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Stepwise Success

Distractions Cause Errors
October 20, 2014 6:01 AM by Scott Warner

A study at Michigan State University found that three second interruptions doubled error rates; longer distractions increased errors. Another study in Australia found that nurse medication errors increased twelve percent for every interruption. And a study at Oregon State University showed that 8 out of 18 surgical residents made serious errors when distracted.

In the laboratory we think of distractions as part of the job. But distractions cause errors.

I’ve never worked in a lab where I wasn’t constantly interrupted by telephone calls, buzzers, STAT work, and chit chat. Most labs are chaotic, noisy places geared around getting work done with minimal error. Yet distractions that cause errors are built into the system.

The Wall Street Journal reports that distractions are increasing in the workplace, partly because of a reliance on internal email and meetings to communicate. One professor at the University of California at Irvine found that workers typically have three minutes of uninterrupted time on a task.

Bench techs loading specimens, monitoring instruments, and verifying results who are constantly interrupted and distracted may have less time than that. Many tests are built around a prep-wait-offload cycle, and those wait times vary from a few minutes to hours. A distraction at either end can be disastrous.

Not all distractions are equal. Many techs will cite telephone calls, but any event that derails a planned prep-wait-offload cycle counts. This includes instrument problems, critical values, failed quality control, nosy colleagues, and even bathroom breaks. Once away from a task, it is even easier to be further distracted and forget one’s place.

While everyone works this way, that doesn’t make it right, especially if it causes serious errors. We all are too busy on the treadmill to step off. It’s a logical quality improvement goal in labs, but I’ve never seen a process designed with a “no distraction” ground rule. We all assume it’s impossible.

But why? It’s not an unreasonable thought. If possible it is not valued despite the evidence that it contributes to medical errors. Phones ring, pagers beep, timers ding, busybodies chatter, and have you checked your email today?

NEXT: Vanity Metrics

For the Best Results, Hire Professionals
October 15, 2014 6:03 AM by Scott Warner

The late oil well firefighter Red Adair said, “If you think it’s expensive to hire a professional to do the job, wait until you hire an amateur.” During staffing shortages or budget crunches it can be expedient to hire a warm body but disastrous in the long run. Amateurs often don’t know what they don’t know, think they know more than they do, and lack an ability to self-correct behavior that all professionals possess. Amateurs just don’t “get it.”

Anyway, it’s a great quote. While it’s easy to toss around labels like “professional” and “amateur,” what do they mean?

Merriam Webster defines professional as “characterized by or conforming to the technical and ethical standards of a profession” and “exhibiting a courteous, conscientious, and generally businesslike manner in the workplace.” An amateur is “a person who does something poorly; a person who is not skillful at a job or other activity” and “one lacking in experience and competence in an art or science.”

Sure, amateur isn’t a compliment, but we hire plenty of them. I’ve seen managers hired because they applied (one euphemism is “stepped up to the plate,” like that’s a qualification for the job), techs hired out of desperation, and travellers hired without a lot of searching or screening. Some -- not all -- exhibited amateurish skills in making decisions, leadership, bench competency, and ethical behavior.

We all recognize an amateur decision or level of skill, yet it’s a taboo subject. I even hesitate to write about it. But I’ve worked for and beside professionals and amateurs, and there is a difference between the two. This is also distinctly different from an inexperienced person, who should not be promoted or placed in a position where he or she can appear to be an amateur.

I’ve never seen it or asked it during an interview, but questions like “Do you consider yourself a professional, and why,” “How do you define professionalism,” and “Give examples of your professional behavior” all work. Assuming someone is professional because he or she has a degree or resume can be an expensive mistake.

NEXT: Distractions Cause Errors

IG# and Sepsis
October 10, 2014 6:15 AM by Scott Warner

Our current hematology analyzer was a big step up from a Sysmex K4500 with a 3-part differential to a Sysmex XT-1800i with a 5-part differential. I remember arranging a conference call between the bean counters and the pathologist to explain why the difference was important. Since then we have successfully eliminated percentage differential reporting, bands on scans, and reduced manual differentials to one or two a day. Automated counts have arrived.

