Creatinine-change criteria and staging, with four selectable baselines

A creatinine rise during a stay: 0.3 within 48 hours, or 1.5 times an earlier value; four ways to pick that value.

Rule and version: kdigo_aki_2012@1.1
Published source: Kidney Disease: Improving Global Outcomes (KDIGO) Acute Kidney Injury Work Group. KDIGO Clinical Practice Guideline for Acute Kidney Injury. Kidney Int Suppl 2012;2:1-138. Recommendations 2.1.1-2.1.2 and Table 2 (staging). KDIGO does not define the baseline; the four baselines below are common choices in the literature and are shown side by side. https://kdigo.org/guidelines/acute-kidney-injury/
Edition: KDIGO 2012 AKI guideline, Rec 2.1.1-2.1.2 and Table 2
Effective: from 2026-11-12
Role: creatinine-change criteria; baseline is a user toggle
Status: draft: encoded from the published source; not yet signed off by a clinical reviewer
Clinical reviewer: —
Coding reviewer: —
Sponsor: none
Body hash: 6927ab44b3d4042994ba6f31a985cbae46ff27734c13546c8469110473baec49

Thresholds and parameters

{
  "abs_rise_mg_dl": 0.3,
  "abs_window_hours": 48,
  "applies_to": "LOCAL CONVENTION: inpatient encounters with at least one in-encounter creatinine; outpatient visits are not assessed",
  "back_calculated_alone": "never: without a pre-admission value, a 48-hour rise or a reverse-comparison fall the result is not assessable",
  "baselines": [
    {
      "key": "lowest_365",
      "label": "Lowest value in the 365 days before admission",
      "lookback_days": 365
    },
    {
      "key": "last_outpatient",
      "label": "Most recent outpatient value 7-365 days before admission",
      "max_days": 365,
      "min_days": 7
    },
    {
      "key": "median_365",
      "label": "Median of values in the 365 days before admission",
      "lookback_days": 365
    },
    {
      "key": "back_calculated",
      "label": "Back-calculated from eGFR 75 (2021 equation, age and sex at admission)",
      "target_egfr": 75
    }
  ],
  "loinc_creatinine": "2160-0",
  "not_encoded": "urine-output criteria and dialysis start (no structured source in this data set)",
  "pre_admission_baselines": [
    "lowest_365",
    "last_outpatient",
    "median_365"
  ],
  "ratio_window_days": 7,
  "reverse_comparison": "admission or peak creatinine >= 1.5x the lowest value in the following 7 days counts as creatinine-criterion evidence of a change on arrival: a statement is then not called unsupported",
  "reverse_window_days": 7,
  "stage3_absolute_mg_dl": 4.0,
  "stage_ratio": {
    "1": 1.5,
    "2": 2.0,
    "3": 3.0
  },
  "unsupported_requires": "a pre-admission baseline, 0 of 4 baselines met, no 48-hour rise and the reverse comparison not met",
  "urine_output": "not evaluated (no structured source); every negative is worded 'creatinine criterion not met; urine-output criterion not evaluated'"
}

Boundary tests: 5/5 pass

pass · baselines 0.8/1.1/1.0/1.077, admission 1.6, no 48-hour rise: expected {'k_peak': 2, 'direction': 'DEFINITIONS_DISAGREE'}, got {'k_peak': 2, 'direction': 'DEFINITIONS_DISAGREE'} (holds only because there is no 48-hour rise)
pass · 1.2 -> 1.6 in 24 h, no pre-admission value: expected {'k_peak': 4, 'direction': 'UNDER'}, got {'k_peak': 4, 'direction': 'UNDER'}
pass · 2.4 falling to 1.2, no pre-admission value, stated: expected {'reverse': True, 'direction': 'CONSISTENT'}, got {'reverse': True, 'direction': 'CONSISTENT'}
pass · stated, flat in-stay values, no pre-admission value: expected {'direction': 'NOT_ASSESSABLE'}, got {'direction': 'NOT_ASSESSABLE'}
pass · stated, flat, baseline 1.0 available: expected {'k_peak': 0, 'direction': 'UNSUPPORTED'}, got {'k_peak': 0, 'direction': 'UNSUPPORTED'}