Anchor decisions¶
Every variable's anchor, and how well it is supported. What an anchor is, with a figure, is under Aim and terms.
Each anchor below has a basis:
- Tested: the data show it.
- Convention: the usual rule, not tested; its largest possible effect is half a step.
- Assumption: relied on, but the data in the release cannot test it; outside evidence could.
- Open: an alternative is plausible and could matter; the study says what would settle it.
5 tested, 55 convention, 2 assumption. The tested ones, the best supported, come first; the unsettled ones (assumption and open) last, in bold. The anchors themselves are read from the value models' pinned snapshot; the basis is the atlas's judgement and can be challenged like any other result (how to contribute).
| Variable | Group | Step | Anchor | Basis | Why |
|---|---|---|---|---|---|
| Estimated blood loss | Fluids and blood | — | nearest | tested | 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). |
| Intraoperative crystalloid | Fluids and blood | — | nearest | tested | Nearest rounding preferred to floor (H1, last graduation passed) by BIC: 47 with the duration covariate, 12 without (same 5863 records; results/2026-10-18_refits_duration_zero.md). |
| Intraoperative urine output | Fluids and blood | — | nearest | tested | 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). |
| Admission time from casestart | Times and durations | 86400 sec | floor | tested | Discharge minus admission is a whole number of days in every case, so each value marks a midnight. |
| Discharge time from casestart | Times and durations | 86400 sec | floor | tested | Discharge minus admission is a whole number of days in every case, so each value marks a midnight. |
| Epinephrine | Drugs | 1 mcg | nearest | convention | Native recording unit, rounding to the nearest assumed; not tested (sparse or exact-count data). |
| Midazolam | Drugs | 0.5 mg | nearest | convention | Native recording unit, rounding to the nearest assumed; not tested (sparse or exact-count data). |
| Vecuronium | Drugs | 1 mg | nearest | convention | Native recording unit, rounding to the nearest assumed; not tested (sparse or exact-count data). |
| Intraoperative colloid | Fluids and blood | 1 mL | nearest | convention | Native recording unit, rounding to the nearest assumed; not tested (sparse or exact-count data). |
| Case end | Times and durations | 1 sec | floor | convention | Clock truncation to the whole second; at most 1 s, negligible. |
| Arterial oxygen saturation | Blood gas | 1 % | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Base excess | Blood gas | 0.1 mmol/L | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Bicarbonate | Blood gas | 0.1 mmol/L | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Lactate | Blood gas | 0.1 mmol/L | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Partial pressure of CO₂ | Blood gas | 1 mmHg | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Partial pressure of O₂ | Blood gas | 1 mmHg | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| pH | Blood gas | 0.01 | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Alanine transferase | Chemistry | 1 IU/L | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Albumin | Chemistry | 0.1 g/dL | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Ammonia | Chemistry | 1 mcg/dL | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Asparate transferase | Chemistry | 1 IU/L | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Blood urea nitrogen | Chemistry | 1 mg/dL | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| C-reactive protein | Chemistry | 0.01 mg/dL | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Creatinine | Chemistry | 0.01 mg/dL | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Creatinine clearance | Chemistry | 1 mL/min | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Glomerular filtration rate | Chemistry | 0.1 mL/min/1.73 m2 | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Total bilirubin | Chemistry | 0.1 mg/dL | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Total protein | Chemistry | 0.1 g/dL | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Activated partial thromboplastin time | Coagulation | 0.1 sec | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Prothrombin time (INR) | Coagulation | 0.01 INR | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Prothrombin time (sec) | Coagulation | 0.1 sec | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Chloride | Electrolytes and glucose | 1 mmol/L | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Glucose | Electrolytes and glucose | 1 mg/dL | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Ionized Calcium | Electrolytes and glucose | 0.01 mmol/L | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Potassium | Electrolytes and glucose | 0.1 mmol/L | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Probably phosphorus (unconfirmed): not in lab_parameters.csv | Electrolytes and glucose | 0.1 | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Sodium | Electrolytes and glucose | 1 mmol/L | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Erythrocyte sedimentation rate | Haematology | 1 mm/hr | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Hematocrit | Haematology | — | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Hemoglobin | Haematology | 0.1 g/dL | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Platelet count | Haematology | 1 ×1000/mcL | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| White blood cell count | Haematology | 0.01 ×1000/mcL | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Preoperative GOT | Preoperative labs | 1 IU/L | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Preoperative GPT | Preoperative labs | 1 IU/L | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Preoperative HCO3- | Preoperative labs | 0.1 mmol/L | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Preoperative K | Preoperative labs | 0.1 mmol/L | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Preoperative Na | Preoperative labs | 1 mmol/L | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Preoperative PaCO₂ | Preoperative labs | 0.1 mmHg | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Preoperative PaO₂ | Preoperative labs | — | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Preoperative SpO₂ | Preoperative labs | 0.1 % | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Preoperative aPTT | Preoperative labs | 0.1 sec | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Preoperative albumin | Preoperative labs | 0.1 g/dL | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Preoperative base excess | Preoperative labs | 0.1 mmol/L | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Preoperative blood urea nitrogen | Preoperative labs | 1 mg/dL | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Preoperative creatinine | Preoperative labs | 0.01 mg/dL | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Preoperative glucose | Preoperative labs | 1 mg/dL | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Preoperative hemoglobin | Preoperative labs | 0.1 g/dL | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Preoperative pH | Preoperative labs | 0.001 | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Preoperative platelet count | Preoperative labs | 1 x1000/mcL | nearest | convention | Laboratory results rounded to the last reported digit; at most half the last digit. |
| Lab timestamp (seconds from casestart) | Result times | 1 sec | floor | convention | Clock truncation to the whole second; at most 1 s, negligible. |
| ICU days | Outcome | — | counting rule | assumption | 815 one-day stays against 98 two-day stays argue against calendar days touched; read as nights or completed days. |
| Age | Patient | 1 years | floor | assumption | The release says only "years"; infants in tenths and the >89 cap point to an exact age cut down to completed years. |