1. Suicidal ideation among long-term opioid users: Its Risk Factors and the role of gender
Kirsten Marchand
PhD Candidate, School of Population and Public Health, University of British Columbia
Canada
Thursday October 26, 2017
Hello everyone, my name is Kirsten Marchand, as mentioned I am a PhD candidate at UBC's in Vancouver Canada. My research focuses broadly on understanding the experiences of people with opioid dependence, with a particular focus on treatment experience and how we can improve services by incorporating participant perceptions. 
In today's talk, I'll be sharing findings from a recent paper exploring suicidal ideation among long-term opioid users and the potential role of gender. 

2. Background & Rationale
Opioid dependence and associated rates of morbidity and mortality continue to increase.
Common causes of mortality include overdose and suicide, with a great amount of research focused on fatal and non-fatal suicidal attempts. 
Suicidal ideation is one of the strongest risk factors for suicide attempts, but we know very little about this experience specifically.
A ‘gender-paradox’ exists in suicidal behaviours and ample gender- specific experiences have been documented among people with opioid-dependence.    
Point 1 – As we have been hearing in this conference, opioid dependence and its associated harms continues to increase in prevalence.
           
Point 2- in particular, we are seeing an increase in overdose related deaths, due to fentanyl and other highly potent opioids, but mortality among opioid dependent populations can also be attributed to suicide. Most of the research on mortality has focused on fatal and non-fatal suicide attempts.  
Point 3- Broadly speaking, suicidal ideation is one of the strongest risk factors for suicide attempts, however, we know very little about suicidal ideation and its risk factors among opioid dependent populations. This is particularly relevant since there is some early theoretical research to suggest that suicidal ideation and suicidal attempts may be explained by distinct processes. 
Point 4-  In exploring suicidal ideation, there is also a need to consider the potential role of gender since it is widely known that a gender-paradox exists for suicidal behaviours in the general population and among opioid dependent people.
              - For example, women tend to have higher rates of nonfatal suicide attempts while men have higher rates of fatal attempts. 
- Also, there is evidence of gender-specific experiences among people with opioid dependence, including differences in the risks and outcomes of opioid dependence.
- For example, women are younger, have more suicide attempts, less education and employment, more dysfunctional families and exposure to more unfavorable social factors, higher standardised mortality ratios, more psychological problems, greater health service utilization. 

3. Study Objectives
In light of the current gaps in the evidence surrounding suicidal ideation among long-term opioid users, the present study had two aims:
To examine factors associated with suicidal ideation among a sample of long-term opioid-dependent women and men;
To explore whether these factors are gender-specific.
In light of the current gaps in the evidence surrounding suicidal ideation among long-term opioid users, the present study has two aims: 
Given that suicide is a preventable cause of mortality, such evidence is critical to earlier intervention efforts that could be incorporated in addiction treatment settings.

4. Methods – ‘Gender Matters’ Study
Cross-sectional data on 176 long-term opioid dependent women (n=81) and men (n=95) in Vancouver’s poorest postal code.
Dependent variable: lifetime suicidal ideation
“Have you ever seriously thought about committing suicide?” (CIDI-Major Depression Module)
Independent variables: (1) Sociodemographic characteristics; (2) History of depression and anxiety; (3) History of opioid use; (4) Addiction treatment history; (5) Childhood maltreatment experiences; (6) Exposure to potentially traumatic life events
Point 1 – we conducted a cross sectional study that largely aimed to understand gender patterns in drug use, victimization, and access to health care among long-term opioid users. 
              -- Participants were eligible if they had been using illicit opioids for at least 5 years, using regularly in the prior 6 months, and had 1 or more episodes of OAT. 
              -- since women are usually underrepresented in addictions research and we wanted to explore gender specific patterns, we worked very hard to reach a similar and representative sample of women, we did this by forming partnerships with organizations in the community and using snowball sampling. 
Point 2- A number of quantitative measures were used to assess socio-demographic characteristics, health, drug use, histories of victimization.
             - For the present analysis of suicidal behaviours, we used the Composite International Diagnostic Interview, which asks about lifetime suicidal ideation. For those reporting such thoughts, additional questions are asked about ideation in the past 12 months, and also suicidal plans and attempts.  
Point 3 - About independent variables – for this analysis, a number of variables were considered based on what is known in the literature about risk factors for suicidal attempts and also what might be relevant to the role of gender, for example, age, history of sex work, education level.
            - Because the dependent variable covered a lifetime reference period, only independent variables covering the same period were included. 

