Renal Registry

Statistical Publication Notice

30 November 2010

Scottish Renal Registry Report 2009

Introduction

This sixth report from the Scottish Renal Registry (SRR) follows the previous outline and presents information about the causes, incidence, prevalence, distribution, methods of treatment, quality of treatment and outcome of patients receiving renal replacement therapy (RRT) for established renal failure (ERF) between 1960 and 31 December 2009. There is no information in this report about patients with acute renal failure (ARF) or those with chronic renal failure (CRF) before RRT is
required.

Detailed information about the SRR computer hardware, software, analytic tools,  office, staff, steering group, projects, data quality assurance, publications, security and confidentiality and details of how data are provided to external bodies are published on the SRR website.

Key Points

The incidence of new patients starting renal replacement therapy (RRT) for  established renal failure (ERF) each year has fluctuated over the past 10 years between 101 per million of the population in 2001, up to 111 in 2007. 104 patients per million population started RRT for established renal failure (ERF) in 2009.

4278 patients were receiving RRT for ERF on 31 December 2009. Of these, 49% of patients had a functioning kidney transplant, 44% were being treated with haemodialysis (HD) and 7% with peritoneal dialysis (PD). In contrast to the number of new patients starting RRT, the number of prevalent patients continues to rise annually.

209 patients received a kidney transplant in Scotland in 2009. 27% of kidney transplants performed between 2005 and 2009 were from live kidney donors. Kidney transplants performed in 2008 had a 93% 1 year kidney transplant survival and a 99% 1 year patient survival.

The life expectancy of patients receiving RRT is shorter than that of the general population. The survival of patients is influenced by their age at the time of starting RRT and also by their primary renal diagnosis (PRD). The median survival for a patient aged 45 to 64 years at the start of RRT with glomerulonephritis is 7.7 years. The median survival of a patient in the same age group with a PRD of diabetic nephropathy is 2.9 years. In contrast: the life expectancy of a male from the general population aged 55 years is 24.2 years. There is a trend of significant improvement in two year survival for patients starting RRT over the past 10 years.

Interpretation

Data pertaining to events prior to 1991 were incorporated retrospectively from the ERA EDTA  (European Renal Association and European Dialysis Transplant Association) registry. Data since 1991 have been entered electronically or manually from each of the renal units in Scotland. The earliest date a patient is recorded as starting renal replacement therapy (RRT) for  stablished renal failure (ERF) in Scotland is October 1960.

Incident patients
All patients starting RRT in Scotland are included in incidence figures, total 12970 patients. Of these, 137 had a (pre-emptive) kidney transplant as their first mode of RRT.
Excluded are those patients who have moved into Scotland already receiving RRT, either dialysis or with a functioning kidney transplant. The SRR does not routinely record the incidence of RRT for acute kidney injury (AKI).

Prevalent patients
Included in the prevalence section are patients whose treatment started on or before 31 December 2009 and who were still alive and resident in Scotland on that date. Five patients who had stopped RRT with no expectation of recovery, but were still alive on 31 December 2009 are also included.
Excluded are those who have moved outside of Scotland are lost to follow-up and those who have recovered renal function (within 90 days of starting RRT).

Survival analyses
The start date for the survival analyses is the first date of RRT. The end date is the date of death or the censor date of 31 December 2009. Also censored are those patients moving outside of Scotland and those lost to follow-up, both groups are censored on the date that the SRR received the last laboratory or treatment information about them. Patients who were lost to follow up or moved, but later came back to have RRT in Scotland had their entire period of RRT included for survival analysis.

Patients recovering native renal function
Patients who recovered renal function within 90 days of starting RRT and have not yet needed to restart RRT were excluded from the analyses.
Patients who recovered, but required more than 90 days RRT remain in the data set.
If a patient had to restart RRT within a 90 day period after initial recovery, the date of first starting RRT is considered as the beginning of the first period of treatment. If however the initial period of  treatment is less than 90 days, and the period of recovery greater than 90 days, the date of first RRT is recorded as that on which they restart treatment that lasts for at least 90 days.
Where a patient started RRT and then died before the 91st day or if they recovered before the 91st day but then died within the next 90 days, their nephrologist was asked to decide whether they had been treated for acute or established renal failure. Only those with ERF are included in this report.

