Study sample
The study’s main goal was to compare White versus Black middle-aged adults (aged 40–60 years old). Participants were recruited using a stratified address-based sampling frame in order to identify households that included middle-aged adults (aged 40–60 years old). Using data from the 2020 American Community Survey, Census block groups were stratified by race/ethnicity (white, black), urbanicity, and educational achievement across eight demographic strata. Invitations were sent via postal mail to a total of 101,999 households sampled across the eight strata. Potential participants were randomly selected from among eligible middle-aged adults within responding households. Eligible respondents were offered $15 to participate and had the option to complete the survey either by mail or online. Initial surveys were completed between February and November 2022. The study’s final sample include 1,581 respondents who represented the adult population of persons aged 40–60 in the United States. Based on criteria from the American Association for Public Opinion Research, this represents a weighted response rate of 3.48% and a weighted completion rate of 58.11% [23]. After assessing for survey completion and accuracy, in particular for questions related to suicide, the study sample included 1,337 middle-aged adults. This study was approved by the institutional review board of the University of Illinois at Chicago (UIC) (protocol #2021 − 0485).
Measures
SI and frequency were measured with two items from the Suicide Behaviors Questionnaire-Revised (SBQ-R) [24]. The primary outcome for the present study was the presence of thoughts of killing oneself in the past year (“How often have you thought of killing yourself in the past year?”; 1 = never, 2 = rarely (1 time), 3 = sometimes (2 times), 4 = often (3–4 times), 5 = very often (5 or more times)). If respondents failed to answer the question related to SI, they were removed from the sample for this analysis. A secondary outcome, SI frequency was categorized by number of times the respondent indicating they experienced SI in the past year. SI frequency was categorized in three mutually exclusive groups: no SI, single thought of SI, and repeated thoughts of SI.
We examined a comprehensive list of domains related to health and wellbeing, such as: sociodemographic, health status, and financial or social stressors. Sociodemographic characteristics included age (years), gender (cisgender male, cisgender female, transgender, non-binary, gender queer, or other gender identification), marital status (married or cohabitating, single, never married, separated, divorced, or widowed), race/ethnicity (Non-Hispanic White, Non-Hispanic Black, Hispanic or other ethnicity), educational attainment (GED or less, high school diploma, or some education post-high school), metropolitan statistical area (urban/suburban or rural), health insurance status (no health insurance, private health insurance or public health insurance). Health status included self-reported health (excellent, very good, good, fair, or poor).
Perceptions of change in economic status as an indicator of economic hardship was assessed by asking “Think about whomever was mainly responsible for raising you when they were the age you are now. Do you think your own standard of living now is much better, somewhat better, about the same, somewhat worse, or much worse than theirs was?” Responses were collapsed into the following groups: better off, about the same, or worse off than their parents/caregivers. As another way to explore the impact of where the respondents live, we examined Social vulnerability index (SVI). This is a community level measure that is comprised of factors related to poverty, lack of access to transportation, and housing environment. SVI was developed by the Centers for Disease Control and Prevention (CDC) and has been found to be directly related to several health outcomes including suicide [25–27].
Social support was measured with a modified version of the Social Support Network Inventory (SSNI), as this tool has been validated and studies demonstrate strong psychometric properties supporting the use as a proxy for social support, which is well known to mediate service mental health issues [28]. A score representing total social support was calculated based on responses related to levels of support for life issues and stressful experiences. The SSNI captures the amount of support an individual has in relation to intimacy, practical help, emotional support and reassurance of self-worth from the most important person to the respondent in each of four categories: partner/spouse, co-worker, friend outside of work, and relative. Support in each area and from each source are assessed on a 7-point Likert-type scale ranging from 1 to 7, with lower scores representing less support and higher scores indicating higher levels of social support. Ratings are summed for each type of support and then averaged over the number of sources of support listed by a respondent, to create a total support score.
Recent substance use was assessed for alcohol, marijuana, opiates, or other illicit substances. Due to small sample sizes, other substances were grouped together and included heroin, methamphetamine, crack, hallucinogens, and inhalants. Respondents who reported using these substances in the past month were further categorized depending on number of substances. Dummy coded variables were created for those who reported any substance use or concurrent substance use. Concurrent substance use was defined as using two or more substances in the past month.
Statistical analysis
Data for this study was analyzed using SAS v9.4 (Cary, North Carolina). Descriptive analysis for all potential predictors were completed using cross tabulations and alpha was set to 0.05 for all tests unless otherwise specified. Bivariate analyses were conducted using chi-square test of differences, for all variables in the dataset known to be linked to suicide or mental health distress (Table 1).
