Blog | Thursday, January 24, 2013

An empirical scientific viewpoint about gun control


For just a moment, let's take a scientific viewpoint about gun control here and try to leave emotions (and the Constitutional argument) out.

The best type of study to determine whether gun control and/or regulation would be a Randomized Trial: randomizing a state or country to regulation or not.

Since that's not going to happen, the next best type of evidence we have to go by is observational, either case-control or cohort studies. The exposure is: gun control regulation. This could be considered dichotomously (yes/no) or continuous (level of regulation from strict to lenient/none).

The outcome is: death by guns. This could be considered in numerous ways: absolute numbers of gun deaths annually; relative numbers of gun deaths adjusting for size of population; number of gun massacres, etc. We could even consider any violent deaths, if you want to be more general.

In a case-cohort study, we'd look at the outcome first (let's say, massacres) and look backward for the exposure, then calculate an odds ratio that the outcome was significantly associated with the exposure.

In a cohort study, we'd look at the exposure first, looking at level of gun control as a continuous variable. This could be done retrospectively or prospectively. As of now, we could only do this retrospectively. Then look for the outcomes (deaths, massacres, etc.), and determine a risk ratio that the outcome was associated with the exposure.

Either way, the data would indicate that countries with increased exposure (increasing regulation) is associated with a decreased odds/risk of the outcome (fewer deaths, massacres).

Please note that I did not say that increasing regulation caused fewer deaths, just that it was associated with fewer deaths.

Now, I do not have numerical data, so I am only going on what I understand to be true, the empirical data. If those who would not believe this to be true, the best way to deal with this is to show data that decreasing the exposure to gun regulation (i.e., increasing the populace's ability to acquire firearms legally) is associated with fewer gun deaths.

Therefore, my preference is the following: until evidence (not raw emotions, beliefs, or Constitutional Amendments) that decreased regulation (including eliminating gun zones) results in decreased odds/risk for the outcome (gun death) is found in other countries, then there is no reason to accept the notion that we need to stop advocating for strict gun control. For that matter, stricter gun control has evidential support (even if not emotional support among some) and should be advanced.

If you choose to comment on this in the opposite direction, please think before you do. The anecdotal evidence currently being provided by those who would oppose stricter regulations is purely speculative. I am open to hearing the data to refute the above contention, but it needs to be at least as strong methodologically. In other words, "case reports" (testimonials by individuals) or "case series" (testimonials by groups, including lobbyists) are weaker forms of evidence scientifically, and I will not consider them as valid as the comparative empirical data I have put forward as an argument.

Ryan Madanick, MD, is an ACP Member, a gastroenterologist at the University of North Carolina School of Medicine, and the Program Director for the GI & Hepatology Fellowship Program. He specializes in diseases of the esophagus, with a strong interest in the diagnosis and treatment of patients who have difficult-to-manage esophageal problems such as refractory GERD, heartburn, and chest pain. This post originally appeared at his blog, Gut Check.