What Haemolysis Actually Costs a Diagnostic Laboratory
There is a number that most diagnostic laboratories track but rarely interrogate deeply: the haemolysis rejection rate. It appears in monthly quality reports, gets discussed briefly in team meetings, and is benchmarked against accreditation thresholds. When it climbs, there is concern. When it stays within an acceptable range, the conversation typically moves on. What that number rarely captures is the true cost of haemolysis , not just to the specimen, not just to the result, but to the laboratory as an operating entity.
The clinical consequences of haemolysis are relatively well understood: falsely elevated potassium, interference with lactate dehydrogenase and aspartate aminotransferase, disruption to coagulation assays, unreliable immunoassay results. These are documented, they are taught, and they are part of the standard vocabulary of laboratory medicine. The operational and financial consequences are talked about
far less. And in high-volume diagnostic environments, they compound in ways that are neither small nor
inevitable.
The Visible Cost: Rejected Specimens and Repeat Collections
The most immediate consequence of a haemolysed specimen is rejection. The sample cannot be analysed as submitted. A rejection notice goes to the requesting clinician or facility. A repeat collection is requested. The process begins again. Each rejection event carries a calculable cost that most laboratories absorb without formally accounting for it.
There is the staff time involved in identifying the non-conformance, logging it, communicating the rejection to the requesting party, and processing the repeat specimen when it arrives. In a laboratory receiving hundreds of specimens per day, even a 2% rejection rate , considered borderline acceptable under most quality frameworks , represents a meaningful administrative burden distributed across laboratory and collection staff simultaneously.
There is the consumable cost. The tubes, reagents, and processing resources used on a specimen that cannot be reported represent a direct write-off. For high-cost analytes , certain immunoassays, specialised coagulation panels, molecular tests , that write-off is not trivial. There is the courier or logistics cost where applicable. If a repeat specimen requires a second collection visit, or if the requesting facility is serviced by a scheduled route that has already passed for the day, the repeat collection may require an unplanned pickup with associated time, fuel, and coordination costs.
And there is the turnaround time impact. A rejected specimen does not simply delay one result. Depending on the clinical urgency and the test type, it may delay a treatment decision, a discharge, or a referral. In a time-sensitive clinical context, the downstream effects of a single rejected specimen extend well beyond the laboratory walls.
The Invisible Cost: Results That Pass and Shouldn't
The rejected haemolysed specimen is, in one sense, the best-case scenario. It is identified. It is flagged. It does not enter the clinical record as valid data. The more concerning situation is the haemolysed specimen that is not visually apparent , or that is not severe enough to trigger rejection , but that has already affected the analytical result in ways that go undetected.
Haemolysis exists on a spectrum. The haemolysis index, now reported automatically by many modern analysers, quantifies free haemoglobin in the serum or plasma and allows laboratories to apply interference thresholds per analyte. This is a significant quality improvement. But it depends on instrument capability, on the availability of interference data for every assay on the platform, and on the laboratory having clearly defined and consistently applied rejection criteria for each analyte at each level of
haemolysis.
Not all laboratories have this fully implemented. And even where they do, the haemolysis index reflects the haemoglobin concentration at the time of analysis , not the full history of what the specimen experienced during collection, storage, and transport. A sample that underwent subtle haemolysis during a temperature excursion in transit, then re-equilibrated in a cooler environment before arrival, may present with a haemolysis index that sits just below the rejection threshold while still producing analyte interference. The result is reported. The clinician acts on it. The error remains invisible unless a clinical discrepancy triggers
a retrospective review.
What Haemolysis Does to Specific Assays
Understanding the cost of haemolysis requires understanding the breadth of its analytical interference which is considerably wider than the commonly cited potassium elevation.
Potassium is the analyte most frequently associated with haemolytic interference. Red blood cells contain a potassium concentration approximately 23 times higher than that of plasma. Even mild haemolysis introduces sufficient intracellular potassium to produce a clinically significant apparent elevation. A patient whose true potassium is 4.0 mmol/L may appear to have a result of 5.2 or higher in a haemolysed sample, a value that could prompt unnecessary clinical intervention.
Lactate dehydrogenase (LDH) is predominantly intracellular and rises substantially with haemolysis, making it unreliable as a marker of tissue damage, haemolytic anaemia, or myocardial injury in a compromised specimen. Aspartate aminotransferase (AST) follows a similar pattern. Magnesium and phosphate are affected by the release of intracellular stores. Bilirubin measurements can be suppressed by haemoglobin interference in certain assay methodologies.
