Association between frailty and depression among hemodialysis patients: a cross-sectional study

ABSTRACT BACKGROUND: Frailty is consensually understood to be a clinical syndrome in which minimal stressors can lead to negative outcomes such as hospitalization, early institutionalization, falls, functional loss and death. Frailty is more prevalent among patients with chronic kidney disease (CKD), and those on dialysis are the frailest. Depression contributes towards putting patients with CKD into the frailty cycle. OBJECTIVE: To assess frailty and its relationship with depression among patients with CKD undergoing hemodialysis. DESIGN AND SETTING: Observational and quantitative cross-sectional study conducted in a renal therapy unit, located in the interior of the state of São Paulo, Brazil. METHODS: This investigation took place in 2019, among 80 patients. The following instruments were applied: a sociodemographic, economic and health condition characterization and the Subjective Frailty Assessment (SFA) and Patient Health Questionnaire-9 (PHQ-9). RESULTS: Among the patients, there was higher prevalence of females, individuals with a steady partner and retirees, and their mean age was 59.63 (± 15.14) years. There was high prevalence of physical frailty (73.8%) and depression (93.7%). Depression was associated with frailty, such that patients with depression were 9.8 times more likely to be frail than were patients without depression (odds ratio, OR = 9.80; 95% confidence interval, CI, 1.93-49.79). CONCLUSION: Based on the proposed objective and the results achieved, it can be concluded that depression was associated with the presence of frailty among patients with CKD on hemodialysis.


INTRODUCTION
Frailty is consensually understood to be a clinical syndrome in which minimal stressors can lead to negative outcomes such as hospitalization, early institutionalization, falls, functional loss and death. 1 There are several models for frailty, but the two that have been most widely used are the deficit model, developed by Mitnitski, Mogilner and Rockwood, 2 and the phenotype-based model, developed by Fried et al. 3 Because of the high incidence and prevalence of physical and cognitive impairment among patients with chronic kidney disease (CKD), these individuals are more likely to develop frailty early. 4 According to a systematic review carried out by Chowndhuty et al., 5 frailty is very prevalent in patients with CKD, and those on dialysis are the frailest. Furthermore, frailty has been shown to be associated with increased risk of hospitalization and mortality among patients with CKD. An association between frailty and higher risk of mortality among patients seen at rapid diagnostic clinics (RDCs) has been found in other studies in the literature. 4,6,7 According to Wu et al., 6 in addition to sociodemographic factors and health issues, depression contributes towards putting patients with CKD into the frailty cycle. A study by Perez et al. 7 among frail and non-frail adults with diabetes mellitus (type 1 and type 2) and with chronic kidney disease (stages 1 to 5) demonstrated that frail participants presented depression more often (P ≤ 0.005) than did the non-frail participants. In addition, depression has been found to be the most recurrent psychiatric condition among patients with CKD, with a rate of 20 to 30% among patients on hemodialysis. 8

OBJECTIVE
The aim of the present study was to assess frailty and its association with depression among patients with CKD undergoing hemodialysis.

Design
The present study was of observational and quantitative crosssectional nature. The investigation took place in 2019, at a dialysis service located in the interior of the state of São Paulo, Brazil.

Sample
The final sample was 80 patients who met the following inclusion criteria: having a medical diagnosis of CKD, being on hemodialysis and possessing preserved oral communication. The exclusion criterion was presentation of dementia that could be verified in the medical records. An initial non-probabilistic convenience sample of 180 patients was used; seventy patients were excluded from the study, 46 did not meet the study's eligibility criteria and 64 did not agree to participate in the study.

Data collection
The data collection process took place as follows. At the initial contact with the patients, the research project was explained to them and they were invited to participate in the study. Patients problems with concentration; feelings of slowness or restlessness; and thoughts of suicide. The frequency of each symptom over the past two weeks is assessed on a Likert scale from 0 to 3 corresponding to the answers "no days", "less than a week", "more than a week" and "almost every day", respectively. The questionnaire also includes a tenth question that assesses the interference of these symptoms in performing daily activities, such as working and studying. If the final score reaches 5, the individual is characterized as having mild depression; 10, moderate; 15, moderately severe; and 20 or more, severe.

Data analysis
The statistical treatment of the data was performed with sup- August 27, 2019). Participants needed to sign an informed consent statement before entering the study.

