Our findings provide evidence that social inclusion (social support, gender-specific support from parents, identity documents), protection from transphobia (interpersonal, violence), and undergoing medical transition have the potential for sizeable effects on the high rates of suicide ideation and attempts in trans communities. In contrast, we did not find statistically significant effects for social transition, gender support from sources other than parents, or religiosity/spirituality, other than an unexpected finding regarding strong gender support from leaders. Given that statistical power was not high, as evidenced by the width of our confidence intervals, a lack of statistical significance does not mean that these other factors should be dismissed, as smaller effects may exist below the threshold for detection.
Our results provide support for the potentially strong impact of trans-specific discrimination or harassment (e.g., experiences of transphobia), interpersonal factors (e.g., strong parental support for gender identity or expression) and structural factors (e.g., having an identity document with a gender marker concordant with one's lived gender) on suicide ideation or attempts. This reinforces our earlier descriptive findings that risk of suicide ideation and attempts varied greatly among trans people, and reinforces the need to look beyond proximal determinants toward sites of early prevention or intervention. It is not clear to what extent results from this study may also apply to gender non-conforming cisgender persons, but we note that among sexual minority youth, early gender non-conformity has been associated with increased suicidal behaviour or risk, a process that may be mediated by gender harassment or bullying,[53–55] or by parental disapproval of gender expression.
The large effect sizes observed support the possibility for preventing suicidal ideation and attempts in a large number of individuals. Using the transphobia results as an example, combining the population effects of a reduction in ideation and a reduction in attempt risk among the reduced cases of ideation, and given a population estimate of 53,500 trans adults in Ontario, we would estimate that reducing experiences of transphobia could prevent 8,560 trans persons in the province from experiencing suicidal ideation and 4,601 persons from a suicide attempt within a year.
Our results represent the most detailed analysis of this issue to date; our study was based on a respondent-driven sample of trans people from a large provincial geographic area. The analysis takes account of differential probability of recruitment related to differences in network size, but other biases unrelated to network size may remain. Our use of past-year suicide-related measures represents an improvement over studies that used lifetime measures, as we are able to analyse impact on recent or current risk, which is most relevant to prevention. However, temporality remains a concern. It is possible that some potential causes occurring in the past year followed rather than preceded the outcome. This is one potential explanation of the unusual finding of support from a leader (teacher, supervisor, institution) being associated with increased suicide attempts among those with ideation, in that an attempt may trigger the involvement of leaders. Moreover, as we were unable to determine the exact sequences of events for each participant, it is likely that we have partially controlled for some mediating effects or not controlled for some confounding. For example, borderline personality disorder is adjusted for as a confounder, though it is possible that for some participants its etiology includes experiences of transphobia such as those we assess, and it may thus play a mediating role. Despite these limitations, we attempted to address temporality within a cross-sectional design through time designations within questionnaire items (e.g., childhood abuse prior to the age for inclusion in this study) and use of past-year outcomes.
Our finding that completing a medical transition was associated with reduced risk has implications for interpretation of existing studies on completed suicides. Because trans people are not identifiable in death records, and because completed suicides may occur among those who know they are trans but are not known by family members to be trans, valid studies of completed suicides have only been done where patient records from gender clinics have been matched to population death records (e.g., in Sweden). Our results suggest these estimates of completed suicide among those who have medically transitioned likely underestimate the risk of suicide among broader trans communities.
As all surveys are, by definition, studies of survivors, survival bias remains an issue. Frequencies for attempts will likely be underestimated. Factors that predict lethality may be missed, if those who completed suicide differ from those who survived attempts. Given that we assessed suicide attempts only among those who indicated past-year serious consideration, our data may also have missed additional attempts that were impulsive and unplanned. Moreover, past-year prevalence may not represent a first incident of suicide ideation or attempt; thus, this analysis cannot distinguish between factors that lead one to first become suicidal versus to continue being suicidal.
Proximal factors theorized and demonstrated to increase risk of suicide ideation and/or attempts (e.g., risk factors from epidemiological research and interpersonal factors from Joiner's Interpersonal Model) were conceptualized as mediators, but not included in these analyses. Moreover, our analysis could not disaggregate effects of intervenable variables on other intervenable variables. For example, it is possible that increased parental support for gender may affect whether or not someone is able to medically transition; it is also possible that medical transition results in increased parental support for gender, as parents are able to more clearly see their child in their felt gender. These areas represent opportunities for future research. In general, suicide research regarding gender and sexual minorities has tended to overlook existing theoretical frameworks within suicidology, though they are not incompatible with other frameworks or methods. Future research with trans populations could draw on interdisciplinary theories as well as evidence from trans-specific and broader population research on suicide ideation and attempts to study mediated pathways.
Future prospective cohort studies of broadly defined trans populations are needed to alleviate many of the limitations of this and other studies. With prospective data, we may be able to differentiate between factors that cause initial ideation and factors that prolong its duration, as well as those that lead to first and repeated attempts. We could also begin to study completed suicides in a non-clinical trans population, at least among those who are willing to identify as trans to researchers. Moreover, with clear information on temporality, we would be able to design better controlled and more valid analyses, and to examine mediated pathways (including pathways between intervenable factors as well as proximal factors) to better understand the process through which social marginalization may impact suicide ideation and attempt.
Our goal of evaluating intervenable factors should be interpreted as a screening of potential strategies rather than an analysis of actual population intervention effects. While background factors are structured to represent those that are in the past, unchangeable, or not likely to change in response to other factors in the model, our analytic approach then considers intervenable factors singly; it was not possible to tease apart causal pathways among these factors and combining them into one model would by default serve to prioritize the proximal causal factors while reducing the effect sizes of other potentially important causes (a general effect of multivariable models that is not often explicated but is commonly understood with regard to control for a mediator reducing a causal effect[59,60]). Depending upon inter-individual variation, as in all individual-level studies, also results in an inability to detect simultaneous effects at the group level. For example, reducing transphobic assaults from the current prevalence of 21.2 to 0 % may affect suicide risk not only by saving individuals from the trauma of hate-based assault, but may have additional effects on these individuals and others based on living in a society where transphobic assaults do not occur, versus where they are common.
BMC Public Health. 2015;15(525) © 2015 BioMed Central, Ltd.