A Systematic errors can result from both internal and external causes. The key to managing systematic errors in test results lies in identifying both the cause of the error and the individuals or groups that are affected by the erroneous results.
If reagents are improperly prepared or calibrated by the company supplying them, the laboratory may not realize, at least initially, that the results being produced are in error. In such a situation, the lab will be somewhat insulated from liability if it has adhered to reasonable, usual, and customary protocols for the tests being performed.
The simple fact that the source of the error lies in the reagents provided does not completely excuse the lab from responsibility for identifying that there may be a problem in testing. If, for example, the introduction of a new set of reagents produces a shift in the usual pattern of results, or if alternative methods used in the same lab show varying results, the laboratory has an obligation to investigate the discrepancy and to identify the source.
The other source of systematic errors lies within the lab itself, generally when improper calibration and correction factors are entered for automated testing. In such a situation, prevention is better than cure. The laboratory should have a fail-safe policy for ensuring that the appropriate adjustments are made whenever reagent lots are changed.
The laboratory should have a system for tracking reports of both internal and external systematic errors, not only to make appropriate notification to patients and physicians but also to apply the lessons learned from prior incidents in ongoing risk management. Technologists should be encouraged to be alert and to report discrepant results promptly.
One of the cases discussed in a recent article “Responding to large-scale testing errors” by Valenstein, Alpern, and Keren (Am J Clin Path, March 2010) involved aberrant HIV results that were recognized because an alert technologist noticed that a repeat result on a patient was negative when the initial test had been positive. In addition to reagent production errors, Valenstein and co-authors provide case studies of calibration problems and non-dispense events (resulting in dilutional errors) as causes for systematic errors, so the article is valuable as an exercise in evaluating the ways in which such problems may surface and the indirect effects they may have.
Once an error has been identified, the immediate task is to halt all testing by the involved method until the appropriate changes can be made and correct results ensured. As in any case of erroneous results, patients and physicians must be notified and additional testing offered. Determining how to make notification and whether patients as well as physicians need to be contacted directly should involve collaboration between the lab and its legal resources. Administrative convenience or the desire to limit exposure to economic liability are not a sufficient reasons to avoid making required notification.
Acknowledging the possibility in advance and developing a response plan is a sensible exercise for the laboratory — a kind of “internal disaster response” plan. Any such discussions should include the laboratory management, physicians, legal resources, and representatives from the hospital or corporate administration. An effective policy will include the following points:
- a way to monitor internal results as well as media and industry reports of potential errors;
- a mechanism for bringing these to the attention of laboratory management for evaluation and action when needed. This should include notification of the general laboratory staff of the problem. Laboratory staff should be aware of what is happening, but should also be instructed about how to respond to inquiries from others. In general, individual communication by laboratory staff on the subject should be discouraged, and all questions should be routed through designated individuals who are both informed and prepared to discuss the situation;
- designated personnel to spearhead investigation and corrective actions. This should provide “bench strength”— at least two individuals — so the absence of one staff member does not delay or compromise the process;
- a step-by-step procedure for investigation, and train the appropriate individuals. In addition, the entire staff should be familiar with the overall policy, especially as it affects privacy and security concerns;
- a process, including specifying stakeholders and resources, for determining who needs to be notified of a testing error. This process should include developing plans for necessary retesting and determining under what circumstances, if any, the patient will bear the cost of retesting;
- a notification and documentation process; and
- designated individuals to manage inquiries from physicians and patients; to communicate the status of corrective efforts to administration; and designated individuals to respond to media inquiries. There is generally no obligation to contact media or the public, but such inquiries may be made. There are circumstances that require public notification, such as anonymous testing in a health fair or when an environmental risk is involved. A policy that involves appropriate representatives early on, keeps them informed, and allows for a prepared response is desirable.
Barbara Harty-Golder is a
in Chattanooga, TN. She
maintains a law practice with
a special interest in medical
law. She writes and lectures
extensively on healthcare law,
risk management, and human