This examination of national MCOD data identifies probable health-data disparities across a range of decedent characteristics. Controlling for demographics and other key determinants, suicide data quality for Blacks, and to a smaller extent for Hispanics, seems inferior to that for Whites. We estimated that Blacks were over twice as prone to potential suicide misclassification as Whites and Hispanics 17% more prone. Excess potential for misclassification was also indicated for youth and the lesser educated. Results may support a previously proposed but understudied hypothesis that medicolegal authorities are more hesitant to attribute suicidal intent in death investigations involving the young [
28]. We further estimated that decedents with no mention of psychiatric comorbidity on their death certificates carry a three-fold greater potential for suicide misclassification than opposites. Although the association between mode of injury and potential misclassification was marked, incorporating injury mode into the multivariate analysis nullified only the gender association. Our findings confirm that documentation of psychiatric comorbidity on US death certificates is deficient [
17] and that deficits are magnified among the two major racial/ethnic minorities [
18]. General deficits in death certificates and clinical training in death certification have been widely reported [
33-
35], and training problems extend to medical examiners and coroners [
10]. Despite low prevalence, factoring in psychiatric documentation into our study suggested excess potential for suicide misclassification for Hispanics as well as for Blacks.
Confined to death certificate data, our study only indirectly assessed the relationship between race/ethnicity, other decedent characteristics, and suicide misclassification, a formidable target. A second and related limitation is that representation of true suicides among undetermined injury deaths, our proxy for misclassified suicides, likely varies by decedent demographics including race/ethnicity [
36]. A strong mitigating factor was our control for mode, method, or mechanism of injury death. While undetermined intent deaths comprise the category most susceptible to misclassification, other mortality categories can also obfuscate suicides [
4]. Some dwarf that category, notably ill-defined and unknown causes and unintentional poisonings [
2,
37,
38]. These and other categories, such as "suicide-by-cop" [
24], subsumed under subject-precipitated homicide, all possibly contribute to differential suicide data quality between Blacks, Hispanics, and Whites. Our analysis focused on the undetermined intent category because the evidence base for its inclusion remains stronger in comparison to other categories [
11,
13]. Nonetheless, the issue of differential susceptibility to suicide misclassification by cause of death warrants in-depth research.
A third study limitation, but selectively problematic owing to small numbers, our results might have been modified had we been able to factor in uncontrolled heterogeneity inherent in all three racial/ethnic groups. A potentially important confounder is the immigration status of decedents. However, beyond the constraint of small numbers, the MCOD files lack data on duration of residence in the United States and on country of origin. Implicating the acculturation process, future research might address the impact of these variables since they could relate to within and across group assessment of risk for both suicide and suicide misclassification.
Since suicide case ascertainment is typically local, a fourth study limitation is our omission of contextual factors. A focus for our future research, these factors include community attitudes and actions in response to suicide, as well as poverty, discrimination, segregation, healthcare, and type and trust of the medicolegal system.
Ideally we would have had access to medical examiner and coroner records on psychiatric histories of our study population. We found that a proxy for these data, absence of documentation (versus documentation) of psychiatric comorbidity on the death certificate, was a strong predictor of potential suicide misclassification. And the very low prevalence of this documentation, taken at face value, might suggest that official knowledge or lack of knowledge of the psychiatric history of decedents is a minor contributor to differential misclassification by race/ethnicity. We appreciate that these officials likely know much more about such history than is reflected on the death certificate. Nevertheless, germane to preliminary comprehension of the black-white suicide paradox, we had no a priori reason to believe that the nature and magnitude of the relative racial comorbidity gap manifest from death certificates would not mirror a similar gap in medical examiner and coroner records. However, this remains an empirical question.
The potential of a social group to have their suicides misclassified is related to the extent to which members leave a suicide note, a key piece of forensic evidence for classifying a death as suicide [
39,
40]. In a preliminary analysis of 2003-2006 data from the National Violent Death Reporting System, a system currently confined to less than 20 states [
41], we determined that 31% of white suicides left a note, but only 18% of black suicides and 21% of Hispanic suicides. We suspect that this differential in forensic evidence contributes to misclassification-proneness and the suicide paradox.
Risk factors collectively predict much higher suicide rates for Blacks than their official rates. On the other hand, although not yet subjected to rigorous testing, countervailing forces may diminish their suicide risk relative to Whites. Blacks manifest higher religiosity and less cultural acceptance of suicide [
42,
43]. Some researchers suggest that Blacks possess a preference for externalizing extreme aggression as homicide rather than internalizing it as suicide [
44], an ad hoc explanation we find uncompelling. Indeed, no research explains how being Black protects against suicide, especially when viewed in context with other violent behaviors like homicide [
45]. Moreover, cultural factors within Black communities could foster relative under-documentation of psychiatric comorbidity on the death certificates of their suicides. Arguing for the value of sociocultural autopsies in comparative racial/ethnic suicide research [
46], these factors include greater self-stigma and public stigma which these communities attach to mental illness and treatment compared to White communities [
47].