1. Hospital Episode Statistics (HES)
Andy Muirhead (Derby City PH)
Analyst Training Course 2012
Day 2 – Session 6

2. Learning Objectives: What is HES? Where does the data come from?
What data is available?
How is the data used?
Examples of HES use.
Advanced HES issues.

3. What is HES?
A data warehouse covering hospital activity relating to NHS patients in England.
Contains 3 ‘universes’: Inpatients, Outpatients & Accident and Emergency.
HES service run by Northgate Information Solutions on behalf of the NHS Information Centre.

4. Creation of HES Data SEM: SUS Extract Mart PbR: Payment by Results
RTT: Referral To Treatment
Copyright © , Health and Social Care Information Centre.
Accessed 11/06/2010

5. Inpatients Outpatients A & E What Data is Available?
Data from 1989/90*
16 Million records annually
Annually / Monthly update
Outpatients
Data from 2003/04*
60 Million records annually
A & E
Data from 2007/08* (experimental)
12 Million records annually (set to increase to 19m)
Annually

6. Organisation / Geography
HES DATA
Discharge Info (dates, destination)
Admission Info (dates, source, type)
Patient Demo-graphics
Diagnosis
(ICD10)
Procedures
(OPCS-4)
Bed Days / Waiting times, etc...
Organisation / Geography
(Treatment and Residence)
Patient Identifiers
(No Names)

7. Key Terms and Definitions
Episodes Vs Spells: The Definitions
Episode
A continuous period of care under the same consultant
If the patient is transferred to another consultant or to a different provider this would end the current episode and new one would begin
Spell
A patients entire stay with a hospital provider (from admission to discharge)
If the patient dies, is discharged or transferred; this would end the current episode and spell
THEREFORE, ONE SPELL CAN CONTAIN MULTIPLE EPISODES
Episode 2
Episode 1
Episode 3
1 Spell

8. Structure of HES Data: Admitted Patient Care - 1
All Activity vs Admissions vs Discharges.
(1 patient, 1 spell, 3 episodes)
Each episode is a separate HES record.
Hence the above spell is contained in 3 different years, leading to double counting of patients and spells when comparing years.
When comparing years we count only admissions or only discharges.
Admission
Discharge

9. Structure of HES Data: Admitted Patient Care - 2
Spells vs Episodes vs Patients.
A patient’s entire stay in hospital (admission to discharge) counts as a ‘spell’. Within a spell, each period of care under a consultant is an ‘episode’.
Within a given year one patient may have multiple spells, each of which may have multiple episodes.

10. How is the data used?
Support analysis of NHS activity, including benchmarking, monitoring and clinical audit.
Inform public health policies and initiatives.
Detailed spatial and temporal picture of the health of England.
Support operational decision-making such as commissioning and performance management.
Linkage to other data sources (e.g. mortality, crime, NHS costs).
Feeds into NHS performance indicators.

11. How is the data accessed?
Method one: freely available data online.
Main source: HES online
Other websites containing HES data:
Information Centre:
- (see also: Neighbourhood Statistics).
NCHOD: - now the IC Indicator Portal!!
APHO: Their e-Atlas: -

12. How is the data accessed?
Method two: regional Public Health Observatories (PHOs).
PHOs provide a responsive ad-hoc service for PCTs, SHAs, other NHS organisations, LAs, academics and the research community.
The service is free at the point of enquiry.

13. HES Online Exercise

14. Examples of HES use.
Trends (temporal comparisons).

15. Examples of HES use.
More comparisons (spatial and inequalities).

16. Examples of HES use. Mapping of geographic data.
Based on Ordnance Survey Material. © Crown Copyright. All rights reserved. EMPHO

17. PROMS
Patient
Reported
Outcome
Measures

18. What are PROMs?
DH led programme supported by partners including The IC
A means of collecting information on the effectiveness of care delivered to NHS patients as perceived by the patients themselves.
Cover 4 elective surgical procedures:
Unilateral hip replacement
Unilateral knee replacement
Groin hernia
Varicose vein surgery

19. What do they involve?
Since 1st April 2009, contractual obligation that providers collect and report PROMs
Patients invited to complete a pre-operative questionnaire
Post-operative questionnaires then sent to patients following surgery, after a specified time period.

21. Advanced HES issues Linkage Confidentiality Strengths of HES
Limitations of HES.

22. Linkage
Linking HES to other databases makes it even more useful and powerful.
Internal linking of data allows new analysis; e.g. readmissions.
Exact (deterministic) links can be performed using NHS number / PSEUDO_HESID
Approximate (stochastic) links can be performed using D.o.B / Postcode / Sex etc.
Patient names are not on HES.

23. Confidentiality HES Protocol Rules about disclosure control
Low numbers (1-5)
Sensitive fields
Postcode, DOB, NHS Number, Consultant
Restricted conditions
HIV / AIDS
Deaths
Personally responsible 23

24. Confidentiality (2)
National Information Governance Board for Health and Social Care (NIGB)
Ethics and Confidentiality Committee (ECC)
Undertake the responsibilities of the NIGB for Health and Social Care under section 251 of the NHS Act 2006 and advise on ethical issues relating to the processing of health or social care information
Replace Patient Information Advisory Group (PIAG)
Considers applications for access to:
Identifiable HES data
Identifiable and Sensitive HES data
Database Monitoring Sub-Group (DMSG)
HES data containing sensitive but not identifiable data
Previously done by Security and Confidentiality Advisory Group (SCAG) 24

25. Strengths of HES
Almost complete coverage of NHS activity relating to Outpatient and Inpatient care.
Spatially and temporally referenced in great detail (down to postcodes and days).
Standard codes for diagnoses (ICD10) & procedures (OPCS-4)
Freely available data.

26. Limitations of HES Specific data-quality issues:
Boundary and organisational changes over time.
Poor data: Maternity, Critical Care, earlier years.
Only covers hospital-based activity...
No mortality: “Cause of death data cannot be obtained from HES” (HES protocol).
Not everything results in hospital activity, e.g: Alcohol, Drugs, Cancer, Mental Health, Obesity.
...But we can link to external databases.

27. The HES Quiz!