Reviews⁴ and large-scale analyses of Medicare beneficiary data⁵ indicate that medical need is the primary factor accounting for ED usage among elders but have noted that existing studies and surveillance databases often do not assess psychological and behavioral factors, which may affect older adults’ success at accessing ED services. Among other things, these might include dispositional tendencies such as the ability to remain calm under stress, assert one’s need for care, reliably follow-through on the intention to visit the ED, and interact with caregivers and medical staff. A large range of psychological factors potentially affecting ED use can be parsimoniously captured by the so-called “Big Five” personality traits, which reflect the five major axes of dispositional cognitive, emotional, and behavioral variation in humans.^7,8 Empirically derived and representing roughly equal portions of genetic and environmental variance,⁹ the Big-five taxonomy includes the dimensions of neuroticism or the tendency to experience negative emotions and emotional instability; extroversion, or a disposition toward sociability, positive emotions, dominance, and high-activity level; openness to experience, or interest in new things, ideas, and courses of action; agreeableness, or deference, acquiescence, amiability, and trust; and conscientiousness, reflecting diligence, reliability, organization, and goal striving. These traits are associated with several aspects of health in older adults,¹⁰ including health behaviors,^11,12 subjective and objective medical burden,^13,14 and all-cause mortality,^15,16 and predict utilization of other health services in the general populations.^17-20 We hypothesized that the following Big Five Big personality traits would be associated with ED use in a prospective cohort study of older adults drawn from primary care, controlling for a range of other factors in the Andersen model reflecting healthcare need, enabling, and predisposing factors:

First, extroversion may enhance the odds that older persons would visit the ED because the physical energy and vigor, coupled with social confidence indexed by this trait,^24,25 enable decisive action in the face of urgent health problems. Prior findings have also linked extroversion to greater sense of control over health^11,26 and to hope for future health among older adults.¹³ These tendencies may index expectations of positive healthcare experiences, and more favorable attitudes toward health services have been associated with ED use among elders in prior work.⁴⁰

Second, lower agreeableness was also associated with greater odds of ED use among older adults. Low levels of this trait reflect assertiveness, manipulativeness, and self-interest and can result in resistance to others’ directions, authority, or efforts to control.^24,25 Often socially unpleasant, the potential adaptive value of these tendencies may lie in their ability to assert one’s need for urgent care stridently enough or cleverly enough to circumvent potential obstacles to ED access faced by older adults. For instance, consider an older adult with an incipient health crisis who is told on Friday by a primary care physician without weekend office hours to return on Monday for further evaluation. An assertive older patient may be more capable of resisting this advice and instead reporting to the ED. In contrast, an overly agreeable older patient may comply out of concern for potential conflict with or for inconveniencing outpatient office staff, ED personnel, the primary care doctor, or others in their support system who must transport them to and provide supervision during the ED visit. Other barriers to ED access for older adults, such as convincing emergency services or triage personnel to attend to one quickly, obtaining transportation, and instrumental assistance, or alerting caretakers to emergent problems may also be surmounted by the combination of social confidence, vigor, assertiveness, and insistence encapsulated by high extroversion and lower agreeableness.

Third, although higher neuroticism seemed associated with higher odds of ED use in unadjusted models, we did not observe hypothesized effects after multivariate adjustment. One reason may be that neuroticism is a longstanding predisposition toward distress and negative emotion, which greatly increases risk for depressive episodes.^28,41 In this cohort, current depression symptoms were prominently associated with higher likelihood of ED use, suggesting that current depressive symptoms represent a more proximal correlate of ED use in older patients than neuroticism. Higher conscientiousness was also associated with lower odds of ED use in unadjusted but not adjusted analyses. However, higher conscientiousness is associated with less illness burden,¹² which in turn was a significant determinant of ED use (consistent with prior findings^4,5), so a mediating relationship may prevail among these factors. More primary care visits were also associated with greater likelihood of an ED visit, contrary to prior findings,⁴ perhaps reflecting a sample-specific pattern wherein outpatient services promote ED access. Finally, ED use tended to decline over the study period, probably reflecting selective survivorship and retention of more medically stable participants over the course of the study.