Detailed Findings

13308 patients have been registered with the SRR from its inception in 1991 until 31 December 2009 when the data for this report were collated.

On 31 December 2009, there were 10 adult and one paediatric renal units in Scotland with 21 satellite dialysis units between them. All units contribute fully to the Scottish Renal Registry (SRR) and all patients receiving RRT for ERF are registered.

The incidence of new patients starting RRT ranged from 51 per million population (pmp) aged 20-44 years, up to 321 pmp in those aged ≥75 years. 24% of patients starting RRT in 2009 had ERF due to diabetic nephropathy.

Several measures of quality of care are reported by the SRR thus contributing to improving standards across Scotland.

The incidence of peritoneal dailysis related peritonitis across Scotland was 20.3 months between episodes in 2009. The UK Renal Association (UKRA) standard is

78% of patients treated by heamodialisys  had a blood haemoglobin (Hb) concentration ≥10 g/dL in June 2009. While only 4 of the 10 adult renal units in 2009, reached the NHS Quality Improvement Scotland standard (which is that ≥85% of such patients should achieve this level), there was very little variation between units in observed median haemoglobin levels. 52% of patients had Hb in the range 10.5-12.5 g/dLwhich is the UKRA recommended range.

86% of patients treated by haemodialysis achieved a urea reduction ratio (URR) of ≥65% which is the UKRA standard. URR is a measurement of adequacy and therefore quality of haemodilaysis..

Vascular access describes the connection between a patient’s circulation and a haemodialysis machine. In June 2009, 75% of HD patients had an arteriovenous fistula which is regarded as the best form of access. 25% were using central venous catheters which are prone to infection.

The overall use of arteriovenous (AV) access for HD patients has not improved over the past 4 years; however several individual renal units have greatly improved their usage of AV access between 2007 and 2009. 69% of patients treated by HD had a pre-HD phosphate of

The mean body mass index (BMI) of haemodialysis patients across Scotland in June 2009 was 27 kg/m2 (overweight).

The mean pre-HD blood pressure has fallen over the past 4 consecutive years to 137/70 mm/Hg in June 2009.

The time spent travelling to, waiting for and travelling home from dialysis significantly impact upon patients’ experience and is an aspect of dialysis care that is very important to patients, who usually receive such treatment three times each week. In a survey conducted in September 2008 10.7% of patients waited more than 30 minutes from their allotted time to be picked up from home, 46% travelled for more than 30 minutes to reach their dialysis unit, 21% waited for more than 30 minutes for their treatment to start and 22% waited more than 30 minutes to be picked up at the end of their treatment.

The choice of initial RRT modality does not appear to influence patient survival when adjustment is made for co-morbidity.

