DR.Tony Chan：Clinical Laboratory Errors

云康集团首席医学官，加拿大多伦多大学终身教授，博士生导师，检验医学及生化科学、数学科学及计算机科学双博士，现任国际临床和实验室标准化协会（CLSI）委员，美国临床化学协会（AACC）委员，中国合格评定国家认可委员会技术委员会（CNAS）医学分委会委员、评审专家、顾问。

Clinical Laboratory Errors

By Tony Chan, PhD, Professor, PhD supervisor.

In clinical laboratory operational cycle, there are three phases of operations, namely Pre-analytical, Analytical, and Post-analytical. Errors can occur during these three phases of operation. Which improvements should be made first? Unfortunately, we seem to be arguing that some errors are more important (worse) than others. But rather than make a Chicken-or-Egg choice, we need to analyze these types of errors. The answer to the question of which improvements come first need not be “pre-analytical”, or “analytical”, or “post-analytical” – it should be all three phases at once.

01

Making sense of conflicting priorities in clinical laboratory.

We have often heard the opinion that the Quality Control of clinical laboratory testing is not the biggest problem we are facing. Sometime people quote a statistic that 40% of the errors in clinical laboratory are pre-analytical, 40% are post-analytical, and "only" 20% are analytical.

There are more "P-errors" than "A-errors", therefore, many clinical laboratories believe they should put a higher priority on pre- and post-analytical errors than on analytical errors.

Firstly, you may find it depressing when we admit we've got problems everywhere and we only argue over which problems are worse, which problems will be fixed next, and which problems will be ignored for the time being. Ignoring problems is not a good thing. We should be incensed that we have got so many errors in so many different areas of clinical laboratory testing and patient care.

The source of this commonly accepted knowledge about clinical laboratory errors is an abstract,not a peer-reviewed paper. It seems that people want to believe that analytical errors are not as frequent as the pre-analytical and post-analytical errors. This belief is part of today's quality compliance mentality that assumes analytical quality is okay if clinical laboratories follow rules and regulations. Clinical laboratories assume they do not have any problems with analytical quality. If forced to admit they do, then they respond that there are other bigger problems that are more important, therefore they don't need to deal with analytical quality.

This "Sources of Errors" assumption threatens to become an excuse to avoid Quality Control. If we refuse to confront our analytical errors, if we postpone improving them while we work on the "bigger" problems, we let the QC problem fester and grow. The longer we wait, the worse the problem gets. No one denies that there are pre-analytical and post-analytical errors in healthcare. Nor can we, unfortunately, say that these errors are small or insignificant.

However, we must challenge the notion that analytical errors are the "smallest" and therefore least important problems we face in clinical laboratory. We hope, by examination of the problem and by a few crude analogies, we can convince you of this.

02

Whose Errors are More "Obvious"?

What's the most obvious error?

1. A patient sample that doesn't get to the lab.

2. An instrument with a systematic bias.

3. A test result that gets reported on the wrong patient.

Pre-analytical and post-analytical errors tend to fall into the "obvious" categories. When patient samples are improperly collected, mislabeled, are not delivered in time, or are lost, it is obvious that some sort of error has occurred in the pre-analytical stage. When the results of a test are not reported in time, or if they are entered into the wrong patient record, it's also obvious.

Perhaps we should unify the pre-analytical and post-analytical error categories. They fall into one bigger, more important category. It's the "This Error Makes the Doctors Angry" category.

The doctor can quickly identify when a pre- or post-analytical error has occurred and find fault with those "responsible" for the error. Since doctors throw a lot of weight around a hospital, their complaints become the most important. This is probably why pre-analytical and post-analytical errors are believed to be the "bigger" problems. The doctors' shouting tends to be louder, and heard more, than any other voices.

