Null vs 'Not Recorded': Why Absent Data Shouldn't Be Guessed

It sounds like a small design choice. It is actually one of the most important safety decisions in any clinical documentation tool: what to do when a piece of data simply was not captured during the appointment. Get it wrong and the tool produces records that are subtly false; get it right and it produces records that are honest about their own limits.

Three ways to handle a gap

When a finding was not discussed or measured, a tool can do one of three things with it.

It can invent a plausible value. This is the most dangerous option, because it puts data into the record that has no basis in what happened.

It can insert a placeholder like "not recorded" or "N/A" into every empty field. This looks tidy but creates its own problems, as we will see.

Or it can leave the field genuinely empty, reflecting the simple fact that nothing was captured.

Why genuinely empty is safest

A clinical note should reflect reality. If a score was never given, the honest state is that there is no score, not a zero and not a default. Returning nothing keeps the note truthful and avoids implying findings that were never made. A zero is a clinical value; absence is not. Conflating the two by defaulting empty fields to zero can mislead anyone who later reads the record into thinking an assessment was done and produced that result.

Why placeholders create problems too

Filling every unmentioned field with "not recorded" seems thorough, but it adds noise and, in some contexts, can read as though something was actively checked and found to be absent or unremarkable. It also clutters the note with boilerplate that buries the content that matters. The cleaner approach is to record what was said and stay silent on what was not, leaving the clinician to fill any genuine gap if it needs filling.

The principle in practice

Absent data should stay absent. A clinical note is a record of what happened, and the most accurate thing a tool can do with a gap is to leave it as a gap for the clinician to address. This is not the tool being unhelpful; it is the tool being honest. A documentation system that respects this distinction produces records you can trust precisely because it does not pretend to know things it does not.

A worked example

In an appointment, periodontal scoring is not carried out. A tool that defaults the field produces a note showing, say, all-zero or "normal" periodontal scores. A clinician glancing at the signed note sees a complete periodontal assessment that never took place. A tool that leaves the field empty produces a note with no periodontal scores, which is exactly correct, and the clinician adds them only if the assessment was actually done. The first record is false in a way that is hard to spot; the second is accurate and self-evidently incomplete where it should be.

Frequently asked questions

Why not just default missing values to zero?

Because zero is a clinical value implying an assessment was done, while absence means none was. Conflating them misleads later readers.

Aren't placeholders like "not recorded" helpful?

They can clutter the note and, in some cases, imply an active check that did not happen. Leaving the field genuinely empty is cleaner and more honest.

Whose job is it to fill the gap?

The clinician's. The tool reflects what was captured; the clinician completes anything that was actually done but not picked up.

Why does this matter for safety?

Because a falsely complete record can be signed without anyone noticing the fabrication, whereas a genuine gap is visible and can be corrected.