Risk factors for unplanned and crash dialysis starts: a protocol for a systematic review and meta-analysis
Molnar et al. Systematic Reviews
Risk factors for unplanned and crash dialysis starts: a protocol for a systematic review and meta-analysis
Amber O. Molnar 2
Swapnil Hiremath 1
Pierre A. Brown 1
Ayub Akbari 0 1
0 Division of Nephrology, The Ottawa Hospital Riverside Campus , 1967 Riverside Drive, Ottawa K1H 7W9, Ontario , Canada
1 Division of Nephrology, Department of Medicine, University of Ottawa , Ottawa, Ontario , Canada
2 Division of Nephrology, Department of Medicine, McMaster University , Hamilton, Ontario , Canada
Background: Many patients with kidney failure “crash” onto dialysis or initiate dialysis in an unplanned fashion. There are varying definitions, but essentially, a patient is labeled as having a crash dialysis start if he or she has little to no care by a nephrologist prior to starting dialysis. A patient is labeled as having an unplanned dialysis start when he or she starts dialysis with a catheter or during a hospitalization. Given the high prevalence and poor outcomes associated with crash and unplanned dialysis starts, it is important to establish a better understanding of patient risk factors. Methods: We will conduct a systematic review and meta-analysis with a focus on both crash and unplanned dialysis starts. The first objective will be to determine patient risk factors for crash and unplanned dialysis starts. Secondary objectives will be to determine the most common criteria used to define both crash and unplanned dialysis starts and to determine outcomes associated with crash and unplanned dialysis starts. We will search MEDLINE, EMBASE and Cochrane Library from inception to the present date for all studies that report the characteristics and outcomes of patients who have crash vs. non-crash dialysis starts or unplanned vs. planned dialysis starts. We will also extract from included studies the criteria used to define crash and unplanned dialysis starts. If there are any eligible randomized controlled trials, quality assessment will be performed using the Cochrane Risk of Bias Assessment Tool. Observational studies will be evaluated using the Newcastle-Ottawa Scale. Data will be pooled in meta-analysis if deemed appropriate. Discussion: The results of this review will inform the design of strategies to help reduce the incidence of crash and unplanned dialysis starts. Systematic review registration: Prospero CRD42016032916
Systematic review; Unplanned; Crash; Dialysis; Risk factors
Background
Chronic kidney disease (CKD) defined by an estimated
glomerular filtration rate (eGFR) <60 ml/min/1.73 m2
affects 8.1 % of the American adult population
(approximately 16.2 million people) [
1, 2
]. The estimated
prevalence among Canadian adults is lower at 3.1 %
(0.73 million adults). However, this figure is much higher
(18.6 %) when restricted to Canadian adults ≥65 years
[3]. Studies show that the prevalence of CKD in the
USA and Canada has increased over the past decade,
likely due to a higher prevalence of risk factors for CKD,
such as diabetes and hypertension, and an aging
population [
1–3
]. Although showing signs of stabilization, the
annual growth of dialysis programs worldwide over the
past two decades has ranged between 6 and 12 % [
2
].
Unfortunately, many patients will “crash” onto dialysis
or initiate dialysis in an unplanned fashion.
A patient is labeled as having a crash dialysis start
when he or she is referred late to a nephrologist and
therefore has minimal or no nephrology care prior to
starting dialysis [
4
]. An unplanned dialysis start is when
a patient does not start dialysis using his or her chosen
modality, starts dialysis during a hospitalization or, in
certain studies, starts dialysis with a central venous
catheter (CVC) as opposed to a permanent access
(arteriovenous fistula (AVF), arteriovenous graft (AVG), or
peritoneal dialysis catheter) [
5
]. Unfortunately, there is
no consensus definition on the exact timing of referral
that qualifies a patient as “crashing” onto dialysis. Various
studies have used different time cutoffs, ranging from
referral to a nephrologist within 90 days to 12 months of
dialysis initiation [
6–13
]. Certain studies have also used a
definition that includes the number of nephrologist visits
in the year prior to dialysis initiation [
6, 7
]. The criteria
used to define an unplanned dialysis initiation also differ
across studies [
5
].
The prevalence of crash or unplanned dialysis starts
varies somewhat in the literature, likely in large part due
to inconsistent definitions across studies, but overall, the
prevalence is high. Studies have found that 23 to 38 % of
patients “crash” onto dialysis [
8, 14–16
], and 33 to 63 %
of patients initiate dialysis in an unplanned fashion
[
10, 17–22
]. Crash or unplanned dialysis starts are
both associated with increased patient morbidity and
mortality and lower quality-of-life scores [
4, 5, 10, 23–26
].
Given the high prevalence and poor outcomes
associated with crash (...truncated)