Comprehensive geriatric assessment of older patients with renal disease: a cross-sectional survey

Multidimensional health function impairments are common in older patients with chronic kidney disease (CKD). The purpose of this study was to explore whether the risk or severity of geriatric syndrome increased with a decline in renal function. This survey was conducted for CKD patients aged  ≥ 60 years and hospitalized at West China Hospital of Sichuan University (Center of Gerontology and Geriatrics, Nephrology, and Endocrinology) and Chengdu Kangfu Kidney Disease Hospital from September 01, 2013 to June 30, 2014. Patients underwent multidimensional individualized assessments by trained doctors. Logistic regression analysis found that the risk of assisted walking (P = 0.001) and urinary incontinence (P = 0.039) increased with a decline in renal function. Regression analysis revealed that the scores of activities of daily living (P = 0.024), nutritional status (P = 0.000), total social support (P = 0.014), and objective support (P = 0.000) decreased with a decline in renal function.

With the advancement in social economics, living standards, and healthcare, the aging trend is prominent worldwide, and China is not an exception.The results of the seventh census in 2020 in China showed that 18.7% of the population was aged ≥ 60 years, which was 5.44% higher than that of the 2010 census, and 13.5% of them were aged ≥ 65 years, which was 4.63% higher than that reported in 2010 1 .The increase in the older population will undoubtedly bring great challenges to the socioeconomic development of China.
Older adults acquire more chronic illnesses than younger ones.Hypertension, diabetes, and coronary heart disease remain the primary diseases affecting the health of older adults, and these chronic diseases can lead to kidney damage.Therefore, chronic kidney disease (CKD) is increasingly common in older adults 2 .A new large cross-sectional survey in China in 2012 showed that the total prevalence of CKD in adults was 10.8%, with more female patients than male patients, and 18% and 24.2% of females were aged 60-69 years and ≥ 70 years, respectively 3 .CKD is highly prevalent in older adults, and this leads to a heavy social and family burden and considerable medical costs.According to the 2016 data report of the China Kidney Disease Network, the total inpatient medical expenditure for patients with CKD (including end-stage renal disease) was 27.646 billion RMB.It was higher than in diabetic patients and patients without CKD 4 .

G1-G2
As individuals age, their ability to perform daily living activities tends to decrease.ADL impairment is associated with increased mortality and often leads to additional adverse outcomes [15][16][17] .It had been shown that both mild and moderate CKD were significantly associated with disability in daily activity 23,24 .Therefore, assessing ADL in CKD patients is needed as soon as possible.This study found that with the decline in renal function, the scores of ADL decreased.This study was inconsistent with previous findings.Looking forward to more relevant studies in the future.
Cognitive impairment is common in older CKD patients.This study found a relatively high occurrence rate of cognitive decline, including mild cognitive decline and severe cognitive decline, in older CKD patients, accounting for 36.1% and 18.6%, respectively, especially in dialysis patients (42.4% and 14.1%, respectively).This showed a good agreement with the findings of some previous studies 25 .In 2010, a multicenter study in the US studied the overall cognitive impairment in this population, and a positive correlation between decreased eGFR and cognitive scores was reported, i.e., the lower the eGFR, the more severe the cognitive impairment 10 .Cognitive changes occur and skills decline at different rates early in CKD.Orientation, attention, and language are particularly affected in these patients 26 .Therefore, there is a need for proactive assessment of cognitive function in older CKD patients to provide appropriate interventions.
Depression is common in the older adults and especially among patients who suffer from chronic diseases 27 .This study showed that the occurrence rate of depression was 22.9% in older CKD patients, especially endstage patients (nearly 30%), which was consistent with many previous results [28][29][30][31] .One prospective cohort study monitored over 20 years indicated a bidirectional association between depression and CKD 32 .This study did not find a progressive increase in depression scores with decreasing renal function.But the higher the occurrence rate of depression in patients with CKD was incontestable.Studies have shown that depression was negatively associated with the patient's quality of life and that it was an independent risk factor for death in maintenance hemodialysis patients 13,29,30,33 .Therefore, it is particularly important to evaluate depression as early as possible in older patients with CKD.
The results of this study showed that older CKD patients had a high occurrence rate of poor nutrition, especially in end-stage renal disease (G5ND: risk of malnutrition, 60.9% and malnutrition, 10.9%; G5D: risk of malnutrition, 54.9% and malnutrition, 20.0%).Thus, nutritional health problems were prevalent in older CKD patients, corroborating some previous findings [34][35][36] .Malnutrition not only affects the quality of life and aggravates renal dysfunction but is also an indicator of poor prognosis in older patients.Malnutrition plays an important role in the mortality-related factors of patients with end-stage renal disease.In this study, we found that nutrition status became worse as renal function declined.Hence, in older patients with CKD, providing reasonable nutritional assessment and nutritional support are important responsibilities of the medical staff.
Social support refers to positive group and family interactions.Good social support has a positive effect on the patient's mental health 37 .It has been shown that addressing patient perception of social support could potentially improve outcomes 14,38 .This study found that social support gradually decreased in older CKD patients as the renal function declined.Therefore, for older CKD patients, we need to understand their families and their surrounding social environment and accordingly conduct health education for them and their families to enhance family support and care.For clinical workers, it is necessary to encourage the patient's access to social activities.
Impaired mobility can be a temporary or permanent condition (it can have both physical and psychological consequences), and it can be caused by a variety of modifiable and non-modifiable risk factors 39 .This study showed that the occurrence rate of assisted walking was 33.9%, which was consistent with previous results 40 .The study found that the risk of assisted walking increased with a decline in renal function.Strategies to prevent and improve mobility limitations are strongly needed.
Due to the embarrassment associated with urinary incontinence, most patients never discuss this bothersome urinary symptom with their physicians or seek treatment 41 .This study revealed that the risk of urinary incontinence increased with a decline in renal function.At present, the cause of urinary incontinence in older CKD patients is unclear, and relevant studies are expected.
This study has several limitations.First, the analysis used a cross-sectional design.Second, Inability to establish causality.Third, subgroup sizes were relatively small, thus resulting in a lack of sufficient basis for conclusion.Despite these shortcomings, the strength of our study was that the included subjects covered all stages rather than a single stage and are more representative.

