13 Research methods, statistics, critical review and evidence-based practice13.11 Clinical governance

13.11 Audit, change planning, feedback and PDSA

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Written by Resident Doctor Committee · Published

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Series
Days from referral to first appointment by period20 points with a median of 9.0. 1 shift: something other than chance is acting on this process.5101514710131619Week1Median 9.0
Ordinary variationShift: 6 or more on one side of the medianTrend: 5 or more rising or falling (square marks)
Median
9.0Days from referral to first appointment
Shifts
1
Trends
0
Variation
Special cause1 shift: something other than chance is acting on this process.
  1. 1Week 13. PDSA 1: pharmacist on ward round
Weekly missed medication doses, with a pharmacist joining the ward round at the PDSA 1 marker. Watch the shift rule highlight at the sixth point below the median, then change a later value to 11 and see whether the shift still holds.

Quality improvement, audit and research

  • Quality improvement is the systematic, continuous, systems-focused and blame-free effort to make care safer and better, joining analysis of system performance to tested changes.

  • Clinical audit compares care with an explicit standard, acts on the gaps and measures again, so it covers only one part of quality improvement.

  • Service evaluation asks how an existing service performs.

  • Research tests interventions whose benefit is not yet established, whereas quality improvement tests changes that stay within accepted standards of care.

  • Randomising treatment generally makes a project research needing Research Ethics Committee review, which audit and service evaluation do not need on those grounds alone.

  • A local project that finds affected patients, reviews them, educates staff and changes the prescribing system to close a known safety gap is quality improvement, not observational research.

  • SQUIRE is the consensus reporting guideline for formal studies of healthcare quality improvement.

The audit cycle

  • Define the criterion, target standard, eligible denominator and legitimate exceptions, such as refusals, before collecting data.

  • Closing the cycle means acting on the gaps, then measuring again on comparable definitions.

Clinical governance and incident reporting

  • Clinical governance holds organisations accountable for the quality and safety of care through incident learning, complaints, mortality review, audit, appraisal and regulation.

  • A patient safety event is formally recorded through the organisation's incident reporting system before any Plan-Do-Study-Act (PDSA) work begins.

  • Under the statutory duty of candour, being open or apologising is not an admission of liability.

The Model for Improvement

The Model for Improvement (Langley, Nolan and colleagues) opens with three fixed questions, then tests changes in PDSA cycles.

Question

What it defines

What are we trying to accomplish?

The aim

How will we know a change is an improvement?

The measure

What changes might produce improvement?

The changes to test

  • The questions are revisited as PDSA cycles generate learning, not settled once as a rigid prerequisite.

Plan-Do-Study-Act cycles

PDSA cycles test a change on a small scale against a prediction made beforehand, refining it before wider implementation.

Stage

What happens

Plan

Set out the change, roles, timing, measures and prediction

Do

Run the change and record what happens

Study

Learn from the data by comparing results with the prediction

Act

Adopt, adapt or abandon the change for the next cycle

  • A reminder tested on five patients predicts four complete checks; when broken equipment leaves two complete, the team fixes the process instead of sending more reminders.

  • PDCA (Plan-Do-Check-Act) is the older wording suited to error correction and fault detection, where Check means inspection against a standard.

  • Clinical audit also cycles, but it measures compliance with a standard rather than testing a change against a prediction.

Other improvement approaches

Approach

What it does

FOCUS-PDCA

Five preparatory steps (find a process, organise a team, clarify what is known, understand why it varies, select the improvement), then PDCA

DMADV (Six Sigma)

Define, measure, analyse, design, verify or validate, to build a new process or service to a set standard; DMAIC improves an existing one

Lean Thinking

Removes waste: defines value from the user's view, maps the value stream and strips out steps that add no value

Root cause analysis

Looks back at a single incident, used only after harm has occurred

Failure mode and effects analysis

Looks ahead for failures proactively

  • PDSA is prospective and iterative, while Lean and statistical process control look at whole ongoing processes.

Tools for understanding a problem

Tool

Layout

What it shows

Flow chart (process map)

Stages of a pathway in order, with standard symbols for actions, decisions and hand-offs

Waits, loops and duplicated steps

Fishbone (Ishikawa, cause and effect) diagram

Problem at the head, possible causes grouped under category headings off a central spine

Root causes brainstormed before data are gathered

Pareto chart

Counted causes as bars from most to least frequent, with a cumulative percentage line

The vital few causes behind most of the problem (80/20 rule)

Driver diagram

Aim, then broad primary drivers linked directly to it, narrower secondary drivers and specific testable change ideas

Change ideas, each testable in a PDSA cycle

In a Pareto chart, counted causes run from most to least frequent and the cumulative line shows the vital few: here the first three of six categories already account for 82% of complaints (illustrative figures). Drawn for MRCPsychiatrist
  • The links in a driver diagram are hypotheses to test, not established causes.

Measuring change over time

Measure

Example

What it shows

Outcome

Median length of stay

Whether the targeted result changes

Process

Discharge date recorded within 72 hours

Whether the intended process changes, not causation

Balancing

28-day readmission

Consequences elsewhere

Chart

Centre line

Limits

Signal

Run chart

Median

None calculated

Patterns such as six points on one side of the median

Control chart (Shewhart or statistical process control chart)

Mean

Upper and lower limits at three standard deviations

A point beyond a limit, meaning special cause variation rather than routine noise

Points are plotted in the order collected and joined by a line, with a horizontal median (73) drawn through the data; shifts and trends are judged against this median. w:User:Craigkbryant, Public domain, via Wikimedia Commons
A Shewhart control chart adds calculated upper and lower control limits around a centre line, and the red points beyond the upper limit signal special cause variation rather than routine noise. DanielPenfield, CC BY-SA 3.0, via Wikimedia Commons
  • Both charts plot points in time order, and a signal does not reveal its own cause.

Feedback and interpreting results

  • A 2025 Cochrane review found audit and feedback gave a median absolute improvement of 2.7 percentage points (interquartile range 0.0 to 8.6).

  • Feedback works better from a trusted source, with relevant benchmarks and a clear statement of what to do.

  • A before-and-after improvement may reflect a secular trend, regression to the mean, an observation effect or a changing case mix.