The testing blind spot

While the NHS pours millions into state-of-the-art laboratory analysers boasting near-perfect precision, a chaotic, paper-heavy pre-analytical sample collection process undermines patient safety. From degraded blood samples to labelling errors, the critical four-hour window before analysis has become a major diagnostic blind spot costing the health system unnecessary money and risking patient harm. This article analyses why the healthcare sector must shift its focus from laboratory instrumentation to digital integration, pioneering software and better workflows to bridge the dangerous gap between clinical diagnosis and laboratory insight.

Four hours is the time a blood sample has before cellular degradation sets in and haemolysis begins to compromise the result. In a hospital laboratory processing thousands of bloods per day, that clock is already running by the time a sample arrives. Delays in specimen reception – caused by having to relabel tubes, register date and time of arrival, prioritise urgent samples, cause tubes to build up and delays in analysis. This has led some labs to stabilise all samples soon after arrival through centrifugation – which separates the serum or plasma from the red blood cells. It is the breakdown of the red cell membrane which leads to leakage of potassium and other enzymes into the serum or plasma leading to ‘unsuitable for analysis’ or incorrect results. At best, patients are recalled, re-bled and rebooked, doubling the cost of the test. For a fragile oncology patient or an infant in a neonatal unit, this repetitive venepuncture is not merely an administrative inconvenience; it represents physical trauma and a direct delay in time-critical treatment. At worst, when the sample is used anyway, the results are inaccurate.

The reality is that most so-called lab errors (70%) are not lab errors at all.1 They happen before a sample has even reached the analyser, at the point of ordering, collection, labelling and transport. Poor label quality alone means that between 12 and 15% of all tubes must be pulled from the analyser and manually relabelled, introducing delay and fresh opportunity for error.2,3 The problem is worst for samples arriving from community diagnostic centres and GP surgeries, where relabelling is almost the rule rather than the exception. When low-resolution thermal printers or misaligned label templates are used at the bedside, the resulting barcodes are often unreadable by automated laboratory systems. This forces skilled biomedical scientists to step away from clinical analysis to manually transcribe data and reprint labels, creating a prime opportunity for human error.

This reliance on manual intervention also creates a parallel, low-tech workflow inside high-tech facilities, completely defeating the purpose of multimillion-pound laboratory automation. Every year in the UK, more than 50 million blood tubes are relabelled on arrival at the lab. Common missteps in blood draw technique, patient verification, tube selection, or transport timing can skew results or lead to misdiagnoses that have very real and dangerous consequences for patients. Many large labs are relabelling between 10,000 and 15,000 tubes every single day. In emergency departments, where the pressure is highest and the stakes are greatest, haemolysis rates run at 17 to 25%. Among inpatients the figure sits between 4.5 and 10%.2,3 Laboratories have responded to this tide of unusable samples with the only tool available to them: centrifugation, stabilising thousands of tubes so that plasma or serum separates from the erythrocytes before degradation takes hold.

Labelling is also a key issue that causes direct patient harm. In some hospitals, phlebotomists print blood tube labels at a central nursing station before beginning their ward rounds, then attempt to match labels to patients as they go around. It’s hardly surprising that they sometimes get it wrong. A mismatch rate of just 0.6%, observed in one studied hospital, translates to roughly two incorrect results every day for a 1,000-bed teaching hospital bleeding 300 patients daily, or around 800 incorrect results per year. If only 5% of those tests are clinically critical, the estimate is that 40 patients are harmed annually from labelling errors alone. Wrong blood in tube (WBIT) incidents remain among the most serious patient safety threats in diagnostic medicine. A WBIT error occurs when a blood sample is drawn from one patient but placed into a tube bearing another patient’s label, or when the tube is completely mislabelled at the bedside. In the context of blood transfusion medicine, the stakes of this logistical failure are catastrophic. If an incorrect sample leads to a misidentified blood group, the patient may be transfused with incompatible blood, triggering an acute haemolytic transfusion reaction.

The bitter irony is that the NHS has spent heavily on the analytical end of this chain. Modern laboratory analysers achieve error rates as low as 0.0001%. That precision is extraordinary. It is also almost entirely undermined when the tube arriving at the analyser carries the wrong patient’s name, or has been degraded in transit, or cannot be read by the machine at all. Investing millions in a state-of-the-art analyser while tolerating a broken pre-analytical workflow is an unjustifiable waste of investment. Many healthcare systems still depend on paper request forms, handwritten labels, and fragmented communication between clinical and laboratory teams. Research by Barak and Jaschek confirms this and demonstrated that IT-driven interventions such as barcoded tubes, centralised laboratory information system integration or automated clinical-to-lab data transfer reduced pre-analytical errors from 2.7% to 0.77% across millions of tests.2,3

The tools to fix the blood workflow in the NHS exist but their introduction depends on how the diagnostics supply chain thinks about its role. Pathology laboratories can no longer position themselves as passive recipients of whatever arrives at the intake hatch. The NHS Getting It Right First Time (GIRFT) programme is clear on this point: quality must be measured and improved across the entire diagnostic journey, from the moment a clinician places an order to the moment a result lands in front of her.

For labs this is both a challenge and a call to action: labs must become internal champions within their Trusts. That means showing CEOs and operational decision-makers that without intervention at the pre-analytical stage, the hospital will continue to waste money and generate incorrect blood results. Lab leaders need to build clear financial use-cases demonstrating that reducing pre-analytical errors frees up bed capacity, reduces length of stay and lowers procurement costs for wasted collection materials. Trusts that modernise their pre-analytical workflows will stop haemorrhaging money on relabelling, repeat bleeds and wasted high-precision analysis. Those that do not will keep generating the kind of incorrect results that erode clinician confidence in diagnostic testing altogether. accumulate year-on-year, that is not a small claim.

The North Central London Integrated Care Board (NCL ICB) offers a working proof of concept at scale. Across NCL, digital integration at the point of care has fundamentally changed how blood testing works. Clinicians order digitally, patients can be bled anywhere in the area (in a pharmacy, a community clinic, a GP’s surgery) without a paper form and without the risk of being turned away for incomplete documentation. Primary and secondary care are no longer operating as separate systems with incompatible paperwork. Pharmacy and community phlebotomy could work in tandem, with results routed correctly to the ordering clinician regardless of where the draw took place. For laboratory professionals, the significance is immediate: relabelling is eliminated and full chain-of-custody tracking runs from order placement to confirmed lab arrival. The GIRFT objective is no longer an aspiration in NCL. For a sector that has watched pre-analytical backlogs

What NCL demonstrates, and what the healthcare system should take seriously, is that the pre-analytical crisis is not unsolvable. It is a process failure. Mislabelled tubes, incompatible barcodes, degraded samples, wrong patient assignments are not problems that require a new equipment. What they require is smarter integration at the point of care, and the willingness to treat the diagnostic journey as a single connected system rather than a series of handoffs between departments that do not talk to each other. The consequences of continuing to ignore the pre-analytical stage are measurable in patient harm, in wasted laboratory capacity and in the slow erosion of confidence in diagnostic results among the clinicians who depend on them.

A professor of Medicine at University College London, UK, an experienced clinician working in the Royal Free London as a hepatologist, acute physician and a clinical pharmacologist, Professor Kevin Moore is also an author of the Oxford Handbook of Acute Medicine with 200,000 sold copies. As a clinician, he has experienced the many frustrations of manual workflows, which lead to patients becoming lost in the system, either in referral or long-term follow-up. During COVID, the problems faced by the many patients under long-term surveillance became acutely manifest, leading him to tackle the technological challenges impacting patient safety head-on by co-founding Salutare.