When the clock starts

The referral to treatment (RTT) pathway is the clock the 18-week standard is measured against, and it starts on the day your referral is received by the service you are being sent to, whether that is a hospital, a clinic or another provider on the NHS's list. If you book your first appointment through the NHS e-Referral Service, the clock starts on the day you make that booking. It is the referral itself that starts the count.

What ends the clock

The clock ends when your first treatment begins, when a clinician decides no treatment is needed, or when you are discharged back to whoever referred you without further action. Until one of these happens, your referral is an incomplete pathway: still open, still running, and still part of the group the monthly waiting-time figures describe.

These rules are not the same for every kind of referral. A routine consultant-led referral, a suspected cancer referral, a diagnostic test and an ambulance call each carry their own standard and their own clock start. Use our which waiting-time standard applies to me? tool to check which set of rules applies to your own pathway, with its source and the day it was checked.

The 18-week standard covers routine, consultant-led referral to treatment. Three other pathways run to their own clock, and each is published separately.

Suspected cancer

A referral for suspected cancer is not measured against the 18-week standard. Cancer should be confirmed or ruled out within 28 days of the referral, under what the NHS calls the Faster Diagnosis Standard. This standard measures how long it takes to give the patient an answer.

Diagnostic tests

A referral for a diagnostic test on its own, such as a scan or an endoscopy, sits on a separate pathway again. NHS England publishes monthly figures for diagnostic waiting times apart from the 18-week referral-to-treatment figures, covering people waiting for the test itself rather than for a course of treatment.

Ambulance calls

An ambulance call is measured differently again. Response times are published monthly for each of the eleven ambulance services in England, broken down by call category, against the standard set for that category, so a Category 1 call and a Category 4 call are reported and judged separately.

If you are not sure which of these applies to the referral or the call you are dealing with, use our Which Waiting-Time Standard Applies to Me? tool. Choose the pathway you are on and it shows the published standard for that pathway, what it measures, when its clock starts and what ends it, each with its source and the day it was read.

Most people on a waiting list have not been treated yet and have not been discharged. That is called an incomplete pathway, and it is the group the monthly waiting-time statistics are built from. If your referral has been made and you are still waiting for your first appointment, a test or your treatment, you sit inside this group, and the published figures for your provider and specialty describe people in the same position as you, for that month only.

The mean wait and the eight-in-ten figure

A mean wait is the average number of weeks across everyone still waiting on an incomplete pathway, for one provider and one specialty, in one month. It can be pulled upward by a small number of people who have waited a long time, so it will not always match what a typical patient on that list is experiencing.

The eight-in-ten figure measures something different: the length of time within which eight out of every ten patients on that pathway were seen. The NHS's 18-week standard applies to a routine, consultant-led referral; a suspected cancer referral, a diagnostic test, an A&E attendance and an ambulance call are each measured against a different published standard. If you are not sure which one covers your own referral, use our Which Waiting-Time Standard Applies to Me? tool: choose the pathway you are on and it shows the standard, what it measures and when its clock starts, each with its source and the day it was read.

Neither figure tells you what happens to any one patient. Both describe the whole incomplete pathway for a provider and specialty in a given month, and a patient waiting six weeks and one waiting sixty weeks both sit inside the same average.

Why the published month may not match your own wait

A monthly publication is a snapshot of everyone waiting at that point. Your referral date, your provider and your specialty determine your own position on the clock, and that position can move between publications as your appointment is booked, delayed or completed. The published figure tells you how that provider and specialty have been running recently; it does not tell you where your own referral currently sits, and it is not a prediction of your own appointment date.

Reading your own wait against the published figures for the same provider and specialty is still useful, because it shows whether the service is running close to the standard or well past it. The published month and the day the figure was read should always sit next to the figure itself, since a wait recorded several months ago describes conditions that may since have changed. If you want to see where your own referral sits against the 18-week clock right now, use our How Long Have I Been Waiting? tool: enter the date your referral was made and it works out the weeks waited and the date the standard was or will be passed, from the date you give it and nothing else.

Questions about symptoms, diagnosis or what treatment is right for you are for your GP, a pharmacist, NHS 111 or, in an emergency, 999. The Data and Sources page sets out where each waiting-time figure is published and how to check it, and the About Healthcare.uk page explains how those figures are kept up to date.