Deciphering a laboratory test report

Dr Th Dhabali Singh *

People have now direct access to their laboratory test results. This has enabled the patients to act as partners with their healthcare providers and take more active role in healthcare decisions. However, a ready access to test results places the patient in a position of greater responsibility.

One may encounter complex test results on lab reports and will need to recognise that there is a context in which healthcare providers use the results to make treatment decisions.

Once a patient gets hold of his report from the laboratory, it may not be easy for him to read or understand, leaving him with more questions than answers. There are specific sections that may be found on a typical lab report that are more or less common for most laboratories.

Different laboratories generate reports that can vary greatly in appearance and in the order and the kind of information included. The reports also vary according to the type of the tests conducted. For instance, a Pathology report, such as for a biopsy, will look very different from a normal Biochemistry test.

Elements of a typical laboratory report

Despite the differences in format and presentation, all laboratory reports must contain certain elements as mandated by the regulatory authority bodies. The report may also contain additional items not specifically required but which the lab chooses to include to aid timely reporting, delivery and interpretation of the results.

Some items are also included on lab reports that deal with administrative or clerical information such as:

o Patient Name, Patient Identification Number, Unique Patient Identifier or Identification Number: These are required for proper patient identification and to ensure that the test results in the report are correctly linked to the patient on whom or on whose sample the tests were run. The Patient Identification number or Lab ID is unique for each registration while the Patient Unique ID is unique for the patient for every registration. This aids in easy retrieval of reports from the archives and to maintain uniformity in the patient’s details.

o Name and address of the laboratory where the test was performed: The name of the laboratory, lab’s logo and logos of accreditation bodies to specify the adherence to testing protocols are included.

o Registration date and time: This is the time and date on which the patient had registered for the tests.

o Test report date: This is the date (and time) on which the results were generated and authenticated by authorised persons such as the Pathologist or Biochemist. Tests may be run on a particular patient’s sample on different dates. Since a patient may have multiple results of the same test (such as a culture report), it is important that the report includes this information for correct interpretation of results.

o Report print date and time: This is the date (and time) on which the report was printed. The date of printing may be different than the date on which the results were generated.

o Name of the doctor or legallyauthorised person authenticating the results: This information enables the labto specify the person who forwarded the results to the person who requested the test.

o Specimen source or sample type: Some tests can be performed on more than one type of sample. For example, protein can be measured in blood, urine or cerebrospinal fluid and the results from these different types of specimens can indicate very different information.

o Date and time of specimen collection: Some results may be affected by the day and time o the sample collection. This information may help the health practitioner interpret the results.

o Name of the test performed: Test names are written on the reports. Sometimes abbreviated names are printed.

o Name of the lab department: The tests are conducted in different department of the laboratory. Thetest could be performed in the Haematology, Clinical Chemistry or other sections. This information is also given on a lab report.

o Test result: Some results are written as numbers when a substance is measured in sample such as sugar levels or cholesterol levels (quantitative).Other reports may simply give a positive or negative result as in malaria test (qualitative). Still others may include texts, such as the name of the bacteria for the result of a sample taken from an infected site.

o Abnormal test results: Lab reportswill often draw attention to results that are abnormal or outside the reference range by setting them apart or highlighting them in some way such as in bold letters.

o Units ofmeasurement (for quantitative results): The units of measurement that labs use to reportthe results can vary from lab to lab. It is similar to the way, for example, the health practitioner chooses to record the weight during an examination. Labs may choose to use different units of measurement for the test results. Regardless of the units the lab uses, the results will be interpreted in relation to the reference ranges supplied to the laboratory.

o Reference ranges: These are the ranges in which “normal” values are expected to fall. The ranges that appear on the lab report are established and supplied by the laboratory that performed the test.

o Interpretation of results: In certain circumstances, the lab may note on the report what certain test results may indicate. This may be provided as a footer note.

o Condition of the specimen: Any pertinent information regarding the condition of specimens that do not meet the laboratory’s criteria for acceptability may be noted. This type of information may include a variety of situations in which the specimen was not the best possible sample needed or testing.

For example, haemolysed or lipemic samples may be noted on the report. There are thousands of medical tests used on patients to diagnose, measure progression of a disease or condition, or measure the effectiveness of a treatment. But they all have some basic truths about what they mean to a patient, and how they are best interpreted.

If the results are not what a patient expected, then the best way forward is to ask the doctor what the results mean and how they should be interpreted in context of his medical history before jumping to conclusions.