This study indicates that individuals reporting both a high amount of stress and the perception that stress affects their health may be at a greater risk of premature mortality, over and above those who report high stress or perceived health effects of stress alone. These findings have significant implications for theories of stress and health. The hypotheses and results support the notion that stress appraisal is critical in determining outcomes (Lazarus & Folkman, 1984
). This study provides a key contribution to the theoretical literature by building on this notion, in testing whether or not the perception that stress affects one’s health is associated with adverse health outcomes. The results suggest that the appraisal of both the amount of stress and
its impact on health may work together synergistically to increase the risk of premature death. These findings provide new insights into the pathways by which stress may impact health outcomes and suggest new ways of understanding the linkages among stress, coping, and health.
In this study, the perception that stress affects health was found to act synergistically with amount of stress to predict an increased risk of premature death. Specifically, reporting a lot of stress and
perceiving that stress affected one’s health a lot increased the risk of premature death by 43%. To capture the potential clinical and public health significance of this finding, the cumulative hazards models were used to estimate the number of excess deaths attributable to this combination of stress measures. If this were in fact a causal relationship, 20,231 deaths each year would be attributable to having a lot of stress and perceiving that stress affects health a lot. Based on the 2006 Centers for Disease Control and Prevention (CDC) rankings, this would coincide with the number of deaths attributable to essential hypertension and hypertensive renal disease (the 13th
leading cause of death in the U.S) and Parkinson’s disease (the 14th
leading cause of death) (CDC, 2011
). While this study is unable to establish a causal relationship, these results highlight the necessity for further research into the relationship between the perception that stress affects health and current health, mental health, and mortality.
Possible explanations for the synergistic effect seen between the amount of stress and the perceived impact of stress on health include a person’s negative expectancies, resiliency, and locus of control regarding health. An individual’s perception of health plays an important role in determining health outcomes. Studies have shown that having negative (i.e. pessimistic) expectations of life events is predictive of poor physical and mental health and increased use of the health care system (Geers, Kosbab, Helfer, Weiland, & Wellman, 2007
; Maruta, Colligan, Malinchoc, & Offord, 2002
). Furthermore, individuals with negative expectations are even more likely to exhibit negative health symptoms, even when given placebo treatments (Geers et al., 2007
). In light of this finding, a possible explanation of the results could be that the perception that stress affects one’s health is a proxy for negative expectations; therefore, those with this perception will subsequently report their health as poor (i.e. self-fulfilling prophecy).
Resiliency is an important and often overlooked resource for coping with stress. Individuals who have experienced a moderate amount of adversity in the past exhibit more resilience to recent adversity (Seery, Holman, & Silver, 2010
), suggesting that previous experiences with stress may help individuals cope with current stress. Resilient individuals, therefore, may not perceive that stress affects their health or experience negative health outcomes even when faced with a lot of stress. Research is needed to evaluate the relationship between resiliency and the perception that stress impacts one’s health in order to further determine if resiliency-development interventions could improve health outcomes among those with high stress.
An individual’s health locus of control, defined as their beliefs in the control they have over their own health (Wallston, Stein, & Smith, 1994
), may also contribute to a heightened perception of the health implications of stress. Those who perceive that stress affects their health may have an external locus of control, believing that their health is not in their control, but attributable to external circumstances. Studies have indicated that individuals who have a high external locus of control experience worse outcomes than those who feel that their health is within their control (Heath, Saliba, Mahmassani, Major, & Khoury, 2008
; Preau et al., 2005
). Although much of this research has focused on those with an illness, the present study suggests that health-related locus of control (as seen in a greater perceived impact of stress on health) may also contribute to outcomes in healthy populations. As such, encouraging active attempts at problem solving and increasing an individual’s sense of control over their stress levels and health may potentially lead to better health outcomes by allowing individuals to better utilize coping resources (Thoits, 1995
In addition, reverse causality may partially explain the findings in this study. Adults who reported poor health may have been more likely to report that stress impacts their health simply due to their poor health status; moreover poor health status could also have influenced the amount of stress reported. The cross-sectional nature of these data precludes us from examining the direction of causality among the amount of stress, the perception that stress affects health, and health outcomes.
