Epidemiology and demographic aspects of treated end-stage renal disease in the elderly

Safety of a 24-h-or-less break-in period in elderly patients undergoing urgent-start peritoneal dialysis: A multicenter retrospective cohort study

BACKGROUND

Several elderly patients with end-stage renal disease (ESRD) had to undergo urgent-start peritoneal dialysis (USPD). This study aimed to determine whether break-in period (BI) within 24 h was feasible in elderly patients undergoing USPD.

METHODS

Patients with ESRD who underwent PD at five hospitals were screened. Patients were divided into the BI ≤24 h and >24 h groups. Complications were compared between the two groups. Multivariate logistic regression model was used to determine whether BI ≤24 h was associated with complications.

RESULTS

A total of 175 elderly patients were included: BI ≤24 h group, 78; and BI >24 h group, 97. There was no significant difference in the rate of complications between the two groups (all p > 0.05). Furthermore, BI ≤24 h was not an independent risk factor for complications (all p > 0.05).

CONCLUSIONS

Starting PD within 24 h after PD catheter insertion was feasible in elderly ESRD patients.

Survival of Older Patients With Advanced CKD Managed Without Dialysis: A Narrative Review

Shared decision making is important when deciding the appropriateness of dialysis for any individual, particularly for older patients with advanced chronic kidney disease who have high mortality. Emerging evidence suggests that patients with advanced age, high comorbidity burden, and poor functional status may not have any survival advantage on dialysis compared with those on a conservative kidney management pathway. The purpose of this narrative review is to summarize the existing studies on the survival of older patients with stage 4 or 5 chronic kidney disease managed with or without dialysis and to evaluate the factors that may influence mortality in an effort to assist clinicians with shared decision making. Median survival estimates of conservative kidney management patients are widely varied, ranging from 1-45 months with 1-year survival rates of 29%-82%, making it challenging to provide consistent advice to patients. In existing cohort studies, the selected group of patients on dialysis generally survives longer than the conservative kidney management cohort. However, in patients with advanced age (aged ≥80 years), high comorbidity burden, and poor functional status, the survival benefit conferred by dialysis is no longer present. There is an overall paucity of data, and the variability in outcomes reflect the heterogeneity of the existing studies; further prospective studies are urgently needed.

Factors Associated With Withdrawal From Dialysis Therapy in Incident Hemodialysis Patients Aged 80 Years or Older

OBJECTIVES

Among kidney disease patients ≥80 years progressing to end-stage renal disease, there is growing interest in conservative nondialytic management approaches. However, among those who have initiated hemodialysis, little is known about the impact of withdrawal from dialysis on mortality, nor the patient characteristics associated with withdrawal from dialysis.

STUDY DESIGN

Historical cohort study.

SETTING AND PARTICIPANTS

We examined 133,162 incident hemodialysis patients receiving care within a large national dialysis organization from 2007 to 2011.

MEASURES

We identified patients who withdrew from dialysis, either as a listed cause of death or censor reason. Incidence rates and subdistribution hazard ratios for withdrawal from dialysis as well as 4 other censoring reasons were examined across age groups. In addition, demographic and clinical characteristics associated with withdrawal from dialysis therapy among patients ≥80 years old was assessed using logistic regression analysis.

RESULTS

Among 17,296 patients aged ≥80 years, 10% of patients withdrew from dialysis. Duration from the last hemodialysis treatment to death was 10 [interquartile range 6-16] days in patients with available data. Withdrawal from dialysis was the second and third most common cause of death among patients aged ≥80 years and <80 years, respectively. Among patients ≥80 years, minorities were much less likely than non-Hispanic whites to stop dialysis. Other factors associated with higher odds of dialysis withdrawal included having a central venous catheter compared to an arteriovenous fistula at dialysis start, dementia, living in mid-west regions, and less favorable markers associated with malnutrition-inflammation-cachexia syndrome such as higher white blood cell counts and lower body mass index, albumin, and normalized protein catabolic rate.

