Multimorbidity and use of health services in the oldest old in Brazil

REV BRAS EPIDEMIOL 2021; 24: E210014.SUPL.2 ABSTRACT: Objective: To estimate the prevalence of multimorbidity in long-lived Brazilian individuals (age ≥80 years) and to associated it with the use of health services. Methods: Cross-sectional population-based study with data from the 2019 National Survey of Health (n=6,098). Frequencies of use of services were estimated for older people with multimorbidity and according to sex, health insurance ownership, and self-rated health. The prevalence rates, crude and adjusted prevalence ratios, and the respective 95% confidence intervals were calculated. Results: The average age of the older adults was 85 years and about 62% were women; the prevalence of multimorbidity was 57.1%, higher in women, in those who have health insurance, and who reside in the southern region of the country (p<0.05). In the oldest old with multimorbidity, the use of services in the last 15 days reached 64.6%, and more than 70% were hospitalized in the last year or did not carry out activities in the previous two weeks for health reasons. Differences were observed for the indicators of service use in relation to sex, health insurance ownership, and self-rated health, according to multimorbidity. Conclusion: Indicators for the use of health services were higher in older individuals who have two or more chronic diseases, regardless of sociodemographic conditions and self-rated health, showing the impact of multimorbidity per se in determining the use of services among the oldest old.


INTRODUCTION
The demographic aging observed in recent decades in Brazil, associated with changes in the epidemiological pattern and in the social and family structure and behaviors, results in new needs that imply the reformulation of social and health policies [1][2][3] . The subgroup of the oldest old has been growing faster than the population of older adults in general. Projections indicate that in 2050, in the world, this age group could reach 434 million and, in Brazil, it is estimated that the number could reach 13.3 million, i.e., 6.5% of the total population and 19.6% of the older adult population 4 . Health services have faced difficulties in offering quality access to this population, as at this stage of life the dependence on health services is greater and care is long-lasting 2 .
Increased longevity is associated with the increase in people's time living with chronic diseases and disabilities 2 . Multimorbidity is defined by the presence of two or more chronic diseases 5 , with an increase in the proportion in older people. According to the Brazilian Longitudinal Study of Aging -ELSI/Brazil (2015-2016), the prevalence of multimorbidity was 68.7% for individuals aged 50 years or over and 82.4% for older adults aged 80 years or over 6 . In a survey involving 15 countries in Europe (Survey of Health, Ageing and Retirement in Europe -SHARE), the prevalence of multimorbidity reached 31.4% for the total population (age ≥50 years) and 51.4% for those aged 80 years or older 7 . It is known that individuals with multimorbidity are at greater risk of functional decline, worse quality of life, greater use of health services, and increased mortality 2,5 . RESUMO: Objetivo: Estimar a prevalência de multimorbidade em idosos longevos brasileiros (idade ≥80 anos) e relacioná-la com o uso de serviços de saúde. Métodos: Estudo transversal de base populacional com dados da Pesquisa Nacional de Saúde de 2019 (n=6.098). Foram estimadas as frequências de uso de serviços nos idosos com multimorbidade e segundo sexo, posse de plano de saúde médico e autoavaliação de saúde. Calcularam-se as prevalências e razões de prevalência brutas e ajustadas e respectivos intervalos de confiança de 95%. Resultados: A média de idade dos idosos foi de 85 anos e cerca de 62% eram mulheres; a prevalência de multimorbidade foi de 57,1%, maior nas mulheres, naqueles com plano de saúde e nos residentes na região Sul do país (p<0,05). Nos muito idosos com multimorbidade, o uso de serviços nos últimos 15 dias alcançou 64,6%, e mais de 70% estiveram internados no último ano ou deixaram de realizar atividades nas duas semanas anteriores por motivo de saúde. Observaram-se diferenças para os indicadores de uso de serviços em relação ao sexo, posse de plano de saúde médico e autoavaliação de saúde, segundo multimorbidade. Conclusão: Os indicadores de uso de serviços de saúde foram mais elevados nos idosos que acumulavam duas ou mais doenças crônicas, independentemente das condições sociodemográficas e da autoavaliação de saúde, o que denota o impacto da multimorbidade per se na determinação do uso de serviços entre os idosos mais velhos. Regarding living conditions that can influence the attention and health care of people with chronic conditions, particularly older adults, the effects of social inequality on health, accumulated throughout life, are highlighted, which cannot be separated from the social context 8,9 , with emphasis on women 6 and on economically disadvantaged individuals 10 .