I’ve had my eye on analyzers for a year or more, and it’s time to upgrade again. The new analyzers perform a 6-part differential, adding an immature granulocyte (IG#) parameter. This has been available on the 1800 under the “Research” tab, but it isn’t anything we have used. Reporting it routinely will be useful.

In cases of SIRS (systemic inflammatory response syndrome), the IG count can differentiate between infected and non infected patients; one source cites a sensitivity of 89.2%. Another study points out the correlation between bacteremia and the IG is high, correctly stating that the so-called “shift to the left” is difficult to measure using manual differential techniques. A hospital in St. Louis found a significant correlation between manual counts that included myelocytes, metamyelocytes, and promyelocytes and the IG parameter on the Sysmex XE-2100.

I’m evaluating two instruments: the Sysmex XN-1000 and the Beckman-Coulter DxH-600. This is very early in the process, but my understanding is that the latter does NOT report an IG parameter. If anyone has experience with these two analyzers, please comment below. I’d love to hear about it.

My point isn’t to proselytize so much as observe that laboratory medicine follows this steady progression toward better accuracy and precision using automation. Tests have gotten better over my career, and the jump to reliable cell counts is huge compared to the old manual dilution - stopcock days on a Coulter counter. And that was really cool compared to manual counts using spit tubes (yes, they were as disgusting as that sounds). Choosing technology is about recognizing that growth curve as much as anything else. The IG parameter is just one example.

NEXT: For the Best Results, Hire Professionals

The Cult of Busy
October 6, 2014 6:00 AM by Scott Warner

A hospital’s culture defines how it responds to customers and crises, whereas a cult is defined by the dictionary as “a group or sect bound together by veneration of the same thing, person, ideal, etc.” Cults have ideology, rituals, and symbols. Most hospitals have a cult of busy.

  • Ideology - the belief that “busy” means “important,” no matter how much important work actually exists
  • Rituals - tardiness, complaining, not taking work breaks, maintaining a to do list, constantly checking a pager
  • Symbols - overflowing email box, piles of paperwork, unfinished projects

The NZ Herald points out that a cult of busy could be a smokescreen for other issues: fear of getting fired, lack of direction, lack of skills, or boredom. Being busy sends a message that you matter more than those who aren’t. But there’s a difference between working harder instead of smarter.

Author Tim Kreider correctly writes in The New York Times that whining “Busy!” is “a boast disguised as a complaint.” This is behavior we have all chosen as a reassurance of self worth, perhaps; if we are constantly busy we must matter. “Obviously your life cannot possibly be silly or trivial or meaningless if you are so busy, completely booked, in demand every hour of the day,” Kreider writes.

This isn’t to say techs don’t work hard. Lab techs work hard! Everyone has days that are busier than others. Departments can be understaffed or overwhelmed with workload. Doing more with less is always a challenge. But serious professionals approach this with a “How do we get this done?” attitude.

Trying to do everything at once to be “busy” is a different attitude. We’ve all met these people who chronically overbook their lives, subsisting on caffeine, sugar, and bragging to anyone within earshot how busy they are, how much work they haven’t yet done, and how little time they have. They always find time to complain, don’t they?

When that person is your boss it’s a nightmare. Maybe, you work or have worked for one of these cult leaders. If so, please share your stories in the comments.

NEXT: IG# and Sepsis

More Sample Lookback
October 1, 2014 6:00 AM by Scott Warner

In 2011 I blogged about using a binary search algorithm to find a point of failure when performing a sample lookback with a large number of samples. In dealing with sample lookback and revising our own policies since then, we’ve hit a few snags:

  • How should we account for other instrument variables e.g. scheduled maintenance?
  • How should we handle qualitative testing? Example: microbiology biochemical testing.
  • How should we handle blood bank testing?

