Numerous changes occur in the biological domain with age, and these are the product of an accumulation of molecular and cellular damage, which translates into the progressive loss of the physiological reserves needed to face the aggressions of the environment and greater susceptibility to a decline in an individual’s intrinsic capacity (Urtamo et al., 2019).

In addition to all these physiological changes, there are also adjustments in the roles, social status, and ability to deal with the loss of close relationships. Motivation, life goals, and preferences tend to change as well, therefore aging can be a new state of learning for greater subjective wellbeing.

The aging of the population is a worldwide challenge considering the better response to the needs of the elderly, particularly in terms of healthcare. The statistical projections indicate a demographic profile, in terms of aging, that is unprecedented in history and is a product of the cumulative effect of the decrease in mortality and birth rates that has been occurring over the past several decades (OECD, 2019). According to Bao et al. (2019), multimorbidity, that is, suffering from more than one chronic disease, significantly increases the risk of dependence when combined with conditions that affect patients’ cognitive and mental status (Arco et al., 2021). Storeng et al. (2020) concluded in a cross-sectional analysis that people between the ages of 60 and 69 who suffer from three or more diseases fit into a complex morbidity profile that, over the years, reflects those who develop severe disabilities in carrying out their basic activities of daily living and have a moderate risk of mortality. The presence of multimorbidity or having visual, hearing, or mobility limitations cannot, by themselves, define the health condition of the older person. Disease classifications cannot capture all health statuses, as is the case of frailty in older people, with a prevalence of around 10%, which is characterized by a decrease in the individual homeostatic reserve to respond to endogenous and/or exogenous aggressions. This allows us to conclude that the functional profile/condition, as well as the health status of older people, cannot be established by the presence or absence of illness. All the circumstances of their life will interfere with their wellbeing, emotional state of mind, and other functional items. Studies more comprehensive will better demonstrate the impact of survival and quality of life predictors (Bao et al., 2019; Storeng et al., 2020; Arco et al., 2021).

Robine et al. (2019) argues that longevity is not synonymous with health, as well as living for many years does not necessarily graduate the quality of life. Societies more involved in the study of aging, chronic disease control, and the impact of the frailty of older adults have better results on healthy aging because they will improve social interactions, and their functional profiles and act as promoters of better cognitive status to achieve the “compression” of morbidity levels (Robine et al., 2019).

To integrate this need for continuous care and social support, the National Network of Integrated Continuous Care of Portugal was created in 2006 to support people who, regardless of age, fall into a situation of dependency. The Network intends to contribute to the quality of life, and to the consolidation of a fairer and more solidary society and involves the public and private sectors with the goal of rehabilitation, readaptation, and reintegration. It comprises different unit typologies, such as convalescence units, medium-term and rehabilitation units, long-term care units, integrated continuing care teams, inpatient units of pediatric integrated care, integrated continuing mental healthcare units, pediatric outpatient units, day units, and promotion of autonomy units (Pereira et al., 2021).

The long-term care unit aims to prevent and delay the worsening of patients’ de-pendency situations, providing maintenance care to advance comfort and quality of life. This unit is intended for people who need hospitalization for more than 90 consecutive days, and its typology ensures medical care, daily nursing care, drug administration, and prescription, supportive care such as physiotherapy, occupational therapy, psychosocial support, maintenance and stimulation activities, support in activities of daily living and in instrumental activities of daily living, care of hygiene, comfort, and food and promotion of conviviality and leisure. Care is provided 24 h a day, 7 days a week (Pereira et al., 2021). Based on the objectives of long-term care units, assessing their functionality is important to assessing health outcomes (Maresova et al., 2019; Ramos et al., 2022). The World Health Organization developed the International Classification of Functioning, Disability, and Health (ICF) to standardize the assessment of international functioning and disability related to the disease process, considering the structures and functions of the body and environmental factors (World Health Organization, 2001). The assessment of health status is an important indicator in determining care needs (World Health Organization, 2020; Coelho et al., 2022), and the literature suggests the assessment of several items, such as the self-perception of health status, limitations in basic life and instrumental activities, and mental health status (Hazra et al., 2018; Sicsic et al., 2020). Healthy aging encompasses a more global and holistic concept, in which all components of an older person’s life is valued. It is seen as a process of development and maintenance of functional capacity, which allows wellbeing in old age. The individual’s capacity does not remain constant over the years, it is shaped by life choices and interventions at different times, which determine the trajectory of each person. The World Health Organization (2020) declares 2021–2030 as the decade of healthy aging, to improve the quality of more years of life. The experience of healthy aging can be positive, depending on access to healthcare and the type of inclusion in a supportive environment (World Health Organization, 2020).

