Bolton — Redesigning Diagnostics to Improve Patient Flow

The case describes patients waiting in hospital for scans and results, followed by changes to scheduling, information access and staff capabilities. The lesson is to investigate the actual delay before choosing a familiar solution.

What was reported

The original account reports that Bolton NHS Foundation Trust reduced diagnostic turnaround from weeks to days through Lean Six Sigma improvement work, supported by Statistical Process Control (SPC) tracking.

That is a claim about diagnostic flow. The material presented does not establish a quantified reduction in corridor care or show that diagnostics was the only constraint. Faster results can support discharge decisions, but further evidence is needed to connect the pathway improvement with hospital-wide outcomes.

What changed in practice

The team used value-stream mapping—following the patient’s journey and the information needed at each step—to examine diagnostic waits. The account identifies three changes:

• More responsive scheduling: replacing inflexible booking arrangements with queues that can respond to clinical need and inpatient urgency.
• Expanded staff capabilities: training and authorising radiographers to undertake appropriate procedures, with the required competence and clinical governance.
• Accessible imaging: making existing images available across teams to reduce unnecessary repetition and delays caused by missing information.

The approach is described as Define, Measure, Analyse, Improve, Control (DMAIC). The value is in connecting observation, a supported explanation and follow-up measurement—not in the method’s name alone.

Why this matters

A queue in one place may be produced by a delay elsewhere. A patient waiting for a bed may be affected by another patient’s wait for a diagnostic decision. Investigate the whole pathway rather than assuming that every flow problem requires the same discharge intervention.

Ask what decision is waiting, what information it needs and what prevents that information arriving. A similar redesign elsewhere must account for demand, staffing, equipment, skills and the needs of other patients. See Finding the Real Constraint for the underlying investigation question.

What remains unproven

The account describes sustained SPC improvement, but the underlying charts and dataset are not reproduced here. SPC can provide meaningful evidence; a separate Bootstrap CUSUM analysis is not a prerequisite for recognising it, nor can its result be assumed from a description.

• Outcome: did faster diagnostics affect length of stay, discharge decisions and corridor-care exposure?
• Safety and displacement: were diagnostic quality, outpatient waiting times and staff workload maintained?
• Persistence: do skills, scheduling arrangements and information access remain reliable as demand and personnel change?

For a future test, agree expected effects and evaluation criteria beforehand. Check implementation and other changes as well as the outcome series. A detected change does not establish which component caused it.