Journal Club: Firearm Ownership and Risk of Suicide
Lately I have found myself in discussions with my peers about gun ownership. Several people I know have recommended that I purchase a firearm (non-hunting) to protect my family due to the current civil unrest and the COVID pandemic. Most of the people I talk to site the fear of home invasion as a reason to own a firearm as well. When I am given this recommendation I often rebuttal with the simple question…After the purchase, what do you think are the most likely actions to be taken with the firearm?
Everyone I’ve talked to has the same response, “if you have to use it, you’ll use it to kill or disable someone invading your home.” Then I ask them the same question again, but to think more broadly, more in terms of probabilities. Then one of two things happen; 1) we both go through imaginative scenarios in which the firearm is used, 2) I’m asked “what the heck are you taking about?” Then I ramble off the most likely uses for the firearm.
1) Nothing- gun never gets used
2) Gun goes to range with owner every 5 years or so for fun and practice
3) Owner uses gun to commit suicide
4) Spouse of gun owner uses gun to commit suicide
5) Son or daughter of owner uses gun to commit suicide
6) Owner uses gun to hurt spouse
7) Spouse uses gun to hurt owner of gun
8) Child of spouse uses gun to hurt parent
9) Owner of gun uses gun to hurt spouse’s mister/mistress
You get the picture.
At this point I estimate that around #20 on this list is owner uses gun to stop home invasion. Most people say, “Oh. I would never do any of those things above.” Then I quip something like “As did every person that committed one of those acts when they purchased the gun.”
My argument was mostly theoretical based on my experience with suicide as a physician and a general impression of local nightly news. Most of the research on uses of firearms by domestic non-criminals is sparse.(1) Until a recent study in NEJM was published addressing one of the specific topics above.
The title of the paper is “Handgun Ownership and Suicide in California.” This is a case control study. The cases in this study were handgun owners. The controls were non handgun owners. The outcome was death by any cause then further categorized as death by suicide. They used the handgun purchases and transfer registry (DROS) and statewide voter registration database to construct the groups. They linked these datasets to California Death Statistic Master File to identify deaths in each group. Causes of death were coded on death certificates.
To analyze this article, I will first determine the validity of the results, interpret the results, and discuss the applicability of these results.
Validity of Methods
When considering the composition of the two groups a researcher wants to ensure the risk of exposure is equal. In this study the exposure would be the acquisition of a firearm. They excluded individuals under 21 and those that had purchased firearms prior to the study period to equalize exposure in both groups. In California you cannot purchase a gun if you are under 21. Excluding those that owned firearms prior to the observation period makes sense since it would be difficult to determine which group to place these individuals.
Next, researchers will want to ensure that measuring the exposure and outcome was the same in both groups. In this case, the state of California has database that records gun purchases and transfers. This database was used to divide cases and controls. They did not account for the possibility of illegal firearm sales and trades. The state death registry was used to determine cause of death. Although death certificates can often be inaccurate, suicides are not often mistaken for other causes of death.2 Suicides are reviewed and often confirmed by the coroner.
Finally, the investigators would want to analyze the groups for confounding. Remember, confounding is a known or unknown variable not being studied that may significantly impact the results. The researchers did not look beyond the state of California. They were able to collect minimal demographic data from the registries. They were able to correct for age, race, sex, and long-gun vs. handgun ownership, but not much else. They ran an analysis to determine how much an unknown variable could affect their results as well.
Overall their methods were valid for an observational study. The risk of exposure was equal in both groups. The measurement of exposure and outcome was the same for both groups. They attempted to correct for confounding through statistical analysis.
The study followed 26 million people for roughly 7 years. In that time 676,425 individuals purchased one or more firearms. There were 18,000 suicides, of which 6,700 were by firearm. Male handgun owners had a 3 times higher overall suicide rate and Female handgun owners had a 7 times higher suicide rate. Suicide by firearm was 7 times higher in men and 35 times higher in women compared to nonowners. If you are having a difficult time wrapping your head around the multiple effect, a 2 times higher rate is equivalent to double the rate or a 100% increase. Seven times is doubling the rate 7 times or 700%.
The state of California has a 10-day waiting period after purchasing a gun before the owner can possess it. They found 14% of suicides by gun owners occurred within the first week of possession. They reported 52% of suicides occurred after the first year of gun ownership.
The researchers conducted a sensitivity analysis. A sensitivity analysis is a statistical method that determines how big of an impact an unknown variable would have to be to explain the results. They stated the unknown variable would need to increase the risk of suicide by a factor of six and be six times more common in handgun owners than non-owners.
Even though this is an observational study and it cannot prove causality, the results provide significant evidence that gun ownership is associated with suicide. Studies like this will be the best data we will get since it is unethical to randomize individuals to gun ownership then observing to see if they commit suicide.(3) So, I consider this “best” quality evidence.
There were several things I liked about this study design. A large population was observed. The data was objective. Previous gun owners were excluded. Time to event was analyzed to gauge impulsivity. Finally, the sensitivity analysis revealed the large impact a confounder would have to have to explain the results.
