Several non-pathological factors may influence the measured concentration of specific analytes, resulting in falsely increased or decreased results. The following are some common factors that may affect the interpretation of laboratory results. 

1. Effect of haemolysis, lipaemia and icterus

Haemolysis, lipaemia, and icterus may interfere with the measurement of various biochemistry analytes, resulting in falsely increased or decreased results.

All routine and non-routine tests performed on chemistry analysers, as well as vitamin B12 and folate assays performed on immunoassay analysers, are screened for haemolysis, lipaemia, and icterus indices. Where applicable, affected analytes will be flagged.

If significant interference is detected, the affected analyte result may not be reported. Further information or advice regarding affected results can be obtained from the Duty Scientific Officer or Chemical Pathologist.

2. Measurement Uncertainty 

All laboratory assays are subject to a degree of uncertainty associated with the measurement process. This is referred to as measurement uncertainty and is commonly expressed as a percentage of the reported result.

Measurement uncertainty provides an estimate of the range within which the true value is expected to lie. With approximately 95% confidence, the true value is expected to fall within the reported result ± the stated measurement uncertainty.

Further information regarding measurement uncertainty for individual laboratory assays is available from the Duty Scientific Officer or Chemical Pathologist during routine working hours.

3. Common Factors Affecting Blood Test Results