ارتباط بین ادراک خطر، دانش ذهنی و افسردگی در جامعه خانه سالمندان در ژاپن

Risk perception is one of the core factors in theories of health behavior promotion. However, the association between knowledge, risk perception, and depressed mood in depression is unknown. The aim of this study was to clarify the relationships between subjective knowledge, risk perception, and objective scores of depression in community-dwelling elderly people in Japan. A total of 747 elderly participants (mean age: 76.1, female: 59.8%) who completed the 15-item Geriatric Depression Scale (GDS-15) along with items assessing subjective knowledge and risk perception were included in the analysis. We assessed the correlation between subjective knowledge and risk perception, and then compare GDS-15 scores by level of subjective knowledge and risk perception. Subjective knowledge was weakly associated with risk perception and related to lower GDS-15 scores in a dose–response pattern, which did not change after adjusting for age, gender, basic activities of daily living (ADL), instrumental ADL, years of education and history of depression. There was no significant association between risk perception and GDS-15 scores. The relationship between knowledge, risk perception, and depressed mood in younger generations is unclear, but warrants examination.

Risk perception is a core factor in most theories of health behavior promotion, such as fear appeal theory, protection motivation theory, the health belief model, and the extended parallel process model. The basic concept across theories is that perception of high personal risk increases the likelihood of taking precautions and changing behavior; however, the factors that lead to modified behavior differ across the various theories (Weinstein and Nicolich, 1993). For example, in the extended parallel process model, precautionary behavior depends on two appraisals: threat and efficacy. If perceived threat or perceived efficacy is low, precautionary behavior will not be taken. Precautionary behavior is taken only when both perceived threat and perceived efficacy are high (Witte, 1992). Several meta-analyses have shown that risk perception influences health behavior in empirical settings, although effect sizes have varied. For example, in a review of 34 studies with 15,988 participants about vaccination, risk likelihood (r=0.26), susceptibility (r=0.24), and severity (r=0.16) significantly predicted vaccination behavior ( Brewer et al., 2007). Another review of 15 studies with 16,293 participants about protection motivation theory reported an effect size (as expressed by Cohen׳s d) of threat vulnerability and severity of 0.54 ( Floyd et al., 2000). Witte and Allen conducted a meta-analysis of fear appeal and reported the effect size of severity was r=0.13 (16 studies, n=2528) and susceptibility was r=0.14 (11 studies, n=1797) ( Witte and Allen, 2000). There is evidence that knowledge of depression affects attitudes and behavior. Indeed, “Blues-out,” a depression awareness campaign targeting the gay/lesbian community in Switzerland, was found to significantly reduce the lifetime prevalence of suicidal ideation and suicide plans of studied participants (Wang et al., 2013). The campaign included brochure and website offering basic information on depression, a symptoms checklist, a list of gay-friendly providers and institutions for consultation, a hotline, and emergency cards. Furthermore, the “Defeat Depression Campaign” in the United Kingdom positively changed public attitudes toward depression, reported experiences of depression, attitudes toward antidepressants, and attitudes toward treatment from general practitioners, by about 5–10% (Paykel et al., 1998). In addition, 40.7% of general practitioners definitely or possibly made changes in practice as a result of the campaign (Rix et al., 1999). Thus, knowledge of depression may positively influence attitudes or behavior, however the relationship between knowledge and risk perception in depression remains unclear. Clarification of this relationship is important for effective health promotion regarding depression. The relationship between knowledge, risk perception, and depressed mood in depression is another concern. Few studies have investigated the influence of risk perception on depressed mood. A study of patients with multiple sclerosis showed that a higher perception of short-term risk of wheelchair dependence was significantly related to higher levels of anxiety (regression coefficient B=0.78, P<0.001) and depression (B=0.45, P<0.01)( Janssens et al., 2004), whereas another study reported that knowledge of evidence-based patient information increased the accuracy of leukemia risk estimation without increasing concerns ( Hofmann et al., 2013). In summary, the relationship between knowledge, risk perception, and depressed mood remains unclear. Currently, no studies, to our knowledge, are examining this relationship in depression research. However, it would be important to clarify this relationship in the field of depression because if knowledge of depression increase depressed mood of people, the enlightenment campaign of depression could be good will with big side effect. The depression in elderly population is especially important in the aging society and Japan is one of the most aged countries in the world. According to research on community-dwelling older adults, the proportion of individuals reporting depressive symptoms is 2.8–35% (Beekman et al., 1999). The natural course of laterlife depressive disorders is poor: a 6-year follow-up study showed that 76% of patients followed an unfavorable but fluctuating course or a severe chronic course of depression. A study in the United States found that the additional medical cost per one depressed older adult was USD 686 for 1 year and USD 5271 for 4 years (Unutzer et al., 1997). Thus, the aim of this study was to clarify the relationship among subjective knowledge, risk perception, and objective scores for depression among community-dwelling elderly people in Japan.

Table 1 shows the basic characteristics of participants by level of subjective knowledge and risk perception. One-way independent ANOVAs were conducted to compare the differences in subjective knowledge and risk perception by each continuous variable. There was a significant effect of subjective knowledge on age, BADL score, and IADL score. Post-hoc test revealed that there are significant differences between “hardly anything” and “a little” (p<0.001), “hardly anything” and “a lot” (p<0.001) in age; “hardly anything” and “a lot” (p<0.005), and “a little” and “a lot” (p<0.005) in BADL; “hardly anything” and “a little” (p<0.05), “hardly anything” and “a lot” (p<0.001), and “hardly anything” and “a lot” (p<0.05) in IADL. Both subjective knowledge and risk perception differed significantly by gender; however, there was no significant difference by a history of depression. There were no significant differences in level of risk perception by age, years of education, BADL score, and IADL score.