Self-care is a central concept in nursing care, defined as a regulatory human function, which refers to “the practice of activities that individuals initiate and perform for their own benefit, for the maintenance of life, health, and wellbeing” (Orem, 2001). When an individual cannot satisfy their self-care needs, they depend on someone or something for help and support, which means they are facing a self-care deficit (Orem, 2001; Martínez et al., 2021). The objective of the present study is to assess the functional profile of older people admitted to long-term care units in Portugal and to evaluate the relationship between the functional profile and other variables such as age, sex, education level, and emotional state of this population.

The current study was a longitudinal retrospective study conducted in Portugal, including all the long-term units of the National Network of Integrated Continuous Care. Data were collected from 1 January 2008, to 27 February 2017.

This study evaluated the functional profile and evolution of older people hospitalized in the long-term care units of the National Network of Integrated Continuous Care in Portugal and then related that profile to sex, level of education, and emotional state. In the first 90 days of hospitalization following admission, we observed an increase in both mobility dependency and performance among instrumental activities, as well as an improvement in the cognitive status and basic activities of daily living. However, recovery is evident after 180 days (2nd follow-up) in all domains. It should be noted that from 360 to 450 days, the dependence on activities of daily living and the cognitive state both begin to deteriorate. The degree of dependence on the basic activities of daily living is not exclusively determined by mobility because of the strong influence exerted by the cognitive state in this process, so these results are not surprising (de Oliveira Silva et al., 2019; Lovett et al., 2020). After 450 days, all domains declined, increasing the degree of dependence. It must be considered that this type of care is intended for people with chronic diseases that have a high degree of complexity, for whom this care cannot be provided at home (Administração Central do Sistema de Saúde ACSS, 2014; Administração Central do Sistema de Saúde ACSS, 2016). These data are in line with studies that demonstrate that during hospitalization, older people with compromised mobility tend to worsen at the beginning of their stay in terms of carrying out their activities of daily living, but during the period of hospitalization in long-term care units, these patients tend to show an improvement with physical rehabilitation (Crocker et al., 2013; Cuevas-Lara et al., 2021). However, an analysis of the study carried out in convalescence units shows an improvement in all domains in the first 30 days (Ramos et al., 2021). Therefore, we can infer the importance of correctly assessing people’s needs and rehabilitation potential prior to referral to an integrated continued care unit. If people have the potential for a quick recovery, then they should be referred to convalescence units; on the other hand, if more time is needed for rehabilitation or they just need the care to sustain their wellbeing, then they should be referred to a long-term care unit.

When it is not possible to revert the situation of severe/complete dependency and people do not have family support or resources in their homes to deal with their care needs we have other options, outside the Network, such as the residential structures. In Portugal, residential structures are not included in the LTC, but they can guarantee the continuity of care under an institutionalization regime (Pereira et al., 2021).

In terms of age, individuals who are over 85 years old are in the severe/complete dependence group, the group between 65 and 84 years old are in the moderate dependence group and most individuals between 65 and 74 years of age are in the mild dependence group, which is in line with studies that show that older people have poor functionality (Yeh et al., 2014; Micheli et al., 2018). The same fact was verified when analyzing global data from the National Network of Integrated Continuous Care (Convalescence Units) in Portugal (Ramos et al., 2021).

When analyzing the clusters by sex, there is a higher percentage of females in the “Severe/Complete” and “Moderate” clusters, while males are more prevalent in the mild dependence cluster. These findings should be carefully analyzed due to the contradictory findings that can be found in the literature. We found studies that confirm these results, assuming there are no great differences between the sexes in ages above 65 years and concluding that sex is not a major predictor of dependence levels (James et al., 2018; Ek et al., 2021). On the other hand, we have also found evidence from other authors concluding that females experience higher levels of functional dependence (Schmitz and Lazarevič, 2020; Fonseca et al., 2021; Lopes et al., 2021). It is necessary to take into account the fact that females live longer, so reaching more advanced stages of life gives them a degree of dependence that men do not tend to reach because they die earlier, which is a phenomenon referred to as the “feminization of old age” (Goes et al., 2020).

Regarding the level of education, the results indicate that people without formal education more predominately fall into the “Serious/Complete” dependency cluster, while most older people with 7 years of school education or more fall into the “Moderate” and “Slight” dependency clusters. There are several recent studies that corroborate these results, indicating that lower levels of education are associated with higher levels of dependence (Serrano-Alarcón and Perelman, 2017; Abalo et al., 2018; Coutinho et al., 2018; Cui et al., 2019). In addition, a Portuguese study that evaluated the functional and cognitive profiles of both the institutionalized and noninstitutionalized older population, as well as the consequence of sociodemographic factors on functionality and cognition, concluded that the lack of education is one of the main predictors of decreased functionality at elderly ages (Lopes et al., 2021).