5. Statistical Analyses
Binary outcome variable - lifetime history of suicidal ideation yes vs. no
Descriptive statistics (Student’s t-test, chi square test) to examine bivariate association between each X and Y.
Three multivariable logistic regression models built for:
Full study sample (age, gender, ethnicity forced in);
Women only (age, ethnicity forced in); and
Men only (age, ethnicity forced in).
Model building: backward elimination for variable selection; AIC and BIC for model selection. Separate analyses conducted for full sample, women only, and men only.
Point 1- as mentioned the dependent variable for this analysis was suicidal ideation in the lifetime.
Point 2 – descriptive statistics were used to summarize each variable and to examine the bivariate association between each x and y.
Point 3 – In keeping with our aim to conduct a gender-sensitive analysis, we built three separate multivariable logistic regression models, one for the full sample and one each for men and women separately. 
Point 4 -- Backward elimination was then used, where one-by-one, variables with the least significance were dropped from the model. In addition to this process, at each step, the reduced model’s Akaike information criterion (AIC) and Bayesian information criterion (BIC) were compared with the prior model. The final model was selected based on the AIC and BIC (i.e., given the collection of models, lower values indicate better relative quality of statistical model). T
             -- Firth’s penalized likelihood was used to fit all models, a method that is commonly used to avoid bias typically found in models built with a small number of observations in 1 or more groups

6. Descriptive Results – Suicidal Ideation
43.8% (n=77) had ideation in lifetime
Average age of first suicidal thoughts = (sd=11.66)
36.4% had thoughts in past 12 months
Socio-demographic, substance use and addiction treatment histories were similarly distributed by ideation group.
Among those with suicidal ideation histories…
Lifetime suicidal plans:
62.3% made a plan in lifetime
29.2% made a plan in past 12 months
Lifetime suicidal attempts:
75.3% made a suicidal attempt in lifetime
10.3% made an attempt in past 12 months
Point 1 – Suicidal ideation was reported by approx. 44% of the overall study sample, with no significant differences between the proportion of women and men reporting suicidal ideation.
            -- When exploring the characteristics of participants with suicidal ideation to those without suicidal ideation, we found that Socio-demographic characteristics, substance use and addiction treatment histories were similarly distributed.
            -- However, we found that histories of sex work, depression and anxiety and all measures of victimization were significantly higher among those with suicidal ideation. 
Point 2 – as mentioned the suicide questionnaire used only asks further questions about plans and attempts to those with suicidal ideation, and among the 77 participants with this history, we found that 62% had made a plan in their lifetime and 75% had made an attempt. Fewer participants reported these patterns in the last year.  

7. Factors associated with suicidal ideation (Full Sample)
Variable a
Full Sample (n=169)
Adjusted Odds Ratio
(95% Confidence Interval)
Lifetime history of depression (yes vs. no)
2.96 ( )*
Lifetime history of anxiety (yes vs. no)
3.98 ( )**
Lifetime number of accidental overdoses
1.04 ( )
Childhood emotional neglect score
1.09 ( )*
Lifetime number of potentially traumatic events score
1.13 ( )**
When looking at the full sample, the results of the multivariable logistic regression analysis showed that, lifetime histories of depression, anxiety, childhood emotional neglect and the number of traumatic life events were independently associated with an increased odds of lifetime suicidal ideation.
You’ll note that for the categorical variables for depression and anxiety, the confidence intervals become wide due to the relatively small cell sizes, thus, caution is required with the interpretation of these findings.
Also, although not reaching statistical significance, lifetime number of accidental overdoses improved the model fit.
A few notes to aid in the interpretation:
Of the 176 participants in the study, 7 were excluded from the full model due to missing data on the childhood trauma questionnaire, potentially traumatic life events, and lifetime depression and anxiety variables. The final number of observations used for the analysis was 169 (74 women, 95 men), 74 of whom were individuals with lifetime suicidal thoughts.
Full model also adjusted for age, gender and ethnicity.
Wide CI’s for the categorical variables for depression and anxiety, which can be attributed to the relatively small cell sizes. For depression variable, in this model there were 107 participants who reported lifetime depression and 62 without. For the anxiety variable, there were 116 with anxiety and 53 without.
Model adjusted using firth’s penalized likelihood, a method that is commonly used to avoid bias typically found in models built with a small number of observations in 1 or more groups.
a) Age, gender, ethnicity forced in; * p<0.05; **P<0.01; ***p<0.001

