Examining the Interfacility Variation of Social Determinants of Health in the Veterans Health Administration

Social determinants of health (SDoH) are social, economic, environmental, and occupational factors that are known to influence an individual’s health care utilization and clinical outcomes.^1,2 Because the Veterans Health Administration (VHA) is charged to address both the medical and nonmedical needs of the veteran population, it is increasingly interested in the impact SDoH have on veteran care.^3,4 To combat the adverse impact of such factors, the VHA has implemented several large-scale programs across the US that focus on prevalent SDoH, such as homelessness, substance abuse, and alcohol use disorders.^5,6 While such risk factors are generally universal in their distribution, variation across regions, between urban and rural spaces, and even within cities has been shown to exist in private settings.⁷ Understanding such variability potentially could be helpful to US Department of Veterans Affairs (VA) policymakers and leaders to better allocate funding and resources to address such issues.

Although previous work has highlighted regional and neighborhood-level variability of SDoH, no study has examined the facility-level variability of commonly encountered social risk factors within the VHA.^4,8 The aim of this study was to describe the interfacility variation of 5 common SDoH known to influence health and health outcomes among a national cohort of veterans hospitalized for common medical issues by using administrative data.

Methods

We used a national cohort of veterans aged ≥ 65 years who were hospitalized at a VHA acute care facility with a primary discharge diagnosis of acute myocardial infarction (AMI), heart failure (HF), or pneumonia in 2012. These conditions were chosen because they are publicly reported and frequently used for interfacility comparison.

Using the International Classification of Diseases–9th Revision (ICD-9) and VHA clinical stop codes, we calculated the median documented proportion of patients with any of the following 5 SDoH: lived alone, marginal housing, alcohol use disorder, substance use disorder, and use of substance use services for patients presenting with HF, MI, and pneumonia (Table). These SDoH were chosen because they are intervenable risk factors for which the VHA has several programs (eg, homeless outreach, substance abuse, and tobacco cessation). To examine the variability of these SDoH across VHA facilities, we determined the number of hospitals that had a sufficient number of admissions (≥ 50) to be included in the analyses. We then examined the administratively documented, facility-level variation in the proportion of individuals with any of the 5 SDoH administrative codes and examined the distribution of their use across all qualifying facilities.

Because variability may be due to regional coding differences, we examined the difference in the estimated prevalence of the risk factor lives alone by using a previously developed natural language processing (NLP) program.⁹ The NLP program is a rule-based system designed to automatically extract information that requires inferencing from clinical notes (eg, discharge summaries and nursing, social work, emergency department physician, primary care, and hospital admission notes). For instance, the program identifies whether there was direct or indirect evidence that the patient did or did not live alone. In addition to extracting data on lives alone, the NLP program has the capacity to extract information on lack of social support and living alone—2 characteristics without VHA interventions, which were not examined here. The NLP program was developed and evaluated using at least 1 year of notes prior to index hospitalization. Because this program was developed and validated on a 2012 data set, we were limited to using a cohort from this year as well.

All analyses were conducted using SAS Version 9.4. The San Francisco VA Medical Center Institutional Review Board approved this study.