Healthcare

Mapping Laboratory Test Names

While we talk about healthcare data standardization, it’s important to look at the constituents of healthcare data being captured within EMRs used by Providers. The following are the typical subsets of the information captured by providers within their EMR systems:

  • Patient Demographics
  • Lab orders & results
  • Medication orders
  • Medication administration records
  • Imaging orders & results (ECG, Echo, USG, CT, MRI, etc.)
  • Problems
  • Notes and documentation (SOAP, HPI, ROS, referrals, )
  • Physical examination
  • Diagnosis and coding (ICD, SNOMED, READ, LOINC)
  • ADT
  • Billing & Claims

Of the above, laboratory, medications and diagnosis data is the most structured since it does not include comments, descriptive notes or images that need interpretation.  Diagnosis data is captured by the ICD-9 and now the ICD-10 code sets, while Medication information could use RxNorm or the NDC code systems. For laboratory data, traditionally, most US care providers followed their own nomenclature for test names. This is, however, now changing with the ‘Meaningful Use’ mandates which recommend LOINC codes for describing laboratory test names within EMR systems. However, this entails a huge effort for mapping local provider laboratory test names to LOINC formats. To illustrate the challenge better, the following could be the local variations in the test names associated with the test Serum Glucose

TEST NAME (Glucose-related)

2HROB

DXGLUC

GLUC 28 WEEK

FS GLUC

GlucInOfc

GLUCLOSE

GLUHEM

Now,if were to analyzethe test names only and determine a match, it would be difficult to tag a correct standard LOINC test since these names do not exactly point to a correct test. To interpret, if these were really Serum glucose tests or even close to a glucose test, we possibly need some more insights into the test data. Let’s assume, you now have some additional information pertaining to these tests as shown below,

TEST NAME (Glucose-related)

UNITS

REF RANGE

2HROB

mg/dl

105-140

DXGLUC

mg/dl

85-125

GLUC 28 WEEK

mg/dl

100-130

FS GLUC

mg/dl

70-99

GlucInOfc

Null

Negative

GLUCLOSE

Null

Negative

GLUHEM

mg/dl

90-110

As mentioned above, the units and reference range information gives us a better insight in understanding, interpreting and subsequent mapping of the above set of names. From our analysis of the presented data, most of the tests look to be tallying with the reference range and units associated with a serum glucose test. We can also see that test names ‘Gluclose’ and ‘GlucInOfc’ do not have numerical reference range or relevant units. These could possibly be Urinary glucose tests. If we had access to the actual observation values, it would enhance this analysis further so that we could confidently map these tests to a serum or a urinary glucose.

Thus, while mapping lab test names to a standard name, it is important for a terminology analyst to be presented data not just around the test name but also the reference range, units, observation or result values, the frequency distribution or spread of the observation results (incase these are numerical) as well as whether the results are numerical or textual. This would improve the accuracy of an analyst trying to map lab test data to a standard nomenclature such as the LOINC code-sets.

In our next post, we will explore and understand LOINC code sets and how to interpret laboratory test data to map it to these codes.