Palavras
In older adults, multimorbidity can present a greater challenge for care in the face of other conditions that mainly affect older people, such as frailty and dementia, polypharmacy and the need for long-term care and procedures of medium and high complexity, and the need for hospitalization and rehabilitation services 2,8 . Concerning subjective well-being, studies show that the presence of chronic diseases influences self-rated health and, overall, they demonstrate a consistent association between worse perceived health and an increase in the number of diseases or other objective health indicators 11,12 . It is known that the use of health services is mainly determined by health needs (diseases and disabilities) as well as their severity and urgency [13][14][15] . The users' demographic characteristics, particularly age, sex, socioeconomic conditions, and place of residence, are also related to demand for services, among other factors 13 . The higher prevalence of multiple chronic diseases indicates social inequalities that challenge health services and the training of professionals for the proper management of care. The impact of multimorbidity on the increased use of health services suggests the need to ensure coordination of healthcare practices at different levels and complexities 16 , thus avoiding concurrent treatments or unnecessary replication of diagnostic tests 17 .
In Brazilian older adults, the sociodemographic conditions -even among the oldest oldare very heterogeneous 1 , as well as the conditions for seeking and using health services, management of chronic diseases, disabilities, social support, lifestyle, and psychosocial aspects. For the Brazilian health system, information about aging and health is essential, mainly to project and modulate its impact on the provided services and to ensure the maintenance of functional capacity that enables well-being in old age 16,18 , in addition to redesigning the care provided to older individuals considering their particularities 2 . The objective of the present study was to estimate the prevalence of multimorbidity in long-lived Brazilian individuals (age ≥80 years) and to associated it with the use of health services.

METHODS
This is a cross-sectional study with data from the National Survey of Health (Pesquisa Nacional de Saúde -PNS), a population-based health survey conducted between 2019 and 2020 in partnership with the Brazilian Institute for Geography and Statistics (IBGE), to investigate the health determinants, conditions, and needs of the Brazilian population 19 .
The sample estimated for the PNS was 108,525 households, for a nonresponse rate of 20%. Individuals aged ≥15 years, residing in permanent private households, were included. At data collection, a questionnaire was used; it comprised modules focused on: 1. household; 2. all residents of the household -to obtain socioeconomic and health-related data (resident aged ≥18 years -proxy); and The sampling design had a three-stage cluster plan, with stratification of primary sampling units (PSU) -consisting of census sectors or a set of sectors -and selection of these units for the master sample, with probability proportional to size (number of households). The selection of PSU also considered equally proportional probability. At the second stage, households from the National Address List for Statistical Purposes were selected by simple random sampling. Then, from each household, a resident aged ≥15 years was randomly selected, based on a list of residents obtained during the interview 19,20 .
Based on some indicators from the PNS 2013 (NCDs, violence, use of health services, smoking habit, physical activity, etc.), the sample size was dimensioned with the intended level of precision for the estimates. Factors of sample expansion or weighting for selected households and residents were incorporated into the data. The final weight is a product of the inverse of the selection probabilities at each stage, including correction for nonresponses and adjustments to population totals. The history and aspects related to the PNS 2019 were described in detail and are published elsewhere 19,20 .
