Consequences of chronic diseases and other limitations associated with old age – a scoping review

Abstract

Background

The phenomenon of the increasing number of ageing people in the world is arguably the most significant economic, health and social challenge that we face today. Additionally, one of the major epidemiologic trends of current times is the increase in chronic and degenerative diseases. This paper tries to deliver a more up to date overview of chronic diseases and other limitations associated with old age and provide a more detailed outlook on the research that has gone into this field.

Methods

First, challenges for seniors, including chronic diseases and other limitations associated with old age, are specified. Second, a review of seniors’ needs and concerns is performed. Finally, solutions that can improve seniors’ quality of life are discussed. Publications obtained from the following databases are used in this scoping review: Web of Science, PubMed, and Science Direct. Four independent reviewers screened the identified records and selected relevant publications published from 2010 to 2017. A total of 1916 publications were selected. In all, 52 papers were selected based on abstract content. For further processing, 21 full papers were screened.”

Results

The results indicate disabilities as a major problem associated with seniors’ activities of daily living dependence. We founded seven categories of different conditions - psychological problems, difficulties in mobility, poor cognitive function, falls and incidents, wounds and injuries, undernutrition, and communication problems. In order to minimize ageing consequences, some areas require more attention, such as education and training; technological tools; government support and welfare systems; early diagnosis of undernutrition, cognitive impairment, and other diseases; communication solutions; mobility solutions; and social contributions.

Conclusions

This scoping review supports the view on chronic diseases in old age as a complex issue. To prevent the consequences of chronic diseases and other limitations associated with old age related problems demands multicomponent interventions. Early recognition of problems leading to disability and activities of daily living (ADL) dependence should be one of essential components of such interventions.

Introduction

The phenomenon of the increasing ageing population is one of the most important economic, social, and medical issues of current times. Recent demographic trends outline that the number of people of old age will continue to rise dramatically. Today most people can expect to live to age 60 and beyond [1]. Between 2000 and 2020, the fastest growing segment of the United States (US) population will be individuals aged 65 years and older [2]. By 2030, the number of people in the world aged 60 years or over will increase by 56%, and by 2050, the global population of senior persons is projected to more than double its size in 2015. The number of people aged 65 or older is about to grow to nearly 1.5 billion in 2050, with most of the increase in developing countries [3]. These demographic transitions essentially require shifting the global focus to cater for the preventive healthcare and medical needs of the elderly population [4]. A wide gamut of determinants, such as social concerns and maltreatment of elderly individuals, poor knowledge and awareness about the risk factors, food and nutritional requirements, psycho-emotional concerns, financial constraints, health care system factors, and physical correlates determine the medical problems and thus cast a significant impact on the quality of life (QoL) of elderly individuals [5,6,7,8].

The ageing population tends to have a higher prevalence of chronic diseases worldwide today [9]. For example, six in ten adults in the US have a chronic disease and four in ten adults have two or more [10], while Sweden reports multiple chronic conditions of 56.3% [11]. These chronic conditions are significant and profound economic issue for any person, the healthcare system, and society as a whole [12]. Such diseases account for 86% of all medical costs in the US being even greater worldwide [13]. The presence of multiple chronic conditions in the same individual has profound implications for healthcare costs and utilisation [14]. For example, a Swiss study estimated that the average total healthcare costs were 5.5 times higher in elderly patients with multiple chronic conditions as compared with elderly patients without multiple chronic conditions [15]. The combined cost savings from the health and productivity that results from a small reduction in the prevalence of chronic disease cannot be ignored, resulting in a genuine return on investment in a very small span of time [16].

Chronic diseases require a long period of treatment that leads to the increase in demand for healthcare services and changes its nature [17,18,19,20,21]. This need for long-term care can lead to a decline in the QoL of elderly individuals [22]. This phenomenon will put pressure on healthcare systems to adapt in order to meet these changing demands. New and emerging technologies have the potential to change healthcare at home and in community [23]. Recognising the needs of elderly individuals suffering from chronic diseases and other constraints would fix many problems that patients face and results in an improved QoL, safety and overall health. Also, by investing in better QoL, safety and overall health in elderly, their productivity will rise as well thereby contributing to the economic and social opportunities.

