# Clinic measurements data

The Clinical measurements data set contains data that has been collected at the Our Future Health in-person appointment. Our Future Health appointments include measurements of basic physical characteristics, anthropometry, and circulatory function. These measurements are non-invasive, quick to obtain during a short, in-person appointment, and provide greater accuracy than may not be achievable through self-reported or questionnaire data.&#x20;

Information on the invitation process, how participants book appointments, and type of appointment venues can be found in the page on [programme-design-and-recruitment](https://ourfuturehealth.gitbook.io/our-future-health/programme/programme-design-and-recruitment "mention")

Information on how appointments are conducted can be found in the [procedure-for-clinic-measurements](https://ourfuturehealth.gitbook.io/our-future-health/data/clinic-measurements-data/procedure-for-clinic-measurements "mention")

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### The appointment process

#### What happens during an appointment?

Participants book their in-person appointment at a location, date, and time of their choosing. At the 15 to 20-minute appointment, we collect several health-related measurements including:

* height (1 measurement)
* weight (1 measurement)
* waist circumference (1 measurement)
* blood pressure, heart rate and rhythm (2 to 3 readings)
* blood samples (2 x 6 ml EDTA tubes)

Point-of-care cholesterol measurements were also measured during the appointment between 2022 and 2025. Data on POCT cholesterol measurements is not included in the latest data release, but is planned for a future release. For more information, see [#what-other-data-is-collected-during-the-appointment](#what-other-data-is-collected-during-the-appointment "mention")&#x20;

Devices used during the appointment are:

* height measurements: Marsden HP-250P stadiometer
* weight measurements: SECA875 scales
* heart measurements: Omron 3 BP monitor or Omron HBP 1320.

For further details on what happens during an appointment, see [procedure-for-clinic-measurements](https://ourfuturehealth.gitbook.io/our-future-health/data/clinic-measurements-data/procedure-for-clinic-measurements "mention").

#### What types of measurements do we collect? <a href="#what-types-of-measurements-do-we-collect" id="what-types-of-measurements-do-we-collect"></a>

The components of physical health measured during an Our Future Health appointment include the following:

* height: the distance from the bottom of the feet to the top of the head in a human body, standing erect without shoes on (in centimetres – cm)
* body weight: the measurement of weight without shoes or heavy accessories such as mobile phones and wallets, using a weighing scale (in kilograms – kg)
* waist circumference: measured around the middle at a point halfway between the inferior margin and the superior border of the iliac crest, just above the belly button (in centimetres – cm)
* blood pressure: a measure of the force that the heart uses to pump blood around the body (in millimetres of mercury - mmHg)
  * systolic pressure: is measured when the heart contracts
  * diastolic pressure: is measured when the heart muscle rests in between contractions
* heart rate (also known as pulse rate): the number of times the heart beats in one minute (in beats per minute - bpm)
* heart rhythm: The heart's rhythm is controlled by electrical signals. An arrhythmia is an abnormality of the heart's rhythm. It may beat too slowly, too quickly, or irregularly. Heart rate measurements we take are not intended for clinical or diagnostic use, and only record heart rhythm as either "regular" or "irregular

#### Do all participants provide every measurement? <a href="#do-all-participants-provide-every-measurement" id="do-all-participants-provide-every-measurement"></a>

Not all participants attend a in-person appointment, and those who do may choose to skip some or all measurements. Data fields for measurements which may be skipped are referred to here as dynamic fields.

Participants from NHSBT only provide blood samples and do not undergo measurements.

* 60.6% of consenting participants attended a in-person appointment&#x20;
* 92.5% of participants who attended an in-person appointment also provided a complete questionnaire
* 2.0% of participants 'skipped' one or more measurements where optional

Third reading prompts:

Third readings for blood pressure, heart rate, and heart rhythm are obtained at the end of the appointment ONLY if *at least* *one* of the following criteria is met:

* systolic blood pressure readings 1 and 2 are either both greater than or equal to 160 mmHg or both less than 90 mmHg
* heart rate readings 1 and 2 are either both greater than or equal to 100 bpm or both less than 60 bpm
* heart rhythm readings 1 and 2 are both "irregular"

Records for measurements that were not presented to a participant are recorded as NULL.

For comprehensive details on each dynamic field please download the Clinic measurements logic file provided below. This file outlines the logic using pseudocode, including the relevant field names and measurement values.&#x20;

{% file src="<https://1915937830-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F2tKGBkuXj4uUxFc6HobA%2Fuploads%2FzjeLaJaxNK35VltD71aY%2FOur%20Future%20Health%20Clinic%20Measurements%20Logic.xlsx?alt=media&token=d56bf39f-ed5f-45e2-8048-5fea08b1d416>" %}
Clinic Measurements logic information
{% endfile %}

#### What other data is collected during the appointment?

**Cholesterol**

Until December 2024, each participant will have had the opportunity to have their cholesterol measured using point-of-care testing (POCT), including total cholesterol levels (mmol/L) and the associated sub-readings LDL (low-density lipoprotein), HDL (high-density lipoprotein), and triglycerides. The last available appointments including finger-prick cholesterol testing were on the 23rd December 2024. Data on POCT cholesterol measurements is not included in the latest data release, but is planned for a future release.&#x20;

**Clinic Location**

At present, there is no indicator available to identify the location of appointments or to group appointments occurring within the same setting. As we recognise that location or setting information can help in accounting for variations between sites, we are exploring options to include information about location and setting in a future release.

**Device Metadata**

Similar to location, device metadata could be a valuable attribute for various analyses. While all venues use the same devices (some information about devices is available in the [procedure-for-clinic-measurements](https://ourfuturehealth.gitbook.io/our-future-health/data/clinic-measurements-data/procedure-for-clinic-measurements "mention")), it is not currently included in the Clinic Measurements table.