Conclusion
In this study, we found the scores of ADL, nutritional status, total social support and objective support decreased with a decline in renal function.Meanwhile the risk of assisted walking and urinary incontinence increased with a decline in renal function.The findings of this study can provide guidance to healthcare providers to assess assisted walking, urinary incontinence, ADL, nutritional status, total social support and objective support in older patients with CKD.There is a need for further research into the underlying cause of geriatric syndromes in CKD with a view to developing therapeutic interventions.

Participants
This study enrolled CKD patients aged ≥ 60 years and hospitalized at West China Hospital, Sichuan University (Center of Gerontology &Geriatrics, Nephrology, and Endocrinology) and Chengdu Kangfu Kidney Disease

Inclusion criteria
The inclusion criteria were as follows: (1) age ≥ 60 years; (2) diagnosis and staging of CKD according to the 2012 International Kidney Disease Organization "Kidney Disease: Improving Global Outcomes" guidelines 42 ; and (3) CKD combined with two or more chronic diseases or geriatric syndromes, including CKD complications, as per the diagnosis recorded by the in-charge physician in the medical records.

Exclusion criteria
The exclusion criteria were as follows: (1) any acute disease, such as acute heart failure, acute kidney failure, acute liver failure, and acute respiratory failure; and (2) severe hearing or visual impairment or severe mental disorder.

Study design
Data were collected by trained doctors during face-to-face interviews, using standardized questionnaires.At least one family member was asked to accompany the participants.When the patients could not understand unclear objective questions, the companion was allowed to answer.When subjective questions were involved, the companion was asked to avoid answering, and the participant was asked to respond personally.Informed consent was obtained from all participants or their caregivers after a thorough explanation of the study details.
Baseline demographic data included sex, age (based on identity card number), marital status, education, smoking (World Health Organization [WHO] defines "continuous or cumulative smoking for ≥ 6 months in a lifetime" as smokers), and alcohol consumption (no uniform definition of alcohol consumption and drinking pattern available currently).This study defined drinking as consuming at least one standard drink per week in the past month for > 6 months.According to the WHO recommendation, one standard drink is equivalent to the amount (mL) of various types of alcoholic drinks based on the fixed pure ethanol content (10 g) 43 .The etiology of CKD was based on the final diagnosis recorded by the physician in charge in the medical records.We determined whether dialysis was performed by asking the patients and doctors.
(2) Physical examinations and laboratory indicators in the last 3 months.
Physical examinations included height (cm), weight (kg), body mass index (kg/m 2 ), midpoint circumference of the upper arm (cm), and gastrocnemius muscle circumference (cm).Laboratory indicators included routine blood tests, biochemical parameters (serum albumin, glycosylated hemoglobin, parathyroid hormone, serum creatinine, serum phosphorus, and random urine albumin/creatinine ratio), and urine tests.All indicators were the results of examinations of patients conducted in secondary hospitals or higher in the last 3 months.Based on the serum creatinine level, the GFR was calculated using the Chronic Kidney Disease Epidemiology Collaboration formula, which was considered the eGFR 44 .
Gait speed and balance were assessed using the "timed up and go" test 45,46 .Falls-We asked the patients if they had fallen on the ground or hit other objects (such as chairs or walls) in the past year (yes or no).
Assisted walking-We asked the patients if they needed someone else or an aid to walk, such as walking stick, wheelchair and walking frame (yes or no).(4) Neurosensory deficits-impairment of hearing and/or vision (yes or no).
If their hearing was satisfactory for daily conversations, watching TV, or using the phone, and if their eyesight was satisfactory for reading books or newspapers and watching TV. ( 5) Constipation (yes or no).
Constipation was defined as defecation < 3 times per week without laxatives and subjective discomfort due to difficulty and/or incomplete defecation at least 25% of the time, which lasted for at least over 2 weeks.(6) Urinary incontinence (yes or no).
The patients were asked if they had involuntary urine leakage in the past year.