While this study is unable to investigate the biological processes responsible for the findings in this study, allostasis – the process of achieving homeostasis through adjustments to the biological system in response to stress (McEwen, 1998
) – may be one potential mechanism. Although protective in the short term, increased levels of hormonal mediators associated with the human stress response can be deleterious to the individual if repeated or prolonged (Lantz et al., 2005
; McEwen & Seeman, 1999
). Moreover, increased allostatic load has been associated with worse physical and cognitive function and an increased risk of mortality (Seeman, McEwen, Rowe, & Singer, 2001
). Individuals who report a lot of stress and the perception that stress affects their health may be experiencing the negative health consequences of increased allostatic load, where the individual’s stress response system has been taxed to the point of inciting negative physiological and psychological responses.
Although this study did not find any significant relationship between attempts at reducing the amount of stress and the psychological distress and mortality outcomes, it did find that the association between attempting to reduce the amount of stress experienced and the likelihood of reporting being in poor physical health to be of borderline significance. The lack of significant evidence of a clear relationship between attempts at stress reduction and health outcomes could be due to selection issues, as it is possible that adults who attempt to reduce the amount of stress they experience may be different than those who do not. Further experimental research is needed to understand the relationship between attempts at stress reduction and health outcomes.
The findings in this study may have important implications for shaping future research aimed at furthering the understanding of the effects of stress on health. Future work may benefit from incorporating measurements of the perceived impact of stress on health in addition to measures of specific stressors and perceived stress. While the role, if any, of these findings in health improvement interventions focusing on overall stress reduction is unclear, the study findings indicate that this area merits future exploration.
This study has several limitations. First, all data used for these analyses except mortality were cross-sectional and thus limited the ability to assess the temporality of stress and health outcomes. However, despite the fact that the questions ascertaining the amount of stress and the perceived effects of stress on health were asked at the same time as those used to operationalize health and mental health status, the reference time period differed. The stress measures referred to the past 12 months, the mental health status questions to the past 30 days, and the health status question to the respondent’s health at the time of the interview. To account for the possibility that prior health status may have influenced individuals’ perceptions of how stress affected their health, a flag for chronic conditions was included in the model. This did not appear to change the findings for the physical or mental health outcomes; however, this measure may not have adequately captured prior health status. Second, the cross-sectional nature of the data limits the ability to explore possible mechanisms for the findings of the study related to: 1) the health and psychological distress outcomes and 2) the potential mediating role of self-rated health on stress and mortality. The available data also limits the ability to fully determine the independent nature of the stress variables used in the analysis. However, this study demonstrates that the perceived impact of stress on health deserves further exploration. Future research will need to explore these relationships over time. Third, information about the amount of stress and the perception that stress affects health was obtained through self-report using a sole reporter. This may have resulted in misclassification of some respondents. In addition, the health behavior measures used, particularly physical activity level, are based on self-report and may be prone to errors in reporting, as research indicates that respondents typically over-report their physical activity level (Duncan, Sydeman, Perri, Limacher, & Martin, 2001
; Troiano et al., 2008
). Finally, this study was unable to address the role of factors that may be associated with perceptions of stress and health outcomes such as personality (e.g. neuroticism).
This study has important strengths. First, the results are based on national, population-based data, providing insight into the individual and family-level sociodemographic, health-behavior, and healthcare factors associated with the perception of stress affecting the health of U.S. adults. Due to the large sample size of the NHIS, several key predictors of perceiving that stress affects one’s health could be examined together in one model, allowing for adjusted estimates of the contributing effect of each characteristic. Additionally, the study incorporated a large number of deaths over a 9-year follow-up period.
This study extends previous research on the relationship between stress and health by examining the perception of stress affecting health in a nationally representative population-based sample of adults. The findings show that individuals who reported the perception that stress affected their health and reported a large amount of stress have an increased risk of premature death. Further research focused on the relationships between the perception of stress affecting health and morbidity and mortality outcomes will be essential to understanding the health effects of stress.