CONCLUSION/IMPLICATIONS

Among very-elderly incident hemodialysis patients, dialysis therapy withdrawal exhibits wide variations across age, race and ethnicity, regions, cognitive status, dialysis vascular access, and nutritional status. Further studies examining implications of withdrawal from dialysis in older patients are warranted.

Seasonal variation in hemodialysis initiation: A single-center retrospective analysis

The number of new dialysis patients has been increasing worldwide, particularly among elderly individuals. However, information on seasonal variation in hemodialysis initiation in recent decades is lacking, and the seasonal distribution of patients’ conditions immediately prior to starting dialysis remains unclear. Having this information could help in developing a modifiable approach to improving pre-dialysis care. We retrospectively investigated the records of 297 patients who initiated hemodialysis at Hiroshima Prefectural Hospital from January 1st, 2009 to December 31st, 2013. Seasonal differences were assessed by χ² or Kruskal-Wallis tests. Multiple comparison analysis was performed with the Steel test. The overall number of patients starting dialysis was greatest in winter (n = 85, 28.6%), followed by spring (n = 74, 24.9%), summer (n = 70, 23.6%), and autumn (n = 68, 22.9%), though the differences were not significant. However, there was a significant winter peak in dialysis initiation among patients aged ≥65 years, but not in those aged <65 years. Fluid overload assessed by clinicians was the most common uremic symptom among all patients, but a winter peak was only detected in patients aged ≥65 years. The body weight gain ratio showed a similar trend to fluid overload assessed by clinicians. Pulmonary edema was most pronounced in winter among patients aged ≥65 years compared with other seasons. The incidences of infection were modestly increased in summer and winter, but not statistically significant. Cardiac complications were similar in all seasons. This study demonstrated the existence of seasonal variation in dialysis initiation, with a winter peak among patients aged ≥65 years. The winter increment in dialysis initiation was mainly attributable to increased fluid overload. These findings suggest that elderly individuals should be monitored particularly closely during the winter.

Early dialysis initiation does not improve clinical outcomes in elderly end-stage renal disease patients: A multicenter prospective cohort study

Background

The optimal timing for initiating dialysis in end-stage renal disease (ESRD) is controversial, especially in the elderly.

Methods

665 patients ≥65 years old who began dialysis from August 2008 to February 2015 were prospectively enrolled in the Clinical Research Center for End-Stage Renal Disease cohort study. Participants were divided into 2 groups based on the median estimated glomerular filtration rate at the initiation of dialysis. Propensity score matching (PSM) was used to compare the overall survival rate, cardiovascular events, Kidney Disease Quality of Life Short Form 36 (KDQOL-36) results, Karnofsky performance scale values, Beck’s depression inventory values, and subjective global assessments.

Results

The mean patient age was 72.0 years, and 61.7% of the patients were male. Overall, the cumulative survival rates were lower in the early initiation group, although the difference was not significant after PSM. Additionally, the survival rates of the 2 groups did not differ after adjusting for age, sex, Charlson comorbidity index and hemoglobin, serum albumin, serum calcium and phosphorus levels. Although the early initiation group showed a lower physical component summary score on the KDQOL-36 3 months after dialysis, the difference in scores was not significant 12 months after dialysis. Furthermore, the difference was not significant after PSM. The Karnofsky performance scale, Beck’s depression inventory, and subjective global assessments were not significantly different 3 and 12 months after dialysis initiation.

Conclusions

The timing of dialysis initiation is not associated with clinical outcomes in elderly patients with ESRD.

Symptom Management in Patients with Stage 5 CKD Opting for Conservative Management

Chronic kidney disease (CKD) stages 3–5 now affects 8.5% of adults in the United Kingdom; with 4% of patients expected to reach stage 5 CKD. Increasing numbers of older patients are contributing to the growth of demand of kidney services. With the exception of transplantation, dialysis has been the main form of renal replacement therapy (RRT) for advanced CKD. This elderly population is usually too frail and has many other co-existing medical complaints or co morbidities to undergo transplantation. Dialysis is an invasive treatment, and some frail elderly patients can experience many dialysis related symptoms. An alternative option for these patients is to choose conservative management (CM) of their stage 5 CKD. These patients often have complex supportive and palliative care needs. The frequency, severity and distress caused by symptoms related to stage 5 CKD are often under recognized and under treated. There is a need for early identification and management of symptoms as they present in patients with stage 5 CKD being managed conservatively. Symptom assessment should be focused on anticipating, identifying and alleviating any symptoms. This needs to be incorporated into the regular practice of those managing CM patients.