Most sample lookbacks occur in chemistry, but many times they don’t at all. Techs used to repeating a control may not think to perform a lookback if they need to replace or rehydrate reagent to obtain acceptable QC. But it’s a good analytical phase quality indicator and a chance to educate techs. Quality control records can be audited, etc.

If quality control is performed weekly or monthly on qualitative kits, a sample lookback may be impossible. In these cases values have to be pulled and a decision made regarding recollection and retesting, essentially an internal recall. It can be difficult to know how significant these failures are, because there often isn’t enough data.

Blood bank lots are spot checked with daily quality control; new vials opened may not be checked unless it’s a new lot or a new day. Tube testing reagents are reliable or contain procedural controls, but most techs I’ve known are nervous enough in blood bank that any lookback would entail repeating all testing. I’ve never seen a lookback in blood bank, but I do occasionally see product notices about reaction strength e.g. we might see weaker reactions with control cells for a particular lot.

Point is there is no “one size fits all.” A technologist suspecting a method failure has to investigate and decide if and when the method failed. That takes time. Maybe, a lot of time. If one is working alone or in a lab that is short staffed, time is a luxury.

I’d like to see information systems or middleware smart enough to analyze and perform virtual sample lookbacks. Does such software exist?

NEXT: The Cult of Busy

Virtual Keystrokes
September 26, 2014 6:00 AM by Scott Warner

In my last blog I said computers are stupidly reliable. They do whatever they are told, over and over. And they don’t get bored or make mistakes. It’s easy, for example, to create little programs that send keystrokes to applications. I use a freeware program called AutoIt for Windows (there are others, such as AutoHotkey) to create simple and effective time savers, including:

  • Print mailing labels by linking a turnaround time report to an address database
  • Change thousands of item master names to “Tallman” lettering
  • Standardize associated charge item master names
  • Add thousands of blank templates to the item master to add new items quickly
  • Keep a terminal alive that switches between two system status screens every 2 minutes

... and many others. While I have a programming background in a half dozen or so languages, you don’t need to understand a lot of programming to use a tool like AutoIt. Its BASIC-like syntax is straightforward, and Notepad is all you need. These “virtual keystroke” programs can save time and money.

To give it a try, download and install AutoIt from the “Download AutoIt” button. Don’t worry about the add-ons and tools, you won’t need them.

AutoIt has many built in “functions,” bits of code that do one of three things: run a task, change a value, or return a value. You can write your own functions -- effectively expanding the AutoIt language -- and while cool, that’s for geeks. Let’s face it, it’s silly to spend weeks learning something that will save minutes. You need a fast solution.

Their documentation contains good instructions. But here’s a trivial example from one of their tutorials, which you can save as a text file called npad.au3, that sends a message to Notepad:

WinWaitActive(“Untitled - Notepad”)
Send(“This is some text.”)

From here it’s a hop and skip to automating Excel, maintenance programs, and your laboratory information system. The Send function is powerful, sending any keystroke or combination of keystrokes. (You can send mouse clicks, too.) That’s what I call smart computing.

NEXT: More Sample Lookback

Computers are Stupid
September 22, 2014 6:00 AM by Scott Warner

Back in the day we imagined computers were smart. In a 1964 Twilight Zone episode called “The Brain Center at Whipples,” a CEO who heartlessly replaces workers with robots is himself replaced by Robby The Robot from the 1956 classic Forbidden Planet. Capek to H.A.L. to Nomad to Tron’s Master Control -- science fiction is a junkyard of them -- machine intelligence is smarter than us and invariably malevolent, paranoia culminating in the 1999 thriller The Matrix.

All fiction, luckily. Fact is computers are stupid.

Merriam-Webster defines “stupid” as “not intelligent: having or showing a lack of ability to learn and understand things.” (The fourth definition includes “exasperating,” and they are that, too.)

