What You Need to Know About Medical Tests

photo vials of blood in a lab - medical testsTests are an important part of medicine. They help doctors determine a diagnosis and possible treatments. But, testing, and getting the results, is not a seamless process. Firstly, it’s not uncommon for doctors prescribe tests that are unnecessary. Secondly, mistakes in the testing process can lead to erroneous results. And lastly, doctors can fail to follow-up on test results. Certainly, these issues can lead to delays in diagnosis and subsequent delays in treatment which can negatively impact patient health.  So, what do you need to know about medical tests?

Testing, testing, testing!

In 2014, experts estimated that approximately 13 billion medical tests are performed every year in the US. My guess is that the number is even higher today! And these tests are important – an estimated 2/3 of decisions made by doctors regarding diagnosis and treatment are based on laboratory test information. But sometimes, tests are not necessary.

Test results are not always a simple positive/negative.

It’s easy to think of test results as simply positive/negative, or normal/abnormal. But, in reality, the results from medical tests are generally more nuanced, with more information, than a simple yes/no. For example, when testing the blood for cholesterol levels, the actual number is an important factor when considering how aggressively to treat the condition. Is the level slightly elevated, or through the roof? Similarly, a result of 30 for the PSA blood test for prostate cancer means something different than a value of 20, or 5, even though all of those values are considered “abnormal”.

In conclusion, the magnitude of the test result matters. Therefore, doctors should consider the absolute value of the test result to determine a diagnosis and treatment options. And, they should discuss this with their patients!

Unnecessary testing puts patients at risk.

photo MRI machine - medical testsAre all 13 billion yearly tests necessary? No.

Firstly, it’s important to understand that all medical tests carry some degree of risk, including side effects, false positives, and false negatives. This is especially a concern for tests involving radiation, particularly CAT scans, since exposure to radiation is dangerous in cumulative doses. Additionally, everyone has some abnormalities that would turn up with enough probing, so increased testing can lead to increased treatments. Furthermore, many doctors believe patients, including their own, receive too much care, including testing.

Why do doctors order tests?

Many doctors order tests “just to be sure” and to “rule things out”. And, patients ask for tests to give them the peace of mind that nothing serious is wrong. A 2014 report from Choosing Wisely illustrates doctors’ opinions on the ordering of tests and procedures:

  • 75% of doctors think unnecessary tests and procedures are a serious health care issue
  • 93% feel they have a responsibility to help their patients avoid unneeded tests
  • 47% say patients ask them for unnecessary tests and procedures at least once a week
  • 53% state they perform unneeded tests and/or treatments when patients are insistent
  • Doctors frequently order unnecessary tests and treatments to reassure themselves that they are on track with a diagnosis

For more information, read The Dangers of Too Many Tests and Treatments for Patients.

The results of medical tests can be inaccurate.

photo caution sign - medical testsJust like anything else in life, there is room for error when it comes to medical tests. In fact, according to lab director, those who work in labs know that “no test performs perfectly”. Lab tests are not always right. For instance, technicians can perform a test incorrectly. And doctors can misinterpret the findings. And anyone along the way can make an administrative error. Mistakes can occur with any kind of test, including blood tests, MRIs, x-rays, mammograms, and biopsy procedures.

Lab test limitations.

All lab tests have limitations. Some of the most common causes of errors in lab tests include:

  • Ordering mistakes – doctors don’t always order the right test at the right time.
  • Issues with test accuracy and availability.
  • Misinterpretation of test results.
Radiology mistakes.

woman getting a mammogram - medical testsExperts estimate the error rate for radiology diagnoses is estimated to be between 10-15%. Why do radiologists make mistakes? Making a radiologic diagnosis is a very complex process, and a variety of factors can impact the diagnostic process, including work environment and workplace distractions, the volume of imaging studies, pressure for fast results, limited patient information.

For more information, read Radiology Diagnostic Errors Are Surprisingly High.

One woman’s story of a missed breast cancer diagnosis.

At an annual OB/GYN appointment in 2012, Sandra Kaus’ doctor found a small lump in her breast and recommended a mammogram. She was told that the radiologist would call her if something was wrong, so when she didn’t hear back, she assumed the lump was nothing to worry about. In 2013, during her next annual exam, her doctor notices the lump is significantly larger and recommends another mammogram. After weeks of testing, doctors diagnosed her with Stage 3 breast cancer. Then Sandra learned that in 2012 the radiologist found a suspicious spot in her mammogram, but someone accidentally checked off a form stating the mammogram had been compared to a previous mammogram. But no radiologist compared the 2 results, and no one told Sandra she might have cancer. Sadly, her cancer went untreated for a year due to a diagnostic error.

