Lab Tests Online - Explaining Pathology

Reading your results

Increasingly, people are having direct access to their pathology test results and with the introduction of the Australian Government's My Health Record this is expected to become even more commonplace.
However, reading the results can be confusing.  Understanding what is normal and what is abnormal can be a little daunting. Here, we give a couple of examples to explain some of the essential information.
Who prepares your test results report?

The pathology report is a medical document produced by the pathology practice. All pathology reports contains certain compulsory information that is essential for interpreting your results. Individual pathology laboratories often add their own information and they can vary in the way it is presented.

Your tests will have been performed by scientists and/or pathologists.  The pathologist-in-charge who is  a medical doctor who specialises in interpreting test results and observing and evaluating biological changes to make a diagnosis, will be responsible for your report. The pathologist is available to discuss your results with your doctor.

All that is red is not always abnormal

 Here is a cumulative report for the full blood count results for a 17-year old girl who first came with her mother to her family doctor in mid-April complaining of very heavy periods and tiredness.  (A cumulative report is one that provides successive test results over a period of time.)

Name and address of doctor or health practitioner to whom your results will be sent

Patient's name and identifiers used to link the results to the correct person

Date this report was printed. This date may be different to the date results were generated, such as this example of a cumulative report.

The date and time your sample was collected

Reference ranges (sometimes called reference intervals or normal ranges) into which your results are expected to fall

Unit of measure this particular lab uses

Unique id number assigned by the lab

A 'L' flag signifies it is lower than the reference range. An 'H' flag means that the result is higher than the reference range.

1 Requesting Doctor   2 Patient
Dr Peter Green   SMITH, Alicia
Brown St Medical Centre   21 Riverton Road
233 Brown Street   WHITEVILLE, NSW
WHITEVILLE, NSW   DOB: 2/Feb/1997 Sex: Female
3 Date: 23/Jul/2016
      Latest Results    
4 Collection date: 15/Apr/16 18/May/16 23/Jul/16 Reference5 Units6
Collection Time: 09:00 09:30 09:30    
7 Request No: H123278 H123344 H123456    
Haemoglobin 118 L 8 132 L 146 (135-175) g/L
Haematocrit 0.35 L 0.40 0.47 (0.40-0.54)  
RCC 2.9L 4.1 L 4.8 (4.5-6.5) 10^12/L
MCV 70 L 75 L 97 (80-100) fL
WCC 6.0 9.0 4.2 (3.5-10.0) 10^9/L
Neutrophils 4.56 4.96 2.72 (1.5-6.5) 10^9/L
Lymphocytes 1.14 2.27 0.99 L (1.0-4.0) 10^9/L
Monocytes 0.13 1.0 H 0.36 (0-0.9) 10^9/L
Eosinophils 0.10 0.50 0.13 (0-0.6) 10^9/L
Basophils 0.03 0.05 0.03 (0-0.15) 10^9/L
Platelets 251 356 178 (150-400) 10^9/L

The results of the blood test taken on the 15th of April are in the first column of results under the date of 15/Apr/16.
The abnormal results in this report are clearly marked in red and have a letter after them to show whether they are high (H) or low (L).
The second to last column on the right marked "Reference", gives the reference interval (or range) of values against which the results are being compared. It is important that you only use the reference range on the report from the lab that performed the analysis and not from any other source as reference ranges may differ between laboratories for some tests. See Reference ranges and what they mean for more information about how these are calculated and why they differ between laboratories.

The results show a low haemoglobin, low haematocrit, low RCC (red cell count) and low MCV (mean cell volume) all of which are typical of iron deficiency anaemia and which would have been caused by the heavy periods. You will see that there are two other abnormal results – high monocytes on the 18/May/16 and low lymphocytes on the 23/Jul/16.

If you look at the reference ranges you will see that these results are only just outside the limits and both of them are normal on the other two occasions tested. These abnormal results are almost certainly not clinically significant. If you have enough tests done it is very likely that one or more results will fall just outside the reference range by chance. All that is red is not always really abnormal!

Reading HbA1c results

This is test results report showing the results of a 70-year old man with type 2 diabetes.

1 Requesting Doctor   2 Patient
Dr Melissa Black   SMITH, James Edward
Brown St Medical Centre   Unit 26
233 Brown Street   Happy Days Lifestyle Village
    DOB: 13/May/1944   Sex: Male
3 Date: 23/Jul/2016
      Latest Results    
4 Collection Date: 2/Aug/15 21/Jan/16 23/Jul/16 Reference 5 Units 6
Collection Time: 10:00 10:30 09:30    
7 Request No: B135791 B024681 B123456    
HbA1c (NGSP) 8.1 H 8 7.3 H 6.0 (4.0-6.0) %
HbA1c (IFCC) 65 H 56 H 42 (20-42) mmol/mol
Control zones for diabetes management NGSP (%) IFCC (mmol/mol)
Non diabetic level 4.0-6.0 20-42
Good control 6.1-7.0 43-53
Suboptimal control 7.1-8.0 54-64
Poor control 8.1-9.0 65-75
Very poor control >9.0 >75

Method: HPLC (lon-exchange)

In patients with a significant risk of adverse outcomes from hypoglycaemia (children <16 and elderly >70 years) higher target values may be appropriate.

Medicare permits the HbA1c test to be used for diagnosing diabetes.
The MBS item allows the test to be done once per patient per year for this purpose with an HbA1c level equal to or greater than 6.5% (48 mmol/mol) required for a diagnosis.

These results show changes in HbA1c at about six-monthly intervals. Again, abnormal results are shown in red followed with H for high. The results are followed by information provided by the laboratory to assist with interpretation of the results.

The results show a steady improvement in control of the diabetes with the final HbA1c in the non-diabetic range. This final result may or may not be a good thing in this elderly man. Sometimes if treatment is too strict, blood sugar levels may fall to very low levels at times and this is potentially dangerous. The key here is communication with the doctor and diabetes educator. Target HbA1c levels should be individualised for each patient.

Highlighting abnormal results

These lab reports clearly mark abnormal results by printing them in a different colour and following them with an indicator showing whether they are high or low.

Not all lab reports may use this particular convention. For example, abnormal results may not always be highlighted in a different colour. There will however, always be some indicator of abnormality, most commonly an H for high or L for low but some labs may use other marks such as # or * signs to indicate the result is outside the reference range.
If in doubt, talk to your doctor as results need to be interpreted in the context of all the other information available.
For more information read Validation, Use and Interpretation