How a patient starts kidney replacement therapy shapes how they live on it. A planned start, on a modality they chose, with access already working, is a different experience — and a different outcome — from a crash start in hospital through an emergency catheter. The predialysis pathway exists to make the first the norm and the second the exception, and at its heart is a decision that is genuinely the patient's: which modality, or whether to dialyse at all.
Timing the pathway by risk
The pathway must begin early enough to do its work, and the trigger is risk, not a single eGFR. The kidney-failure risk equation of Chapter 1 identifies who is likely to reach kidney failure within a timeframe that demands preparation — and 'early enough' is defined by what needs to happen: a fistula takes months to mature, transplant work-up takes time, and education and a considered modality choice cannot be rushed. Referring too late forecloses these options and forces the very crash start the pathway is meant to prevent. So a high predicted risk, a progressive trajectory, or an eGFR approaching the low twenties should prompt referral to a low-clearance or predialysis clinic, with the risk equation calibrating the timing rather than a reflexive single threshold.
What the pathway does
The predialysis pathway is a coordinated programme, not a single appointment. It delivers modality education and the modality decision; it plans vascular or peritoneal access in time for it to be ready (the subject of the next chapter); it works up transplantation and, ideally, lists suitable patients pre-emptively; it vaccinates, notably against hepatitis B, while the response is still good; it optimises nutrition; it provides psychosocial support and advance care planning; and it continues to manage the complications and progression of the CKD. This breadth is the point — a patient approaching kidney failure needs all of it, coordinated, and a structured pathway with a multidisciplinary team is how a unit reliably delivers it. The quality of this pathway is a marker of the quality of a kidney service.
Avoiding the crash start
The clearest measurable failure of predialysis care is the crash start — unplanned dialysis begun urgently, usually through a temporary catheter, often during an inpatient admission, in a patient who was not prepared. Crash starts carry higher mortality, more catheter-related infection and complications, less use of home therapies and transplantation, and a worse start to life on dialysis. In many systems a substantial fraction of dialysis starts are unplanned, and reducing that fraction is one of the most meaningful quality improvements a kidney service can make. The whole pathway is, in a sense, machinery for converting potential crash starts into planned ones: identify early, educate, choose, prepare access, and start electively on the chosen modality with working access. When a crash start does happen, it is usually a marker of late referral or a missed pathway step.
The modality options
Modality education must cover the full set of options honestly. Transplantation — from a living or deceased donor — offers the best survival and quality of life for suitable candidates, and a pre-emptive transplant performed before dialysis is needed is the ideal, so eligible patients are worked up and listed early, with living donation actively explored. Haemodialysis can be delivered in-centre or, for the capable and supported, at home, the latter offering more frequent treatment and autonomy. Peritoneal dialysis is a home-based therapy that preserves residual kidney function, is gentler haemodynamically, and frees the patient from the dialysis unit, at the cost of peritonitis risk and eventual technique failure in some. And conservative kidney management — active care without dialysis — is a genuine option, developed in the conservative-management and frailty chapters, for those who choose not to dialyse. The educator's job is to present all of these without steering.
Why the choice is the patient's
The reason modality choice is genuinely preference-sensitive, rather than a clinical recommendation, is the evidence. For most patients, haemodialysis and peritoneal dialysis offer broadly equivalent survival, with the differences between them driven by lifestyle fit, home circumstances, comorbidity, and what the patient values, not by one modality saving more lives than the other. So the decision turns on questions only the patient can answer: how much they value the autonomy and home-based nature of peritoneal or home haemodialysis against the structure and clinical oversight of in-centre care; how dialysis fits their work, family, and travel; what burdens they will and won't accept. Transplantation, where suitable, is the exception that clinicians can recommend on outcomes — but the dialysis choice, and the choice of dialysis versus conservative care, belong to the patient, informed by unbiased education.
Effective care, and the shared decisions
As in the other equipoise chapters, it helps to separate what is owed from what is chosen. The effective-care elements of the pathway are not preference-sensitive: referring in time, vaccinating, optimising nutrition, working up transplantation for the eligible, planning access once a modality is chosen, and avoiding a crash start are simply good care, delivered regardless. The preference-sensitive decisions — which modality, home versus in-centre, whether to pursue a pre-emptive transplant, and dialysis versus conservative management — are the patient's, made through the unbiased education and shared decision-making the chapter's scripts support. Keeping the two clear ensures the patient is offered timely, comprehensive preparation as a matter of course while genuinely owning the modality decision.
Where the evidence is firm, and where values govern
The firm parts are the outcome ones: transplantation, and pre-emptive transplantation in particular, gives the best results for suitable candidates; crash starts are worse than planned starts; and HD and PD are broadly survival-equivalent. The part that evidence cannot settle is which dialysis modality, or whether to dialyse at all, is right for a given person — because that depends on values the trials do not measure. So the clinician's expertise is to recommend transplantation where it applies, to build a pathway that prevents crash starts, and then to present the dialysis and conservative options without bias and let the patient choose. The proper close to the preparation chapters is a planned, chosen start — or a chosen conservative path — that fits the patient's life.