Main Contacts

Diana Beard
Project Manager (NAT)
0131 242 3862
diana.beard@nhs.net

Jan Kerssens
Senior Information Analyst
0131 275 6842
j.kerssens@nhs.net

Jennifer Boyd
Senior Information Analyst
0131 275 6167
Jennifer.Boyd@nhs.net

Glossary

Body mass index (BMI): a measure of body weight based on a person's weight and height. Though it does not actually measure the percentage of body fat, it is used to estimate a healthy body weight based on a person's height, assuming an average body composition.
Co-morbidity: The presence of one or more disorders (or diseases) in addition to established renal failure (ERF).
Central venous catheter: See venous catheters.
Diabetic nephropathy: Kidney disease that has developed as a result of diabetes. One of the main groups of primary renal diagnosis (PRD).
Established renal failure (ERF): Established renal failure is loss of kidney function to a point where this becomes life threatening.
Graft survival relates to the success of the kidney transplant. Graft being a general name for any organ or tissue transplanted.
Glomerulonephritis: The inflammation of the filtering units in the kidneys which alters their normal functions. One of the main groups of primary renal diagnosis (PRD).
Haemodialysis (HD): A treatment for kidney failure in which blood is purified by passing it across an artificial membrane outside the body to remove waste products.
Haemoglobin concentration: Haemoglobin in the blood is what transports oxygen from the lungs to the rest of the body.
Haemoglobin concentration is the amount of haemoglobin in the blood, usually measured in gram per deciliter (g/dL).
Peritoneal dialysis (PD): A treatment for kidney failure in which dialysis fluid is introduced into the space in the abdomen that contains the intestines and other internal organs, to remove wastes and water from the blood via the peritoneum, the thin membrane that surrounds the outside of the organs in the abdomen.
Peritonitis: Inflammation of the peritoneum, the thin membrane that surrounds the outside of the organs in the abdomen. This is often a complication of peritoneal dialysis.
Pre-HD or pre-dialysis measurements: At the start of haemodialysis some measurements are taken to monitor the safety of the procedure. Included are blood pressure and blood concentration of haemoglobin, and minerals (calcium, potassium and phosphate).
Pre-emptive kidney transplant: Transplant in a patient just before dialysis is needed.
Primary renal diagnosis (PRD): Diagnosis of the primary disease that caused established renal failure. The PRD is often coded according to in internal classification of renal diagnosis (ERA EDTA) which also provides groupings of diagnoses and causes of death. Diagnoses are grouped into five categories: glomerulonephritis, interstitial nephritis, diabetic nephropathy, multi-system disorders and unknown diagnosis.
Renal replacement therapy (RRT): Treatment to replace the function of the kidneys in a person whose kidneys no longer work, eitherdialysis or kidney transplant.
Satellite dialysis units: Units scattered throughout Scotland, where patients can receive haemodialysis locally. There are 21 satellites (anno 2009) affiliated with 11 Renal units.
United Kingdom Renal Association (UKRA) is the professional body for United Kingdom nephrologists (renal physicians, or kidney doctors) and renal scientists in the UK.
UKRA standard: a guideline for the management of patients with kidney disease in the UK developed by the UKRA.
Urea: A waste product which is formed when the body breaks down protein.
Urea reduction ratio (URR): A measurement of adequacy of haemodialysis.
Vascular access: Entry to the blood stream for haemodialysis.
Venous catheters: A  tube inserted into a large vein usually in the neck, chest, or leg near the groin. It has two lumens to allow a two-way flow of blood for haemodialysis.

Pre-Release Access

Under terms of the "Pre-Release Access to Official Statistics (Scotland) Order 2008", ISD are obliged to publish information on those receiving Pre-Release Access ("Pre-Release Access" refers to statistics in their final form prior to publication). The standard maximum Pre-Release Access is five working days. Shown below are details of those receiving standard Pre-Release Access and, separately, those receiving extended Pre-Release Access.

Standard Pre-Release Access

Scottish Government Health Department (Analytical Services Division)
NHS Board Chief Executives
NHS Board Communication leads
Chief Executives of all participating Health Boards and Hospitals
Medical Directors of all participating Health Boards
Medical or Associate Medical Directors of all participating hospitals
Lead Audit Consultants in participating units.
SRR Steering group

Extended Pre-Release Access

Scottish Government Health Department (Analytical Services Division)
This extended Pre-Release Access is given to a small number of named individuals in the Scottish Government Health Department (Analytical Services Division). This Pre-Release Access is for the sole purpose of enabling that department to gain an understanding of the statistics prior to briefing others in Scottish Government (during the period of standard Pre-Release Access).

History of this Publication

Last Published: November 2009
Next Due: November 2011
Data Available Since: First report containing 1960-1998 data published in 1999

Main contact: Diana Beard