In the module regarding the selected resident, 86,820 interviews were conducted in the household. In the present study, data from individuals aged ≥80 years (n=6,098) were considered. For multimorbidity, defined as the co-occurrence of two or more chronic conditions 5,21 , the following diseases were considered: hypertension, diabetes mellitus, heart disease, cerebrovascular accident (CVA), asthma, arthritis or rheumatism, work-related musculoskeletal disorder (WMSD), cancer, chronic kidney disease, chronic back pain, depression, other mental illness, and lung disease (pulmonary emphysema, chronic bronchitis, or chronic obstructive pulmonary disease -COPD). For all these conditions, the question concerned the previous self-reported medical diagnosis. Chronic back pain was self-reported and, in the case of depression and mental health, a previous diagnosis made by a physician/mental health professional (psychiatrist/psychologist) was considered. A variable related to the number of chronic diseases was also created and categorized as: none, one, two, three, and four or more.
Data on the use of services were obtained from the household questionnaire (module "J" of the PNS, answered by the proxy), using the following questions: 1. in the last two weeks, did you look for any place, service, or health professional for health-related care ( J14)?; 2. when did you last see a doctor ( J11=1=in the last 12 months)?; 3. in the last 12 months, have you been hospitalized for 24 hours or more ( J37)?; 4. in the last two weeks, did you stop performing any of your usual activities for health reasons (J2)?

DATA ANALYSIS
The prevalence of multimorbidity and respective 95% confidence intervals (95%CI) were estimated according to sociodemographic characteristics and self-rated health. The association between these variables and multimorbidity was verified by Pearson's χ² test (Rao-Scott).
Initially, the aim was to describe the relationship between the number of chronic diseases and each of the indicators of service use. To do so, figures were created in the Excel program (version 19) considering the estimated prevalence rates. In order to verify the relationship between multimorbidity and use of services -by the indicators -, the prevalence rates and the crude and adjusted prevalence ratios (PR) were estimated; the later were adjusted for sociodemographic variables. To better understand the importance of the characteristics associated with multimorbidity in this relationship with the use of services, analyses stratified by sex, ownership of health insurance, and self-rated health were carried out.
Statistical analyses were performed using the Stata software, version 14 (survey module) considering the effects of stratification and clustering on the estimation of indicators and their precision measures (95%CI). All tests considered a 5% significance level.
The PNS was approved by the National Commission of Ethics in Research (Process No. 3.529.376 of August 23, 2019). All respondents were previously consulted, received clarifications, and agreed to participate in the research.

RESULTS
Data from 6,098 oldest old, whose average age was 85 years (with no difference between sexes), were analyzed. About 62% were women and 32% had no formal education; 68.2% had no health insurance; 46.3% lived in the southeast region; and 36.7% considered their health to be very good/good. The prevalence of multimorbidity was 57.1% (95%CI 54.4-59.8), higher in women, in those who have a health insurance, and in those residing in the southern region of the country, compared with those who live in the north and northeast regions and those who rated their health worse (p<0.05) ( Table 1).
As for the association between the number of chronic diseases and the indicators of use of health services (Figure 1), the prevalence of use of services in the last two weeks increased with the number of chronic diseases and became similar for those with three and four or more diseases ( Figure 1A). Regarding medical appointments in the last year, the prevalence reached a level above 90% in the presence of one disease ( Figure 1B). In the case of hospitalization, there was a growing increase with similarity for those with three and four or more chronic conditions ( Figure 1C); conversely, as for the restriction of usual activities due to health problems, there was an increase with the number of diseases ( Figure 1D).
Regarding the considered indicators of use of health services, overall, the percentages were high. The use of health services in the two previous weeks was observed in 64.6% (95%CI 60.0-68.9) of older people. It is noteworthy that over 70% of those with multimorbidity have been hospitalized in the last 12 months (3,157,255 older adults, considering the estimate of the IBGE population projection for 2019) and stopped carrying out activities in the last two weeks for health reasons. Greater difference between groups (with and without multimorbidity) was observed for medical appointments in the previous year (PR 1.99; 95%CI 1.53-2.58). It is noteworthy that, for the group of the oldest old, even after adjustment for sociodemographic variables, there were no relevant changes in the magnitude of the estimated ratios ( Table 2). Estimates of the prevalence of use of services according to sex demonstrated that the use of health services in the last two weeks and medical appointments in the previous year were more frequent among older women. Among men, there was no difference regarding the use of health services and the restriction in performing usual activities, according to the presence of multimorbidity (p>0.05).
