Sample
We extracted data from the VHA’s Corporate Data Warehouse (CDW), which contains administrative and EHR data.24 Detailed information about the structure and components of the CDW is available from the VA Information Resources Center.25 Data were from all Veteran Integrated Service Network Region 4 (VISN-4) patients with at least 1 inpatient or outpatient visit during the study period of fiscal year (FY) 2016 (October 1, 2015–September 30, 2016), culminating in an analytic sample of 293,872 patients after excluding 41 patients missing data on age. This research focused on VISN-4 because it was supported through a VISN-4 competitive pilot project award.
Key Independent Variables
We categorized seven types of adverse SDH: experience of violence, housing instability, employment or financial problems, legal problems, social or familial problems, lack of access to care or transportation, and non-specific psychosocial needs that were documented during FY2016. Data on SDH came from three primary sources. First, we searched for International Statistical Classification of Diseases and Related Health Problems (ICD)-10 codes indicative of SDH, such as TX74.11 adult physical abuse, Z56.0 unemployment, Z59.0 homelessness, and Z65.1 imprisonment or incarceration. Second, we included any VHA code indicative of receiving services (i.e., stop codes) related to SDH, such as counseling for MST, job rehabilitation services, VHA Homeless Programs, and services for justice-involved Veterans. Third, we used selected standardized fields from a table of Health Factors data in the CDW captured through progress notes authored by master’s prepared social workers, primarily delivering social work services in Patient Aligned Care Team (PACT) settings. These standardized fields included information on “presenting issues” (e.g., abuse, housing instability, or lack of transportation) and “concerns” (e.g., concerns about housing, income, access to care, and social support). Each “concern” field could have an acuity level (1 to 4) assigned: all needs met, minor concern, major concern, or crisis, which we recoded as dichotomy of all needs met vs. minor/major concern or crisis. Although VA’s Health Factors includes various data about numerous patient indicators, there are few standardized fields. For example, to create a smoking status variable from Health Factors data, McGinnis et al. had to review over 3,800 individual Health Factor categories related to tobacco use.26 Reviewing all Health Factors data was beyond the scope of this pilot project, and the use of the social work template presented an existing standardized categorization of SDH-related indicators. Appendix Table 6 presents the ICD-10 codes, VHA stop codes, and VA Health Factors codes.
We summarized adverse SDH as experiencing any one of the several indicators. For example, if a patient had an ICD-10 code indicating violence and a VHA stop code indicating experience of military sexual trauma, the patient was coded as “yes” for having experienced any violence. In addition to coding presence of each category of adverse SDH separately (e.g., “any violence”), we also created a variable of the number of categories of adverse SDH identified (0, 1, 2…7).
Covariates
We extracted data on several covariates, such as socio-demographic information on race, ethnicity, sex, marital status, and age. Because transgender Veterans have high risk for suicide morbidity and mortality and prevalent SDH-related issues (e.g., housing instability),22, 27 we included transgender status using methodology in previous VHA-based research using ICD codes (e.g., gender identity disorder). We included patients’ locale, which was defined by VHA’s Planning Systems Support Group (PSSG) data source that identifies a patient as living in an urban, rural, or highly rural area.28 Patients who had different entries for their locale during the study period or were missing were recoded to a category of “unknown” locales. Lastly, because of their strong relations with suicidal ideation and attempt, we extracted the following diagnoses for patients during the study period: major depressive disorder, alcohol use disorder, drug use disorder, anxiety disorder, posttraumatic stress disorder, schizophrenia, and bipolar disorder.
Dependent Variables
The two key outcomes of suicidal ideation and suicide attempt were coded using two forms of data. First, we used presence of any ICD-10 code for suicidal ideation or for suicide attempt during FY2016. Second, the VHA has a unique registry of patients who have experienced suicidal ideation, attempt, death, or non-suicidal self-harm, known collectively as the Suicide Prevention Applications Network (SPAN) and input by a national network of VA Suicide Prevention Coordinators (see Hoffmire et al.).29 We coded any patient that had either a SPAN record or an ICD code indicating suicidal ideation or attempt during the study period as having the outcomes of interest; patients without either notations during the study period were considered not to have the outcomes of interest. Suicide ideation and attempt are related—but distinct—phenomena,30 and we elected to analyze them separately rather than as a combined outcome.
Analyses
We summarized the frequencies and point prevalence estimates of all socio-demographic characteristics and adverse SDH. We generated a co-prevalence matrix illustrating the co-occurrence between any two adverse SDH; a correlational analysis (i.e., tetrachoric) was not plausible because one could not assume the adverse SDH variables had underlying normally distributed continuous structures. To assess the association of the count of adverse SDH with suicidal ideation and with suicide attempt, we used multiple logistic regression to adjust for socio-demographic and mental disorder diagnoses. We also conducted a series of separate multiple logistic regression analyses to determine the independent association of each adverse SDH with suicidal ideation and with suicide attempt. For multivariable models, we top-coded the count of adverse SDH to > 4 because of the relatively scant frequency of patients in the categories of having indicators of 5, 6, or all 7 adverse SDH. Missing values in socio-demographic variables were recoded to “unknown” to preserve the observations from list-wise deletion in multivariable analyses. Because of the large sample size, statistical significance was assessed at the p < .01 level, and all adjusted odds ratios (aOR) included 99% confidence intervals (CI). All analyses were conducted using Stata/MP Version 15.31 This study was approved by the VA Pittsburgh Healthcare Systemp institutional review board.