<name>
<surname><![CDATA[Chu]]></surname>
<given-names><![CDATA[P]]></given-names>
</name>
<name>
<surname><![CDATA[Toh]]></surname>
<given-names><![CDATA[S]]></given-names>
</name>
<name>
<surname><![CDATA[Zaslavsky]]></surname>
<given-names><![CDATA[AM]]></given-names>
</name>
<name>
<surname><![CDATA[Soumerai]]></surname>
<given-names><![CDATA[SB]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Potential bias of instrumental variable analyses for observational comparative effectiveness research]]></article-title>
<source><![CDATA[Ann Intern Med]]></source>
<year>2014</year>
<volume>161</volume>
<numero>2</numero>
<issue>2</issue>
<page-range>131-8</page-range></nlm-citation>
</ref>
<ref id="B9">
<label>9</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Benson]]></surname>
<given-names><![CDATA[K]]></given-names>
</name>
<name>
<surname><![CDATA[Hartz]]></surname>
<given-names><![CDATA[AJ]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[A comparison of observational studies and randomized, controlled trials]]></article-title>
<source><![CDATA[N Engl J Med]]></source>
<year>2000</year>
<volume>342</volume>
<numero>25</numero>
<issue>25</issue>
<page-range>1878-86</page-range></nlm-citation>
</ref>
<ref id="B10">
<label>10</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Furlan]]></surname>
<given-names><![CDATA[AD]]></given-names>
</name>
<name>
<surname><![CDATA[Irvin]]></surname>
<given-names><![CDATA[E]]></given-names>
</name>
<name>
<surname><![CDATA[Bombardier]]></surname>
<given-names><![CDATA[C]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Limited search strategies were effective in finding relevant nonrandomized studies]]></article-title>
<source><![CDATA[J Clin Epidemiol]]></source>
<year>2006</year>
<volume>59</volume>
<numero>12</numero>
<issue>12</issue>
<page-range>1303-11</page-range></nlm-citation>
</ref>
<ref id="B11">
<label>11</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Sanderson]]></surname>
<given-names><![CDATA[S]]></given-names>
</name>
<name>
<surname><![CDATA[Tatt]]></surname>
<given-names><![CDATA[ID]]></given-names>
</name>
<name>
<surname><![CDATA[Higgins]]></surname>
<given-names><![CDATA[JPT]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Tools for assessing quality and susceptibility to bias in observational studies in epidemiology A systematic review and annotated bibliography]]></article-title>
<source><![CDATA[Int J Epidemiol]]></source>
<year>2007</year>
<volume>36</volume>
<numero>3</numero>
<issue>3</issue>
<page-range>666-76</page-range></nlm-citation>
</ref>
<ref id="B12">
<label>12</label><nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Wells]]></surname>
<given-names><![CDATA[G]]></given-names>
</name>
<name>
<surname><![CDATA[Shea]]></surname>
<given-names><![CDATA[B]]></given-names>
</name>
<name>
<surname><![CDATA[O'Connell]]></surname>
<given-names><![CDATA[D]]></given-names>
</name>
<name>
<surname><![CDATA[Peterson]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
<name>
<surname><![CDATA[Welch]]></surname>
<given-names><![CDATA[V]]></given-names>
</name>
<name>
<surname><![CDATA[Losos]]></surname>
<given-names><![CDATA[M]]></given-names>
</name>
</person-group>
<source><![CDATA[The Newcastle-Ottawa Scale (NOS) for assessing the quality of nonrandomised studies in meta-analyses]]></source>
<year>2014</year>
<publisher-loc><![CDATA[Ottawa ]]></publisher-loc>
<publisher-name><![CDATA[Ottawa Hosp Resea Insti]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B13">
<label>13</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Wells]]></surname>
<given-names><![CDATA[GA]]></given-names>
</name>
<name>
<surname><![CDATA[Shea]]></surname>
<given-names><![CDATA[B]]></given-names>
</name>
<name>
<surname><![CDATA[Higgins]]></surname>
<given-names><![CDATA[JP]]></given-names>
</name>
<name>
<surname><![CDATA[Sterne]]></surname>
<given-names><![CDATA[JA]]></given-names>
</name>
<name>
<surname><![CDATA[Tugwell]]></surname>
<given-names><![CDATA[P]]></given-names>
</name>
<name>
<surname><![CDATA[Reeves]]></surname>
<given-names><![CDATA[B]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Checklists of methodological issues for review authors to consider when including non-randomized studies in systematic reviews]]></article-title>
<source><![CDATA[Res Synth Meth]]></source>
<year>2013</year>
<volume>4</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>63-77</page-range></nlm-citation>
</ref>
<ref id="B14">
<label>14</label><nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Sterne]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
<name>
<surname><![CDATA[Higgins]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
<name>
<surname><![CDATA[Reeves]]></surname>
<given-names><![CDATA[B]]></given-names>
</name>
</person-group>