8. Gender-specific Results
Variable
Women Only (n=74)
AOR (95% CI)
Men Only (n=95)
Lifetime history of depression
(yes vs. no)
5.33 ( ) *
2.68 ( )
Lifetime history of anxiety
6.68 ( ) *
3.31 ( )
Lifetime number of accidental overdoses
0.96 ( )
1.09 ( )
Childhood emotional neglect score
1.08 ( )
1.10 ( )*
Lifetime number of potentially traumatic events score
1.10 ( )
1.19 ( )*
In this second table, results are shown for women only and men only.
And here we see that the same variables entered the models for women and men, but what remained independently associated with suicidal ideation appeared to be gender specific.
Among women, histories of depression and anxiety remained independently associated with lifetime suicidal ideation among women.
For men, childhood emotional neglect and the number of lifetime potentially traumatic events was independently associated with lifetime suicidal ideation.
Like the full sample results, caution with interpretation of these findings is required since the cell sizes for categorical variables in particular are quite small. For the depression variable among women, there were with and without depression; among men it was
For anxiety variable, among women, it was and among men it was
a) Age, ethnicity forced in; * p<0.05

9. Discussion
The prevalence of lifetime suicidal ideation was 44% and 75% of this sub-sample also reported histories of suicidal attempts, suggesting that this remains a significant public health concern in this population.
Gender-specific analyses revealed that men and women’s risks for suicidal ideation may be unique.
Mental health variables for women and adverse life events for men.
Allows us to make recommendations for tailored addictions services (e.g., trauma informed care).
Bivariate analysis showed that histories of addiction treatment were similar for participants with and without histories of suicidal ideation.
Point 1- In this study we focused on suicidal ideation, rather than suicide attempts, since emerging evidence suggests that distinct processes may explain suicidal ideation and attempts.
- Although there are limitations to consider with this data mostly due to the cross sectional design and relatively small sample size, our results suggest that suicidal behaviours among people with long-term opioid dependence remain a significant public health concern.
Point 2- Recognizing the important role of gender in both suicidal behaviours and the experience of opioid dependent women and men, we conducted our analyses separately for women and men.
- In doing so, we found that mental health variables were associated with suicidal ideation among women, while adverse life events were associated with suicidal ideation among men.
- There are a number of plausible explanations for these observed associations. For example, among men there is some evidence suggesting that exposure to traumatic events is often underreported due to cultural norms and expectations of masculinity. Such masking may lead to suicidal behaviours.
- It was not surprising to see depression and anxiety associated with suicidal ideation, however, this association persisted among women only, and suggests the need to consider these comorbidities further in research and clinical interventions.
- Taken together, the findings emphasize that that addictions services could be tailored to the mental health needs of women and to better understanding the ongoing traumas faced by men.
Point 3- Importantly and to end on a more positive note, the bivariate analysis showed that participants with suicidal ideation had similar histories of addiction treatment access, for example, a similar number of prior opioid agonist attempts. This suggests that individuals with suicidal ideation who enter the healthcare system through addiction treatment will have opportunities for assessment and intervention, thus, potentially working to reduce the incidence of fatal and non-fatal suicide attempts in this population.

10. Acknowledgements
Special thank you to the GeMa study participants, research staff Jill Fikowski and Kurt Lock, and our funding support from the Canadian Institutes of Health Research
For more information, please contact:
Kirsten Marchand