This paper will be presenting an up-to-date survey of the limitations of seniors in connection with their chronic diseases and helps to provide a more detailed image of the research that has been done in this field. Additionally, the paper underlines the main research areas within seniors’ needs in relation to chronic diseases and the limitations associated as an informative summary for further research. To appreciate the scientific progress that has been made, with an emphasis on the literature dedicated to the economic field, a systematic review has been conducted by using keywords such as elderly activities of daily living (ADLs), elderly QoL, and elderly instrumental activities of daily living (IADLs).

This paper is organized as follows: After the Introduction covering the background for this research given in the first section, section 2 describes in detail the used methodology. The challenges faced by seniors with chronic diseases and other limitations associated with old age are specified in section 3. After reviewing seniors’ needs and concerns, the solutions that can improve their QoL are discussed in section 4. Finally, section 5 concludes the paper and gives open research areas for the future activities.

Methods

This scoping review is performed to identify and summarise up-to-date conditions leading to ADLs dependency in relation to chronic diseases and other limitations associated with old age. “A 4-step systematic review was conducted using empirical studies: locating and identifying relevant articles; screening located articles; examining full-text articles for inclusion or exclusion; and a detailed examination of the 21 articles included.”

Search strategy and eligibility criteria

In February 2018, four investigators performed a systematic literature search of the Web of Science, PubMed, and Science Direct. The period of interest covered the years from 2010 to 2017, and the electronic search included the following keywords: elderly and (Activities of daily living) ADLs, elderly QoL, elderly and (Instrumental Activities of daily living) IADLs, senior and ADLs, and senior and ADLs.

“In the Web of Science database, 829 publications were identified. Only two types of publications were considered eligible for the purpose of this study: ‘article’ and ‘review’, which includes the following: ‘review articles’, ‘research articles’, ‘data articles’, ‘book reviews’, ‘mini reviews’, ‘product reviews’, and ‘video articles’. This criterion reduced the initial set of papers to a total of 172 research articles, which were selected for further processing. For PubMed and Science Direct, a semi-automated framework or aiding surveys was used [24]. The framework first used the search tools of the libraries with the aforementioned keywords. Next, after eliminating duplicate records from the retrieved papers, it analysed the title, abstract, and keywords section of each paper to evaluate whether any of the following properties or their synonyms (listed in parenthesis) were mentioned: ADLs and IADLs. The paper distribution based on property (keyword) is presented in Table 1.”

Table 1 Paper distribution by property

ADLs (or ADL) is a term used in healthcare to refer to people’s daily self-care activities. Common ADLs include feeding, bathing, dressing, grooming, working, homemaking, cleaning after defecating, and leisure [25]. Adaptive equipment and devices may be used to enhance and increase independence in performing ADLs. Basic ADLs consist of self-care tasks that include but are not limited to, bathing and showering, personal hygiene and grooming, dressing, toilet hygiene, functional mobility, and self-feeding. One way to think about basic ADLs is that they are the things many people do when they get up in the morning and get ready to go out of the house: get out of bed, go to the toilet, bathe, dress, groom, and eat [26]. IADLs, such as cleaning and maintaining the house, preparing meals, shopping, managing money, moving within the community and many other activities are not necessary for fundamental functioning, but they let an individual live independently in a community [27].”

This paper includes 1916 publications that were acquired based on a given set of properties from different databases. The publications were automatically analysed and assessed, and then four properties were chosen to be further processed from the existing pool. False positive papers that had the relevant properties but were not relevant to the study at hand were discarded manually after being checked. This resulted in the overall pool of studies being narrowed down to 52 papers and articles. This set was then processed further, and the final number was brought down to 21 full length papers subsequent to the manual and semi-auto search. This excluded papers that did not fall into the description underscored in subsection 2.2.

Data extraction and study quality evaluation

Each publication’s data was extracted – the main team consisted of four researchers that worked to outline data individually. The following data was extracted: the country and type of study, the study’s author, and the study’s title. A study was included if it qualified as per the following requirements:

• Published after 2010;

• Focused on chronic diseases and other limitations associated with old age;

• Posed questions concerning seniors’ needs;

• Described diseases or specific needs of seniors;

• Discussed the limitations of seniors in connection with their chronic diseases;

• Focused on elderly individuals’ QoL and ADLs;

• Focused on older people’s community-dwelling; and

• It was in English.

