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Publication, Part of

Fit Notes Issued by GP Practices, England December 2020

Official statistics

Current Chapter

Fit notes issued by GP practices in England Extract specification

Fit notes issued by GP practices in England Extract specification

Information on the data extraction criteria for the fit notes issued by GP practices statistical publication.

Dataset specification

An electronic fit note on a GP system is known as a Med3 file.

The extracted Med3 activity file comprises an envelope and a payload.  The following details the data items that are included in the practice envelope and each Med3 activity record.

Data items

Data items in the extract envelope file for each practice


A count of the number of records extracted and contained in the payload



A GUID assigned by the supplier on extraction and stored for future reference; used for manual diagnostic transaction identification/correlation


The date and time of Med3 activity extraction


It is expected that transmission will occur immediately after extraction so this will be the same timestamp as above


The practice ODS code


The full post code of the practice


A code to identify the GPSOC system of the PMS (suppliers can choose how to populate this)


The Version and Release number of the PMS doing the extract (suppliers can choose how to populate this)


OPTIONAL: nominated email address for receipt acknowledgement by NHS Digital


OPTIONAL: nominated email address for process acknowledgement by NHS Digital


OPTIONAL: nominated email address for any error notification by NHS Digital


Data items included in the extract payload and are described as used by the GP at the GP practice

Data item 



Date assessed by the Clinician.

This is the date the GP assessed/examined the patient or considered a report from another healthcare professional.  It can be the same date the statement is issued (which is normal and should be the default date displayed at the outset of the transaction), or it can be any date preceding the issued date.  It cannot be a future date.  There is no limit on how far in the past the date can be.  However, if the GP inputs a date which is 26 weeks or more before the day of issue, (the current date), a dialogue box should prompt the GP to confirm that the correct assessment Date has been entered.  If confirmed, the six-month flag should be set and if not confirmed allow for re-entry of the assessment date



The text of appropriate Admin Code for the NEW statement being issued. Either of the 2 sets of text depends on how the supplier chooses to implement users’ navigation to Med3 functions.  That is, at this point it can be chosen from a drop-down list of the 2 NEW codes (NFW and MFW), or it can be simply the text “NEW Statement” with the NFW/MFW choice determined by what the user ticks in steps 4/5.  



This field is the principal diagnosis causing the statement to be issued, with user control over the text actually printed on the statement.  This field is MANDATORY.




Two tick-boxes where ONE AND ONLY ONE MUST be ticked.





If NFW.flag is set, then these 4 tick boxes should be disabled and displayed in background grey-scale.

If MFW.flag is set, these 4 tick-boxes enabled and are optional.  Any combination of the 4 boxes may be ticked, including all and none.









These steps enable the GP to define the period of time for which the statement is valid, either using days/weeks/months or specifying a start and end date.

The anchor date is the Date of Assessment for both modes.  Suppliers must comply with current standards regarding the handling of dates as specified in the CUI (Common User Interface)


Ticked if a follow-up assessment is required at the end of the period.  The date is entered or auto calculated 



Med3.Unique.ID is calculated


Med3.Statement.Date and Med3.Statement.Time are set automatically, but can be amended by GP.

Med3.Printed.flag or Med3.Duplicate.Printed

Signifies end of fit note process


The linking ID is to be machine-generated and stored with the Med3 transaction in the patient’s record and included in the Med3 transaction data transferred to NHS Digital. The linking ID should be in the form of a DCE UUID assigned to each patient within the record.

The fit note functionality in a GP practice system provides additional data fields for free text and patient information. These were considered too disclosive for the extract and are not included. 

Fit note selection/rejection criteria


File: extract from supplier, contains many envelopes.

Envelope: extract from a given GP Practice, contains the individual fit notes and header information.

Fit note: individual Med3 extract.

During the extract stage

Reject whole file:

The fit note file must correspond structurally to the schema: else Reject whole file.

If the Extract Reference is duplicate: Reject whole file.

Reject individual Med3:

The ValidPeriodDays value (if supplied) must be no more than 4 characters in length: else Reject individual Med3.

The ValidPeriodWeeks value (if supplied) must be no more than 3 characters in length: else Reject individual Med3.

The ValidPeriodMonths value (if supplied) must be no more than 2 characters in length: else Reject individual Med3.

