MERS: Effect of sex on mortality in KSA vs. non-KSA cases

As promised, today we’re going explore how sex impacts likelihood of MERS mortality – in the KSA and otherwise… However, I present the following information with a very important caveat. Last week, 113 previously unannounced cases (and 92 deaths) were added to the KSA MERS tally – but we don’t know much about them yet. Because of this, I couldn’t include these newly reported cases in the analysis below; when we learn more about them, I’ll revisit and revise as necessary. Moreover, because of recent changes in KSA reported, I haven’t been able to match 13 of the deaths that have been published in recent MOH media reports to previously reported cases; they haven’t been included below either. Needless to say, the charts and calculations that follow are very much subject to change! But without further adieu…

Let’s first take a look at sex and mortality among all cases for which we currently have information:

Yates Chi-Square: 4.3 (p = .038) RR: 1.35 [95%CI: 1.02, 1.78] (p = .034)

Yates’ Chi-Square: 4.3 (p = .038)
RR: 1.35 [95%CI: 1.02, 1.78] (p = .034)

Now, let’s split up KSA and non-KSA MERS deaths:

Yates' Chi-Square: 4.6 (p = .031) RR: 1.38 [95%CI: 1.04, 1.84] (p = .028)

Yates’ Chi-Square: 4.6 (p = .031)
RR: 1.38 [95%CI: 1.04, 1.84] (p = .028)

Yates' Chi-Square: .59 (p = .44) RR: 1.75 [95%CI: .58, 5.26] (p = .32)

Yates’ Chi-Square: .59 (p = .44)
RR: 1.75 [95%CI: .58, 5.26] (p = .32)

Hm. A couple of  interesting findings:

1. Outside of the KSA, there appears to be no statistically significant relationship between mortality due to MERS and sex. (It’s important to note that this relationship may or may not be an artifact of the relatively small number of non-KSA MERS cases for which we currently have information.)
2. For cases originating in the KSA, there is a statistically significant relationship; men with MERS are 35% more likely to die than women with MERS. (However, this relationship may be confounded by differences in age distribution or comorbidity status between the sexes in KSA.)

As more information becomes available, we’ll be able to develop a clearer understanding of whether or not Saudi men are really more at risk of dying from MERS than Saudi women – and whether there’s really no relationship between sex and mortality outside of the KSA. The confounders listed definitely need to be tested, which will be easier to do in a more statistically rigorous fashion once details on the 113 previously unreported cases and 92 deaths are released. If these findings still hold true after correcting for confounders, we’ll need to start investigating why this relationship between sex and MERS mortality exists in the KSA, but doesn’t exist elsewhere. For the time being, I’ll definitely be keeping an eye on this emerging phenomenon… And searching for a mechanism that might explain this current, observable difference between non-KSA and KSA cases.

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5 thoughts on “MERS: Effect of sex on mortality in KSA vs. non-KSA cases

  1. Pingback: MERS: [New] Updated Charts | Mens et Manus

  2. Pingback: MERS: [New] Updated Charts | Mens et Manus

  3. Pingback: WHO DON on 113 Previously Unreported KSA MERS Cases, Visualized | Mens et Manus

  4. Pingback: MERS: [New] Updated Charts | Mens et Manus

  5. Pingback: MERS: [New] Updated Charts | Mens et Manus

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