Background: Research suggests that access to firearms in the home increases the risk for violent death.
Purpose: To understand current estimates of the association between firearm availability and suicide or homicide.
Data sources: PubMed, EMBASE, the Cochrane Central Register of Controlled Trials, and Web of Science were searched without limitations and a gray-literature search was performed on 23 August 2013.
Study selection: All study types that assessed firearm access and outcomes between participants with and without firearm access. There were no restrictions on age, sex, or country.
Data extraction: Two authors independently extracted data into a standardized, prepiloted data extraction form.
Data synthesis: Odds ratios (ORs) and 95% CIs were calculated, although published adjusted estimates were preferentially used. Summary effects were estimated using random- and fixed-effects models. Potential methodological reasons for differences in effects through subgroup analyses were explored.Data were pooled from 16 [not 15] observational studies that assessed he odds of suicide or homicide, yielding pooled ORs of 3.24(95% CI, 2.41 to 4.40) and 2.00 (CI, 1.56 to 3.02) [not 1.94 (CI, .44 to 2.93)], respectively [corrected], respectively. When only studies that used interviews to determine firearm accessibility were considered, the pooled OR for suicide was 3.14 (CI, 2.29 to 4.43).
Limitations: Firearm accessibility was determined by survey interviews in most studies; misclassification of accessibility may have occurred. Heterogeneous populations of varying risks were synthesized to estimate pooled odds of death.
Conclusion: Access to firearms is associated with risk for completed suicide and being the victim of homicide.
Primary funding source: None.