An analysis of emotional states suggests that older people who experience long periods of anxiety predominately fall in the “severe/complete” dependency cluster, and individuals who experience lower rates of depression and anxiety tended to fall into the moderate and mild dependency cluster. A study that sought to investigate the relationship between multimorbidity and dependence in older people concluded that the risk of dependence is higher for participants who suffer from depression than for those who do not (Quiñones, Markwardt, Thielke, Rostant, Vásquez, Botoseneanu; Morgado et al., 2021). Although we have not concretely evaluated the diagnosis of depression, we have evaluated symptoms, such as anxiety and sadness, that are part of the depressive symptomatology. In fact, studies indicate that the mental health conditions associated with other chronic conditions serve to increase dependence in hospitalized older people (James et al., 2018; McClellan et al., 2021), which influences functionality (Pinho et al., 2017; Pinho et al., 2020). Activities of Daily Living and Instrumental Activities of Daily Living disabilities were associated with depressive symptoms even after controlling people’s sociodemographic characteristics, welfare, health conditions, and informal care (Zhao et al., 2022).

According to Doroszkiewicz (2022) the socio-demographic variables of older people (such as sex, age, marital status, dwelling typologies, self-evaluation of health, and loneliness), their physical functional status (according to the Barthel scale) and the Instrumental Activities of Daily Living (such as locomotion, vision and hearing, emotional and cognitive state, and risk of falls or pressure sores) are related to the self-care dependency. The results of this study show that the increasing impairment of cognitive functions in older people has an important impact on the care-dependency level (Doroszkiewicz, 2022). The most prevalent healthcare needs in people with moderate or severe dementia and moderate or severe frailty were food preparation, medication/taking pills, looking after their home, toilet use, sensory disabilities, memory, communication and social interaction, bowels, sleeping, feeding and drinking and falls prevention (Abreu et al., 2019).

Being overweight or obese may cause many chronic illnesses. Furthermore, several studies have shown that high body mass index is associated with mortality and morbidity among older people. However, some studies reported the opposite and conclude that obesity is protective against Activities of Daily Living. The study done by Ozturk et al. (2017) showed increased values of body mass index and Activities of Daily Living ability, as this study, which could be indicative of protective effects.

On the other hand, being underweight was associated with an impaired Mini-mental State score and worse performance in Instrumental Activities of Daily Living. Also, being overweight was associated with a better score on the Mini-mental State and the Instrumental Activities of Daily Living. For both outcomes education level significantly influenced the predictions (Borda et al., 2021).

From the global analysis of the data obtained, the recovery of the ability to walk and the improvement in performance in basic activities of daily living were clearly the most evident achievements, compared to instrumental activities and cognitive state. These findings emphasize the importance of memory and complex reasoning for carrying out instrumental activities, such as going shopping, managing money, doing housework, or using the telephone, among others. Thus, when there is a deficit in carrying out instrumental activities, there is a high possibility of a decline in mental and cognitive functions, and their restitution is difficult and slow, which explains their shorter recovery curve. The study carried out shows the close relationship between the determinants of self-care ability, such as older age, low education, low body mass index, and depressed and/or anxious mood, which contribute to a greater degree of dependence, as reported in those studies that are explained. Dependence on self-care can be permanent or temporary, which means that it can be prevented, reduced, or reversed since that exists an appropriate environment and assistance.

In the first 90 days of hospitalization in a long-term care unit, an increase in dependence was verified relating to both mobility and Instrumental Activities of Daily Living, while a decrease in dependence relating to both cognitive state and Activities of Daily Living was also seen. Hospitalization in the long-term care unit was shown to result in functionality gains; however, after 450 days of hospitalization, dependence worsened across all domains. We also conclude that in the severe or complete dependence cluster, women, older people over the age of 85, and those with no education are more prevalent. This study thus highlights the importance of schooling and literacy for recovery and rehabilitation from an acute illness or a chronic disease exacerbation and for the regaining of independence. Strategies should therefore be delineated to promote the population’s focus on active and healthy aging and the best ways to recover from various levels of dependence.

With this study, we also point out the importance of developing future studies to evaluate the effectiveness of interventions that promote the mental health of older people as a structural axis for improving their functional capacity and level of self-care. Further research is also recommended to study the weight of other determinants (pressure ulcers; polypharmacy; pain; hydration status; respiratory status; consumption of psychotropic drugs; physical restriction/mechanical restraint; health literacy and infections) on functional capacity as well as the study of the potential of analytical information extracted from electronic health systems and records in the quality of long-term care.

This study represents a relevant contribution to the older population and health services because by knowing the predictors of dependency in self-care it is possible to outline health policies and early, individualized, and appropriate interventions for the preservation of their functional capacity.

The study carried out has several limitations related to the study design once researchers could not control exposure or outcomes and must rely on records that others have made. The retrospective collection of data up to 2017 from a convenience sample will not represent the general population and would benefit from recent data in order to analyze other variables such as the COVID-19 pandemic impact.

Another limitation of the present study is the lack of assessment of the frailty condition of older people and it should be considered in further research once has a high impact on the dependence profile in activities of daily living.