<source><![CDATA[A Cochrane risk of bias assessment tool: for non-randomized studies of interventions (ACROBAT-NRSI)]]></source>
<year>2011</year>
</nlm-citation>
</ref>
<ref id="B15">
<label>15</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Higgins]]></surname>
<given-names><![CDATA[JPT]]></given-names>
</name>
<name>
<surname><![CDATA[Altman]]></surname>
<given-names><![CDATA[DG]]></given-names>
</name>
<name>
<surname><![CDATA[Gøtzsche]]></surname>
<given-names><![CDATA[PC]]></given-names>
</name>
<name>
<surname><![CDATA[Jüni]]></surname>
<given-names><![CDATA[P]]></given-names>
</name>
<name>
<surname><![CDATA[Moher]]></surname>
<given-names><![CDATA[D]]></given-names>
</name>
<name>
<surname><![CDATA[Oxman]]></surname>
<given-names><![CDATA[AD]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[The Cochrane Collaboration&#8216;s tool for assessing risk of bias in randomised trials]]></article-title>
<source><![CDATA[BMJ]]></source>
<year>2011</year>
<numero>343</numero>
<issue>343</issue>
<page-range>889-93</page-range></nlm-citation>
</ref>
<ref id="B16">
<label>16</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Sterne]]></surname>
<given-names><![CDATA[JA]]></given-names>
</name>
<name>
<surname><![CDATA[Hernán]]></surname>
<given-names><![CDATA[MA]]></given-names>
</name>
<name>
<surname><![CDATA[Reeves]]></surname>
<given-names><![CDATA[BC]]></given-names>
</name>
<name>
<surname><![CDATA[Savovic]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
<name>
<surname><![CDATA[Berkman]]></surname>
<given-names><![CDATA[ND]]></given-names>
</name>
<name>
<surname><![CDATA[Viswanathan]]></surname>
<given-names><![CDATA[M]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[ROBINS-I a tool for assessing risk of bias in non-randomised studies of interventions]]></article-title>
<source><![CDATA[BMJ]]></source>
<year>2016</year>
<numero>355</numero>
<issue>355</issue>
<page-range>i4919</page-range></nlm-citation>
</ref>
<ref id="B17">
<label>17</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Austin]]></surname>
<given-names><![CDATA[PC]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[An Introduction to Propensity Score Methods for Reducing the Effects of Confounding in Observational Studies]]></article-title>
<source><![CDATA[Multivariate Behav Res]]></source>
<year>2011</year>
<volume>46</volume>
<numero>3</numero>
<issue>3</issue>
<page-range>399-424</page-range></nlm-citation>
</ref>
<ref id="B18">
<label>18</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Norris]]></surname>
<given-names><![CDATA[S]]></given-names>
</name>
<name>
<surname><![CDATA[Moher]]></surname>
<given-names><![CDATA[D]]></given-names>
</name>
<name>
<surname><![CDATA[Reeves]]></surname>
<given-names><![CDATA[B]]></given-names>
</name>
<name>
<surname><![CDATA[Shea]]></surname>
<given-names><![CDATA[B]]></given-names>
</name>
<name>
<surname><![CDATA[Loke]]></surname>
<given-names><![CDATA[YK]]></given-names>
</name>
<name>
<surname><![CDATA[Garner]]></surname>
<given-names><![CDATA[S]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Issues relating to selective reporting when including non-randomized studies in systematic reviews on the effects of healthcare interventions]]></article-title>
<source><![CDATA[Res Synth Meth]]></source>
<year>2013</year>
<volume>4</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>36-47</page-range></nlm-citation>
</ref>
<ref id="B19">
<label>19</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Valentine]]></surname>
<given-names><![CDATA[JC]]></given-names>
</name>
<name>
<surname><![CDATA[Thompson]]></surname>
<given-names><![CDATA[SG]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Issues relating to confounding and meta-analysis when including non-randomized studies in systematic reviews on the effects of interventions]]></article-title>
<source><![CDATA[Res Synth Meth]]></source>
<year>2013</year>
<volume>4</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>26-35</page-range></nlm-citation>
</ref>
<ref id="B20">
<label>20</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Moscoe]]></surname>
<given-names><![CDATA[E]]></given-names>
</name>
<name>
<surname><![CDATA[Bor]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
<name>
<surname><![CDATA[Bärnighausen]]></surname>
<given-names><![CDATA[T]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Regression discontinuity designs are underutilized in medicine, epidemiology, and public health A review of current and best practice]]></article-title>
<source><![CDATA[J Clin Epidemiol]]></source>
<year>2015</year>
<volume>68</volume>
<numero>2</numero>
<issue>2</issue>
<page-range>122-33</page-range></nlm-citation>
</ref>
<ref id="B21">
<label>21</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Greenland]]></surname>