Primary care doctors struggle with follow-up of test results.

stressed doctor sitting at desk - medical testsIt is common to assume that “no news is good news” when it comes to medical test results. Although most of us think our doctor will notify us if a test reveals a potential issue, you can’t count on that! High patient loads, large volumes of test results, Electronic Health Records and other demands overwhelm doctors. And this overwhelming workload can cause doctors to miss test result alerts. Missed medical test results can lead to a delay in diagnosis, or a missed diagnosis altogether. It would be horrible to learn that you have a serious illness that has worsened over time because your doctor missed a test result that indicates a problem.

It’s such a big issue, experts consider the failure of doctors to follow up on test results a critical patient safety issue.

What does the research show?

A study conducted at the VA Medical Center in Houston surveyed 2,590 primary care doctors. The findings show that doctors must process a large number of test results. Moreover, most of the respondents reported they feel it’s too much to manage. A summary of the findings:

  • The median number of alerts was 63 per day/per doctor.
  • 86.9% of the doctors felt this was an “excessive” number of alerts.
  • 69.6% stated that they felt they were receiving more alerts than they could effectively manage.
  • 29.8% reported that they had personally missed abnormal test result alerts that led to delays in patient care.

Hospitals also struggle with follow-up of medical test results.

photo child in hospital with doctorResearchers analyzed the results of 12 studies, published between 1990 – 2010, to determine the frequency and impact of missed test results for hospital patients. They found the lack of follow-up on test results spanned wide range:

  • Inpatients: 20.04% – 61.6% of tests lacked follow-up.
  • Emergency department patients: 1.0% – 75% of tests had no follow-up.

Unsurprisingly, the researchers noted that missed follow-up of test results was particularly problematic for:

  • Critical test results.
  • Results for patients moving across healthcare settings.
What was the impact of the missed follow-up?

photo of older coupleFor hospital patients, test results that lacked proper follow-up included urgent and critical lab tests and diagnostic imaging results. Several of the studies found the failure to follow-up on test results led to missed diagnoses of cancer, osteoporosis, hypothyroidism, and other conditions.

Additionally, results that are pending when patients are discharged from the hospital are particularly challenging. For more information, read Make Sure You Get Your Test Results When You Leave the Hospital.

For patients treated in the emergency department, follow-up failure occurred for a variety of tests, including blood and radiology tests. Researchers found the impact of missed follow-up for ED patients ranged from the prescription of unneeded antibiotics and delayed diagnoses to missed cancer and deaths.

Do electronic health records reduce follow-up issues?

In the 12 reviewed studies, the hospital used a variety of systems to manage test follow-ups, including paper-based, electronic and hybrid paper/electronic systems. Interestingly, the results indicate that electronic test management systems were of limited effectiveness regarding follow-up. Importantly, the studies evaluated took place 10 – 30 years ago. It is certainly possible that technological advances in electronic systems have reduced the likelihood of missed test results follow-up.

What should you do when you need medical tests?

Fortunately, many of the issues around test results can be easily addressed, although tackling the issue of medical errors is obviously harder for patients to address. To reduce your risk of issues related to medical tests, consider these suggestions.

Before testing:
  • Realize decisions about testing (and treatment) are up to you. So, before agreeing to any test, ask your doctor:
    • Why he/she is ordering the test.
    • What he/she hopes to learn from the test.
    • About possible risks of the test.
    • How the test will impact treatment.
    • About taking a “wait and see” approach.
  • Properly prepare for tests by asking for and following instructions. For instance, should you fast before the test, avoid certain medications, and/or have the test at a particular time of day?
  • If you will need to collect a sample yourself and submit it to a lab, make sure you carefully follow the instructions on how to collect, store, and handle the sample. And, fill in any labels neatly and completely.
Find out when the test results will be ready:
  • When you have tests done in the hospital, in the emergency department or as an outpatient:
    • Ask the doctor, nurse, or test technician when the results will be ready. Do this for all tests, including blood work, x-rays, MRIs, and colonoscopies.
    • Mark your calendar on the date the test result(s) are expected. When the expected date arrives call your doctor’s office for your test results if they haven’t notified you. Then follow-up as needed until you get the results.
Discuss the results with your doctor:
  • Discuss the results of all tests with your doctor, even for a result considered “normal”.
    • Ask if there have been any changes since prior tests and what these changes mean (for blood tests, mammograms, and other tests you regularly undergo).
    • Ask your doctor for the absolute value of the test result, and for the range considered normal for someone of your gender, age, race, and ethnicity.
  • If you think a test results doesn’t make sense:
    • Ask your doctor about the possibility of errors, including diagnostic errors caused by radiologists, and false-negative or false-positive results.
    • Request a repeat of imaging or a simple test; for a more expensive and/or more invasive test or imaging, ask your doctor to have your results evaluated by another radiologist.

Learn more…

Being engaged in your care can help you get the best health care and outcome possible. Read these blog posts for more information:



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