RESULTS
Regarding frailty assessed according to the SFA scale, it was found that only four participants were non-frail, while 17 (21.2%) were pre-frail and 59 (73.8%) were frail. The sociodemographic, economic and comorbidity profile did not show any statistically relevant difference between the levels of frailty. The majority of the participants were female, white and retired, and had a steady partner. Their average age was less than 61 years; their average schooling level did not exceed 8.5 years; and their average per capita income did not exceed 1.5 minimum monthly wages ( Table 1).
Regarding the comorbidities of diabetes and hypertension,

Depression (PHQ-9)
Non-frail (n = 4) 5.00 Pre-frail (n = 17) 8.88 0.001 Frail (n = 59) 15.92 In the analysis on depression as a predictor of frailty, it was noted that depression was associated with frailty. Patients with depression were 9.8 times more likely to be frail than were patients without depression (OR = 9.80; 95% CI, 1.93-49.79). For the other variables analyzed (sex, age and education level), there was no statistically relevant relationship ( Table 2).

DISCUSSION
In the present study, among the sociodemographic, economic and health condition characteristics of the participants, female sex was more prevalent, the mean age was 59.63 years and the mean schooling level was 6.66 years. It was noted that 83.7% of the patients presented depression. This profile has also been found in other studies conducted in Brazil and in other countries among patients with CKD. 4,13,14 Assessing the occurrence rates of frailty and depression syndromes is challenging given the diversity of models and measurements that have been used in studies to identify their prevalences.
In this, the heterogeneity of the conditions themselves needs to be borne in mind: their expression of signs and symptoms varies according to age and socioeconomic context. 5 With regard to frailty, 21.3% of the patients were considered pre-frail in the present study. However, in the study by Gesualdo et al., in which the objective was to evaluate frailty and identify its associated factors among adults and elderly people with CKD who were undergoing hemodialytic treatment, most of the adults were pre-frail (54.84%). Their study corroborates the findings of the present study regarding the prevalence of frailty. 4 Another study that addressed factors associated with frailty was conducted by Duarte et al. 17 In that study, the aim was to describe the prevalence of frailty among elderly people, in order to analyze associated factors and the evolution of the syndrome.
A total of 1,399 older adults aged 60 years or older, living in the state of São Paulo, Brazil, participated in the study. Frailty syndrome was evaluated based on the phenotype proposed by Fried et al., 10 composed of five components: unintentional weight loss, self-reported fatigue, reduction in strength, low walking speed and low level of physical activity. Duarte et al. 17 found that out of the total number of elderly subjects (n = 1,399), 8.5% were frail and presented factors associated with age, functional impairment, cognitive decline, hospitalization and multimorbidity. Over a fouryear period, 3.3% of the non-frail and 14.7% of the pre-frail elderly people became frail. In the present study, we found that the prevalence of frailty among the patients was 73.8%.
Although most definitions of frailty focus primarily on physical and biological indicators of vulnerability, it is significant to consider the risk of adverse health outcomes associated with mental disorders. As well as frailty, depression among the elderly has been characterized in terms of diminished reserve capacity, thus representing a lack of resources to respond to stressors. 15 Hence, depression can serve to accentuate physical frailty: not because it is associated with any disease process or model of frailty in particular, but because it represents a lack of psychological and social coping resources. 15,16 The association between frailty and depression demonstrated in the present study was also found in other studies, such as the one by Tavares et al. 17 In that study, the aim was to describe the socio- the findings of the present study, in which depression was associated with frailty, thus indicating that patients with depression were 9.8 times more likely to be frail than were patients without depression. In the light of this exposure, it is possible to infer that patients with CKD who are undergoing hemodialysis treatment are more vulnerable to becoming affected by depressive symptoms.
Another study that addressed depression in CKD patients was conducted by Pretto. 18  Depression scores are three to four times higher among patients with CKD than in the general population and two to three times higher than among people with other chronic diseases. In the present study, it was found that 83.7% of the patients had depressive symptoms, i.e. more than half of the patients presented depression, just as in the study by Pretto. 18  Nursing plays an important role in this scenario. Nurses are the professionals who establish greatest contact and bonding with these patients, given the long periods of time spent with them.
Health education plays a fundamental role in promoting quality of life for patients affected by CKD. Moreover, this raises awareness among patients, family members and the nursing team, thereby stimulating changes to behavioral strategies.
Future research should continue to explore the reasons for comorbidities and the implications of comorbidities in predicting adverse health outcomes. Therapies to combat depression can prevent or mitigate the symptoms of frailty.
The limitation of the present study was that its sample was selected for convenience.

CONCLUSION
From the proposed objective of this study and the results achieved, it can be concluded that depression was associated with the presence of frailty among patients with CKD who were undergoing hemodialysis. Thus, it is important to highlight the need for early screening of frailty in this population.
In addition, there is an urgent requirement to create healthcare policies that meet the social and psychological needs of these patients, given that this is a predictable and preventable syndrome.
In addition, professionals must pay attention to the signs and symptoms of depression that can lead patients to frailty, in addition to other outcomes.