Correspondence *Birmingham Heartlands Hospital, Bordesley Green East, Birmingham B9 5SS, UK

Email indranil.dasgupta@heartofengland.nhs.uk

Original article

Murtagh FEM et al. (2007) Dialysis or not? A comparative survival study of patients over 75 years with chronic kidney disease stage 5. Nephrol Dial Transplant 22: 1955–1962   PubMed

Synopsis

Background

Few data are available on the factors that influence the decision of whether or not to start dialysis, which can be particularly difficult in older patients.

Objectives

To compare survival rates in elderly patients with stage 5 chronic kidney disease (CKD) managed with dialysis or conservative treatment, and to pinpoint variables associated with survival in this population.

Design and intervention

This study was a retrospective review of data from four UK renal units. Patients aged >75 years who received dedicated multidisciplinary predialysis care between 1 September 2003 and 31 August 2004 were included. Multidisciplinary care is indicated for patients who are anticipated to need dialysis within 18 months, excluding those who have presented late with CKD or who have experienced a sudden unexpected decline in renal function. Exclusion criteria for this analysis were glomerular filtration rate (GFR) <15 ml/min (as estimated by the Modification of Diet in Renal Disease equation) upon initial presentation to the nephrologist, and incurable solid organ cancer. Follow-up data to 30 June 2005 were analyzed, according to the intention to treat principle.

Outcome measure

The primary outcome measure was survival from the time at which an estimated GFR of <15 ml/min was first recorded.

Results

A total of 129 patients were eligible for inclusion, of whom 52 elected to undergo dialysis and 77 chose conservative treatment. Gender, ethnicity, cause of CKD and comorbidity score were not significantly different between the dialysis and conservative management groups, but the latter group was older (median age 83.0 years vs 79.6 years; P <0.001). Patients who chose dialysis survived for a median of 588 days (range 67–2,528 days) and those who opted for conservative treatment survived for a median of 540 days (range 4–2,193 days). Survival at 1 year was 84% in patients who selected dialysis and 68% in patients who elected to be managed conservatively; corresponding 2-year rates were 76% and 47%. Kaplan–Meier analysis confirmed that survival was better in patients who opted for dialysis than in those who chose conservative treatment (logrank statistic 13.63; P <0.001), but this was not the case in patients who had a 'high' Davies comorbidity score (n = 24; logrank statistic <0.001; P = 0.98). Choice of dialysis as the treatment modality was associated with a 2.9-fold greater chance of survival (95% CI 1.6–5.5; P = 0.001) and presence of ischemic heart disease was associated with a 1.81-fold reduction in the chance of survival (95% CI 1.09–3.03; P = 0.023) according to Cox regression analysis. Kaplan–Meier survival curves revealed that choosing dialysis over conservative treatment offered no significant survival advantage in patients with ischemic heart disease (n = 47; logrank statistic 1.46; P = 0.27).

Conclusion

Choosing dialysis rather than conservative management is associated with better survival in patients aged >75 years with advanced CKD, but not in those with high comorbidity scores (particularly not those with ischemic heart disease).

Commentary

With the increasing longevity of the general population and improvements in the treatment of cardiovascular disease and cancer, more elderly patients are reaching end-stage renal disease (ESRD).¹ Such patients and their nephrologists often find it difficult to decide whether long-term dialysis will be beneficial, especially when the patient has multiple comorbidities. Will dialysis prolong life? If so, will it be at the expense of quality of life?

Very few studies of the factors that affect outcomes in elderly patients on dialysis, which would help clinicians and patients make an informed decision, have been performed. Age and multiple comorbidities are, however, known to be predictors of mortality in elderly patients on dialysis.^{1, 2} Functional dependence, impaired intellectual status, diabetes, low serum albumin, peripheral vascular disease and late referral for ESRD treatment are also poor prognostic factors in this setting^{2, 3, 4, 5} (although Murtagh et al. excluded patients who presented late with CKD).

The study by Murtagh et al. demonstrates that, although dialysis is generally associated with longer survival in patients aged over 75 years, those with multiple comorbidities—ischemic heart disease in particular—do not survive longer than those treated conservatively. Importantly, the study by Murtagh et al. was retrospective, observational, and of modest size (only 47 patients with ischemic heart disease were included). Quality of life was not assessed. Furthermore, the median age of conservatively managed patients was significantly higher than that of patients who received dialysis, which could have masked a survival advantage of conservative treatment.

A study conducted by our group supports the conclusion that elderly patients with multiple comorbidities could have little to gain from dialysis.⁶ We analyzed the outcomes of 38 consecutive patients from our multidisciplinary predialysis clinic who were aged over 75 years and had multiple comorbidities. The 19 patients who chose conservative treatment did not differ from the 19 who started dialysis in terms of age, gender, diabetes status or level of comorbidity. The dialysis group had more hospital admissions (14 vs 5; P = 0.008), episodes of infection (8 vs 0; P = 0.003) and deaths (7 vs 2; P = 0.12) than did the conservative treatment group during 1 year of follow-up, although the last difference was not significant.

Further support for a conservative approach to starting dialysis in the elderly comes from a randomized controlled study that compared a very-low-protein diet with dialysis in 112 nondiabetic patients over 70 years old who had a GFR of 5–7 ml/min.⁷ Survival was no different between the groups, and the numbers of hospitalizations and days spent in hospital were significantly lower in the very-low-protein diet group than in the dialysis group. In total, 71% of patients on the very-low-protein diet started dialysis, at a median of 9.8 months (range 6–20 months), and 18% died while still on the diet; 11% remained on the diet at 16.6 months (range 14.7–41.8 months).

The Murtagh study adds to the limited evidence that is currently available to inform discussions between elderly patients, their carers and their physicians about the risks and benefits of dialysis. When renal failure is just one of many conditions affecting an elderly patient, renal replacement therapy might merely add to the burden of illness without increasing the length of remaining life.

Acknowledgments

The synopsis was written by Chloë Harman, Associate Editor, Nature Clinical Practice.

References

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Subject areas under which this article appears: Dialysis (hemodialysis, peritoneal dialysis, continuous renal replacement)