Outcomes of predialysis nephrology care in elderly patients beginning to undergo dialysis

Background

The proportion of elderly patients beginning to undergo dialysis is increasing globally. Whether early referral (ER) of elderly patients is associated with favorable outcomes remains under debate. We investigated the influence of referral timing on the mortality of elderly patients.

Methods

We retrospectively assessed mortality in 820 patients aged ≥70 years with end-stage renal disease (ESRD) who initiated hemodialysis at a tertiary university hospital between 2000 and 2010. Mortality data was obtained from the time of dialysis initiation until December 2010. We assigned patients to one of two groups according to the time of their first encounters with nephrologists: ER (≥ 3 months) and late referral (LR; < 3 months).

Results

During a mean follow-up period of 25.1 months, the ER group showed a 24% reduced risk of long-term mortality relative to the LR group (HR = 0.760, P = 0.009). Rate of reduction in 90-day mortality for ER patients was 58% (HR = 0.422, P=0.012). However, the statistical significance of the difference in mortality rates between ER and LR group was not observed across age groups after 90 days. Old age, LR, central venous catheter, high white blood cell count and corrected Ca level, and lower levels of albumin, creatinine, hemoglobin, and sodium were significantly associated with increased risk of mortality.

Conclusions

Timely referral was also associated with reduced mortality in elderly ESRD patients who initiated hemodialysis. In particular, the initial 90-day mortality reduction in ER patients contributed to mortality differences during the follow-up period.

Spatial distribution of end-stage renal disease (ESRD) and social inequalities in mixed urban and rural areas: a study in the Bretagne administrative region of France

Background

Several studies have investigated the implication of biological and environmental factors on geographic variations of end-stage renal disease (ESRD) incidence at large area scales, but none of them assessed the implication of neighbourhood characteristics (healthcare supply, socio-economic level and urbanization degree) on spatial repartition of ESRD. We evaluated the spatial implications of adjustment for neighbourhood characteristics on the spatial distribution of ESRD incidence at the smallest geographic unit in France.

Methods

All adult patients living in Bretagne and beginning renal replacement therapy during the 2004–09 period were included. Their residential address was geocoded at the census block level. Each census block was characterized by socio-economic deprivation index, healthcare supply and rural/urban typology. Using a spatial scan statistic, we examined whether there were significant clusters of high risk of ESRD incidence.

Results

The ESRD incidence was non-randomly spatially distributed, with a cluster of high risk in the western Bretagne region (relative risk, RR = 1.28, P-value = 0.0003). Adjustment for sex, age and neighbourhood characteristics induced cluster shifts. After these adjustments, a significant cluster (P = 0.013) persisted.

Conclusions

Our spatial analysis of ESRD incidence at a fine scale, across a mixed rural/urban area, indicated that, beyond age and sex, neighbourhood characteristics explained a great part of spatial distribution of ESRD incidence. However, to better understand spatial variation of ESRD incidence, it would be necessary to research and adjust for other determinants of ESRD.

Survival of chronic hemodialysis patients over 80 years of age

BACKGROUND/AIM

The number of elderly patients with chronic kidney disease (CKD) stage 5 management with hemodialysis (HD) is steadily increasing. Therefore we analyzed the number of new CKD patients ≥80 years managed with HD and their survival through the study period. We aimed also, to identify which of several key variables might be independently associated with survival in this very elderly population of patients.