A publication was not included if any of the following were true:

• It was not in English;

• It included a theoretical model;

• Focused on a technical description of the solution;

• Described systems for the diagnosis of the disease;

• Described healthcare management systems; and

• Focused on a disease rather than focusing on the patient.

Search process is described in Fig. 1.

Fig. 1

Publication search process according to PRISMA

Results

Current research on ageing problems and seniors’ ADLs dependency is described in Table 2. For each study, the objectives, problems and diseases, main findings, and limitations are described. Elderly persons will, as they age, continue to progressively decline in terms of their functional capacity. This will affect their frailty, worsen dependency and add to their loss of autonomy [48]. Ageing results in considerable and consistent change in an organism and results in a decline of or limited physical function and an augmented level of comorbidity [40].

Table 2 Summary of studies

Identified major problems that cause seniors’ ADL dependency are classified as follows:

• Disabilities and unmet needs are mentioned in 13 articles.

• Psychological problems are mentioned in six articles.

• Difficulties in mobility are mentioned in four articles.

• Poor insight and cognitive function are mentioned in four articles.

• Falls and incidents are mentioned in four articles.

• Wounds and injuries are mentioned in three articles.

• Prevalence of undernutrition and dysphagia are mentioned in three articles.

• Communication problems are mentioned in one article.

The prevalence and the number of comorbidities increase with age, which might lead to ADL dependency [40]. Part of the potential causal pathway by which the aforementioned problems directly or indirectly affect ADL in elderly people is presented in Fig. 2(a) and (b) [34]. In Fig. 2(a), the findings of the selected studies revealed that as a person ages, his/her psychological issues are intensified and s/he feels more unmet needs [31,32,33, 36, 44]. Furthermore, aging is a factor that could increase the range of disabilities, reduce cognitive abilities, and increase problems related to the teeth, swallowing and nutrition [30, 34] –[42]. Along with these issues, as research has shown, older people find it more difficult to perform everyday activities, move around, and communicate with others; meanwhile they are more likely to fall down, experience incidents, and suffer from wounds and different types of injuries [29, 39, 41]. In Fig. 2(b), there is a conceptual model showing the mutual effects of some aging-related problems on activities of daily living (ADLs). As this dynamic cause-effect diagram illustrates, reduced cognitive abilities and oral hygiene mutually affect each other. Problems could lead to malnutrition in the elderly. The swallowing function, cognitive abilities, and the quality of nutrition can directly affect ADLs.

Fig. 2

(a) Age, gender, and comorbid condition are factors that affect seniors’ conditions. (b) Part of the potential causal pathway by which problems directly or indirectly affect ADL in elderly people. ADL in elderly individuals is impaired by several factors [34]

Table 3 shows the various problems and their impacts on the seniors’ ADL on the basis of selected articles.

Table 3 Problems of elderly people and the articles that refer to them

Disabilities and unmet needs

Disability is one of the most common problems in seniors that leads to ADL dependence; dependence in ADL and IADL is a critical “challenge for community-dwelling elderly people, regardless of whether their needs are met or unmet. As the elderly population continues to grow, the challenges involved in addressing disability and unmet need will also grow [42]. Frailty describes the condition of elderly persons with the highest risk of disability, institutionalisation, hospitalisation, and death [49]. Chronic conditions have been confirmed as the main causes of disability [38].”

“Diseases show a greater contribution to the prevalence of more severe disability, that is, with impairment of basic ADL. Elderly patients with a diagnosis of arthritis, stroke, or diabetes should be monitored more effectively by considering the important contribution of these conditions to disability. Stroke and arthritis were the diseases that contributed most consistently to disability, independent of sex and age bracket. Hypertension and heart disease showed only a significant contribution to the prevalence of both levels of disability in women [32, 33]. Disabling effects of multimorbidity increased in ADL dependency [38].”

“Disabilities after stroke become chronic, and the inability to independently perform ADLs, such as dressing and eating, in a long run causes helplessness and depression in stroke patients and inflicts emotional pain, such as intellectual regression, despair, and anxiety. Functional disorders in daily life in long term are likely to cause deterioration in QoL of stroke patients and maladjustment in social relationships, changes in role, and economic difficulties [30].

