Waiting List Minimum Data Set (WLMDS) Information

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From April 2024, data from the Waiting List Minimum Dataset (WLMDS) will be published alongside the monthly RTT data. This WLMDS release includes a national level timeseries (from Sep-21) and breakdowns by treatment function and by provider for data for the last week in the preceding month for new, open and completed RTT pathways. Information from the WLMDS has previously been released on an ad hoc basis via the NHSE statistics pages as Supplementary Information


Waiting List Minimum Data Set (WLMDS) Data

RTT WLMDS Summary to 28 April 2024 (XLS, 184KB)


Scope and background

The Waiting List Minimum Dataset (WLMDS) is a weekly data collection relating to demand, activity and waiting lists for elective care.

Providers of NHS services that fall within the scope of Referral to Treatment (RTT), such as acute trusts, specialist trusts and any other provider of consultant-led services for NHS patients (including independent sector providers) submit data weekly to NHS England.

Data in the WLMDS must be recorded in line with rules and definitions that are outlined in the RTT Rules Suite, published by the Department of Health and Social Care: https://www.gov.uk/government/publications/right-to-start-consultant-led-treatment-within-18-weeks. NHS England also publishes the RTT Recording and Reporting Guidance (and supporting Frequently Asked Questions document) which supports the RTT Rules Suite by providing further guidance on recording and reporting RTT waiting times: https://www.england.nhs.uk/statistics/statistical-work-areas/rtt-waiting-times/rtt-guidance.

Format of the data collection

The WLMDS RTT data collection template is in three sections:

  • RTT open (incomplete) pathways
  • RTT clock starts (new RTT periods)
  • RTT clock stops (completed pathways)

Data quality

Provider organisations are responsible for ensuring that the data they submit is an accurate representation of RTT waiting and waited times, however, the WLMDS dataset is considered to be management information and is subject to less validation than the monthly official RTT statistics  (https://www.england.nhs.uk/statistics/statistical-work-areas/rtt-waiting-times/). There may be issues regarding the quality and completeness of the recorded WLMDS data which are not routinely reviewed centrally.

Providers began submitting data on a weekly basis in April 2021. Published time series include data from September 2021, allowing a period for bedding-in of data collection requirements.

Where providers are not able to submit before the weekly deadline, or discover an error after submission, they can submit a resubmission request. Published time series data includes resubmissions available at the time of extraction. However, no adjustments or estimations have been made for missing data. The time series includes a count of the total number of providers that have submitted data to give some indication of the data completeness.