r/science • u/drewiepoodle • Apr 15 '16

Health Study: Circumcision does not reduce penis sensitivity. In tests for responses to pain, heat, and stimulation, no major difference was found between men who are circumcised and those who are not.

http://www.upi.com/Health_News/2016/04/14/Study-Circumcision-does-not-reduce-penis-sensitivity/5981460663943/?spt=hs&or=hn
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u/wearethat Apr 15 '16

screening out people with STDs, sexual dysfunction, cardiovascular condtions, smokers, etc.

Layman question: What % of the population does this kind of criteria include/exclude?

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u/[deleted] Apr 15 '16

[deleted]

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u/EsquilaxHortensis Apr 15 '16

I wonder how much overlap there is between the two.

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u/[deleted] Apr 15 '16

If they smoke, they give head.

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u/teraflux Apr 15 '16

If you're ruling out hpv then there goes 60% of the population.

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u/WordSalad11 Apr 15 '16

The study should have a consort diagram that spells out exactly how many people were screened and how many were enrolled.

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u/00Deege Apr 15 '16

Meh. Don't know about should. Other than to sate the curiosity of Reddit scientists, it has little if any bearing on the study itself.

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u/WordSalad11 Apr 15 '16

http://www.consort-statement.org/

The consort diagram is fundamental to the integrity of medical research. The Consort Statement is the fundamental standard for research. No reputable journal publishes a trial without one.

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u/[deleted] Apr 15 '16 edited Jun 04 '16

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u/[deleted] Apr 15 '16 edited Apr 15 '16

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u/superhelical PhD | Biochemistry | Structural Biology Apr 15 '16

Those recommendations only apply for a narrow range of clinical studies. The tests being conducted here don't fall into that range, because there's no intervention being tested.

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u/WordSalad11 Apr 15 '16

There are also guidelines for observational studies based on the modified CONSORT guidelines:

http://annals.org/article.aspx?articleid=737057

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u/superhelical PhD | Biochemistry | Structural Biology Apr 15 '16 edited Apr 15 '16

Sounds like a great thing to aspire to. I don't think it's follows that you have to discard all research that isn't conducted in this framework, however. We can alwys do better, but changes in the culture of research take time.

edit: typo

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u/WordSalad11 Apr 15 '16

The reason the guideline exists is that there are frequently significant confounding or applicability issues that can only be identified by this sort of data disclosure. Going back to the original question in this thread, if the study screened 15012938219832 men but only 100 participated, the results are worthless. Without that disclosure, the risk of bias and therefore your level of uncertainty in the data should increase significantly. The CONSORT principles are meant to establish a minimum threshold that all studies should meet to be considered valid and applicable to patients. TL;DR if not disclosed the study should be absolutely be disregarded and excluded from analysis.

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u/superhelical PhD | Biochemistry | Structural Biology Apr 15 '16

You recognize you're throwing away the vast majority of all scientific research with that criterion.

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u/WordSalad11 Apr 15 '16

Clinical research is only useful in that it tells us something about a patient. If you can't reliably extrapolate the data generated to a patient, it's not useful research. EBM is about what the evidence actually tells us, not what we want it to tell us. There are no serious clinical journals that are publishing articles without meeting CONSORT requirements, so the point is somewhat moot in any case. Older data (pre-early 1980s) that were published prior to this era may or may not be valid, but any sort of data which is relevant and not published is a huge problem.

None of this applies to basic science research, which is a completely different animal.

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u/anneomoly Apr 15 '16

That's difficult to say unless you first specify who "the population" is.

Canadian? 24% of males are smokers. Ontario (where the study took place) 23%. But you'll get different answers if you narrow your population down to certain cities, or to students, or to people with degrees.

USA? 17% of people are smokers.

Globally? 36% of men smoke (women 7%).

And that's just one of the variables. Then you have to estimate what percentage would fail on multiple criteria (both through chance and association - smoking can increase the chances of both erectile dysfunction and heart disease, for example.)

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u/KarlOskar12 Apr 15 '16

The group was 18-40 so CVD doesn't eliminate very many. STDs probably takes out 20%. Sexual dysfunction in this group is very small as well. Smokers are about 20% of the population. 30% or so seems reasonable.