PATIENTS AND METHODS

This was a single-center, retrospective cohort study that took place during the period from January 1987 to September 2012. The study consisted of 78 (50 male and 28 women) very elderly patients (≥80 years of age); the mean age at which HD was initiated was 83.2±2.5 years. Survival and factors associated with mortality were studied. Survival was defined as the time from start of HD treatment to death (or end of study, if still alive).

RESULTS

In the period from 1987 to 2002, patients ≥80 years of age were only sporadically treated with HD, but since 2003, the number of new patients has been steadily increasing. The mean survival for our group of patients was 25.1±22.4 months (range 1-115 months). Furthermore, 30.8% patients survived <12 months, 29.5% patients survived 12-24 months, 30.8% patients survived 24-60 months, and 9% patients survived >60 months on HD treatment. Older patients were less likely to have diabetes, and primary renal disease did not influence survival. Patients with high C-reactive protein levels and poor nutritional status, as well as those who did not have pre-HD nephrology care and those that had a catheter as vascular access for HD had poor survival. In about half of our patients, the cause of death was cardiovascular disease.

CONCLUSION

Among patients who were ≥80 years of age at the start of HD treatment, those who received pre-HD nephrology care that followed a planned management pathway, those who had a good nutritional status, and those with an arteriovenous fistula as vascular access for HD at the time of HD initiation had a better survival.

Factors influencing patients with stage 5 chronic kidney disease to opt for conservative management: a practitioner research study

AIMS AND OBJECTIVES

This study explored decision-making experiences of patients with stage 5 chronic kidney disease when opting for conservative management of their renal failure.

BACKGROUND

Dialysis is an invasive treatment, and for some older patients, there is an associated treatment burden of dialysis-related symptoms. An alternative choice is conservative management, but little is known about those who make this decision and how they are supported through the process.

DESIGN

Qualitative practitioner research study.

METHOD

Data were generated from nine patients' naturally occurring clinic consultations with a renal clinical nurse specialist between May 2010 - July 2010. Interviews were transcribed verbatim and findings fed back at three multi-disciplinary meetings to check for relevance and resonance. Common themes were identified and codes applied.

RESULTS

Patients reported age and having to travel three times a week to hospital for dialysis as reasons not to opt for treatment. Others felt well without dialysis not wanting to upset the 'status quo' or to burden loved ones. Most felt equipped to make the decision following explanation and discussion with the clinical nurse specialist in the renal clinic.

CONCLUSIONS

Patients opting for conservative management give numerous reasons for this including old age, travel limitations, feeling well without dialysis and not wanting to be a burden, but appear content with their decision. One-to-one discussions with the clinical nurse specialist appear helpful during the decision-making process presenting an opportunity for advancing nursing roles in the chronic kidney disease service.

RELEVANCE TO CLINICAL PRACTICE

Understanding patients' reasons for refusing dialysis assists in supporting until death. There is an opportunity for developing nursing practice to meet the multi-faceted needs of this group.

Is maximum conservative management an equivalent treatment option to dialysis for elderly patients with significant comorbid disease?

BACKGROUND AND OBJECTIVES

There is ongoing growth of elderly populations with ESRD in Western Europe and North America. In our center, we offer an alternative care pathway of 'maximum conservative management' (MCM) to patients who elect not to start dialysis, often because of a heavy burden of comorbid illness and advanced age. The objective of our study was to compare clinical outcomes for patients who had ESRD and chose either MCM or renal replacement therapy (RRT).

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This is an observational study of a single-center cohort in the United Kingdom that evaluating 202 elderly (> or =70 yr) patients who had ESRD and had chosen either MCM (n = 29) or RRT (n = 173). We report survival, hospitalization rates, and location of death for this cohort. Survival was measured from a standardized 'threshold' estimated GFR of 10.8 ml/min per 1.73 m(2).

