The low birth rate and an increased life expectancy are transforming the age pyramid of the European Union (EU); probably the most important change will be the marked transition towards an aged society, a characteristic that is already evident in several EU member states. In 2017, the 65+ older adult's population had an increase of 0.3% compared to the previous year, and an increase of 2.4% compared to the previous 10 years. People over 80 years old are increasing at a faster rate than any other age segment of the EU population. This increase is probably linked to a growing demand for long-term care, which represents a significant overload on public health resources. Care/nursing homes are the main providers of long-term care. One of four older adults will spend a period of their life in a care/nursing home, and the dependence for such care will persist until their dead. The older adults who live in a nursing home are the most fragile of our society with high levels of physical dependence and one third of them suffering from cognitive impairment. An acute hospitalization typically is associated with multiple diseases in older people, and disability is frequently followed by high rates of progressive physical decline and mortality in the years following discharge. It is well known that hospital admission can change normal aging due to adverse health outcomes after hospitalization, especially in terms of functional decline, mortality frailty and cognitive impairment.

Frailty is one of the most important concerns regarding our aging population. Evidence grows that the syndrome is linked to several important health outcomes, prevalent in all countries and is a leading contributor to functional decline and early mortality in older adults. The last consensus defined frailty as "a clinical state in which there is an increase in an individual's vulnerability for developing an increased dependency and/or mortality when exposed to a stressor".

The decline in functionality is one of the main issues that affects older people because it limits their autonomy and leads to dependency. In older people, functional capacity can be defined as the ability to carry out a set of activities necessary for an independent life, the ability to carry out basic activities of daily living (BADL), those related to self-care and survival (such as bathing and eating), and more complex actions called instrumental activities (such as shopping and transportation). Functionality decline lead to high financial costs and are close associated with frailty, mobility problems, and increased risk of falls, dependency, hospitalization, and death. The association between functional decay and urinary incontinence (UI) could be bidirectional, which can lead to a cycle where continence reduction results in functional decline, and functional decline leads to further decrease in urinary continence.

The prevalence of UI in Spain is approximately 10% in women between 25 and 64 years old and over 50% in those over 65 years old. In the domain of nursing homes, this proportion is around 50% and is frequently associated with cognitive impairment, physical inactivity and immobility syndrome, among other factors. In this context, we can find a type of UI described as "functional" that it's caused by the inability to move to the bathroom independently, due to a physical or cognitive problem (e.g. dementia). Most older adults mistakenly believe that incontinence is part of the normal aging process and / or is an irresolvable problem. However, UI is a geriatric syndrome that represents an indicator of frailty and quality of health care, as well as a risk factor for pressure ulcers, falls, fractures and even urinary sepsis or death.

Falls, though preventable, are common among older adults, and the resulting injuries can threaten their health, independence, and lives. In 2014, 30% of older adults (aged \> 65 years) in the United States reported falling at least once, and the estimated 29 million falls that year resulted in 7 million injuries and approximately 27,000 deaths. The evidence and research in Spain, shows that 30% of people over 65, independent and autonomous will be affected by an annual fall. This percentage increases progressively as age increases, because age is one of the main factors of risk in falls, being older people the ones with highest risk of suffering injuries, increased dependence, disabilities, institutionalization in centers and death, considering itself as a factor of frailty. In people over 75 years old its risk of fall rises to 35%, and in people over 80 years old it reaches 50%. Several studies estimate that this prevalence increases up to 50% in the case of institutionalized older people. Falls are an important public health problem, being an underdiagnosed problem, because when there are no physical consequences, do not usually go to the health system.

Previous investigations followed by decades of research, confirm that nursing home residents are the less physically active and spend most of their awake time inactives). Doing regular physical activity (PA) limit the development and progression of most prevalent chronic diseases. However, time spent in SB has increased considerably in the last three decades and increases with age. SB has been gaining recognition as a risk factor of specific health conditions and reduced mobility, sometimes independent of PA levels. A typical day for a resident will consist in a sequence of periods of SB, light intensity PA (LPA) and moderate to vigorous intensity PA (MVPA). Care/nursing home residents spend an average of 79% of their day sedentary, 20% in LPA and 1% in MVPA.

Regarding the association between SB and the UI, there is little evidence available. In a recent literature review on the association between SB and UI in women, the review concluded that information available was limited, although suggested that SB could be considered a risk factor for UI in women. If we review the little existing literature concerning the association between SB and UI, there is a consensus among the authors on low levels of PA and prolonged patterns of SB could be direct risk factors for UI in older adults or in the older women, and there is a lack of complementary studies of higher quality in the association between SB and UI.

On the other hand, the COVID-19 pandemic has emerged as a new major public health issue especially affecting NHs. This virus has been shown to be particularly deadly for older adults and those with certain underlying medical conditions. In relation to deaths from COVID-19 in Spain, 87% of the reported deaths were 70 years or more and a 95% presented comorbidity. The population living in NH, generally with older age and multiple comorbidities, are the most vulnerable to COVID-19. In Catalonian NHs 28,418 suspected cases, 11,560 confirmed positive cases and 3,055 deaths were reported until May 2020. Due to the vulnerability of NHs themselves to outbreaks of respiratory diseases and the frailty of NH population, there is a need of analysing the impact of COVID-19 in NH residents in terms of mortality, hospitalisation, as well as other health, social and cognitive-related variables. We also want to learn about the potential risk and protective factors for mortality due to COVID-19 and the impact of this disease on funtioning and hospitalizations.

For all the reasons cited above, they lead us to think that there is a gap in the description of nursing home residents. Consequently, the stage 1 of this study aims at knowing the current state of health-related outcomes of nursing home older adults and the factors that influence their quality of life. Reducing SB patterns and ensuring an increase in PA in an individualized and progressive way can contribute to the stabilization of chronic cardio metabolic pathologies, improve their muscular quality and cardiopulmonary capacity, improve their biopsychosocial sphere and promote their socialization with other residents and health professionals and finally increase their participation in the nursing home. However, the certain association between SB and UI remains unclear. The OsoNaH project will try to cover this lack of knowledge and define the possible aetiology and associated factors with the different types of UI and SB, in order to determine new ways of intervention, treatment and care for the nursing home residents. Finally the stage 2 aims to better know the characteristics of functional decline, continence decline, falls, hospitalizations and mortality due to the importance and impact they generate on older people and their caregivers. This project may help to develop of new lines of interventions, management and treatment. Also, this study will try to fill de gap of knowledge in the region of Central Catalonia about this issues. So it is considered necessary to know from an interdisciplinary and longitudinal field, the evolution / appearance and predictive factors of functional decline, continence decline, falls, hospitalizations and mortality of institutionalized older people.