These findings suggest several implications. First, considerable heterogeneity exists in ED use even among older adults of comparable sociodemographics, medical burden, and functional status. Linking this heterogeneity to personality dispositions can systematically describe the complex array of psychological and behavioral tendencies driving the decision to seek care. This aids in the identification of who or which kind of older patients are more or less likely to use emergency medicine services. Although our findings indicate that more extraverted and less agreeable older patients are more likely, whereas introverted and highly agreeable patients less likely to seek ED care, we make no claims about “over” or “under” utilization. Rather, given that patients are often advised to seek care when in doubt—particularly for time-sensitive conditions such as strokes and myocardial infarctions—a cautious interpretation is simply that more introverted and agreeable older adults may constitute a specific risk-segment of the geriatric population less likely to access ED services.

Introverted and overly agreeable older patients may require particular encouragement from primary care providers to seek ED services, particularly for time-sensitive conditions, for which waiting for the next outpatient appointment may result in a hospitalization that was avoidable or increase fatality risk. Whether through informal clinical advice or formal behavioral intervention, potentially helpful prophylaxis may range from simple reassurances—such as that it is always safer to be evaluated than not—to more elaborate training in assertiveness and proactive coping specific to the steps necessary to obtain ED care. Meta-analytic findings that personality continues to evolve across the life course^38-40 suggest that interventions to reduce dispositional risk for ED underuse or misuse in elders would be theoretically and empirically well grounded. Just as depression and anxiety are commonly screened in primary care, future work may wish to evaluate the feasibility and utility of brief personality measures⁴² for screening, as well as the accuracy with which physicians and caretakers of older patients can judge their patients’ dispositional tendencies,⁴³ obviating the need for formal screening.

We qualify our findings appropriately by study limitations. First, utilization data were self-reported, albeit with a validated instrument, which correlates highly with documented utilization,²⁹ and in the context of an interview, which facilitates accuracy of service use reports in the elderly.³⁰ Second, we were unable to examine specific reasons for ED visits. This makes it difficult to disentangle high rates of use due to legitimate medical emergencies from personalitydriven use. Third, our sample reported levels of neuroticism and agreeableness slightly below and above the population mean. Although response rate was in line with expectations, given the intensive nature of participation, future studies might wish to oversample highly neurotic and disagreeable populations. Fourth, although we controlled extensively for numerous other covariates, the possibility of additional, unmeasured influences can never be ruled out. For instance, we did not measure supplementary insurance or income at the individual level; however, prior reports suggest minimal impact of both upon ED use in older adults with Medicare.⁵ Other factors may drive both depression and ED use, or they may reciprocally influence one another over time. Fifth, our prospective cohort design provides less basis for causal conclusions than randomized clinical trials, but it is impossible to randomize individuals to personalities, rendering prospective cohort designs the most feasible for investigating this area. As causality cannot be strongly inferred, however, we restrain our conclusions to rigorously controlled prospective prediction. Sixth, three conceptual or theoretical hypotheses were tested in this study—one each for neuroticism, extroversion, and agreeableness. Some might use a Bonferroni correction or reduce the p value from the customary value of 0.05–0.01 or another value. However, as we were examining this question for the first time, we favor the use of the conventional value of 0.05 in order err on the side of falsely accepting a hypothesis rather than conclude potentially important factors are nonsignificant and exclude them from further study. Results should be interpreted in this light. A related consideration is that 32 p values appear in Table 2. The left-hand column presents bivariate associations, primarily for descriptive purposes. We draw no inference or scientific conclusions from these unadjusted estimates. Additionally, the p values of covariates, either unadjusted or from the multivariate model presented in the right-hand column of Table 2, are of little interest because these variables were included simply to adjust personality estimates for potential confounders. From one perspective, some of these p values may represent Type I errors. Thus, we caution against drawing inferences about the statistical significance of unadjusted or covariate effects, which were not the factors of interest in this study.