Clinical Relevance of Differences in Glomerular Filtration Rate Estimations in Frail Older People by Creatinine- vs. Cystatin C-Based Formulae

Narrative Review: Clinical Implications and Assessment of Frailty in Patients With Advanced CKD

Frailty is a multidimensional clinical syndrome characterized by low physical activity, reduced strength, accumulation of multiorgan deficits, decreased physiological reserve, and vulnerability to stressors. Frailty has key social, psychological, and cognitive implications. Frailty is accelerated by uremia, leading to a high prevalence of frailty in patients with advanced chronic kidney disease (CKD) and end-stage kidney disease (ESKD) as well as contributing to adverse outcomes in this patient population. Frailty assessment is not routine in patients with CKD; however, a number of validated clinical assessment tools can assist in prognostication. Frailty assessment in nephrology populations supports shared decision-making and advanced communication and should inform key medical transitions. Frailty screening and interventions in CKD or ESKD are a developing research priority with a rapidly expanding literature base.

The prevalence of frailty and pre-frailty among geriatric hospital inpatients and its association with economic prosperity and healthcare expenditure: A systematic review and meta-analysis of 467,779 geriatric hospital inpatients

BACKGROUND

Frailty is a common and clinically significant condition among geriatric populations. Although well-evidenced pooled estimates of the prevalence of frailty exist within various settings and populations, presently there are none assessing the overall prevalence of frailty among geriatric hospital inpatients. The purpose of this review was to systematically search and analyse the prevalence of frailty among geriatric hospital inpatients within the literature and examine its associations with national economic indicators.

METHODS

Systematic searches were conducted on Ovid, Web of Science, Scopus, CINAHL Plus, and the Cochrane Library, encompassing all literature published prior to 22 November 2018, supplemented with manual reference searches. Included studies utilised a validated operational definition of frailty, reported the prevalence of frailty, had a minimum age ≥ 65 years, attempted to assess the whole ward/clinical population, and occurred among hospital inpatients. Two reviewers independently extracted data and assessed study quality.

RESULTS

Ninety-six studies with a pooled sample of 467,779 geriatric hospital inpatients were included. The median critical appraisal score was 8/9 (range 7-9). The pooled prevalence of frailty, and pre-frailty, among geriatric hospital inpatients was 47.4% (95% CI 43.7-51.1%), and 25.8% (95% CI 22.0-29.6%), respectively. Significant differences were observed in the prevalence of frailty stratified by age, prevalent morbidity, ward type, clinical population, and operational definition. No significant differences were observed in stratified analyses by sex or continent, or significant associations between the prevalence of frailty and economic indicators.

CONCLUSIONS

Frailty is highly prevalent among geriatric hospital inpatients. High heterogeneity exists within this setting based on various clinical and demographic characteristics. Pooled estimates reported in this review place the prevalence of frailty among geriatric hospital inpatients between that reported for community-dwelling older adults and older adults in nursing homes, outlining an increase in the relative prevalence of frailty with progression through the healthcare system.

Comparison of Creatinine and Cystatin C to Estimate Renal Function in Geriatric and Frail Patients

The aim of this study was to compare estimated glomerular filtration rate (eGFR) with creatinine (eGFRcrea) and cystatin C (eGFRcys) in geriatric and frail patients. A retrospective, cross-sectional study was performed at a geriatric clinic in Stockholm (n = 95). The revised Lund−Malmö equation was used to calculate eGFRcrea and the Caucasian-Asian-Pediatric-Adult (CAPA) equation was used for eGFRcys. The absolute mean percentage difference between eGFRcrea and eGFRcys was used as a surrogate measure for accuracy in eGFR. Other outcome measures were consistency expressed in Lin’s concordance correlation coefficient and the proportion of consistent staging of renal failure. Subgroup analyses were performed with regard to frailty (according to Clinical Frailty Scale) and age. eGFRcys estimated lower GFR than eGFRcrea across the entire study population as well as in all subgroups (p < 0.05). Difference between the estimates increased with increasing frailty (r2 = 0.15, p < 0.01), but was not significantly affected by age (r2 = 0.004, p = 0.55). In conclusion, eGFRcys was significantly lower compared to eGFRcrea in geriatric and frail patients. Moreover, frailty had greater impact than age on the accuracy of eGFR. However, this study cannot determine if any of the estimates are preferable over the other in this patient group.

Different glomerular filtration rate estimating formula for prescribing DOACs in oldest patients: appropriate dosage and bleeding risk. Post hoc analysis of a prospective cohort

Background

Direct oral anticoagulants (DOACs) pharmacokinetics depends on estimated glomerular filtration rate (eGFR), whose estimation is crucial for optimal risk/benefit balance.

Aims

To assess the concordance among different eGFR formulas and the potential impact on DOACs prescription appropriateness and bleeding risk in oldest hospitalized patients.

Methods

Post hoc analysis of a single-centre prospective cohort study. eGFR was calculated by creatinine-based (MDRD, CKD-EPI_Cr, BIS₁) and creatinine–cystatin-C-based (CKD-EPI_Comb and BIS₂) formulas. Patients were stratified according to eGFR [severely depressed (SD) 15–29; moderately depressed (MD) 30–49; preserved/mildly depressed (PMD): ≥ 50 ml/min/1.73 m²]. Concordance between the different equations was assessed by Cohen’s kappa coefficient.

