From April 2009 onwards, patients undergoing elective inpatient surgical procedures for hip replacement and knee replacement have been invited to complete pre- and post-operative questionnaires on their general and condition-specific health. Patient participation in PROMs is on a voluntary basis.

Responses to these questionnaires are analysed to assess the outcomes of the surgical procedures based on patients’ self-reported health.

PROMs publications and data can be used by patients to inform their choice of hospital provider and are used to by hospital clinicians to inform decisions about individual patients’ direct care. The data have also been used in medical research studies to improve outcomes by comparing scores across different types of treatments.

The reporting schedule for the PROMs publications has been changed which now means the finalised full-year data will be published six months earlier. Previously published in August, this will now be February. 

This decision was made due to address reporting needs amongst key users of the data for calculating more-timely finalised PROMS data. From reviewing the life cycle of historical PROMS data, we can see the majority of records have been received and processed by six months after the first full-year provisional data is released, with little variation seen in the calculated national rates after that point.
 

Analysis in this report is based on provisional data for:

• Pre-operative patient questionnaires completed between 1 April 2019 and 30 September 2019 and any associated in-patient hospital episodes and post-operative questionnaires;
• Episodes of inpatient hospital care where the episode started between 1 April 2019 and 30 September 2019 and included a PROMs-eligible surgical procedure (hip or knee replacement) and any associated pre- and post-operative questionnaires. A small number of episodes recorded more than one eligible procedure; each procedure is treated independently for purposes of analysis. 
• The data source of these episodes is the Hospital Episode Statistics data warehouse (‘HES’) , where possible, PROMs questionnaires have been linked to records of hospital inpatient activity in order to deliver a richer dataset for analysis and to provide key variables necessary for casemix adjustment.

This publication includes:

• Data Quality Tables
• CSV Data Pack (with footnotes)

PROMs scores are adjusted using statistical models which account for the fact that each provider organisation deals with patients of differing complexity or casemix. Some hospitals may treat older, sicker patients and others may be specialist centres that can take patients with more complex conditions than can be treated at a general hospital. 

Casemix adjustment allows for fair comparison between providers and England as a whole. In effect it estimates the score an organisation would have if it treated a population with the same complexity as the national average.

In order for the casemix adjustment to be calculated, certain criteria must be met. Where this criteria is met, the record is called a “modelled record”. The pre-operative and post-operative questionnaire must link together and be complete. They must also be linked to an episode from the HES data set as well as having some complete fields (e.g. IMD) for the episode. More information about the casemux adjustment can be found in the PROMs Methodology document here https://digital.nhs.uk/binaries/content/assets/legacy/pdf/g/t/proms_guide_v12.pdf.