Organisations should no longer collect ‘classic’ or ‘next generation (Medication, Mental Health, Maternity and C&YPS)’ Safety Thermometer data or submit it to the Safety Thermometer portal. Information on replacement metrics drawn from routinely collected data can be found on the Patient Safety Measurement Unit webpage.

The Safety Thermometer, launched in 2010, was one of the largest and longest-lasting data collection exercises in NHS history. It had a powerful impact in its early years. But more recent evaluations, research and feedback have shown that the data was incomplete, and it was no longer able to support improvement in the intended way. Because of this, new data sources were explored that could take the burden of data collection away from clinical staff and support new improvement initiatives. Ending the Safety Thermometer were publicly consulted on in 2019/20 as part of proposed changes to the NHS Standard Contract. The response supported ending the national collection of Safety Thermometer data from April 2020, and using alternative data sources to continue improving pressure ulcer prevention, falls prevention, VTE prevention and prevention of healthcare-associated infection.

All data collection for the ‘classic’ Safety Thermometer and the ‘next generation’ Safety Thermometers will therefore stop after March 2020. Plans for nationally-produced replacement data to support improvement drawn from routinely collected sources will be provided or signposted on the NHS England and NHS Improvement Patient Safety Measurement Unit webpage as soon as possible.


Welcome to the Safety Thermometer Dictionary

       This section is designed to be your easy to use, Safety Thermometer dictionary. Either scroll down the page or click the headings in the Contents box below to view the definitions. If there are any definitions you think are missing, please contact the help desk at: This email address is being protected from spambots. You need JavaScript enabled to view it.




  • Overview
    • What is the Safety Thermometer?
    • How should we collect data?
    • Interpreting Data
    • Outliers
  • Key Terms


  • Measures
    • Falls
    • Pressure Ulcers
    • UTIs
    • VTEs





Overview - Back to Contents

What is the Safety Thermometer and why should we use it?

The NHS Safety Thermometer is a local improvement tool for measuring, monitoring and analysing patient harms and ‘harm free’ care. The tool measures four high-volume patient safety issues:

  • Pressure ulcers
  • Falls in care
  • Urinary infection (in patients with a catheter)
  • Treatment for Venous Thromboembolism

The Safety Thermometer is mandatory if you have contractual obligations from CQUIN. CQUIN (Commissioning for Quality and Innovation) is a national framework for locally agreed quality improvement schemes. It enables commissioners to reward excellence by paying a quality increment to providers using NHS Standard Contracts if they achieve agreed quality improvement goals.

If you do not have CQUIN obligations, then it is up to the organisation whether or not they use this particular tool to measure improvement.


How should we collect data for the Safety Thermometer?

The NHS Safety Thermometer CQUIN requires monthly surveying of all appropriate patients. Data will be collated locally using the NHS Safety Thermometer tool on a single day per month. It is recommended that data collection is integrated into the daily work flow. Data will come from two primary sources: a physical examination of the patient (including a conversation with them or their carer) and nursing / medical records (including pharmacy records). Data collected in the NHS Safety Thermometer is submitted to the NHS Information Centre directly from the Safety Thermometer Tool via a “submit” button.

The data should be collected by a nurse at the point of care. The key to getting this right is to integrate data collection into the daily work flow, for example by completing the NHS Safety Thermometer at handover, in a safety huddle, or during one of your intentional/comfort/hourly rounds. Primarily, data will come from two primary sources: a physical examination of the patient (including a conversation with them or their carer) and nursing / medical records (including pharmacy records).

Particular days of the month on which to conduct the survey have been suggested to providers; it is not obligatory to use these, but the survey should be conducted on a single day. Data resulting from the survey should be entered into the Safety Thermometer and submitted to the NHS Information Centre by a designated cut-off date each month;

To limit the possibility of double counting patient harms, for example if a patient moves between settings, wards or caseloads, the organisation should aim to complete the survey within a specific time period, for example on one morning between 9 and 12.