Results

Among AF patients, 841 (59.2% women, mean age 85.9 ± 6.5 years) received DOACs. By CKD-EPI_Cr equation, 135 patients were allocated in the SD, 255 in the MD and 451 in the PMD group. The concordance was excellent only between BIS 2 and CKD-EPI_Comb and MDRD and CKD-EPI_Cr, while was worse (from good to poor) between the other formulas. Indeed, by adding cystatin-C almost over 1/3 of the patients were reallocated to a worse eGFR class. Bleeding prevalence increased by 2–3% in patients with discordant eGFR between formulas, reallocated to a worse chronic kidney disease (CKD) stage, although without reaching statistical significance. CKD-EPI_Comb resulted the best predictor of bleeding events (AUROC 0.71, p = 0.03).

Discussion

This study highlights the variability in CKD staging according to different eGFR formulas, potentially determining inappropriate DOACs dosing. Although the cystatin-C derived CKDEPI_Comb equation is the most accurate for stratifying patients, BIS₁ may represent a reliable alternative.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40520-021-01986-w.

Frailty, multimorbidity and functional status as predictors for health outcomes of acute psychiatric hospitalisation in older adults

Objectives: Frailty, multimorbidity and functional decline predict adverse health outcomes in community dwelling older people and older patients in general hospitals. This study investigates whether these characteristics separately are independent predictors of health outcomes of acute psychiatric hospitalization.Methods: Observational study in a prospectively sampled cohort of older patients, consecutively admitted to a psychiatric hospital. On admission we assessed frailty (Frailty Index and walking speed); multimorbidity (Cumulative Index Rating Scale Geriatrics (CIRS-G)) and functional status (Barthel Index). We used the Clinical Global Impressions of Improvement scale (CGI-I) as the psychiatric outcome measure, and dichotomized discharge destination as overall outcome measure: favourable (able to return home or previous care level) or adverse (death, or move to higher level of residential care).Results: We included 120 patients, 74.6 years (±7.8). 52.5% of the patients was frail (FI ≥0.25). The mean level of the CIRS-G was 13.5 (5.4). Mean CGI-I at discharge was 2.8 (± 1.0), indicating moderate improvement in the psychiatric outcome. Neither FI, CIRS-G, nor Barthel scores were, independent of age, sex and diagnosis, associated with the CGI-I. FI was predictive for adverse discharge destination (OR 1.91, 95%CI 1.09-3.37 per 0.1), as were higher CIRS-G (OR 1.19 95%CI 1.06-1.34, per point) and lower walking speed (OR 1.35 95%CI 1.06-1.72 per 0.1 m/s).Conclusions: Half of our patients were frail and had a high level of multimorbidity. The FI, walking speed and multimorbidity did not predict improvement of psychiatric symptoms at discharge, but independently helped to predict adverse discharge destination.

Diabetes Management in Older Adults With Chronic Kidney Disease

PURPOSE OF REVIEW

Older adults often live with chronic disease including diabetes and its complications. In this review, we examine the complexity and heterogeneity of older adults with diabetes and chronic kidney disease, explore the nuances in their diabetes-related monitoring, and discuss their best diabetes management.

RECENT FINDINGS

Although there remains an overall lack of studies in older adults with diabetes and chronic kidney disease, recent reports have highlighted their vulnerabilities. These individuals face an increased risk of cognitive impairment and dementia, frailty, dysglycemia, polypharmacy, declining kidney function, and acute kidney injury. Their diabetes management should focus upon safer antihyperglycemic medications, close monitoring, and care individualization. Older adults with diabetes and chronic kidney disease are a complex population who requires careful diabetes management and monitoring. Research efforts might focus on improving the care and outcomes of these patients.

Differences in Kidney Function Estimates Based on Creatinine and/or Cystatin C in Non-Traumatic Amputation Patients and Their Impact on Drug Prescribing

Accurate kidney function estimates are necessary when prescribing renally-eliminated medications. Our objectives were to investigate how amputation affects estimated glomerular filtration rate (eGFR) and to determine if dosing recommendations differ among different eGFR equations. In a cohort study of non-traumatic amputation patients, eGFR based on creatinine and/or cystatin C were measured before and after amputation. Prescribed, renally-eliminated medications were compared with dosing guidelines in Renbase^®. Data from 38 patients with a median age of 75 years were analyzed. The median (range) eGFR was 65 (15⁻103), 38 (13⁻79), and 48 (13⁻86) mL/min/1.73 m² before amputation and 80 (22⁻107), 51 (13⁻95), and 62 (16⁻100) mL/min/1.73 m² after amputation for eGFR_Creatinine, eGFR_CystatinC, and eGFR_Combined, respectively (p < 0.01). From before to after amputation, eGFR increased on average by 8.5, 6.1, and 7.4 mL/min/1.73 m² for eGFR_Creatinine, eGFR_CystatinC, and eGFR_Combined (all p < 0.01), respectively. At least one renally-eliminated medication was prescribed at a higher dose than recommended in 37.8% of patients using eGFR_CystatinC, 17.6% using eGFR_Combined and 10.8% using eGFR_Creatinine. In conclusion, amputation affects eGFR regardless of the eGFR equations. The differences among equations would impact prescribing of renally-eliminated medications, particularly when switching from creatinine to cystatin C.