Data obtained in this observational, retrospective study, including all IOP ≥65 years or non-IOP from nursing homes of Catalonia during 2011-2017, show an increase in IOP mean age and women proportion. Despite observing a reduction in the total number of IOP in our region, these people show greater morbidity, mortality and resource use than non-IOP.
The lack of consensus to define the concept of “nursing home”  makes it difficult to compare results from different studies conducted at a national and international level. However, Spain's official data indicate that the prevalence of IOP in the region where the study was conducted is notably higher than in the rest of the country: 5.9% vs. 3.7% of the total population ≥65 years, respectively . Furthermore, although Spanish data indicate an increase of IOP in the first decade of the century, our data show a progressive reduction—from 7.4% in 2011 to 4.8% in 2017—, a fact that could be related with the economic crisis and the difficulty to afford a nursing home . Regardless of the reasons that may explain this trend, during the second decade of the 21st century, nursing home occupancy is also in a standstill in other European countries .
Concurrently with the increased occupation, various authors have highlighted an ageing trend in residential populations, partially explained by the ageing of the overall population [7,8,17]. In our cohort, the median age of non-IOP experienced a modest increase throughout the study period; conversely, the median age of IOP significantly increased from 83 years in 2011 to 87 in 2017. Like age, the sex distribution among residential populations has shown an evolving pattern, which may depend on the type of residential setting . In our area, the percentage of women was persistently higher among IOP than non-IOP; however, sex distribution among IOP was rather constant throughout the investigated period.
Another key element, and a constant in the health care systems of most high-income countries [6,18] is the tendency to concentrate those people with higher multimorbidities in a nursing home setting, a fact that underlines the imperative need to review/update the health care approach to these centres . Compared to the rest of the population ≥65 years, IOP showed a higher prevalence of most chronic diseases (seven times higher in the case of dementia) and a four-times higher annual mortality. In fact, during the period analysed, mortality and morbidity, which virtually remained constant in non-IOP, increased in IOP despite a 27.5% decrease in the total number of IOP. These observations are consistent with epidemiological studies conducted in our setting, which confirm that the prevalence of IOP in end-of-life transitions is above 50%, with 70% of cases suffering from advanced dementia [20,21]. In line with previous reports [22,23], the prevalence of some comorbidities (including dementia) among IOP showed an increasing trend throughout the investigated period, reinforcing the idea that multimorbidity―most particularly, dementia―is an intrinsic characteristic of IOP and will be increasingly common in the residential setting. As mentioned previously , to improve IOP care, it is necessary to develop integrated care proposals from social and health care perspectives [24,25]. This was, in fact, one of the motivations to develop the new “Integrated medical care model for institutionalized older people” in our region, the objective of which is to improve the duration and continuity of care of these people.
Consistently with studies recently conducted in our setting , our results show that IOP virtually present three times more urgent acute care admissions than the rest of the population ≥65 years; furthermore, our analysis revealed that the mean hospital stay of these patients is twice that of the general population of the same age range. As it has been repeatedly described in the literature, these observations confirm a close relationship between institutionalization and use of resources [27,28]. It is therefore unavoidable to open the debate about the suitability and benefits of these admissions for patients' health [29,30], which are considered appropriate based on classic criteria . In this context, it would be useful to analyse IOP hospitalizations that could be potentially prevented to better improve care planning. Likewise, the medication burden dispensed to IOP is 50% higher than to non-IOP in the same age group. This fact is of special concern since it is estimated that about 40% of this prescribing is inappropriate or suboptimal , at the same time causing a significant number of adverse events, hospital admissions and mortality .
Despite being a population with high care needs, no relevant differences were observed between IOP and non-IOP concerning the number of contacts between them and primary care teams (an increase of 0.1 visits per year), which suggest lack of preventive actions by the latter. This fact might explain, at least partially, IOP higher use of resources in acute care. However, the great variability of care models in our setting makes it difficult to draw conclusions in this sense, so studies that specifically investigate the difference regarding preventive actions between IOP and non-IOP would be necessary .
The results of this study must be interpreted in the context of some methodological limitations. On the one hand, it is very likely that isolated diagnoses collected in the normal course of clinical practice (and therefore subject to heterogeneous criteria), as well as morbidity groupers, do not properly capture the seriousness of clinical processes, mainly in fragile patients with comorbidity. Deepening the knowledge of the severity degree and progression of the diseases described, as well as other chronic conditions (primarily geriatric syndromes and cognitive decline), would enable to give a more accurate clinical description of IOP. Given the descriptive and population approach of the study, comparative analyses have not considered the likely more heterogeneous clinical characteristics of non-IOP—from healthy adults to those in end-of-life transitions—compared with IOP. It would be interesting to analyse paired cases with IOP and non-IOP in the future, for example, in home care programs. Finally, being a large-scale, database-dependent epidemiological study, one key element of the person-centred care process could not be addressed , namely their values and preferences , which would require a qualitative methodological approach.