This is important to remember, since we live in a time when staffing shortages and expansion of information technology gives computers greater authority in laboratories. Autoverification, report distribution, complex reflex rules, and middleware save time by performing routine, mundane tasks. Software increasingly aspires to a role of laboratory assistant. But that doesn’t make it smart.

Fast Company lists these four things that we do better:

  • Unstructured problem solving - novel and unusual problems are extraordinarily difficult to solve with software. This won’t change in my lifetime, if ever.
  • Acquiring and processing new information - we may or may not be approaching “the Singularity” -- a fancy name for smart -- but until then computers gather data without context.
  • Physical work - many tasks we find trivial, improvised or not, are impossible for computers.
  • Being human - obvious, but empathy and compassion are essential to any healthcare mission.

Still if there is anything a computer does, it typically does it better than us. Computers are known for speed, accuracy, and reliability. Many laboratory tasks are algorithmic; our skills will have to evolve to building these in software. This includes Excel spreadsheets, middleware and data manager rules, custom scripts that automate simple tasks, and much, much, much more. IT professionals don’t have the knowledge to make it happen.

Are lab techs being trained for a future in which stupid computers will have to be used intelligently?

NEXT: Virtual Keystrokes

Hold This For Five Minutes
September 17, 2014 6:03 AM by Scott Warner

I hate tape. I don’t really mind having blood drawn, but tape is a pain. Yanking or coaxing it off, it doesn’t matter. Getting hair ripped off my arms always hurts more than a needle.

So when the phlebotomist or medical assistant says, “Hold this for five minutes,” I happily comply. And if they go for the tape, I insist on holding the gauze over the wound. It will stop quickly enough.

One reason we apply some kind of pressure bandage is because many patients do not comply. I’ve said, “Hold pressure on that for five minutes,” and as soon as the patient stands up he or shes daubs the site, shrugs, and chucks the gauze. “I don’t bleed” or “I clot quickly” are two comments I’ve heard many times. Telling the patient that blood will not clot for four or five minutes doesn’t matter, because he or she is too busy thinking about leaving and won’t listen.

I’ve held gauze in place for patients, such as following a therapeutic phlebotomy or arterial blood gas. Otherwise, some kind of pressure bandage involving tape or Coban wrap is needed with most routine phlebotomy patients. The walking and talking prefer to do just that, eager to leave and get on with their day.

But tape doesn’t just pull hair. Patient skin is sensitive to different types, some tape is stickier than others, and older skin can be frail enough to be damaged when tape is removed. Depending on the position of the arm and venipuncture site, a wound can still ooze under the bandage, causing bruising and even a hematoma. Coban adhesive wrap is a neat solution to tape, but it can curl or tighten and be ineffective.

Our morning rounds now include visits to patient rooms. We’ve started looking at skin care issues, especially if the patient has had blood drawn recently. This is good post analytical quality assessment. We’re looking at issues with tape, bruising, hematomas, or other skin issues (such as chafing or signs of infection). Just maybe, some patients hate tape as much as me.

NEXT: Computers are Stupid

Why We Work
September 12, 2014 6:00 AM by Scott Warner

Middle managers are often told to “engage” employees with buzzwords and gimmicks: empowerment, inclusion, work teams with stupid names made of acronyms, action plans, team huddles, and good old-fashioned delegation. We need to train our replacements, mentor those with potential, tell stories, emphasize cultural values, give feedback, hold people accountable, and manage by walking around. And we should have an open door, transparency, communication, standing meetings, one on one meetings, goal setting, and crucial conversations.

Employees will spot a gimmick like a used car lot. And they won’t buy either unless they really have no choice. The further removed management is from the basic purpose of the job, the harder it is to see that. It’s too easy to narrow our focus, clutch our perceived power to our breast, and believe our own hype.

So if gimmicks are a waste of time, why do we work?