RESULTS

Median survival, including the first 90 d, was 37.8 mo (range 0 to 106 mo) for RRT patients and 13.9 mo (range 2 to 44) for MCM patients (P < 0.01). RRT patients had higher rates of hospitalization (0.069 [95% confidence interval (CI) 0.068 to 0.070]) versus 0.043 [95% CI 0.040 to 0.047] hospital days/patient-days survived) compared with MCM patients. MCM patients were significantly more likely to die at home or in a hospice (odds ratio 4.15; 95% CI 1.67 to 10.25). A survey of the literature describing elderly ESRD outcomes is also presented.

CONCLUSIONS

Dialysis prolongs survival for elderly patients who have ESRD with significant comorbidity by approximately 2 yr; however, patients who choose MCM can survive a substantial length of time, achieving similar numbers of hospital-free days to patients who choose hemodialysis.

The epidemic challenge of chronic kidney disease in older patients

Since the introduction of estimated glomerular filtration rate (GFR), the number of patients with chronic kidney disease (CKD) has considerably increased. This is particularly true for elderly patients as the majority have a low GFR. Chronic kidney disease has a significant impact on a patient's outcome. We have reviewed important aspects of CKD in older patients, with emphasis on diagnosis and management, as well as explored decision-making regarding specialist-care referral and renal replacement therapy.

Clinical outcomes after failed renal transplantation-does dialysis modality matter?

Patients returning to dialysis after graft loss (DAGL) are an increasing segment of the end-stage renal disease (ESRD) population. It is unclear whether patients with previous graft loss have equivalent or reduced survival from the time of restarting dialysis when compared with ESRD patients initiating dialysis for the first time. Moreover, the impact of dialysis modality on the survival of patients returning to DAGL is not known. Studies of patients with transplant graft failure returning to hemodialysis (HD) have suggested decreased survival when compared with transplant-naïve dialysis patients, yet some studies of patients with graft failure returning to peritoneal dialysis (PD) have demonstrated equivalent survival. Based on these data, it is unclear whether survival differences may exist between the dialysis modalities, and if they do, whether they can be attributed to either differences in patient characteristics or to factors related to the dialysis modalities. For patients starting back onto dialysis, in whom preservation of residual renal function is important, it is also unclear how immunosuppression reduction or transplant nephrectomy may affect survival. In this review, we will summarize the available literature on survival rates of patients returning to DAGL; compare and contrast survival after initiation of HD and PD and discuss what is known about the impact of transplant nephrectomy and the different approaches to immunosuppression reduction. Practical considerations will be discussed with a specific emphasis on patients treated by PD.

The influence of age on changes in health-related quality of life over three years in a cohort undergoing hemodialysis

OBJECTIVES

To assess the extent to which persons aged 70 and older undergoing hemodialysis (HD) had greater changes in health-related quality of life (HRQOL) over 3 years than younger patients undergoing HD.

DESIGN

Longitudinal.

SETTING

The Hemodialysis Study (HEMO Study) was a randomized, clinical trial of the effects of HD dose and membrane flux on mortality and morbidity in patients undergoing chronic dialysis.

PARTICIPANTS

Secondary analysis of the HEMO Study.

MEASUREMENTS

Participants completed the Index of Well-Being (IWB) and the Kidney Disease Quality of Life-Long Form (KDQOL-LF), which also includes the Medical Outcomes Study 36-item Short Form Questionnaire (SF-36) annually. Changes in subjects those aged 70 and older were compared with changes in subjects aged 55 to 69 and 18 to 54.

RESULTS

At baseline, 1,813 (98%) of HEMO participants completed HRQOL surveys. Their mean age was 58, 56% were female, 64% were black, and mean duration of dialysis was 3.8 years. In subjects with HRQOL data at the first three annual assessments, there were no substantial mean declines in the SF-36 Physical or Mental Component Summary scales over 3 years. In models incorporating effects of attrition, the differences in average change over 3 years between patients undergoing HD aged 70 and older and the younger cohorts were small in magnitude. There were high rates of adverse HRQOL events in all age groups and significantly higher composite event rates of death or clinically significant decline in HRQOL over 3 years was found in subjects aged 70 and older.