“Having knee joint or back pain was significantly associated with a higher risk of incidence of ADL dependency. Older adults with pain have a higher risk of developing incident ADL dependency and commonly have functional limitations. Speculation has indicated that in mutual feedback loops in which pain and functional limitations are mutually reinforcing, pain exacerbates functional limitations and functional limitations exacerbate pain. Age-specific screening and intervention strategies might be necessary for effective prevention of incident ADL dependency among elderly women [40].

Individuals living with chronic health conditions, could not independently perform transportation, to engage in community, social, and civic life; majority had physical disabilities as a limited ability to conduct ADLs independently.”Most persons were independent regarding basic ADLs, for example, self-care activities such as drinking, eating, dressing, and toileting. The activities reported as most dependent were driving, looking after one’s health, and acquisition of goods and services, and assistance was required to perform more complex ADL tasks [46]. The highest percent of unmet ADL needs was for climbing stairs, and the lowest pertained to eating [45].

Dependency in ADL was found more in lower socioeconomic classes compared with higher socioeconomic classes. Compared with males, females are significantly more dependent regarding IADLs. Dependence significantly increased after 80 years of age. The dependence, however, was greater regarding IADL. Education and socioeconomic status have a positive impact on dependency status [47], mainly because learning opportunities can help people develop the skills and confidence to adapt and attempt a healthier ageing process. Elderly people who were working had a lower prevalence of disability for IADLs, which involve more complex activities, and functional disability in general because labour activity implies daily challenges that keep the worker active and contribute to the maintenance of their functional capacity. However, a critical assertion is that elderly individuals might not be working on the grounds of their disability [33].

These elements found to be the most significant: the level of education, the arrangements for living, the number of IADL limiters, the number of diseases, the age of the caregiver, the association of the patient with their caregiver, the size of the household, the burden of care, the link between the service uptake and the welfare expense, and the link between number of IADL limiters and welfare expense [45].

A person who has a mild dependency for care can change into a completely or severely dependent person if the intervention does not take place at the right time. Therefore, it is of utmost importance that care be provided early and that elderly people are monitored to ensure that their progression to complete dependency is slowed down as much as possible [31]. Approximately 93.1% of all disabled people of older age had at least one need that is unmet [31]. The results indicate that early intervention can help decrease the prevalence of reported diseases at more advanced ages [32].

Psychological problems

Unmet needs and disability can impact both mental and physical health. They can also reduce existing level of QoL and physical health in the context of elderly people. Disability can cause or worsen anxiety and depression, the two main elements that make up psychological distress. Both unmet and met IADL needs are linked to augmented mental distress. To put it simply, being IADL dependent is linked with heightened distress [42]. Caregivers will often only focus on the physical needs of a patient that falls in an older age range. However, activities such as social interaction or a hobby are often ignored, which is a problem. It has been observed that disabled elderly people will normally feel inferior and lose their confidence in regard to talking to other people [31]. Costa, FA, et al. in 2013 [32] showed that depression becomes more prevalent with age. The likelihood of a woman with a disability also showing signs of depression is very high, and the opposite link is also true with an increase in age [32]. Ha and Kim pointed out that as cognitive levels fall, even people that have no past history of mental issues are at risk for behaviour that stems from depression, including destructiveness, violence, agitation [36].

At times, disabled people will not have a choice but to remain in their homes or room. Some even stay in bed for a long period of time to avoid issues. However, not being outdoors for longer periods of time has a detrimental impact on a person’s mental health and can lead to psychological distress for the elderly [31]. Especially regarding disability that impedes the basic activity of urinating or evacuating, this finding is worrying and can lead elderly individuals to experience social isolation, in addition to leading to changes in their self-esteem and self-image, reducing their QoL [33].

Quail, Wolfson, and Lippman in 2011 [44] believed that“there are differences in the severity of psychological distress based upon the type of activity in which a woman is disabled (Personal Activities of Daily Living (PADL) versus IADL) and whether the need for physical assistance is met or unmet. The unmet need to perform an IADL is associated with increased psychological distress over and above the level of distress related to meeting the IADL need. For example, for many women of older generations, cooking is a source of enjoyment. Dependency in meal preparation, regardless of whether the need is met or unmet, may lead to distress because of concerns about not wanting to be a burden, not being able to retain power to decide about meals, or not being able to maintain routine in daily living [42]. Elderly people need to maintain good health, feel happy and comfortable and have more opportunities for social interaction. To improve the QoL of community-dwelling elderly individuals in their communities, supporting them to improve their sense of physical and mental well-being and prevent and reduce their depression and physical pain is required [44].”

