Trust-, Local Health Board- and unit-level activity and outcomes

Part Four: Implant- and unit-level activity and outcomes 2014

OUTLIER UNITS FOR 90-DAY MORTALITY OR REVISION RATES FOR THE PERIOD 2003 TO 2014

The observed numbers of revisions of hip and knee replacements for each hospital were compared to the numbers expected given the unit’s case-mix in respect of age, gender and reason for primary.

Hospitals with a much higher than expected revision rate for hip and knee replacement have been identified (and can be found listed over the page). These hospitals had a revision rate that was above the upper of the 99.8% control limits (these limits approximate to +/-3 standard deviations). We would expect 0.2% (i.e. one in 500) to lie outside the control limits by chance with approximately half of these (one in 1,000) to be above the upper limit.

When examined over the life of the registry, a total of 22 hospitals reported higher than expected rates of revision for knee replacement and 39 hospitals had higher than expected rates of revision for hip surgery.

However, revisions taken only from the last five years of the registry show a drop to eight hospitals reporting higher than expected rates for knees, and six for hips.

The 90-day mortality for hip and knee replacement was calculated for all hospitals by plotting standardised mortality ratios for each hospital against the expected number of deaths. One hospital (closed in 2013) had a higher than expected mortality rate for knee replacement while none were identified for hip replacement.

Note: The case mix for mortality includes age, gender and ASA grade. Trauma cases and failed hemi-arthroplasties have been excluded from hip mortality analysis together with hips implanted for metastatic cancer since November 2014 (when recording of this latter reason began).

Note: Any units identified as potential outliers in Part Four have been notified. All units are provided with an Annual Clinical Report and additionally have access to an online NJR Management Feedback system.

Important note about the outlier hospitals listed below

In previous Annual Reports, the NJR have reported outlying hospitals based on all cases submitted to the NJR since 1 April 2003. To reflect changes in hospital practices and component use, the NJR now also reports outlying hospitals based on the last five years of data (21 February 2010 to 20 February 2015 inclusive, the latter date being when the dataset was ‘cut’).

Where an outlier hospital has deviated more markedly than the remainder of the outlier group, this is marked with an asterisk*. This reflects where the revision rate is the upper of the 99.99% control limits.

Outliers for hip mortality rate since 2003: None identified

Outliers for knee mortality rate since 2003: Redwood Diagnostic Treatment Centre (closed in 2013)

Outliers for hip revision rates since 2003 (note 1):

Nevill Hall Hospital *
The Royal London Hospital *
Sussex Orthopaedic NHS Treatment Centre *
Llandough Hospital *
Prince Charles Hospital *
Queen Elizabeth The Queen Mother Hospital
Basingstoke and North Hampshire Hospital *
Homerton University Hospital
The Tunbridge Wells Hospital
Medway Maritime Hospital *
Northampton General Hospital (Acute)
University Hospital Of Hartlepool *
University Hospital Of North Tees *
North Tyneside General Hospital *
St Michael's Hospital *
Salisbury District Hospital
Musgrove Park Hospital *
Rotherham District General Hospital *
Pilgrim Hospital *
Hospital Of St Cross
St Albans City Hospital *
Watford General Hospital *
York Hospital *
BMI Gisburne Park Hospital (Lancashire) *
BMI The Somerfield Hospital (Kent) *
Shepton Mallet Treatment Centre (Somerset) *
Nuffield Health Brighton Hospital (East Sussex) *
Nuffield Health Tees Hospital (Cleveland) *
Nuffield Health Wessex Hospital (Hampshire)
Nuffield Health York Hospital (North Yorkshire) *
Ashtead Hospital (Surrey) *
New Hall Hospital (Wiltshire) *
The Berkshire Independent Hospital (Berkshire)
Clifton Park Hospital (North Yorkshire) *
Dunedin Hospital (Berkshire)
Spire Alexandra Hospital (Kent)
Spire Cardiff Hospital (Glamorgan) *
Spire Gatwick Park Hospital (Surrey) *
Spire Tunbridge Wells Hospital (Kent)

