Perceived Socioeconomic Status: A Strong Predictor of Long-Term Outcomes After Injury.

Abstract

Socioeconomic status (SES) is defined as a total measure of an individual's economic or social position in relation to others. Income and educational level are often used as quantifiable objective measures of SES but are inherently limited. Perceived SES (p-SES), refers to an individual's perception of their own SES. Herein, we assess the correlation between objective SES (o-SES) as defined by income and educational level and p-SES after injury and compare their associations with long-term outcomes after injury. Moderate-to-severely injured patients admitted to a Level 1 trauma center were asked to complete a phone-based survey assessing functional and mental health outcomes, social dysfunction, chronic pain, and return to work/school 6-12mo postinjury. o-SES was determined by income and educational level (low educational level: high school or lower; low income: live in zip code with median income/household lower than the national median). p-SES was determined by asking patients to categorize their SES. The correlation coefficient between o-SES and p-SES was calculated. Multivariate logistic regression models were built to determine the associations between o-SES and p-SES and long-term outcomes. A total of 729 patients were included in this study. Patients who reported a low p-SES were younger, more likely to suffer penetrating injuries, and to have a weak social support network. Twenty-one percent of patients with high income and high educational level classified their p-SES as low or mid-low, and conversely, 46% of patients with low education and low income classified their p-SES as high or mid-high. The correlation coefficient between p-SES and o-SES was 0.2513. After adjusting for confounders, p-SES was a stronger predictor of long-term outcomes, including functional limitations, social dysfunction, mental health outcomes, return to work/school, and chronic pain than was o-SES. Patient-reported p-SES correlates poorly with o-SES indicating that the commonly used calculation of income and education may not accurately capture an individuals' SES. Furthermore, we found p-SES to be more strongly correlated with long-term outcome measures than o-SES. As we strive to improve long-term outcomes after injury, p-SES may be an important variable in the early identification of individuals who are likely to suffer from worse long-term outcomes after injury.