You are looking at the HTML representation of the XML format.
HTML is good for debugging, but is unsuitable for application use.
Specify the format parameter to change the output format.
To see the non HTML representation of the XML format, set format=xml.
See the complete documentation, or API help for more information. 
<?xml version="1.0"?>
<api>
  <query-continue>
    <allpages apcontinue="Care_Coordination_Factors" />
  </query-continue>
  <query>
    <allpages>
      <p pageid="79" ns="0" title="Behavior Determinants" />
      <p pageid="177" ns="0" title="Behavioral &amp; Physical Health Integration" />
      <p pageid="249" ns="0" title="Black Book 2020 Healthcare Analytics" />
      <p pageid="84" ns="0" title="CDC Health Risk Assessments" />
      <p pageid="14" ns="0" title="CMS-HCC Demographic Coefficients" />
      <p pageid="17" ns="0" title="CMS-HCC Disabled/Disease Interactions" />
      <p pageid="15" ns="0" title="CMS-HCC Disease Coefficients" />
      <p pageid="16" ns="0" title="CMS-HCC Disease Interactions" />
      <p pageid="13" ns="0" title="CMS-HCC Risk Adjustments" />
      <p pageid="195" ns="0" title="Capturing Determinants of Health" />
    </allpages>
  </query>
</api>