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Estimated blood loss

Estimated blood loss (clinical table).
Name in the dataset intraop_ebl
Type clinical
Stored in clinical_data.csv
Unit mL

Measurement space

-20020true minus recorded (mL)1. recorded 50 mLdensity-2000200true minus recorded (mL)2. recorded 1000 mLdensity-505true minus recorded (mL)3. recorded 20 mLdensity-505true minus recorded (mL)4. recorded 70 mLdensity

Vertical slices through the measurement space: how the true value is spread around a recorded one, for 4 recorded values chosen to show the different cases. Each panel has its own scale. Each is averaged over every record with that value in the release, from the pinned model; groups of fewer than 20 records are not shown.

  1. 50 mL (the commonest recorded value; 795 records): mean +1.67 mL, SD 13.3 mL, 95% between -24.2 and +22.6. Rounding: 50 mL 60%, preferred small values 38%, 10 mL (base) 2%.
  2. 1000 mL (the widest; 31 records): mean -12.4 mL, SD 82.3 mL, 95% between -224 and +185. Rounding: 100 mL 47%, 500 mL 30%, 50 mL 22%.
  3. 20 mL (the narrowest; 148 records): mean +0.212 mL, SD 2.98 mL, 95% between -6.44 and +4.23. Rounding: 10 mL (base) 58%, preferred small values 42%.
  4. 70 mL (unlike the others; 23 records): mean -0.0556 mL, SD 2.99 mL, 95% between -6.49 and +4.19. Rounding: 10 mL (base) 100%.
Joint map of recorded against true value for Estimated blood loss
Joint map: across, the recorded value; up, the true value minus the recorded one. Colour is the share of all probability in the release (3,976 records), on a log scale. Each column is a slice like those above; tall columns are values people round to, narrow ones values written as measured.

Time

This variable carries no time of its own in the dataset.

Value
Model kind model: fitted rounding model (value kind); posterior over the true value
Resolution heaped: a mixture of rounding modes (see the value model)
Anchor nearest (tested)
Status measured
Studies Rounding and heaping of estimated blood loss

In this release

How wide the true-value distribution is, record by record, over 3,976 of 6,388 records (all clinical rows) that have one. Computed with the pinned model, aggregates only.

Median p10 to p90
Standard deviation 14.3 mL 2.89 to 24.5 mL
95% interval width 47.4 mL 9.81 to 92 mL
Mean minus recorded -0.984 mL -3.83 to 3.02 mL

Anchor

Nearest rounding preferred to floor (H1, last graduation passed) by BIC: 52 with the duration covariate, 25 without (same 3882 records; results/2026-10-18_refits_duration_zero.md). See what an anchor is and every variable's anchor.

Value model

Model file: …/models/intraop_ebl.model.json. Read from the pinned snapshot of vitaldb-resolution at commit bb03ddfc8a (2026-10-18).

How a true value becomes the recorded one. The rules are tried in order: a record not taken by an earlier rule is taken by this one with the probability shown (where its condition holds); the last rule takes the rest. Shares of all records depend on the conditions and the true value, so the model must be evaluated for them; the probabilities below are the fitted ones.

Order Rule Rounds to Probability if reached Applies when
1 preferred small values nearest 42.1 % true value below 75
2 500 mL 500 mL (nearest) 1.9 % varies with the value (shown at 150)
3 100 mL 100 mL (nearest) 23.8 % varies with the value (shown at 150)
4 50 mL 50 mL (nearest) 87.7 % varies with the value (shown at 150)
5 10 mL (base) 10 mL (nearest) the rest always
Recorded resolution 1 (modelled at 10)
True-value density log_spline
Fitted on 3,882 records (VitalDB clinical_data.csv (intraop_ebl), positive values on the 10 mL grid with a usable anaesthesia duration)
BIC 22,390
Fitted 2026-10-18
  • Only 0.7% of values are odd multiples of 5 and 17 are off any 5 mL grid; working resolution 10 mL.

Studies

Study Date Status Summary
Rounding and heaping of estimated blood loss 2026-10-18 current Recorded estimated blood loss is a mixture of 5 rounding modes (preferred small values, 500 mL, 100 mL, 50 mL, 10 mL (base)); the model gives the true value's distribution for each record.

Worked examples

Example Side Status Summary
Intraoperative fluid balance as a distribution value draft Fluids in minus fluids out, each a heaped charted volume, as a distribution per case: the recording alone makes a balance uncertain by about ±60 mL, and by ±190 mL when the blood loss was written as a round 500 mL.

Figures

Histogram of the recorded values of intraop_ebl.
Recorded values in the release: 3,976 records, median 150 mL; 28 outside the 0.5–99.5th percentiles are not shown.

Tags: generated, vitaldb-resolution