The ValidPeriodIndefinite value (if supplied) must equal 10 characters in length: else Reject individual Med3.

During the staging transformation stage

Reject Envelope:

The GP Practice code must be valid as per the DSS corporate reference: else Reject Envelope.

If All Med3's are rejected in the same file: Reject the Envelope.

Reject individual Med3:

The Extract Date must not be before the Statement Date Time: else Reject individual Med3.

The Statement Date must not be before December 2014: else Reject individual Med3.

The Statement Date must be a valid date/time: else Reject individual Med3.

The Med3must have at least one of: else reject individual Med3

  • ValidPeriodDays
  • ValidPeriodWeeks
  • ValidPeriodMonths
  • ValidPeriodIndefinite
  • ValidPeriodStartDate and ValidPeriodEndDate.

Other business rules

GP practices 

NHS Digital corporate reference data is used to create a reference table in the staging database. All distinct entries in that table are brought in the query, entries are not filtered, and information from this table is used only in the event of receiving a fit note submission from a GP practice.

The practice code entry in the fit note is checked against the table, and that the practice does not have a close date.

If both criteria pass the fit note is processed. If any are rejected, this is included in the data quality report.

Duration calculation 

If Indefinite is supplied: The duration is Indefinite.

If Indefinite is not supplied, and

  • Days + (Days in weeks) + (Days in months) >= (EndDate – StartDate) : The Duration is Days + (Days in weeks) + (Days in months)
  • (EndDate – StartDate) >= Days + (Days in weeks) + (Days in months): The Duration is (EndDate – StartDate)

Code mapping to ICD10

Definition: fit note diagnostic codes need to be mapped to ICD10 and aggregated to a chapter level, and up sub-chapter codes. The extracted data includes diagnostic codes in the practice’s coding system. These are read clinical codes version 2 (Read) and clinical terms version 3 (CTV3) or SNOMED which is in the process of replacing Read and CTV3.

Business rule: These codes are mapped to the ICD10 coding system, using NHS Digital reference mapping tools.

Standards: NHS Digital reference mapping tools. Codes are updated by NHS Digital on a 6-monthly basis, and suppliers are expected to update their systems to incorporate new codes. Historical codes are not deleted.

NIS-retired codes: If data contains retired codes, as is likely for the historical data, where possible these will be mapped to the relevant ICD10 chapter even if mapping at sub-chapter level is not possible. It is not clear at the time of writing whether it is possible to obtain information on which ICD10 chapter the retired code used to map to.

Multiple submissions

It is recognised that practices change GP practice systems from time to time. During migration from the old to the new system, it is possible that systems are run in parallel, and data can exist in both systems and therefore be extracted by two (or more) different suppliers for the same practice code.

All extracts will be accepted.

Checks are made in the staging process for any duplicate Unique IDs. The first Unique ID is accepted; any subsequent duplicate Unique IDs is rejected and stored in the rejected table.

The quality report indicates on a weekly basis how many multiple submissions have been received for a given practice code.

Duplicate IDs 

Duplicate Unique IDs are checked at staging, against the existing database. As this will affect the speed performance of staging, the check will be limited to the rolling last month of fit notes.

Linked fit notes

Definition: Fit notes that are linked with the same linking ID are considered to be linked fit notes.

Assumption:  We believe that the same linking ID will be present for consecutive, as well as non-consecutive, fit notes.

Business rule: For calculating duration of a linked episode, two or more fit notes will be considered linked if:

They have the same linking ID.

They are consecutive, that is,

  • the statement date of the newer fit note is the within the period of the previous fit note, or
  • the statement date is the same as the end of the previous fit note, or
  • the statement date falls within 7 days of the end of the previous fit note.

If two fit notes have the same linking ID, but are more than 7 days apart, (end date and statement date) they will be considered separate episodes.

Where a patient moves practices, the linking ID will follow the patient if the fit note data is transmitted successfully by GP2GP record transfer.  In these cases, display of linked fit note data will take the GP Practice ID from the most recent individual Med3 in the episode.

In a series of linked fit notes, the gender and diagnosis code are taken from the first fit note in the series. The GP practice code is taken from the last fit note.

Last edited: 12 July 2021 6:38 pm