Skip to content

Pre-operative PaO₂ decimal rule

Pre-operative PaO₂ in the clinical table mixes 0.1 and 1 mmHg records, so its resolution is set per record by whether a decimal is present.
Date 2026-10-13
Status current
Methods Rounding, heaping and value resolution

Background

  • The pre-operative lab copies (preop_* in clinical_data.csv) generally behave like the lab data.
  • Pre-operative PaO₂ is the exception: it is mixed resolution.

Data

  • 538 pre-operative PaO₂ values.

Method

  • Screened the share of values ending in .0 against the 10% expected at a single 0.1 mmHg resolution.

Results

  • 41% end in .0 against 10% expected, so about a third were recorded as whole numbers.

Discussion

  • This looks like two sources again: probably two blood-gas analysers or a manual transcription step.
  • It is a small field and can take the haematocrit approach: resolution by record, 0.1 or 1 mmHg according to whether a decimal is present.

Open questions

  • Why some PaO₂ records are whole numbers (unexplained phenomenon). Which of the two candidate explanations (two analysers or a manual transcription step) is behind the whole- number records is not known.

Tags: from the resolution work