EQUAL study

In elderly patients >=65 years with end-stage renal disease (ESRD) dialysis is
usually started at an estimated glomerular filtration rate (eGFR) (measure for
renal function) of 5 to 15 ml/min/1.73m2. Over the past decade, there has been
a trend to start dialysis at higher levels of eGFR to make a so-called *healthy
start*.

From the perspective of patient survival and quality of life, the best timing
of starting dialysis is unknown. Furthermore, the effect of dialysis start with
a high renal function versus low renal function and dialysis start with high
number of symptoms and signs and low number of symptoms and signs on survival
and quality of life in elderly ESRD patients is unknown. There is increasing
evidence that in some countries a substantial number of elderly patients wish
to postpone dialysis (or prefer not to start dialysis). Dialysis might indeed
be safely postponed or even not started in elderly ESRD patients with adequate
prescription of relevant medication and diet. For some patient groups the
burden of dialysis may be bigger than the benefit. Moreover, there is
considerable doubt whether especially eGFR, but also other serum
creatinine-based measures of renal function, can be used in the decision to
start dialysis because of their inaccuracy and imprecision to reflect residual
renal function in this stage of the disease. There is, however, no agreement on
a valid method to measure renal function in advanced chronic kidney disease
(CKD) to decide when to start dialysis. Furthermore, it is not known how signs
and symptoms of kidney disease (uremic signs and symptoms) develop during the
progression of CKD towards the start of dialysis and how these uremic signs and
symptoms could be used in decision making for the timing of starting dialysis.
In addition, insight in the decision making process regarding ESRD care,
involving both nephrologists and patients, is lacking.

The aim of our study is to compare outcomes between start of dialysis with
higher renal function versus lower renal function and start of dialysis with a
few signs and symptoms versus many signs and symptoms, to determine a valid
method to measure renal function in advanced CKD in the perspective of starting
dialysis, to provide insight in the development of uremic symptoms in elderly
ESRD patients, to develop a uremic algorithm (decision tree, score) to be used
for decision making on when to start dialysis, and to provide insight in the
decision making process regarding ESRD care. To that end, a prospective cohort
study will be performed in elderly patients with CKD (eGFR <= 20 ml/min/1.73m2)
progressing towards ESRD in four European countries. In total, 3000 patients
(500 from the Netherlands) will be included and followed until death or for
maximum four years.

Prospective, observational, multi-center, international follow-up study with a
maximum follow-up of 4 years.

The patients will be followed for a period of 4 years in the normal treatment
of their kidney disease. For study purposes, on every normal follow-up visit,
there will blood drawn, also the patient's nutritional status will be assessed
with the help of the SGA(subjective global assessment). De study visits will be
planned alongside normal follow-up visits as much as possible, so that the
patients don't need to come to the hospital separately for study purposes.
After every visit patients will be asked to fill in a questionnaire at home and
send this back to the researchers via mail. Patients will be followed for 4
years which means that a patient can have a maximum of 13 study visits.
Furthermore, a tracer study with iohexol(omnipaque) will be performed in a
small portion of the patients. This is done in order to measure a very accurate
kidney function. The iohexol can theoretically cause an allergic reaction, but
since the dosage that will be used in this study is extremely low the risks for
an allergic reaction are negligible. Furthermore, there is 15 years experience
in Sweden with the clinical usage of iohexol to determine a very precise kidney
function and there are no reporterd adverse
events(http://www.ifcc.org/ifccfiles/docs/130201005.pdf ).
The total time burden for patients varies from 1 to 15 hours over the course of
4 years.