Any pathology test is only of value if the result produced is ‘real’, or, representative of that individual, right? So the timing of the test is a major pivot point then: do I tell my patient to present for the test, or collect the sample themselves, on their ‘best’, their ‘worst’ or their ‘average’ day? 🤷‍♀️  Well, that all depends on the question you are trying to answer.

Whenever we reach or refer for a test, we have a question in mind we’re seeking an answer to. But the question always comes in two parts, at least.

Part 1: How much progesterone is she making?
Part 2: …When she’s ovulated & her corpus luteum should be most productive?

A third might refine the question you’re answering further by adding another contextual clarification

Part 3,4,5: …When she’s eating her regular diet, not exercising excessively or under extreme stress

Without these other parts – the answer to the first one: How much progesterone is she making (full stop), is hard to correctly interpret, right? By refining and expanding on the full extent of our question, we can be clear about which elements of this patient’s life the result likely reflects. We might say that for her, this time-point, or set of collection conditions, is a ‘real reflection’ of her generally and therefore, representative.  But what if she does occasionally undertake a 5 day fast, or train for & compete in marathons? If we were to specifically test during these times, we answer a different question, right?  Likewise every time we instruct a patient to present for their blood tests (routine or fancy schmancy): Fasted, Rested, Hydrated and off their supplements – is this sound advice or a misdirection?  Well it depends on the individual in front of you and the real question you want answered about them 🤓

Ahhhhh I love rules: both the making of them and the subsequent breaking of them 🦜🏴‍☠️

Fasted, Rested, Hydrated & Unsupplemented? Exceptions to the rule

The collection conditions for any pathology test – can refine or ruin the question you were hoping to have answered about your patient but is it always appropriate to ask everyone to ensure their preparation for the test was ‘ideal’? What if their real life is far from ‘ideal’ and contrasts dramatically with these ‘conditions’ e.g. they forget to drink water but never alcohol! Or do they run 20km every weekday and 40 on weekends?  And why would we tell some patients to stop their supplements prior to a blood-test and not others? If our goal is to ensure any pathology test answers the question we need answered we need to know how to respond to these and other scenarios.  This new update is all about keeping results ‘real’ & representative.


You can purchase Fasted, Rested, Hydrated & Unsupplemented? Exceptions to the Rule here.
If you are an Update in Under 30 Subscriber, you will find it waiting for you in your online account.
You can become an Update in Under 30 Subscriber to access this episode and the entire library of Update in Under 30 audio’s and resources here.