When disaggregating older adults according to ownership of health insurance, no differences were observed in the prevalence rates of use of services for the considered indicators, nor for those who have a health insurance, according to the presence of multimorbidity, a profile that differs from that observed among older people without health insurance -whose prevalence rates of use are higher for those with multimorbidity (Table 3).
In the analysis stratified according to self-rated health, similar prevalence rates were observed for the indicators in those who considered their health to be fair or poor/very poor. In those with better subjective health status, there were more medical appointments  Crude prevalence ratio, according to multimorbidity and use of health services. b For the total, the prevalence ratio was adjusted for sex, ownership of health insurance, region of residence, and self-rated health. *In the last two weeks prior to the survey.

DISCUSSION
This study estimated the prevalence of multimorbidity in older people aged 80 years and over and verified its relationship with the use of some health services. In this age group, multimorbidity accounted for about 57% of the older adults. This condition was estimated at 53.1% according to data from the PNS 2013 survey (95%CI not shown) 22 . Among older people, women, those who have a health insurance, residents in the south region of the country, and those who did not consider their health to be very good/good had a greater accumulation of chronic diseases. Furthermore, for these older people, high percentages of use of services and abandonment of daily activities due to health problems were observed, Table 4. Multimorbidity and use of health services in the oldest old (aged ≥80 years), according to self-rated health. National Survey of Health, Brazil, 2019. with most of them being subject to the cumulative effects of low education level (78.7%) and high dependence on the public health service (68.2%), a profile similar to that found in a study on multimorbidity and its distribution among older people (age ≥60 years) from the city of Bagé, in southern Brazil 10 . The number of diseases/multimorbidity resulted in increases in the demand for health services (use of services, medical appointments, hospitalization) and in disabilities, according to the literature, which highlights as important determinants of the use of services the existence of the disease, its severity and urgency 13 . Multimorbidity in older people aged 80 years and over is an important indicator of the use of services and should be considered when planning the actions of healthcare managers.
The direct association between socioeconomic indicators and multimorbidity denotes its relevance in the occurrence and maintenance of social inequalities 23 and increases the challenges of the health system for the management of multimorbidity in older individuals 10 . Overall, the provision of health care is largely configured for individual diseases, and not for multimorbidity 10,16,23 , especially concerning older adults.
In this study, women were more affected by multimorbidity, a finding similar to that of a cohort that identified a higher prevalence of multiple morbidities in all age groups and at an earlier age compared to men 24 . In the ELSI/Brazil study (2015-2016), prevalence rates of multimorbidity of 58.9% in men and 75.5% in women aged 50 years or over were identified 6 . These differences have been explained by women's greater demand for health services and health prevention and promotion practices, in addition to greater attention to disease symptoms 24,25 . In the present study, discrepancies in the prevalence of indicators of use of services per sex draw attention because it is a population of older adults, demonstrating the importance of developing healthcare actions in primary care 16 especially aimed at men throughout life.