In contrast, analytical errors fall into the "This Error CANNOT readily be detected by the Doctor" category. When the doctor receives the test results from the laboratory, all he or she gets is the numbers. There is no way to know if those numbers are biased up or down because of method or instrument problems, or if there is some strange random fluctuations that are throwing off the result. Perhaps the doctor might suspect an analytical error, if the test results are extremely divergent from all the other symptoms the patient is showing, but even then the doctor can only guess (and most likely, order more testing!). For analytical quality, the doctors are completely dependent on the laboratory for the detection and correction of errors.

It's common sense that patient samples should be collected in the proper way, and that they should be labeled correctly to clearly identify which patient they were taken from. It's common sense that patient results should be delivered to the correct patient and doctor, too. The reason these don't happen is not a lack of understanding, it is an overload of information and traffic.

Hospitals are strained by the amount of patient information that they must manage. Many times, the clinical laboratory cannot correct those problems -it's a hospital-wide systemic problem. Those kinds of problems likely occur throughout the healthcare process, including the examination and operating rooms.

03

Which Errors are Worse?

Another question raised by the coexistence of pre-analytical, post-analytical, and analytical errors is this: which ones affect the patients most? We think this is a triple dead heat. If you cannot get the patient specimen to the laboratory, if you cannot perform the test correctly, and if you cannot deliver the results back to the patient, the consequence is the same: poor patient care. No error is worse than the other. They are all equally terrible.

Let's put it this way: if you solve all the pre-analytical and post-analytical errors, but have not solved the analytical errors, you are still delivering bad patient care. To be sure, the patient sample got to the laboratory correctly and the result came back to the right patient, but the number is wrong - it's biased or totally off. How can the doctor make a good decision with bad numbers? In many cases, the doctor is forced to run the tests against, or rely on his or her "judgment."

In the end, all the errors are equally bad. No error is worse than another. In every case, you don't get the medical care you deserve.

04

Which Improvements Come First?

Progress in the clinical laboratory testing area needs to happen all at once. We must reject the notion that progress can only be come in one area at a time. The problems are too great to go slowly. We must make efforts on all fronts. Even if this means making small improvements in each area, a unified improvement effort will achieve better test results and better patient care than narrow efforts in either the pre-analytical, post-analytical, or analytical area.

If you improve in just one area, you are still delivering bad results and bad patient care. If your pre-analytical errors are greatly reduced but you have made no improvement elsewhere,nothing is that much better. All you're doing is delivering bad test results faster.

05

Whose job is it to provide correct test results?

That's us-the professional laboratorian. We arethe critical element that remains behind-the-scenes.No patient asks to see the medical technologist who ran the test.Unfortunately,we are the invisible but irreplaceable workforce in the hospital. And our invisibility often makes our problems invisible to upper management.

But just because others don't see us doesn't mean we do not have the responsibility to make our concerns heard and seen.

06

A Final Thought: What's the Core Job of a Clinical Laboratory?

This is another simple question, but laboratorians give a wide variety of answers.

The clinical laboratory produces test results. You feed in samples; it feeds out numbers. The core job of a clinical laboratory is to produce the correct test result. If we cannot get the test results right, then we are not doing our core job.

All three types of errors need to be addressed NOW. Each has different root causes, and each may require a different approach to solve. In some hospitals the clinical laboratory is not responsible for drawing the sample and getting it to the clinical laboratory. Thus, the pre-analytical error is not something that the clinical laboratory can address alone. Similarly, many clinical laboratories report data through a computer system, and it may take the Information Services folks to help with post-analytical errors.

But if we in the clinical laboratory are not producing accurate test results, why are we there in the hospital? A random number generator would be more efficient and certainly cheaper.

It is our profession to know all the details of testing and instrumentation and quality control. It is our profession to assure that test results are correct.

云康

云康集团源于中山大学，致力于医学健康服务业的发展，聚焦于客户的健康需求，提供有竞争力的解决方案与服务，为大众创造幸福生活。

如欲了解更多信息，敬请联系邮箱pr@yunkanghealth.com。