<given-names><![CDATA[S]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[An introduction to instrumental variables for epidemiologists]]></article-title>
<source><![CDATA[Int J Epidemiol]]></source>
<year>2000</year>
<volume>29</volume>
<numero>4</numero>
<issue>4</issue>
<page-range>722-9</page-range></nlm-citation>
</ref>
<ref id="B22">
<label>22</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[MacLehose]]></surname>
<given-names><![CDATA[RR]]></given-names>
</name>
<name>
<surname><![CDATA[Reeves]]></surname>
<given-names><![CDATA[BC]]></given-names>
</name>
<name>
<surname><![CDATA[Harvey]]></surname>
<given-names><![CDATA[IM]]></given-names>
</name>
<name>
<surname><![CDATA[Sheldon]]></surname>
<given-names><![CDATA[TA]]></given-names>
</name>
<name>
<surname><![CDATA[Russell]]></surname>
<given-names><![CDATA[IT]]></given-names>
</name>
<name>
<surname><![CDATA[Black]]></surname>
<given-names><![CDATA[AMS]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[A systematic review of comparisons of effect sizes derived from randomised and non-randomised studies]]></article-title>
<source><![CDATA[Health Technol Assess (Rockv)]]></source>
<year>2000</year>
<volume>4</volume>
<numero>34</numero>
<issue>34</issue>
<page-range>1-154</page-range></nlm-citation>
</ref>
<ref id="B23">
<label>23</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Turner]]></surname>
<given-names><![CDATA[RM]]></given-names>
</name>
<name>
<surname><![CDATA[Spiegelhalter]]></surname>
<given-names><![CDATA[DJ]]></given-names>
</name>
<name>
<surname><![CDATA[Smith]]></surname>
<given-names><![CDATA[GCS]]></given-names>
</name>
<name>
<surname><![CDATA[Thompson]]></surname>
<given-names><![CDATA[SG]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Bias modelling in evidence synthesis]]></article-title>
<source><![CDATA[J R Stat Soc Ser A Stat Soc]]></source>
<year>2009</year>
<volume>172</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>21-47</page-range></nlm-citation>
</ref>
<ref id="B24">
<label>24</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Van Zuuren]]></surname>
<given-names><![CDATA[EJ]]></given-names>
</name>
<name>
<surname><![CDATA[Fedorowicz]]></surname>
<given-names><![CDATA[Z]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Moose on the loose checklist for meta-analyses of observational studies]]></article-title>
<source><![CDATA[Br J Dermatol]]></source>
<year>2016</year>
<volume>175</volume>
<numero>5</numero>
<issue>5</issue>
<page-range>853-4</page-range></nlm-citation>
</ref>
<ref id="B25">
<label>25</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Moher]]></surname>
<given-names><![CDATA[D]]></given-names>
</name>
<name>
<surname><![CDATA[Liberati]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
<name>
<surname><![CDATA[Tetzlaff]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
<name>
<surname><![CDATA[Altman]]></surname>
<given-names><![CDATA[D]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement]]></article-title>
<source><![CDATA[BMJ]]></source>
<year>2010</year>
<numero>8</numero>
<issue>8</issue>
<page-range>b2535</page-range></nlm-citation>
</ref>
<ref id="B26">
<label>26</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Stroup]]></surname>
<given-names><![CDATA[D]]></given-names>
</name>
<name>
<surname><![CDATA[Berlin]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
<name>
<surname><![CDATA[Morton]]></surname>
<given-names><![CDATA[S]]></given-names>
</name>
<name>
<surname><![CDATA[Olkin]]></surname>
<given-names><![CDATA[I]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[MOOSE Statement Meta-analysis of Observational Studies in Epidemiology: A Proposal for Reporting]]></article-title>
<source><![CDATA[JAMA]]></source>
<year>2000</year>
<volume>283</volume>
<numero>15</numero>
<issue>15</issue>
<page-range>2008</page-range></nlm-citation>
</ref>
<ref id="B27">
<label>27</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Schünemann]]></surname>
<given-names><![CDATA[HJ]]></given-names>
</name>
<name>
<surname><![CDATA[Tugwell]]></surname>
<given-names><![CDATA[P]]></given-names>
</name>
<name>
<surname><![CDATA[Reeves]]></surname>
<given-names><![CDATA[BC]]></given-names>
</name>
<name>
<surname><![CDATA[Akl]]></surname>
<given-names><![CDATA[EA]]></given-names>
</name>
<name>
<surname><![CDATA[Santesso]]></surname>
<given-names><![CDATA[N]]></given-names>
</name>
<name>
<surname><![CDATA[Spencer]]></surname>
<given-names><![CDATA[FA]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Non-randomized studies as a source of complementary, sequential or replacement evidence for randomized controlled trials in systematic reviews on the effects of interventions]]></article-title>
<source><![CDATA[Res Synth Meth]]></source>
<year>2013</year>
<volume>4</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>49-62</page-range></nlm-citation>
</ref>
</ref-list>
</back>
</article>
