In Canada, people age 65 and older comprise 13% of the population and it is estimated that this will rise to over 23% by the year 2031 . As individuals age, they may experience worsening health and difficulty performing instrumental activities of daily living (IADL) or personal activities of daily living (PADL). IADL are necessary to maintain a household and function in the community; PADL are essential for self-care in everyday life . Increasing age may lead to disability and the need for assistance to complete ADL, however, this need may not be met.
Allen and Mor (1997) described unmet need as the "perceived [inadequacy] of help received with activities the individual has difficulty performing or is unable to perform alone." The prevalence of unmet need varies according to the definition used, the population studied, and the specific ADL being examined [3–7]. In the community-dwelling disabled population, prevalence estimates of unmet need for PADL range from 11.7% for indoor ambulation to 22.6% for bathing; for IADL, they range from 14.9% for meal preparation to 25.8% for transportation to places beyond walking distance from the home . Clearly unmet need is a common problem among disabled elderly persons.
Unmet need is associated with a variety of negative consequences that can affect the health and well-being of the disabled elderly. These range from feeling distressed because housework is not done to more serious experiences such as being unable to eat or drink when hungry or thirsty [3, 8–10]. Allen and Mor (1997) found that nearly one-quarter (24.5%) of study participants who were disabled in transfers (i.e., moving from a chair to a bed, or from a chair to a wheelchair) had fallen, while 14.2% of those disabled in meal preparation reported they had been unable to eat when hungry. Many elderly people with unmet need continue to perform the tasks for which they need assistance despite both the difficulty of doing so and the potential for self-injury . Given these potential negative consequences, it is not surprising that unmet need was associated with the increased use of health services in the three studies investigating this topic [3, 10, 11].
Allen and Mor (1997) found that community-dwelling disabled adults age 18 and older with any unmet PADL need reported more physician visits, emergency department visits, and hospitalizations than did those with all of their PADL needs met. However, the cross-sectional study design makes it impossible to know if unmet need preceded these events or vice versa. Additionally, Allen and Mor estimated only the crude association of unmet need with the use of these health services and so the findings may be confounded by other factors.
The two other studies expand upon Allen and Mor's work by using a prospective study design. Sands et al. (2006) studied community-dwelling PADL-disabled Americans aged 75 and older. They reported that after adjustment for important factors, those for whom all PADL needs were unmet were significantly more likely to have been hospitalized in the previous six months than those who had at least one of their PADL needs met [Odds Ratio (OR) = 1.26 (95% CI: 1.01-1.57)]. Once these individual's needs became met, however, their likelihood of being hospitalized decreased over the subsequent 12 weeks. Sands et al. limited their study population to only the most disabled seniors (i.e., those disabled in PADL) and so the generalizability of their findings to elderly persons who are less disabled who constitute a greater proportion of seniors living in the community is not known. Kuzuya et al. (2008) also prospectively investigated the effect of unmet need in one IADL, specifically medication management, among disabled community-dwelling elderly adults living in Nagoya, Japan. These researchers found that individuals with self-reported unmet need in medication management had an increased likelihood of being hospitalized, but not dying, in the subsequent three years.
Unfortunately, none of these studies considered the role of psychological distress, although Sands et al. investigated depression but did not include it in multivariable modelling because it was not statistically significantly associated with hospitalization. Unmet need is associated with concurrent depression [3, 7], but depression is only one possible psychological response to, or cause of, unmet need. Anxiety, another relevant feature, may also be important, particularly if seniors are fearful of falling when performing difficult tasks or are frightened about the possibility of placement in a nursing home if they express a need for help. Investigation of psychological factors in relation to unmet need should be broadened to examine psychological distress, which is also associated with increased use of health services. Psychological distress is conceptualized as having four components . In addition to anxiety and depression, psychological distress can manifest as irritability as well as cognitive problems that impede a person's judgement and ability to think clearly, such that a person has difficulty following simple instructions, misinterprets obvious information clues, or has difficulty remembering information and facts that are actually known well.
Previous research indicates that disability can lead to the development of one component of psychological distress, depression [13, 14]. There is also evidence that depression can contribute to the development of disability through impaired ability and/or willingness to maintain one's health through proper nutrition, physical activity, and socialization [15, 16]. This lack of self-care may extend to the development of unmet need. It is possible that the association between unmet need and psychological distress is bidirectional, in that disabled elderly persons with unmet need may become distressed as a result of the daily and difficult struggle to perform ADL, while psychological distress may prevent disabled elderly persons from actively seeking help and/or being able to accept help when it is offered. Over time, the reciprocal effect of one upon the other could lead to a mutually reinforcing cycle.
Andersen (1995) proposed a behavioural model of need, enabling, and predisposing factors that influence the use of health services [17, 18]. Need factors relate to the medical needs that result from trauma, chronic disease, and disability. Enabling factors are those that influence access to health services such as availability of services, or travel and wait times. Predisposing factors are those that influence whether and to what extent a person will use health services and include age, sex, ethnicity, education, and psychological factors. Several studies of adults of all ages have shown that psychological distress can affect perceptions of health as well as health-seeking behaviours, including increased visits to a physician's office [19, 20] or to an emergency department (ED) [21–23]. As a result, psychological distress may modify or confound the relationship between unmet need and health services use. We designed our research to explore this possibility by examining the effects of unmet need and psychological distress upon emergency department visits in a sample of community-dwelling elderly women. We initially set out to explore this association in both men and women. Because of the differences between men and women in the final years of their lives, we stratified our analyses by sex. The traditional role of men of an earlier generation was that of breadwinner and handyman; women's role included being housekeepers and homemakers. Consequently, many elderly men are either unwilling or unable to perform housekeeping and meal preparation. These tasks are usually performed by their wives. Moreover, men are more likely to have a chronic disease associated with high mortality than are women . As their health and functional ability worsen, their needs are usually met by the care their wives provide. Women typically survive their husbands and end up living alone with limited financial resources . Thus, older women are more 'exposed' to the possibility of unmet need. When we conducted the stratified analysis there were too few men with unmet need to be able to conduct an informative analysis and so we report here our findings for women only.
Research on unmet need has so far focused exclusively on disabled individuals since it is not possible to have unmet need without disability. This only allows an understanding of unmet need in reference to met need. We do not yet understand how individuals with unmet or met need differ from non-disabled individuals with regards to health outcomes. For this reason, we included non-disabled women in our research so that we could simultaneously examine the association of both met and unmet need in conjunction with psychological distress upon ED visits.
Based on our literature review, we know that both unmet need and psychological distress are independent predictors of ED visits, and that unmet need is likely to be associated with psychological distress. Thus, our objective is to elucidate the association of unmet need in conjunction with psychological distress upon ED visits. We hypothesize that unmet need, but not met need, is associated with an increased risk of visiting the ED. We further hypothesize that the association will be stronger for PADL unmet need than for IADL unmet need because disability in PADL is more severe. Finally, we hypothesize that psychological distress confounds and/or interacts with unmet need to increase the likelihood of visiting the ED. It is important to determine the effects of both of these factors upon the use of health care resources, especially as the elderly population continues to grow and an already strained health care system experiences increasing demand.