CONCLUSION

Although HRQOL was impaired in the population undergoing HD, HRQOL scores at baseline reflect a better-preserved multidimensional quality of life in respondents in the HEMO Study aged 70 and older than in younger patients undergoing HD. There was no substantial relationship between age and average decline in HRQOL score over 3 years in participants in the HEMO Study.

How to manage elderly patients with chronic renal failure: conservative management versus dialysis

Over the past decade the number of elderly patients reaching end-stage renal disease has more than doubled. A fundamental medical decision that nephrologists commonly have to make is when to start dialytic treatment in elderly patients. Evidence is needed to inform about decision-making for or against dialysis, in particular in those patients frequently affected by multiple comorbidities for which dialysis may not increase survival. In fact, this decision affects quality of life, incurs significant financial costs, and finally mandates use of precious dialysis resources. The negative consequence of initiating dialysis in this group of patients can be deleterious as elderly people are sensitive to lifestyle changes. Furthermore, among dialysis patients, the elderly suffer the highest overall hospitalization and complication rates and most truncated life expectancy on dialysis of any age group. Studies of the factors that affect outcomes in elderly patients on dialysis, or the possibility in postponing in a safe way the start of a dialytic treatment, were lacking until recent years. Recently in the literature, papers have been published that address these questions: the effects of dialysis on morbidity and mortality in elderly patients and the use of a supplemented very low protein diet (sVLPD) in postponing the start of dialysis in elderly. The first study demonstrated that, although dialysis is generally associated with longer survival in patients aged >75 years, those with multiple comorbidities, ischemic heart disease in particular, do not survive longer than those treated conservatively. The second one is a randomized controlled study that compared a sVLPD with dialysis in 112 non-diabetic patients aged >70 years. Survival was not different between the two groups and the number of hospitalizations and days spent in hospital were significantly lower in those on a sVLPD. These studies add to the limited evidence that is currently available to inform elderly patients, their carers and their physicians about the risk and the benefit of dialysis.

Changes in survival among elderly patients initiating dialysis from 1990 to 1999

BACKGROUND

Over the past decade, there has been a steep rise in the number of people with complex medical problems who require dialysis. We sought to determine the life expectancy of elderly patients after starting dialysis and to identify changes in survival rates over time.

METHODS

All patients aged 65 years or older who began dialysis in Canada between 1990 and 1999 were identified from the Canadian Organ Replacement Register. We used Cox proportional hazards models to examine the effect that the period during which dialysis was initiated (era 1, 1990-1994; era 2, 1995-1999) had on patient survival, after adjusting for diabetes, sex and comorbidity. Patients were followed from initiation of dialysis until death, transplantation, loss to follow-up or study end (Dec. 31, 2004).

RESULTS

A total of 14,512 patients aged 65 years or older started dialysis between 1990 and 1999. The proportion of these patients who were 75 years or older at the start of dialysis increased from 32.7% in era 1 (1990-1994) to 40.0% in era 2 (1995-1999). Despite increased comorbidity over the 2 study periods, the unadjusted 1-, 3- and 5-year survival rates among patients aged 65-74 years at dialysis initiation rose from 74.4%, 44.9% and 25.8% in era 1 to 78.1%, 51.5% and 33.5% in era 2. The respective survival rates among those aged 75 or more at dialysis initiation increased from 67.2%, 32.3% and 14.2% in era 1 to 69.0%, 36.7% and 20.3% in era 2. This survival advantage persisted after adjustment for diabetes, sex and comorbidity in both age groups (65-74 years: hazard ratio [HR] 0.76, 95% confidence interval [CI] 0.72- 0.81; 75 years or more: HR 0.86, 95% CI 0.80-0.92).

INTERPRETATION

Survival after dialysis initiation among elderly patients has improved from 1990 to 1999, despite an increasing burden of comorbidity. Physicians may find these data useful when discussing prognosis with elderly patients who are initiating dialysis.

