Version: 1.0.0 | Published: 21 Aug 2026 | Updated: 0 days ago
Summary
Documentation
Associated Media:
Description:
The SUS (Secondary Uses Service) Unified Outpatients Dataset is the national record of all NHS-funded outpatient appointments in London. It captures every booked appointment - whether attended or not - and provides a detailed picture of outpatient activity, patient flow, and service performance.
SUS Unified Outpatients is essential for understanding how patients access specialist care - and how the NHS can make that care more timely, equitable, and efficient. It contains one record per appointment, attended or not.
The data set includes:
1. Patient and demographic details such as Age, Gender, Geographical identifiers (region, trust, GP practice), Ethnicity (grouped categories).
2. Appointment-level information such as Appointment data and time, Attendance status (Attended / Did Not Attend (DNA) / Patient cancellation / Hospital cancellation / Unknown outcome), First vs follow-up appointment flags, Referral source (e.g., GP, consultant-to-consultant).
3. Clinical information such as Diagnoses, Procedures/operations (OPCS 4), Specialty of care (e.g., cardiology, dermatology), Maternity-specific outpatient attendances (where relevant).
4. Provider and commissioning details such as NHS trust and site, Independent sector providers funded by the NHS, Commissioning region, Finance categories for tariff/payment purposes, Data quality indicators (provider responsibility).
5. Coverage includes NHS hospitals, Private patients treated in NHS hospitals, Patient resident outside England, NHS-funded care delivered in independent treatment centres. It excludes private care activity not funded by the NHS.
Researchers use SUS Outpatients to understand demand, access, inequalities, and performance in non-admitted care. Key elements include:
1. Demand and capacity analysis which allows researchers to track rising demand, identify specialties under pressure, forecast future outpatient workload.
2. Non-attendance (DNA) and cancellation patterns which are critical for improving efficiency. Researchers use these fields to:
- Identify groups at risk of non-attendance
- Evaluate digital reminders or pathway redesign
- Reduce wasted clinical time
3. Health Inequalities which include demographic fields (age, gender, ethnicity, region) enable analysis of who attends and who does not, identification of disparities in access, targeting interventions to underserved groups.
4. Clinical pathway evaluation using diagnosis and procedure codes allow mapping outpatient pathways, studying variation in treatment approaches, understanding follow-up patterns and referral behaviour.
5. Provider performance and variation, because the dataset includes all NHS providers, researchers can benchmark trusts, compare cancellation rates, assess specialty-level productivity, evaluate the impact of operational changes (e.g., virtual clinics).
6. Policy evaluation: The dataset supports monitoring elective recovery programmes, assessing waiting time initiatives, evaluating digital outpatient transformation (e.g., remote consultations).
Using SUS Outpatients, researchers can:
- Reduce DNAs by identifying high-risk groups and designing targeted interventions
- Improve access by analysing demographic inequalities
- Optimise clinic scheduling using patterns of cancellations and follow-ups
- Enhance pathway efficiency by understanding referral and treatment flows
- Support personalised care through diagnosis-linked outpatient patterns
- Inform national strategy on elective care, digital transformation, and workforce planning.
In Pipeline:
Available
Coverage
Spatial:
- United Kingdom
- England
- London
Typical Age Range Min:
0
Typical Age Range Max:
150
Material Type:
None/not available
Follow Up:
1 - 10 Years
Pathway:
This dataset contains all Outpatient appointments for London patients. Each
patient will be identified using an unique patient key, this can be used to link
to other London SDE datasets that will help track the patient pathway.
Provenance
Origin
Purpose:
- Administrative
- Care
- Other
Dataset Type:
- Health and disease
- Treatments/Interventions
Dataset Sub-Type:
- Others
- Others
Source:
EPR
Collection Source:
Secondary care - Outpatients
Image Contrast:
No
Temporal
Publishing Frequency:
Monthly
Distribution Release Date:
01 September 2026
Start Date:
01 April 2018
Time Lag:
1-2 weeks
Accessibility
Access
Access Rights:
London Secure Data Environment Enquiry Form
Access Service Category:
TRE/SDE
Access Service:
Researchers will have access to a secure workspace via an airlocked Azure
Virtual Desktop with a specific username and password, MFA (multi-factor
authentication) and OAUTH (open authentication). Researchers will get specific
access to a relevant subset of the datasets that are present in the SDE
catalogue for their project and will be able to carry out their research within
the safe haven. There are restrictions applied which prevent the researchers
from taking data out of the safe haven. Once the research is completed the
London SDE admin team will need to be contacted for any requests to egress
summary analysis out of the safe haven which will not breach secure data
environment disclosure control standards.
Access Request Cost:
Access costs will be determined on a project-by-project basis and will depend on
the specific data requirements, platform setup, and any additional services
needed to deliver the project successfully.
Delivery Lead Time:
1-2 months
Data Controller:
Participating London health care organisations act as Joint Data Controllers
within the London SDE. These organisations include for example GP Practices and
Acute Providers from across London.
Data Processor:
The data processor for the London Secure Data Environment (SDE) is primarily
managed by OneLondon, a partnership of London's five integrated care systems
(ICSs) and three health innovation networks. NHS North East London ICB hosts
OneLondon and operates the London Data Service (LDS) as a data processor on
behalf of those organisations, whilst Imperial College Healthcare NHS Trust
hosts the London Analytics Platform (LAP), with Imperial NHS Trust acting as the
data processor for data processing activities undertaken within the platform.
Jurisdiction:
United Kingdom of Great Britain and Northern Ireland
Usage
Data Use Limitation:
No restriction
Data Use Requirements:
- Collaboration required
- Institution-specific restrictions
- Project-specific restrictions
- Time limit on use
- User-specific restriction
Resource Creator:
- NHS NWL ICS
- London SDE
Format and Standards
Vocabulary Encoding Scheme:
- NHS NATIONAL CODES
- LOCAL
- OPCS4
- ICD10
Conforms To:
- NHS DATA DICTIONARY
- LOCAL
Language:
English
Format:
Text
Enrichment and Linkage
Investigations:
Linkable Datasets
PID
Title
URL
Each patient will be identified by an unique patient key that can be used to link to all other datasets available within London SDE Platform
Observations
Statistical Population
Population Description
Population Size
Measured Property
Observation Date
Events
233490099
Count
21 September 2026
Persons
Distinct Patient Count
11221916
Count
21 September 2026
Origin
Name:
London SDE