Difficulties in mobility

Malnutrition and cognitive impairment are associated with reduced physical performance and poor muscle strength, leading to disability and reducing the ability to perform basic ADLs [34]. Walking ability has a critical role in the ADL independence of older people [40]. Alva et al. in 2013 [28] described that women who are older and afflicted with sarcopenia find it more difficult to be physically mobile. This is particularly true when the try to climb stairs. The loss of skeletal muscle mass is linked to their decreased physical ability. Elderly women with sarcopenia, compared with those without sarcopenia, are approximately twice as likely to develop difficulties in using stairs [28].

Masoudi Alavi, Safa, and Kalahroudi showed in 2014 [39] that people with fractured hips have poor recovery, and this may impact their mobility, making the issue more permanent [39].

Another aspect was highlighted by Genkai et al. in 2013 [35], who said that occlusal support absence resulted in decreased mobility and physical activity. Muscle strength and a person’s balance are extremely linked with their mobility. Strength in the lower extremities is normally higher in older people in good health as opposed to those who are not. People who have maintained good occlusal support are normally going to have better mobility. In effect, the findings show that occlusal support is essential if one is to preserve the ability to walk. Maintaining this ability has been linked with ADL. The research reviewed shows that occlusal support maintenance is an effective strategy to ensure that one’s walking ability is also maintained [35].

Poor insight and cognitive function

“Elderly individuals with cognitive impairment may demonstrate minimal impairment in some complex IADLs. For example, tasks often found to be impaired in MCI usually include finances, telephoning, keeping appointments, driving and transportation, shopping, food preparation, and responsibility for medication [30, 37].”

“Cognitive function is a critical factor that affects ADL. Early detection of cognitive disorders is a critical strategy for lowering morbidity. The factors affecting ADL in elderly individuals are faecal incontinence, regularity of exercise, cognitive function, urinary incontinence, and CVA history [36]. Cognitive impairment causes potential problems related to the inability to eat or lack of access to food, hence leading to malnutrition [34].”

Differences in cultural and social background can have an effect on functional assessment. For instance, family structure in many nations consists of not just the immediate family but also the extended family. Therefore, patients with impairments of a cognitive nature typically live with their partners and children, in addition to their siblings and their partners and children. In this situation, it could prove difficult for the caregiver to actually determine how hindered a patient is in regard to performing a given activity. Furthermore, a good number of people might not even know enough about the symptoms of dementia, or its side effects. They think that many symptoms are simply normal for older people, including forgetfulness and ADL decline [30].

Falls and incidents

Taking a fall could be a marker for “normal” changes that an older person goes through. With age, a person’s strength, gait and vision change. The most significant problem that one faces is the fractures that may result from a fall. Geriatric trauma injuries are also normally the result of a fall [39].“Decreased rapid walking speed increases the risk for falls and therefore increases ADL disability, either from the fracture or post-fall syndrome, in community-dwelling older adults [40].”

Any kind of fracture can have a terrible effect on ADLs; however, hip fractures are the worst. This shows that special follow up in the case of such patients is extremely needed, and this is true for both the postfracture period and the immediate time after it has occurred [41]. Elders can be trained to not get up too quickly in the morning and spend the first couple of minutes sitting on the edge so that they do not cause a fall or topple over [49].

Wounds and injuries

Trauma, wounds and injuries in older people have a considerable negative impact on their ability and ADL function [39]. The leprosy physical impairment grade is linked with IADL dependence, establishing the requirement for more social support and proper monitoring conducted by a multidisciplinary team. “There is a hierarchy in the process of frailty. First, independence is lost in advanced ADLs, and this loss is followed by a loss of independence in IADLs and, finally, BADLs. The follow-up and rehabilitation of these patients are essential [43].

Prevalence of undernutrition and dysphagia

“Undernutrition in elderly individuals is a common and important clinical entity that should be diagnosed early; for example, elderly individuals with sarcopenia had a higher prevalence of undernutrition [28]. Additionally, swallowing function, cognitive ability, and nutritional status had direct effects on ADL. Having fewer teeth leads to wearing dentures, but severe cognitive impairment disrupts denture wearing because of problems with, for example, accessing dental care. Chewing difficulties resulting from having fewer teeth and no dentures can lead to dysphagia. Also cognitive impairment can cause potential problems related to the inability to eat or insufficient access to food, leading to malnutrition [34, 35].”