**Timestamps**

Individual timestamps are obtained alongside each measurement that mark the time of data capture. These are not currently included in the release. For information on the timing and order of appointments, refer to [procedure-for-clinic-measurements](https://ourfuturehealth.gitbook.io/our-future-health/data/clinic-measurements-data/procedure-for-clinic-measurements "mention").

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### Version changes and developments <a href="#version-changes-and-developments" id="version-changes-and-developments"></a>

#### How has the appointment process changed over time?

Since the start of recruitment to Our Future Health, several updates to both the data capture tool (Clinical Staff Application; CSA) and supplementary materials (Standard Operating Procedures; SOPs) have been made to improve various aspects of the data capture and collection process. For details on how the appointment process has changed over time see the [change-log-for-clinic-measurements-appointment-processes](https://ourfuturehealth.gitbook.io/our-future-health/data/clinic-measurements-data/change-log-for-clinic-measurements-appointment-processes "mention").&#x20;

#### How do we use major and minor versioning? <a href="#how-do-we-use-major-and-minor-versioning" id="how-do-we-use-major-and-minor-versioning"></a>

In the Clinic measurements tables, a version indicator has been added under the column `APPOINTMENT_VERSION`. Currently there are two versions, which differ in the addition of new measurements:

* version 1 ("v1") includes the original set of measurements (height, weight, waist circumference, and up to two readings for heart rate, systolic and diastolic blood pressure)
* version 2 ("v2") includes records where appointments included the additional heart rhythm and third readings for heart measurements (heart rate and rhythm, systolic and diastolic blood pressure) in accordance with specific criteria

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### Clinic measurements data processing and release

#### How do we process the data for each release? <a href="#how-did-we-process-the-data-for-each-release" id="how-did-we-process-the-data-for-each-release"></a>

We process the raw data from all participants who were in the programme on or before the cut-off date for each release. Data for participants who have fully withdrawn from Our Future Health is deleted after they request to withdraw. Any participants who have fully withdrawn from the programme since the last data release will not be included in the current data release.&#x20;

To prepare the current data release, we performed minimal additional data processing. This included the following steps:

* migrating data from the CSA into our platform and matching the required format and specifications for the final tables released to the TRE
* validation against predetermined criteria for data characteristics such as data type, length, measurement units, value ranges, and minimum and maximum thresholds, and consistency with the version of the appointment attended
* adding a version indicator for each record

#### How do we de-identify the Clinic measurements data to minimise risks of identifying participants? <a href="#how-did-we-de-identify-the-questionnaire-data-to-minimise-risks-of-identifying-participants" id="how-did-we-de-identify-the-questionnaire-data-to-minimise-risks-of-identifying-participants"></a>

The original, pseudonymised ID for each appointment record was replaced with the participant ID (PID) for the participant. These PIDs are randomly generated to de-identify participants and are the primary IDs used to link the Clinic measurements with the data in the Participant and Questionnaire tables.

Additional de-identification steps include:

* rounding of the appointment time to the nearest hour in `APPOINTMENT_DATETIME`
* redaction of location and provider indicators. Note we intend to incorporate pseudonymised geographic markers or grouping indicators to safely convey this information

#### What exclusions were applied to the Clinic measurements data?&#x20;

We have identified a small number of data entry errors arising from technical duplication of data due to data capture, system or processing errors. Where identified, these records have been excluded from the release.

#### How are the Clinic measurements data organised in the Trusted Research Environment (TRE)? <a href="#how-is-the-questionnaire-data-organised-in-the-trusted-research-environment-tre" id="how-is-the-questionnaire-data-organised-in-the-trusted-research-environment-tre"></a>

The data release includes 30 variables for the Clinic measurements data across all versions of the Clinic measurements data. In the TRE, the data is organised into a single entity which we refer to as the Clinic measurements table. Each entity can be linked to another entity (for example, the Participant table using a unique identifier (called Participant Identifier or PID). Other than the PID, variable names are unique within and between all entities.&#x20;

#### How do I interpret the structured field names? <a href="#how-do-i-interpret-the-structured-field-names" id="how-do-i-interpret-the-structured-field-names"></a>

Field names are short, descriptive, and often abbreviated names used to describe the contents of a particular column. In the Clinic measurements table, each field name consists of two main components in the following format:

\[Primary\_topic]\_\[Unique\_descriptor]

* Primary Topic: A single term (word, phrase, or abbreviation) representing a broad category that describes the overarching family of fields or refers to the main measurement. This primary topic is often consistent across multiple fields e.g. `HEIGHT`.
* Unique Descriptor (optional): One or more terms, joined by underscores, that provide specific details about the field’s content. Unique descriptors are systematically organised with sequential elements, often shared among related fields, to clarify differences and relationships between elements. Examples include `HEIGHT_SKIPPED` and `HEIGHT_SKIPPED_REASON`.

#### What metadata is available to help document the Clinic Measurements release?&#x20;

We provide the following data files on our [Data and cohort page (external link)](https://research.ourfuturehealth.org.uk/data-and-cohort/):&#x20;

* Data dictionary – which defines the raw data fields and metadata information, such as labels, descriptions, and units of measurements&#x20;
* Coding file – which contains the granular details of categorical or raw coded values for fields contained within the Clinic measurements data&#x20;

If using Microsoft Excel to browse these files, for an optimal viewing experience, ensure the encoding settings are set to UTF-8.

On the [#do-all-participants-provide-every-measurement](#do-all-participants-provide-every-measurement "mention") section above we also provide:

* Clinic measurements logic codebook - which includes the conditions required per measurements for the field to be not null in the data table