Patient and technique survival on peritoneal dialysis in patients with failed renal allograft: a case-control study

Failed renal allograft is becoming one of the most frequent causes of dialysis initiation in countries with developed transplant programs. The majority of patients initiate hemodialysis (HD) as their next renal replacement modality and concerns about the success of peritoneal dialysis (PD) in this patient population has been expressed. We evaluated patient and technique outcome in a cohort of 494 patients in the United States who initiated PD after a failed renal allograft in the years 2000-2003, and compared the outcomes to those of two case-matched groups: patients new to dialysis or patients transferred from HD who started PD during the same period. Patients starting PD after a failed allograft had patient survival and technique survival similar to case-matched controls. Transplantation was lower in patients with failed allograft than controls. The high success of PD in patients with failed allograft suggests that it is beneficial to utilize this modality more frequently in this patient group than current practice.

The construct and concurrent validity of the EQ-5D in a renal transplant population

OBJECTIVES

Cost-utility analysis in renal transplant populations requires the use of a generic instrument for health status measurement that generates a single value for health. Such instruments should be widely applicable in diverse patient populations and their validity should be established. The aim of this study was to explore the validity of the EQ-5D in renal transplant patients.

METHODS

The EQ-5D was compared with the Short-Form 36 Health Survey (SF-36), the modified transplant symptom occurrence and symptom distress (MTSOSD) scale, the short-form Beck Depression Inventory (BDI), and the State Trait Anxiety Inventory (STAI). Construct and concurrent validity were tested on cross-sectional data of 350 patients.

RESULTS

Construct validity is good for some but not all EQ-5D dimensions, and the EQ-5D discriminates well among groups of patients with different health states according to the SF-36, MTSOSD scale, BDI, and STAI and between patients and the general public. Concurrent validity is good, as shown by the correspondence of EQ-5D and SF-36 results.

CONCLUSION

It is concluded that the EQ-5D is a valid instrument for the measurement of health status in renal transplant patients.

Estimating the prevalence of renal insufficiency in seniors requiring long-term care

BACKGROUND

Renal function declines with age, but little is known about the extent of renal insufficiency among the institutionalized elderly. The objective of this study was to estimate the prevalence of low glomerular filtration rate (GFR) in a large sample of elderly adults living in long-term care facilities, and to compare two commonly used methods for estimating GFR.

METHODS

A total of 9931 residents aged 65 years and older participated in a retrospective cross-sectional study of 87 long-term care facilities in Ontario. GFR was estimated by the Cockcroft-Gault and Modification of Diet in Renal Disease Study (MDRD) equations. The prevalence of low GFR, using the Cockcroft-Gault equation (<30 mL/min), was compared with the MDRD equation (<30 mL/min/1.73 m2).

RESULTS

A total of 17.0% (95% CI 15.6 to 18.5) of men and 14.4% (95% CI 13.6 to 15.3) of women had a serum creatinine concentration above the laboratory reported upper reference limit of normal. The prevalence of both elevated serum creatinine and low GFR were observed to increase with age (P < 0.0001). The Cockcroft-Gault equation produced a consistently lower estimate of GFR than did the MDRD equation, a discrepancy most pronounced in the oldest residents. Among all men, a low GFR was more prevalent using the Cockcroft-Gault (10.3%, 95% CI 9.2 to 11.5) than MDRD (3.5%, 95% CI 2.8 to 4.2) equation, with a similar difference also seen in women (23.3%, 95% CI 22.4 to 24.3 versus 4.0%, 95% CI 3.6 to 4.5, respectively). Of all residents whose Cockcroft-Gault estimated GFR was under 30 mL/min, 14.7% (95% CI 13.2 to 16.3) were found to have GFR greater than 60 mL/min/1.73 m2 according to the MDRD equation.

CONCLUSION

Age-associated renal impairment is common among elderly long-term care residents, but there exists a clear discrepancy between the Cockcroft-Gault and MDRD equations in predicting GFR. Consideration should be given to medication dose adjustment, based on a practical estimate of GFR. However clarification is needed about which method, if either, is most valid among the frail elderly. Complex patient and societal issues surrounding advanced care directives, treatments associated with renal insufficiency, and, if and when to initiate dialysis, require further attention.