Outliers for knee revision rates since 2003 (note 1): 

Basildon University Hospital
Bradford Royal Infirmary *
Llandough Hospital
Conquest Hospital *
Good Hope Hospital *
Withybush General Hospital *
Charing Cross Hospital
James Paget University Hospital *
Southmead Hospital *
Southampton General Hospital
South Tyneside District Hospital
County Hospital Louth
St Richard's Hospital *
St Albans City Hospital
BMI Goring Hall Hospital (West Sussex)
Shepton Mallet Treatment Centre (Somerset)
Southampton NHS Treatment Centre (Hampshire)
King Edward VII Hospital Sister Agnes (Greater London) *
New Hall Hospital (Wiltshire) *
Spire Alexandra Hospital (Kent) *
Spire Clare Park Hospital (Surrey)
Spire Southampton Hospital (Hampshire) *

Outlier for Hip revision rates since 2010 (note 2)

Wrexham Maelor Hospital
Sussex Orthopaedic NHS Treatment Centre *
Homerton University Hospital
The Tunbridge Wells Hospital
Watford General Hospital
BMI Clementine Churchill Hospital (Middlesex)

Outlier for Knee revision rates since 2010 (note 2)

Charing Cross Hospital
South Tyneside District Hospital
County Hospital Louth
St Richard's Hospital *
BMI The Meriden Hospital (West Midlands)
Southampton NHS Treatment Centre (Hampshire) *
King Edward VII Hospital Sister Agnes (Greater London) *
Spire Southampton Hospital (Hampshire) *

(Note 1) - 1 April 2003 to 20 February 2015 inclusive.
(Note 2) - 21 February 2010 to 20 February 2015 inclusive.

Implant- and unit-level activity and outcomes 2014

Part Four of the annual report gives performance and data entry quality indicators for Trusts, Local Health Boards (many of whom comprise more than one hospital) and independent (private) providers in England, Wales and Northern Ireland for the 2014 calendar year. Outcomes analysis after hip and knee replacement surgery is also provided for the period 2003 to 2014. This year we have also included data for implant outliers.

Clinical activity

Overall in 2014, 151 NHS Trusts and Local Health Boards (comprising 245 separate hospitals) and 178 independent hospitals reported patient procedures to the NJR. The proportion of joint replacements entered into the NJR against those carried out (compliance) is only available by NHS Trust and Local Health Board. No data on this is currently available from private providers.

• 46% of NHS providers reported 95% or more of the joint replacements they undertook
• 37% of NHS providers reported between 80% and 95% and
• 17% of NHS providers reported less than 80%

Note: these figures exclude units in Northern Ireland as compliance is not available.

Of those hospitals submitting data, the proportion of patients who gave consent for their details to be entered into the NJR (consent) were:

NHS hospitals

• 51% of NHS hospitals achieved a consent rate of greater than 95%
• 35% achieved a consent rate of 80% to 95% and
• 14% recorded a consent rate of less than 80%

Independent hospitals

• 74% of independent hospitals achieved a consent rate greater than 95%
• 21% achieved a consent rate of 80% to 95% and
• 5% recorded a consent rate of less than 80%

Similarly, the proportion of entries in which there is significant data to enable the patient to be linked to an NHS number (linkability) are listed below:

NHS hospitals

• 87% achieved a proportion of patients with a linkable NHS number greater than 95%
• 12% achieved a proportion of 80% to 95% and
• 2% recorded a proportion of linkable records of less than 80%

Independent hospitals

• 61% achieved a proportion of patients with a linkable NHS number greater than 95%
• 33% achieved a proportion of 80% to 95% and
• 6% recorded a proportion of linkable records of less than 80%

Independent hospitals might be expected to have lower linkability rates than NHS hospitals, as a proportion of their patients may come from abroad and not have an NHS number.