<story><title>Study: No evidence of efficacy of hydroxychloroquine in hospitalized patients</title><url>https://www.medrxiv.org/content/10.1101/2020.04.10.20060699v1</url></story><parent_chain><item><author>thedudeabides5</author><text>This is a great comment thanks.&lt;p&gt;Title of the paper could (with a tongue firmly in cheek) be called, &lt;i&gt;&amp;quot;Weak evidence for effectiveness of hydroxychloroquine but our sample was likely too small for it to pass a T-test&amp;quot;&lt;/i&gt;</text></item><item><author>capnrefsmmat</author><text>It&amp;#x27;s important to interpret these results carefully: &amp;quot;no evidence of efficacy&amp;quot; does &lt;i&gt;not&lt;/i&gt; imply evidence of no efficacy, and in fact the uncertainty in this study is quite large. The sample size is small enough that it would be very hard for this study to detect the effect of hydroxychloroquine unless that effect is very, very large.&lt;p&gt;From the abstract:&lt;p&gt;&amp;gt; In the HCQ group, 2.8% of the patients died within 7 days vs 4.6% in the no-HCQ group (3 vs 4 events, RR 0.61, 95% CI 0.13-2.89), and 27.4% and 24.1%, respectively, developed acute respiratory distress syndrome within 7 days (24 vs 23 events, RR 1.14, 95% CI 0.65-2.00).&lt;p&gt;The relative risks and confidence intervals are the important numbers here. For example, the relative risk for death is 0.61, meaning the observed risk of death was lower for patients treated with hydroxychloroquine -- but the confidence interval is 0.13 to 2.89, meaning the data is consistent with anything from the risk being much smaller to the risk being much &lt;i&gt;larger&lt;/i&gt;. Since there were only 3 deaths in the treatment group and 4 deaths in the control group, it&amp;#x27;s very hard to draw precise conclusions about death rates.&lt;p&gt;I think we can interpret this result to mean that hydroxychloroquine doesn&amp;#x27;t have a miraculously large effect, but the evidence is weak. Other commenters are correct that large randomized trials will be more definitive.&lt;p&gt;(disclaimer: I am a statistician, not a doctor)</text></item></parent_chain><comment><author>magicalist</author><text>&amp;gt; &lt;i&gt;Title of the paper could (with a tongue firmly in cheek) be called, &amp;quot;Weak evidence for effectiveness of hydroxychloroquine but our sample was likely too small for it to pass a T-test&amp;quot;&lt;/i&gt;&lt;p&gt;It would be irresponsible to choose an experimental design (like significance level) and then use wishy-washy language (&amp;quot;weak evidence&amp;quot;) to work around it when the study criteria aren&amp;#x27;t met.&lt;p&gt;This would be more akin to the headline from the press release for the study from the university PR office.</text></comment>
<story><title>Study: No evidence of efficacy of hydroxychloroquine in hospitalized patients</title><url>https://www.medrxiv.org/content/10.1101/2020.04.10.20060699v1</url></story><parent_chain><item><author>thedudeabides5</author><text>This is a great comment thanks.&lt;p&gt;Title of the paper could (with a tongue firmly in cheek) be called, &lt;i&gt;&amp;quot;Weak evidence for effectiveness of hydroxychloroquine but our sample was likely too small for it to pass a T-test&amp;quot;&lt;/i&gt;</text></item><item><author>capnrefsmmat</author><text>It&amp;#x27;s important to interpret these results carefully: &amp;quot;no evidence of efficacy&amp;quot; does &lt;i&gt;not&lt;/i&gt; imply evidence of no efficacy, and in fact the uncertainty in this study is quite large. The sample size is small enough that it would be very hard for this study to detect the effect of hydroxychloroquine unless that effect is very, very large.&lt;p&gt;From the abstract:&lt;p&gt;&amp;gt; In the HCQ group, 2.8% of the patients died within 7 days vs 4.6% in the no-HCQ group (3 vs 4 events, RR 0.61, 95% CI 0.13-2.89), and 27.4% and 24.1%, respectively, developed acute respiratory distress syndrome within 7 days (24 vs 23 events, RR 1.14, 95% CI 0.65-2.00).&lt;p&gt;The relative risks and confidence intervals are the important numbers here. For example, the relative risk for death is 0.61, meaning the observed risk of death was lower for patients treated with hydroxychloroquine -- but the confidence interval is 0.13 to 2.89, meaning the data is consistent with anything from the risk being much smaller to the risk being much &lt;i&gt;larger&lt;/i&gt;. Since there were only 3 deaths in the treatment group and 4 deaths in the control group, it&amp;#x27;s very hard to draw precise conclusions about death rates.&lt;p&gt;I think we can interpret this result to mean that hydroxychloroquine doesn&amp;#x27;t have a miraculously large effect, but the evidence is weak. Other commenters are correct that large randomized trials will be more definitive.&lt;p&gt;(disclaimer: I am a statistician, not a doctor)</text></item></parent_chain><comment><author>marcosdumay</author><text>This is the kind of study where it would be beneficial for it to be ignore. The correct headline is no headline at all.</text></comment>