I’ve made this simple and told my staff many times, “If my son was in an automobile accident and came into the ED, I would trust his life to any one of you. That’s what it’s all about. That’s what we are doing here. It’s all about the patient.”

We assume the unspoken doesn’t need to be said, but it does, plainly and often. It never hurts to realign a team by stating “the obvious,” because it gives perspective. And it simplifies decisions, because a clear purpose creates a universal litmus test e.g. does this help the patient? All great teams keep their eyes on the prize.

According to a New York Times article, employees need four core needs met to be satisfied and productive. The more of these that are met, the more “engaged” the employee becomes. Here’s the breakdown:

  • Physical - regular opportunities to recharge and renew energy
  • Emotional - feeling valued and appreciated
  • Mental - the when and where of the most important tasks are well defined with a chance to get them done well
  • Spiritual - a chance to do what we enjoy the most while connected to a higher purpose

Is it that simple?

NEXT: Hold This For Five Minutes

Work Friendships Are Crucial
September 8, 2014 6:00 AM by Scott Warner

As much as we would love to believe a job is just a job, it is much more than that: it consumes time, energy, and emotions; it advances, stalls, or kills careers; it creates fulfillment, ennui, or anger. And there’s the other thing: coworkers. One blogger writes, “In business, it’s not always about liking people, it’s about being able to trust -- and work -- with them. Sometimes, you will actually grow to like someone, in addition to trusting them and working well with them - and that is special; but let's face it, it's quite rare.”

That depends on how two people hit it off. Some people just form friendships easily.

Another blog points out that having friends at work is a great morale booster, quoting a survey with 70% of respondents valuing friends over salary. All things being equal, a workplace with friends is a better place to work. Working in a place without friends is almost worse than a hostile environment, where at least you get attention. A great friendship makes an emotionally dark place a little brighter.

There are health benefits to friendships, too. The Mayo Clinic web site lists:

  • Increase your sense of belonging and purpose
  • Boost your happiness and reduce your stress
  • Improve self-confidence and self-worth
  • Help you cope with life trauma
  • Encourage you to make positive changes

Without friendships, it can seem like we work alone, and emotionally we might as well. Without a friendly face to greet, laughter to share, or all-important support a job really is “just a job.” We may do great work but leave feeling a bit empty. Isn’t it better to share success with friends?

Absolutely. More than that friendships are crucial for meaningful success.

But for managers, it is much harder to form friendships. It can be hard for a friend to be promoted into management for everyone. Managers from the outside can find it a minefield to form friendships with staff. And workplace politics is often vicious at a middle management level, arbitrarily isolating a manager. I wonder how many managers fail for those very reasons.

NEXT: Why We Work

Do You Microsleep?
September 3, 2014 6:06 AM by Scott Warner

I keep forgetting about the cool site Stumbleupon, which will find web sites based on your interests. Then I’ll get an email, say “Aha!” and stumble away. I’ve found a few good ideas this way. For example, the other day I read an article on microsleep.

Microsleep, which is caused by sleep deprivation, is just what it sounds like: a short episode of sleep that lasts anywhere from a fraction of a second to thirty seconds. According to Wikipedia, microsleep episodes have caused disasters such as train wrecks, plane crashes, and the Chernobyl nuclear reactor accident.

Researchers at the University of Wisconsin-Madison explain microsleeping as regions of the brain going off-line while the rest of the brain appears to be awake and functioning. Not getting enough sleep, it turns out, can affect some regions of the brain before others, making us check out at random intervals. In an experiment with rats, for example, 18 out of 20 neurons stayed awake; the rats in the meantime made mistakes.

Signs of microsleep include: drooping eyelids, head nods, blinking, blank stare, poor concentration etc. But at times these episode may happen with no outward signs. The person simply stops responding the stimuli. According to one site, these events are more likely before dawn and in early afternoon.

