South East Public Health Observatory Hospital Episodes Statistics (HES) Steve Morgan - Senior Public Health Intelligence Analyst - SEPHO Day 2 – Session 5– April 1 st 2009

Learning objectives What is HES? Where does HES fit in? Examples of use

What is HES ? National record of in-patient/out-patient/ A&E care delivered by NHS hospitals in England from 1989 onwards – approx 13 million records a year for inpatient activity alone. Each financial year, NHS Trusts submit record level data on all Finished Consultant Episodes (FCEs) – Secondary Uses Service (SUS) HES covers all medical specialties and includes private patients treated within NHS hospitals. It does not, however, include private patients treated in private hospitals.

What is HES ? HES information is stored as a large collection of separate records - one for each period of care. Each HES record contains a wide range of information about an individual patient admitted to an NHS hospital. For example:- clinical information about diagnoses and operations patient information such as age group, gender and ethnic category administrative information, such as time waited and date of admission geographical information on where the patient was treated and the area in which they lived.

HES Safe Haven PHOs have access to an full national extract of HES data – SEPHO will hold 1989 – 2009 PHOs also have access to an on-line system (HES2) for the whole of England from 1989 – 2009 PHOs provide ad-hoc service and standard outputsad-hoc service standard outputs

Data Collection HES data for admitted patients, outpatients and A&E comes from the routine exchanges of information between providers of healthcare for NHS patients in England and commissioners of the care. Healthcare providers collect administrative and clinical information locally to support the care of the patient. The data is submitted to the Secondary Uses Service (SUS), which, as well as forwarding it to the commissioners, also copies the information to a database.Secondary Uses Service At pre-arranged times during the year, SUS takes an extract from their database and sends it to HES. Data on SUS will continue to change, but HES data is fixed as it was when that particular extract was taken. HES then validates and cleans the extract, before deriving new items and making the information available in the data warehouse.

No patient names Excludes (most) activity in private hospitals Quality of clinical coding – regional variation Restricted access to certain sensitive fields Consultant code GP code Boundary changes and population denominators (everybody ’ s nightmare, not just HES) HES is not a live system Time lag - always 9-12 months behind 2007/2008 released - March 2009 What are the limitations of HES?

Strengths Probably the second largest 'medical' database in the world after medicare/medi-aid (USA) Un-interrupted data collection since coverage of 18 years to 2007/08 (latest info available) Resident and registered populations Geographically and temporally referenced Diagnoses & procedures coded using standardised coding frames - ICD9, ICD10 & OPCS4, HRG (latest 3.5) Covers population of approx 50,000,000 + (principally England) Covers all NHS hospitals ~ 90-95% of all in-patient care

Secondary Uses Service (SUS) Role-based access You probably only see your own PCT – not good for benchmarking!! Need to ask PHO HES team for comparative data

SUS v’s HES HES has a time delay Will not change Better for research rather than real time monitoring SUS is a live system, updated as your local arrangements, continually changing Therefore data from some trusts might not be complete – need to check you have all you expect

At least one record for each patient’s stay in hospital (either day case or in-patient) A record reflects a patient’s period of care under a consultant, known as a consultant episode. A patient’s SPELL in hospital may comprise of more than one episode What is a patient record ?

Spells vs Episodes 1 Discharge 4 Episodes

Episodes and Spells

Types of hospital admissions Elective admissions – Where the patient has been waiting for treatment Emergency admissions – Immediate admission (also from A&E) Day Case – Elective in-patients admitted just for the day, the treatment can be concluded within the day Maternity – Admission of pregnant women to maternity ward

HES part 2: practical examples of applied HES data

Example - Assault by knife or sharp object Need to define ‘Assault by sharp object’ using ICD10 codes Only ‘emergency admissions’ and 1 st admission for each patient ICD10 codes (diagnosis) - all mentions –Coded as X99 – ‘Assault by sharp object’ (external cause of morbidity) But excluded the following 1.W25 to W26 – Injury may have been in part accidental 2.X78 – Self inflicted 3.Y28 – Undetermined intent

Mapping HES data

HES e-Atlas

Linkage Powerful investigative use of HES Linkage can be either: –Internal within HES (e.g. readmissions/patient pathways) –External to other databases (e.g. linked to cancer registrations, mortality, deprivation) Links are made either –Deterministically using an unique identifier (NHS number) –Or probabilistically using demographics and process measures, e.g. DOB, sex, postcode

HES Quiz - Questions 1.When does a HES data year start? 2.What is the difference between an episode and a spell? 3.What do we mean by clinical coding and what two sets of clinical codes are used within HES? 4.Give 2 limitations of HES data? 5.Give 2 strengths of HES data? 6.Give an example of when you might want to link episodes. 7.What is the main unit of measurement in HES? 8.What are the 2 main admission methods?

HES Quiz - Answers 1.1st April (financial years). 2.An episode is a patients period of care under one consultant and a spell is the patients entire stay in hospital. 3.Clinical coding refers to the diagnosis and operative procedure coding (ICD10 and OPCS4). 4.Data quality, timeliness, excludes private hospitals. 5.Covers all NHS hospitals, consistent, 16 years data, size. 6.To analyse patient care throughout a spell in hospital, identify repeat admissions, information may not appear on all episodes e.g.drug misuse. 7.Finished Consultant Episode (FCE) 8.Elective and emergency.

Top 5 best HES pages HES online Secondary Uses Service (SUS) NHS Classifications Service Unit of Healthcare Epidemiology (University of Oxford) Shape Toolkit (healthcare data with GIS)