Performance indicators: good, bad, and uglyThe report of the Royal Statistical
Society working party on performance monitoring in the public services, chaired by Professor Sheila Bird
“Performance monitoring done well is broadly productive for those concerned. Done badly, it can be very costly and not merely ineffective but harmful and indeed destructive - of morale, reputations and the public services.”
Methodological rigour in selecting indicators
Sample surveys should be designed, conducted and analysed in accordance with statistical theory and best practice
Admin data should be fully auditable Concepts, questions, etc should be comparable and
harmonised where possible – conforming to national or international standards as appropriate
Indicators should be precise and accurate enough to show reliably when change has occurred
Definitions should be precise
Definitions of both indicators and targets should be Precise but practicable
useful definitions should be given for all the key concepts in the indicator or target
Consistent over time any changes to definitions or methods should be fully
documented Unambiguous
there should be no possibility of disagreement about whether progress is the indicator going up or down
Practitioners involved should have input For targets to be ambitious but achievable, a
good understanding of both the practicalities of delivery on the ground, and of the data, is needed
To understand the practicalities of delivery, practitioners should be consulted
Motivational but irrational targets may demoralise
Monitor for perverse outcomes Targets can lead to practitioners playing the
system rather than improving performance to meet badly thought through targets
An example from the report: An indicator for prisons is the number of “serious”
assaults on prisoners “Serious” = proven prisoner-on-prisoner assault The indicator would improve if prisons reduced
their investigations into assaults
Do not ignore uncertainty or variability Insistence on single numbers as answers to
complex questions is to be resisted Natural variability, outliers, recording errors,
statistical error (i.e. confidence intervals around sample estimates), all need to be considered
All need to be clearly presented
Do not set 100% targets 100% targets can lead to perverse outcomes,
demoralise when failure inevitably occurs, and lead to disproportionate resources being used
An example from the report: “No patient shall wait in A&E for more than 4
hours” This becomes irrelevant as soon as one patient
does wait more than 4 hours A&E staff may have very sound reasons for
making a small number of people wait longer
Do not ignore the distribution Performance Indicators are 1 number Single number summaries of data can be
misleading An example from the report:
“Number of patients waiting more than 4 hours” The whole distribution needs viewing to
understand the indicator e.g. has progress been achieved by getting most people seen in 3 hours 59 minutes but some not for 10 hours?
Do not mistake statistical significance for practical importance There can not be a difference of practical
importance if the difference is not statistically significant (because the difference might not be genuine – it could just be chance)
BUT A difference could be statistically significant
but not practically important (because statistical significance can be achieved by getting a huge sample size)
Consider not setting a target until data are well understood The statistical properties of an indicator will
be much better understood after one or two rounds of analysis
It may therefore be sensible to wait before setting a target
Document everything: Others should be able to replicate procedures All assumptions and methods should be fully
documented so that others can fully understand and replicate results
A ‘PM Protocol’ should include: Objectives Definitions Survey methods / information about data Information about context Risks of perverse outcomes How the data will be analysed Components of variation Ethical, legal and confidentiality issues How, when and where data will be published
The report is available on the RSS website here:
http://www.rss.org.uk/PDF/Performance%20monitoring%20231003.pdf