Theoretically, the data make sense. Individuals purchase guns for a variety of reasons. However, life changes, bad things happen, and bouts of despair occur.(4) Suicide by firearms is the most successful method.(5) Although I would not consider the act, if ever completed, to be a success. If the firearm is present in the home, the barrier of acquisition has been eliminated.(6) I would imagine most suicides are impulsive. The person contemplating it unlikely makes a pros and cons list or discuss this openly with friends. A terrible event occurs, the gun is right there, it gets loaded, and boom. A 10-day waiting period provides an opportunity for a broken mind to reconsider. It would be difficult to estimate how many lives waiting period laws have saved. Likely in the 1000’s to 10,000’s.
There were several flaws to the study. First, the sample is from California. Firearm laws, behavior, and culture differ from state to state, and country to country. (7) Although the premise is solid, the effect may be different based on location. Second, the researchers focused mostly on handguns and did not discriminate for long barrel firearms, since most suicides are executed with handguns.(8) The risk of long barrel firearms and suicide may not be as high. Third, there was no assessment to determine if the benefits of handgun ownership, such as prevention or deterrence of home invasion. Fourth, a survey of mental illness among owners and non-owners would be helpful. Mental illness could be a potential confounder that has a significant impact.(9) Finally, substance abuse would be another confounder that could skew the results. They commented and alcohol and tobacco use, but not THC. The link between THC use and mental illness is very strong.(10) California has had medicinal THC for over a decade and legalization for several years.
Despite these flaws the data show that ownership of a firearm is associated with death by suicide. The time from ownership possession to the event demonstrates that even if the firearm was purchased for a non-impulsive reason, it remains a substantial threat to the individual.
Your life is going to change. There are going to be hard times. In those times you are often your own worst enemy. The data in this study doesn’t even include many other scenarios I discussed above. Gun purchasing/transferring laws and waiting periods have likely saved many lives.(11) Implementing these laws on a federal level may provide a significant amount of safety without infringing individual freedoms. Gun owners need to practice individual responsibility as well. Keep your firearms locked away. When tragedy in your life strikes have the courage and humility to get the firearm out of your home. It may save your life.
Individuals that have survived suicide regretted the act as soon as it was committed, unfortunately we will never hear from those that are successful.(12) I’m sure they regret it too. The sun rises each day and with each new day is a new opportunity to pursue.
Link to original article:
1. Global Burden of Disease 2016 Injury Collaborators, Naghavi M, Marczak LB, et al. Global Mortality From Firearms, 1990-2016. JAMA. 2018;320(8):792-814. doi:10.1001/jama.2018.10060
2. Allebeck P, Allgulander C, Henningsohn L, Jakobsson SW. Causes of death in a cohort of 50,465 young men--validity of recorded suicide as underlying cause of death. Scand J Soc Med. 1991;19(4):242-247. doi:10.1177/140349489101900405
3. Principles of research ethics | Lærd Dissertation. Accessed July 6, 2020. http://dissertation.laerd.com/principles-of-research-ethics.php
4. Kessler RC, Borges G, Walters EE. Prevalence of and risk factors for lifetime suicide attempts in the National Comorbidity Survey. Arch Gen Psychiatry. 1999;56(7):617-626. doi:10.1001/archpsyc.56.7.617
5. Shenassa ED, Catlin SN, Buka SL. Lethality of firearms relative to other suicide methods: a population based study. J Epidemiol Community Health. 2003;57(2):120-124. doi:10.1136/jech.57.2.120
6. Dempsey CL, Benedek DM, Zuromski KL, et al. Association of Firearm Ownership, Use, Accessibility, and Storage Practices With Suicide Risk Among US Army Soldiers. JAMA Netw Open. 2019;2(6):e195383. doi:10.1001/jamanetworkopen.2019.5383
7. Giffords Law Center’s Annual Gun Law Scorecard. Accessed July 6, 2020. https://lawcenter.giffords.org/scorecard
8. Hanlon TJ, Barber C, Azrael D, Miller M. Type of Firearm Used in Suicides: Findings From 13 States in the National Violent Death Reporting System, 2005-2015. J Adolesc Health Off Publ Soc Adolesc Med. 2019;65(3):366-370. doi:10.1016/j.jadohealth.2019.03.015
9. Ilgen MA, Zivin K, McCammon RJ, Valenstein M. Mental illness, previous suicidality, and access to guns in the United States. Psychiatr Serv Wash DC. 2008;59(2):198-200. doi:10.1176/ps.2008.59.2.198
10. Ortiz-Medina MB, Perea M, Torales J, et al. Cannabis consumption and psychosis or schizophrenia development. Int J Soc Psychiatry. 2018;64(7):690-704. doi:10.1177/0020764018801690
11. Lee LK, Fleegler EW, Farrell C, et al. Firearm Laws and Firearm Homicides: A Systematic Review. JAMA Intern Med. 2017;177(1):106-119. doi:10.1001/jamainternmed.2016.7051
12. Maple M, McKay K, Sanford R. The Attempt Was My Own! Suicide Attempt Survivors Respond to an Australian Community-Based Suicide Exposure Survey. Int J Environ Res Public Health. 2019;16(22). doi:10.3390/ijerph16224549