Data collected in the NHS Safety Thermometer is submitted by Registered Safety Thermometer Coordinators using the ‘submit’ function in the tool. This sends the survey data to the NHS Information Centre via email. Once the data has been received by the NHS Information Centre and the submitter details have been authenticated against the list of Registered Safety Thermometer Coordinators, the submitter will be sent a confirmation e-mail acknowledging receipt. If you do not receive an email receipt, your data has not been correctly submitted.


Interpreting Data

The control charts will show the data for each organisation and the national aggregate data in the background in a p-chart (for proportions or percentages). The control charts are designed to be used as a high-level overview of the data over time, showing the four harms and providing a visualisation of ‘harm free’ care.

The control charts can be used to assess the average proportion of patients harmed, and to interpret possible improvement by viewing the data over time. Although not appropriate for use at ward level, the control charts will be useful for organisations and their boards to review their data against the regional and national picture.

Data will also be provided in the form of funnel plots. Funnel plots enable organisations to see their performance relative to other organisations in the NHS. In the same way as the control charts, funnel plots show control limits, generally in a funnel shape.

If an organisation lies within the funnel, this means it is statistically indistinguishable from the national average (or whatever is chosen for the centre line); points outside the funnel are statistically different and are examples of special cause variation - they are unlikely to be different by chance and to be systematically different in some way. Organisations or teams that have a corresponding data point outside the funnel are considered to be outliers; they may be positive or negative outliers, depending on which direction is desirable.



What to do if your ward/caseload or organisation is an outlier

Firstly, being an outlier can be a cause to celebrate; it could mean you are one of the best performers. Make sure you are fully aware of the indicator you are an outlier on and in which direction you are an outlier.

The important thing to remember about being an outlier is to treat it as an opportunity for learning; even if the initial picture is not a positive one, this is an excellent chance to really drive forward improvement. Organisations, or even individuals, feeling exposed and vulnerable to criticism, particularly where data collected is used for punitive purposes or those collecting the data do not see and understand the results. In such cases there may be a temptation to artificially change practice to avoid harms being captured. Please remember that this is a tool for development, not criticism.

Your data at an individual ward or team level will have much smaller numbers of surveyed patients than at an organisational or higher level. This means that there will be more variation month to month.




Key Terms - Back to Contents

Term: A&E attendance


An individual visit by one patient to an Accident and Emergency Department to receive treatment from the accident and emergency service.


Term: CICs


Community Interest Companies (CICS) are limited companies created for the use of people who want to conduct a business or other activity for community benefit, and not purely for private advantage.


Term: Day case


A patient admitted electively during the course of a day with the intention of receiving care who does not require the use of a hospital bed overnight (patient classification code = 2) and who returns home as scheduled. If this original intention is not fulfilled and the patient stays overnight, such a patient should be counted as an ordinary admission and included in the NHS Safety Thermometer survey.


Term: Dialysis patients


Patients undergoing regular dialysis who should be recorded as a regular day admission (patient classification code = 3).


Term: Harm (Old)


An ‘old’ harm is defined as being a harm that was present when the patient came under your care, or developed within 72 hours of admission to your organisation.


Term: Harm (New)


A ‘new’ harm is defined as being a harm that developed 72 hours or more after the patient was admitted to your organisation.


Term: Health visiting


Teams employed to visit people in their homes and give help and advice on health and social welfare, specifically to mothers of preschool children, to the disabled, and to elderly people.


Term: Neonatal patients


Babies in care who are 28 days old or less.


Term: Old age mental health and learning disability services


Mental health and learning disability services provided to patients generally over the age of 65. Inpatient older people’s mental health services would usually be recorded under the treatment function 715 (Old Age Psychiatry).


Term: Outpatient


An Out-Patient Attendance is an attendance at which a patient is seen by or has contact with (face to face or via telephone/telemedicine) a health care professional, in respect of one referral, in a clinic setting.


Term: Prophylaxis


Treatment given or action taken to prevent disease.


Term: Regular day attenders


Patients undergoing regular treatments (e.g. chemotherapy) who should be recorded as a regular day admission (patient classification code = 3).


Term: School nursing


Teams/staff working with school-age children and young people in a range of settings including schools.





Welcome to the Safety Thermometer tool. For a full definition for each of the measures, please see the list to the right. This also includes which of the indicators the data calculates.

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