Table 1
Characteristics of middle-aged adults by past year suicide ideation status
| Overall | No suicide ideation (n = 1,197) | Suicide ideation (n = 140) | p-value |
Demographic | Median | IQR a | Median | IQR a | Median | IQR a | |
Age | 50 | 44–56 | 50 | 44–56 | 50 | 43–56 | 0.69 |
Social vulnerability index (SVI) | 0.80 | 0.58–0.92 | 0.80 | 0.58–0.92 | 0.78 | 0.60–0.91 | < 0.001* |
Social support network inventory score | 4.75 | 3.67–5.71 | 3.75 | 5.77 | 4.07 | 3.00–5.00 | < 0.001* |
| N | % | n | % | n | % | |
Gender | < 0.001* |
Cisgender male | 849 | 63.50 | 756 | 63.16 | 93 | 66.43 | |
Cisgender female | 471 | 35.23 | 429 | 35.84 | 42 | 30.00 | |
Transgender, non-binary, etc. | 11 | 0.82 | 6 | 0.50 | 5 | 3.57 | |
Marital Status | 0.03* |
Single, never married, separated, divorced, widowed | 727 | 54.38 | 637 | 53.22 | 90 | 64.29 | |
Married or cohabitating | 596 | 44.58 | 546 | 45.61 | 50 | 35.71 | |
Race/ethnicity | < 0.001* |
Non-Hispanic White | 653 | 48.84 | 570 | 47.62 | 83 | 59.29 | |
Non-Hispanic Black | 435 | 32.54 | 405 | 33.83 | 30 | 21.43 | |
Hispanic or other race | 249 | 18.62 | 222 | 18.55 | 27 | 19.29 | |
Household income | 0.02* |
Under $30,000 | 574 | 42.93 | 498 | 41.60 | 76 | 54.29 | |
$30,001 to $60,000 | 319 | 23.86 | 288 | 24.06 | 31 | 22.14 | |
$60,000-$90,000 | 166 | 12.42 | 156 | 13.03 | 10 | 7.14 | |
Over $90,000 | 239 | 17.88 | 217 | 18.13 | 22 | 15.71 | |
Educational attainment | 0..37 |
High school diploma, GED, or less | 468 | 35.00 | 423 | 35.34 | 45 | 32.14 | |
Some education post-high school | 858 | 64.17 | 763 | 63.74 | 95 | 67.86 | |
Employment status | < 0.001* |
Not employed | 491 | 36.72 | 419 | 35.00 | 72 | 51.43 | |
Employed | 807 | 60.36 | 739 | 61.74 | 68 | 48.57 | |
Rurality | 0.65 |
Urban/suburban | 625 | 46.75 | 557 | 46.53 | 68 | 48.57 | |
Rural | 712 | 53.25 | 640 | 53.47 | 72 | 51.43 | |
Health insurance status | 0.07 |
No health insurance | 217 | 16.23 | 200 | 16.71 | 17 | 12.14 | |
Private health insurance | 500 | 37.40 | 455 | 38.01 | 45 | 32.14 | |
Public health insurance | 483 | 36.13 | 417 | 34.84 | 66 | 47.14 | |
Public and private insurance | 134 | 10.02 | 122 | 10.19 | 12 | 8.57 | |
Health status | < 0.001* |
Good, very good, or excellent | 968 | 72.40 | 892 | 74.52 | 76 | 54.29 | |
Fair or poor | 366 | 27.37 | 302 | 25.23 | 64 | 45.71 | |
Change in standard of living | < 0.001* |
Worse | 227 | 16.98 | 183 | 15.29 | 44 | 31.43 | |
About the same | 282 | 21.09 | 264 | 22.06 | 18 | 12.86 | |
Better | 748 | 55.95 | 683 | 57.06 | 65 | 46.43 | |
Substance use | |
Binge drank in past year | 435 | 32.54 | 388 | 32.41 | 47 | 33.57 | 0.80 |
Any substance use in past month | 0.003* |
No | 653 | 48.84 | 601 | 50.21 | 52 | 37.14 | |
Yes | 684 | 51.16 | 596 | 49.79 | 88 | 62.86 | |
Concurrent use of substances in past month | < 0.001* |
No | 1,203 | 89.98 | 1,098 | 91.73 | 105 | 75.00 | |
Yes | 134 | 10.02 | 99 | 8.27 | 35 | 25.00 | |
Type of substance use in past month | |
Alcohol use | 597 | 44.65 | 523 | 43.69 | 74 | 52.86 | 0.10 |
Marijuana use | 183 | 13.69 | 143 | 11.95 | 40 | 28.57 | < 0.001* |
Opiate use | 39 | 2.92 | 29 | 2.42 | 10 | 7.14 | 0.007* |
Other substance use | 20 | 1.50 | 15 | 1.25 | 5 | 3.57 | 0.03* |
a Interquartile range (IQR) |
* Indicates statistical significance (p < 0.05). |
Using multivariable logistic regression, the aORs for past year SI were calculated for sociodemographic, substance use, economic and social support variables. Multivariable logistic regression was used to provide a more direct interpretation for the relationship between the predictors and SI. A subsequent multinomial logistic regression was performed to identify factors associated with single or repeated SI compared to those with no past year SI among the study population.
Assumptions were tested by assessing multicollinearity among predictors using a variance inflation factor (VIF) with a critical value greater than 10.0. Goodness of fit indices such as the Type 3 Analysis of Effects and Wald chi-square test for maximum likelihood estimates were examined for all predictors.
Adjusted odds ratios (aOR) with 95% Confidence Intervals (CIs) were calculated for each of the significant predictors in the final model. Odds ratios indicate factors significantly associated with increased odds of reporting SI in the past year, adjusted for all potential confounders. Similarly, using a multinomial logistic regression model can produce aORs and corresponding 95% CIs for those significant factors associated with SI one vs. multiple times in the past year.