Like most of us in our sleep-robbed world, I’ve had this happen. I’ve felt sleepy behind the wheel, struggled to stay away in meetings, and periodically “zoned out.” I’ve always thought this was simply fatigue. But the above suggests that parts of my brain are literally shutting down and not responding for short periods of time. That is far more dangerous, and more than a little frightening.

Repetitive tasks that require less attention than novel tasks may be more susceptible to microsleep episodes, such as computer data entry. I wonder, too, about some laboratory testing. We all joke that after so many years of doing this job we can do it in our sleep. Ironically, we may be doing just that.

How about you? Do you microsleep?

NEXT: Work Friendships Are Crucial

Fast Facts About Diabetes
August 29, 2014 6:03 AM by Scott Warner

The more I hear about diabetes, the worse it sounds. The statistics on the disease, recently updated by the CDC, are alarming:

  • 29.1 million people have diabetes (9.3% of the US population)
  • 8.1 million people are undiagnosed (about 1 in three with the disease)
  • Based on fasting glucose or glycated hemoglobin levels, 37% of adults 20 years or older have prediabetes (about 86 million Americans)
  • Most diabetics (56.9%) are treated with oral medications, but a third take insulin

We all seen and heard the horror stories: patients in the ED in diabetic ketoacidosis, those who get feet and legs amputated, and peripheral skin wounds that refuse to heal. I hear from diabetics who can’t feel their feet describing that walking has no sensation. It all sounds bad to me.

According to the same CDC publication above, “Many people with type 2 diabetes can control their blood glucose by following a healthy meal plan and a program of regular physical activity, losing excess weight, and taking medications.” That’s a tall order for an insidious disease created by lifetime habits. It is the hardest thing in the world to change habits related to diet and exercise.

If 94 million Americans are really walking diabetic time bombs -- that is an incredible number of people -- we will see an increased need for screening and diagnostic testing in the laboratory. Rapid glucose, ketone (and tests such as beta hydroxybutyrate), and glycated hemoglobin (A1C) are some of the tests on the front lines. But on the periphery -- literally -- are tests arising from complications of this disease, such as wound care and antibiotic stewardship.

As laboratorians we have an obligation to teach nursing and other team members doing point of care testing proper collection and testing technique as well as why quality control is important. But we also have a role in diabetes education. A nurse educator may do the initial education and teaching on using a home meter, for example, but we can help answer any further questions a patient may have. We’ll be busy, that’s for sure.

NEXT: Do You Microsleep?

How Can I Help?
August 25, 2014 6:00 AM by Scott Warner

Scripting has been imposed on us, like many organizations, to standardize the customer experience. From answering the telephone to directing traffic, guidelines are set to make sure no matter who a patient or family member interacts with they receive similar treatment. This practice is so common in retail these days it’s expected in many other settings.

Most often I’ve seen scripting developed by committees or teams to enhance satisfaction scores e.g. “To protect your privacy...” or comply with a policy e.g. “Would you please state your full name?” These become cultural dogma, assumed to be crucial for service excellence, and never seriously questioned. Of course, this kind of scripting must be effective, because the experts tell us it is. And it meets our goal: a common customer experience. Doesn’t it?

But when was the last time you applied for a Walmart credit card because you heard the cashier asked the four people before you in line, “Would you like to apply for a Walmart credit card today?” And did that question meet your expectations as a customer, or make you feel like the scripting was all about the company’s bottom line?

Hospitals aren’t Walmart; retail goals are conspicuously financial by necessity. But it seems clear that scripting in a hospital setting should consider the needs of the patient more than the organization. Scripting by committee, it strikes me, has a bias toward the latter; the goal will always be to improve a score, comply with a policy, impose a change, or meet some theoretical need of an imaginary customer. I don’t think I’ve ever worked in a place that has asked a patient or family member directly how they want to be treated. The idea seems strange.

