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Intraoperative urine output

Intraoperative urine output (clinical table).
Name in the dataset intraop_uo
Type clinical
Stored in clinical_data.csv
Unit mL

Measurement space

-50050true minus recorded (mL)1. recorded 100 mLdensity-202true minus recorded (mL)2. recorded 0 mLdensity-505true minus recorded (mL)3. recorded 80 mLdensity-505true minus recorded (mL)4. recorded 10 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. 100 mL (the commonest recorded value; 324 records): mean -1.47 mL, SD 16 mL, 95% between -41 and +34.9. Rounding: 50 mL 55%, 100 mL 23%, 10 mL 19%.
  2. 0 mL (the narrowest; 23 records): mean +0.255 mL, SD 0.508 mL, 95% between -0.44 and +1.72. Rounding: latent below half the base resolution 52%, true zero 48%.
  3. 80 mL (unlike the others; 105 records): mean -0.517 mL, SD 2.69 mL, 95% between -4.99 and +4.4. Rounding: 10 mL 86%, 5 mL (base) 14%.
  4. 10 mL (unlike the others; 26 records): mean +0.763 mL, SD 2.64 mL, 95% between -4.71 and +4.6. Rounding: 10 mL 85%, 5 mL (base) 15%.
Joint map of recorded against true value for Intraoperative urine output
Joint map: across, the recorded value; up, the true value minus the recorded one. Colour is the share of all probability in the release (3,707 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 intraoperative urine output

In this release

How wide the true-value distribution is, record by record, over 3,707 of 6,388 records (all clinical rows) that have one. Computed with the pinned model, aggregates only.

Median p10 to p90
Standard deviation 2.73 mL 2.46 to 16.3 mL
95% interval width 9.42 mL 9.19 to 76.2 mL
Mean minus recorded -0.0823 mL -1.64 to 0.546 mL

Anchor

Nearest rounding preferred to floor (H1, last graduation passed) by BIC: 383 with the duration covariate, 317 without (same 3630 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_uo.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
1 100 mL 100 mL (nearest) 5.8 % varies with department
2 50 mL 50 mL (nearest) 38.7 % true value within 20 of the rounded one; varies with department; varies with the value (shown at 160)
3 10 mL 10 mL (nearest) 75.4 % varies with department
4 5 mL (base) 5 mL (nearest) the rest always
Recorded resolution 1 (modelled at 5)
True-value density log_spline
Covariates department
Fitted on 3,630 records (VitalDB clinical_data.csv (intraop_uo), positive values on the 5 mL grid with a usable anaesthesia duration)
BIC 30,008
Fitted 2026-10-18
  • Only 15 of 3,707 values (0.4%) are not multiples of 5; treated as typos or over-precise readings and flagged off_grid.

Studies

Study Date Status Summary
Rounding and heaping of intraoperative urine output 2026-10-18 current Recorded intraoperative urine output is a mixture of 4 rounding modes (100 mL, 50 mL, 10 mL, 5 mL (base)); the model gives the true value's distribution for each record.

Worked examples

Example Side Status Summary
A regression that carries rounding uncertainty through value draft Acute kidney injury after surgery against intraoperative urine output (mL/kg/h), fitted once on the recorded numbers and once per draw from the true-value distributions: the rounding moves 14% of cases across the oliguria threshold, but widens the confidence interval of the cohort's regression by at most 4%.
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.
Oliguria labels for a prediction model value draft One label per patient, oliguric or not, from three rounded numbers: 10% of labels are uncertain and 2.6% are expected to be wrong, which sets a floor under the error any model can be measured to have. A typical model is barely affected; a good one is.
Urine output in mL/kg/h as a distribution value draft Intraoperative urine output per kilogram per hour, from three rounded inputs, as a probability distribution per case: one case in ten cannot be placed confidently on either side of 0.5 mL/kg/h.

Figures

Histogram of the recorded values of intraop_uo.
Recorded values in the release: 3,707 records, median 160 mL; 19 outside the 0.5–99.5th percentiles are not shown.

Tags: generated, vitaldb-resolution