Risk adjusted Visual Acuity loss rate (%)

What this data shows:

For cataract surgery, the most important outcome is vision; this is what matters most to patients. Vision worse after the operation is adverse outcome.

How the data is gathered:

The VA data recording is currently not complete at most participating trusts. This has been recognised as a risk for the audit from the outset and despite significant efforts to improve this, including electronic data return tools for optometrists to use, this remains an issue. Data completeness varies widely by centre depending on the local patient pathway for post-op care. Centres and surgeons with <= 40% of both pre- and post-op VA data will be excluded from this outcome with a note to indicate that data completeness is inadequate for reporting. (The audit will be piloting the collection of a PROM as a patient focused primary outcome metric for benefit.)

When the data is shown:

Please note that some surgeons’ result will be above the overall consultant rate. The expected limits consider the number of operations undertaken by a surgeon (i.e. the sample size) and whether the rate is statistically higher or lower than might be expected for the number of operations. Small samples are associated with greater uncertainty and therefore wider limits, bigger samples have greater precision and narrower limits. It is normal for different clinicians and units to have different results and there is an expected range results can fall in. Sometimes results may fall outside the expected range, which could be an indication that the care provided is either significantly poorer or significantly better than expected. But sometimes these results just happen by chance. Detecting whether a result falls outside the expected range by change or because of a significant reason can be challenging. We want to reduce the times when we identify a unit or individuals results as being outside of the expected range just because of chance. We can do this by using a wide definition of the expected range. The narrower the definition of the expected range the greater the chance of a result being labelled as outside of it just because of chance. Audits participating in publication on NHS Choices and My NHS are asked to use statistical analysis to do this. Where we are able to identify a unit or individuals results as being significantly outside of the expected range using a wide definition, we will show this on the site. We don’t show units or individuals as being outside of the expect range using a narrower definition.

More information about the data source:

The data presented have been collected by NHS trusts and Independent Sector Treatment Centres (ISTC) providing NHS funded cataract surgery in England and submitted to the National Ophthalmology Database (NOD) Audit for analysis.

Data Source:

Trust electronic medical record (EMR) systems: e.g. Medisoft, OpenEyes, EPIC and in-house databases compliant with RCOphth national cataract dataset. For all sources, data used for the audit comprise actual (anonymised) hospital record for each patient.

Data Period:

01 September 2016 to 30 June 2017

Data Supplier:

The Royal College of Ophthalmologists’ National Ophthalmology Database (NOD) Audit

Further Information:

noa.project@rcophth.ac.uk www.nodaudit.org.uk