“What are your expectations?” is abstract and buzzwordy. Patients and family members may reflect that they expected different treatment, but I wonder if it’s possible to list those expectations in advance. As a patient myself I had one: I needed help. Many of our patients are helpless.

Is scripting that simple? Why can’t we just ask, “How can I help?”

NEXT: Fast Facts About Diabetes

We Never Got The Result
August 20, 2014 6:04 AM by Scott Warner

“We never got the result!” is our most common complaint, followed closely by “My doctor never got the result!” It is frequently delivered in an accusatory tone instead of the more accurate “We can’t find it. Did you send it?” Or even, “Did you perform the test?”

We hear the latter once in a while. We look up the patient who hasn’t been seen in our hospital since 2008, and on the other end of the telephone a frustrated office working just hangs up in exasperation. Or the patient was seen, but we didn’t perform the test because it wasn’t ordered. Or it was ordered, but it wasn’t sent in time. Etc.

Our most bizarre complaint was from a physician who claimed he ordered a free T4 and we performed a total T4. Since we don’t have T4 on our test menu, I couldn’t figure out at first what he was angry about. He berated me for a few minutes while I looked at the report. It turned out that he confused a CPSI interface code (T4) with the name of the test (Free T4); both appeared on the report, viz.

[T4]         Free T4    __

Clearly, he only saw the interface code. He still insisted we had run the wrong test and demanded that we redraw the patient.

Along with confused, frustrated, or angry telephone calls, this kind of failure is expensive. Physicians reorder tests or demand that they be collected or sent elsewhere if they aren’t done or the report is missing, translating into extra cost or lost revenue. Over time, these events whittle away a lab’s reputation and bottom line.

As partners in the patient’s healthcare, we can be treated like an obstacle, blamed for not doing a test that the doctor didn’t order. But many of our customers are genuinely frustrated. They may have no idea what lab work has been ordered by other providers or if the patient has complied. And sometimes they really don’t get a report when they should. As a fee for service business, how can a lab possibly fix this?

NEXT: How Can I Help?

Using SDI
August 15, 2014 6:01 AM by Scott Warner

Standard deviation index (SDI) measures bias using simple, easy to understand criteria. I also like this for daily quality control, because it works on all levels. Here’s the calculation:

SDI = (Value - Target Mean) / Standard Deviation

Thus, a glucose of 97 with a control range of 80-100 has an SDI of 1.4. A positive SDI indicates a value above the mean; a negative value indicates a value below the mean.

Also called z-score, the SDI corresponds to where on a run chart a value falls. As James Westgard explains on his web site, “It is very helpful to have z-scores when you are looking at control results from two or more control materials at the same time, or when looking at control results on different tests and different materials on a multitest analyzer.”

SDI is commonly used on laboratory peer reports, comparing to dozens or hundreds of other laboratories. Here are some guidelines for interpreting an SDI:

  • 0.0 - perfect match peer group
  • Less than or equal to 1.25 - acceptable performance
  • 1.25 - 1.49 - some investigation may be required
  • 1.5 - 1.99 - investigation is recommended; marginal performance
  • Greater than or equal to 2.0 - unacceptable performance

Typically, peer reports are scanned for high or low SDI values, especially if they are seen across multiple levels. But the SDI is useful internally, too. If your information system calculates an SDI a tech can quickly see what’s in, what’s out, and what’s trending instead of just responding to Westgard flags. For example, if all levels of QC on an analyte have a negative SDI, there may be a calibration bias.

As I’ve described, our lab uses a program that plots SDI values instead of standard run charts. Every chart looks similar with plus or minus 2 SDI; actual means and standard deviations are indicated. Because this data depends on the parameters at the time of posting, these charts reflect QC at run time and answer the question, “What did the QC look like on a particular day?”

NEXT: We Never Got The Result



About this Blog

    Scott Warner, MLT(ASCP)
    Occupation: Laboratory Manager
    Setting: Critical Access Hospital
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