Communication problems

“Communication is likely to have a significant effect on QoL, considering that it is an ability necessary for instrumental daily life. In particular, stroke patients experience deterioration of social functions due to communication limitations, and when they have difficulty in understanding the meaning of what another party says, or in producing speech, even when they have clear consciousness, it is highly possible that they feel extreme frustration and depression [29].”

Discussion

Based on the reviewed articles, reducing the problems and improving the conditions of elderly people can be divided into three sections: First, the stage before disability, disease, and their associated problems. Second, the identification and timely diagnosis of disease and problems in elderly people. Finally, the improvement of the conditions of elderly people with disabilities, chronic illnesses, and problems.

Given the issues raised in the papers and the categories of the problems experienced by the elderly (as mentioned in the results section), such problems, apart from the developmental time-specific categories, could be further divided into two other types: physical needs and psychological (mental) needs. As the majority of the papers report, most of the age-related disabilities leave a negative psychological impact on old people, along with the limitations that affect the physical aspects of their lives. In Fig. 3, old people’s needs are illustrated based on the distinction between categories of physical needs and psychological needs. As Fig. 3 clarifies, the problems/needs mutually affect each other. Physical problems could intensify psychological ones, while psychological disorder could in turn affect physical well-being. Such problems can reinforce one another’s impact though the relationships they have in dynamic circles. Finally, all of these needs/problems lead to limitations in performing ADLs.

Fig. 3

Seniors’ needs based on the distinction made between psychological and physical needs

The needs related to mobility, disabilities, and cognition are significant because such dimensions control many everyday life human activities [31, 32]. Such limitations increase the probability of falling, injury and fracture cases, while preventing the individual from attending open urban spaces or from participating in social activities. This negative experience could deeply affect old people psychologically [36, 42]. Therefore, one of the specifically important concerns in this regard is focusing on the solutions that help the elderly to reduce the impacts of disabilities, especially in the case of impaired motor skills [50,51,52].

Furthermore, cognitive disorders, along with the needs arising from such disorders, represent another important concern [53,54,55]. Cognitive disorders, besides generating numerous problems for old people in their ADLs, could even result in malnutrition [30, 34], or injures and fractures.

Many studies have mentioned losing independence, pride and confidence as the most serious psychological issues in the elderly. Not being able to do basic activities could isolate old people and undermine their self-esteem [29]. A wide diversity of studies have shown that the ability to do many activities (e.g. procuring food and cooking) brings about a pleasant sense of independence for the elderly; therefore it would be remarkably important to pay attention to needs that can improve an old individual’s independence in addressing his/her personal affairs [34]. Along with these concerns, methods inspiring old people to participate in social activities can prove to be highly important, because depression is one of the consequences of social isolation and limited social interaction [44].

Conclusion

Chronic diseases can result to ADLs dependency in old age. The major issues that lead to ADLs malfunction in the elderly are disability, psychological disorders, mobility problems, poor cognitive functioning, falling and incidents, wounds and injuries, malnutrition, and communication problems. Within interrelated cycles, old people’s problems are interrelated, and each problem can result in other disorders in such people and finally leave a negative impact on their QoL. On this account, the needs of the elderly are divided into two categories, namely the psychological and the physical. Psychological needs include communication, cognitive and psychological needs. Physical needs are associated with disability, mobility, nutrition, incidents, and wounds. Overall, it would be specifically important to pay attention to methods that can enhance old people’s cognitive abilities, and to methods that can improve their mobility- and disability-related issues; meanwhile establishing conditions inspiring the elderly to take part in social activities could significantly help to improve their life conditions.

This scoping review supports the view on chronic diseases in old age as a complex issue and to prevent the related problems demands multicomponent interventions which includes early recognition of problems leading to disability and ADL dependence. Education and training for health professionals and the general public, can prevent many problems at different levels. Government support and welfare systems should be designed counting complex needs of elderly people. Additionally, the new, upcoming age will be digital and technology based and therefore technology needs to be oriented to solve this problems, which are grouped by this review in eight categories. Satisfying of elderly people will improve their QoL, which should be the ultimate goal.