Immunoassay interference is less predictable and more assay-specific. Haemoglobin can interact with antibodies, alter reaction kinetics, and produce non-linear interference patterns that are difficult to characterise across all analyte-assay combinations. Hormone assays, tumour markers, and drug level monitoring can all be affected to varying degrees depending on the platform and methodology in use.
Coagulation testing presents a particular challenge. Haemolysis in a coagulation specimen introduces tissue factor from lysed red cells, which activates the extrinsic clotting pathway and artificially shortens prothrombin time and activated partial thromboplastin time. For patients on anticoagulation therapy , where precise INR measurement guides dosing decisions , a haemolysis-affected coagulation result is not merely inconvenient. It is potentially dangerous.
The Staff and Workflow Cost
Haemolysis management consumes laboratory staff time in ways that aggregate significantly at scale. Specimen assessors must visually inspect incoming samples for gross haemolysis before loading. Analysers with built-in serum indices require review of flagged results. Technologists must evaluate interference thresholds per analyte for borderline specimens, make decisions about partial reporting, and communicate selectively valid or invalid results to requesting clinicians , a nuanced communication task that takes more time than a standard result release.
In laboratories running lean staffing models, as most do, this time comes from somewhere. It comes from the pace of processing other samples, from the attention available for analytical quality monitoring, and from the bandwidth of senior staff who are often called to adjudicate borderline rejection decisions. The administrative overhead of haemolysis management is real, recurring, and largely invisible in any cost model that only tracks reagent expenditure and instrument throughput.
The Relationship Cost: Clinician Confidence and Referral Patterns
Diagnostic laboratories exist in a referral ecosystem. GPs, specialists, clinics, and hospitals choose where to send their specimens. In a competitive market , and in Johannesburg’s private healthcare sector, the market is competitive , the quality of the diagnostic relationship matters. A laboratory that consistently returns rejections, requests repeat collections, or occasionally reports results that clinicians find clinically implausible tends to create friction. In time, referral patterns shift.
This is not a hypothetical scenario. It is the quiet commercial consequence of a quality problem that is almost always attributed, when it is attributed at all, to collection technique at the referring facility , not to the handling that occurred after the specimen left that facility. The transport leg sits in a grey zone of accountability. The laboratory blames the phlebotomist. The phlebotomist is confident the collection was correct. No one has data on what happened to the specimen between the two. Chain-of-custody documentation and temperature logging during transport would resolve that question. In most cases, they
do not exist.
Where the Cost Originates and Who Absorbs It
Haemolysis originates at multiple points: patient factors, collection technique, post-collection handling, centrifugation, storage, and transport. Each of these is a potential source, and each sits under different institutional ownership. The laboratory owns the analytical and post-receipt process. The phlebotomist owns the collection. The collection facility owns post-collection storage. The courier owns transit. When haemolysis occurs, the cost is almost always absorbed by the laboratory , regardless of where in the chain the failure actually originated.
This misalignment between where costs land and where accountability sits is one of the structural problems of pre-analytical quality management. It creates limited incentive for upstream improvement, because the upstream parties rarely see the downstream bill. Laboratories that have meaningfully reduced haemolysis rates have typically done so by extending quality oversight into the pre-analytical chain working with transport partners to ensure that specimen conditions during the transit leg are monitored, documented, and held to a defined standard.
Reducing Haemolysis: The Lever Most Laboratories Underuse
Investment in collection training and phlebotomy technique is the most common lever laboratories reach for when haemolysis rates are elevated. It is a legitimate and often necessary intervention. But it is incomplete without parallel attention to what happens after the blood is drawn.
Temperature-controlled transport that maintains specimens within validated parameters, containers that minimise mechanical agitation during transit, couriers trained in the handling requirements of different specimen types, and documented temperature and time records from pickup to delivery , these are not premium features of a medical logistics service. They are foundational requirements for a transport partner that is genuinely contributing to diagnostic quality. The cost of haemolysis to a diagnostic laboratory is measurable. The cost of preventing it, through appropriate transport standards, is considerably smaller. The arithmetic of that comparison tends to become clearer when someone does the calculation.