For older people with health insurance, the use of services was not associated with multimorbidity, unlike what has been observed for those dependent on public health services. Higher levels of education and income reflect in better health conditions in all age groups, and are associated with the acquisition of private health insurance 26 . Therefore, having a health insurance can be a determinant of access to health services, medical appointments 27 , greater health care 28 , greater access to prevention measures and earlier diagnosis, in such a way that this subgroup presents better general health conditions, regardless of the number of chronic diseases. Moreover, the logic of care centered on the disease and its management in private health services must be considered 29 . Among older people with multimorbidity who did not have health insurance, 30% stopped performing daily activities for health reasons, which denotes the greatest limitation imposed by the accumulation of chronic conditions in those with worse socioeconomic conditions. Self-rated health is widely used in research and clinical practice, as it is an important indicator of well-being in the subjective judgment that each person makes about the quality of their physical and mental health 30 . In this study, it is worth highlighting the higher prevalence of medical appointments among older people with multimorbidity who rated their health as very good/good and the higher prevalence of hospitalization among those who worse rated it. These results indicate the moderating effect of self-rated health on the perceived needs regarding the use of health services 31 , being a fundamental indicator in decision-making about health care for older adults 32 . Considering population aging and the greater burden of chronic diseases, studies aimed at investigating the relationships between self-rated health and social determinants can help to establish priorities in services and in actions for promoting health and disease prevention.
It is noteworthy that most older people reside in the community and, with the greater proportional growth of the oldest old, the demand for care increases while there is less availability of family members to care for dependent older people, due to multimorbidity and its association with other previous needs 10, 23 . If, on the one hand, global aging and the expansion of life expectancy in Brazil are praised as indicators of the relative success of previously implemented public policies, on the other hand, it is understood that this process imposes urgent demands and challenges for the care of this population 2,33 .
Currently, it is observed that the provision of health services disaggregates the care for the older adults -at the expense of integrated care -with multiple specialist appointments, lack of shared information, inadequate use of pharmacotherapy and polypharmacy 34,35 and tests, among other procedures, which overload the system with a strong financial impact at all levels of care and without significant benefits for the users' quality of life 16 . In addition, in the current care model, there is an excess -already in younger age groups among older people -of users at the highest levels of complexity due to the lack of care at the first levels of health care 16,36 .
Studies on patterns of multimorbidity can provide data for its inclusion in clinical protocols 10 , broadening the approach to older users when considering "disease combinations." It is noteworthy that most clinical guidelines address diseases in isolation, not considering that patients have several diseases at the same time, which generates negative implications, especially for pharmacological treatment, with a tendency to polypharmacy and the risk of adverse drug events. Thus, it is urgent to develop methods for the management of care and guidelines centered on older people with multimorbidity to ensure adequate clinical management and the formulation of prevention and treatment strategies for these chronic diseases 37,38 .
Among the strengths of the study, it is noteworthy that this is the first research to assess the relationship between multimorbidity and the use of health services in older individuals aged 80 years and over. This age group shows a marked increase among the older adult population and little is known about the behaviors and health conditions of the oldest old. The national scope of the PNS and the breadth of covered topics allow for more detailed investigations about older people, providing advances in research in the field of aging.
As for the limitations of the present study, it is necessary to consider that multimorbidity is restricted to the self-reported diagnosis of NCDs, being subject to underreporting due to memory bias, as well as information on the use of health services 7 . Another limitation is the prevalence bias, considering the higher mortality of older people with worse health conditions. The cross-sectional design of the PNS does not allow interpreting the observed associations between multimorbidity and use of services as causal. In addition, the PNS sample did not include institutionalized older adults, a fact that may have underestimated the use of services by the evaluated indicators, considering that this is a more vulnerable population, which requires treatment and health care 39 .
Health services must take into account socioeconomic and demographic aspects, considering that health inequalities experienced in Brazil impact the access to health services, verified in differences in regional prevalence rates and social inequalities 40,41 . Multimorbidity is a frequent condition among older adults and its prevalence increases with age 23,42 , being a predictor of mortality and negative outcomes 43 . Understanding the complex phenomena that permeate multimorbidity is paramount to guarantee integrated health care for older people with multimorbidity 44 .
All in all, indicators for the use of health services were higher in older individuals who have two or more chronic diseases, regardless of sociodemographic conditions and self-rated health, evidencing the impact of multimorbidity per se in determining the use of services among the oldest old.