{"success":true,"version":"v1","request":{"tool":"get_calculator_schema","calculator_id":"meld-score"},"result":{"entity_type":"calculator","id":"meld-score","calculator_id":"meld-score","canonical_url":"https://tttkmbb.com/medical/meld-score","name":"MELD Score Calculator","title":"MELD and MELD-Na Score Calculator – 2016 OPTN/UNOS Formula with 3-Month Mortality Bands","category":"medical","category_name":"Medical & Clinical","tool_name":"calculate_meld_score","featured_mcp_tool":false,"description":"Computes the Model for End-Stage Liver Disease score from bilirubin, INR and creatinine (with the OPTN bounding and rounding rules) and MELD-Na when sodium is supplied, and reports the observed 3-month mortality band from Wiesner 2003.","use_when":"You need the MELD or MELD-Na score for an adult with chronic liver disease, for example to compare severity or describe transplant listing priority.","do_not_use_when":"The patient is under 12 (PELD is used) or you need the newer MELD 3.0 (adds albumin and sex), which this calculator does not implement.","inputs":[{"name":"bilirubin_mg_dl","label":"Total bilirubin","type":"number","unit":"mg/dL","required":true,"max":100,"exclusive_min":0,"description":"Serum total bilirubin in mg/dL (µmol/L ÷ 17.1). Values below 1 are set to 1.","example":2},{"name":"inr","label":"INR","type":"number","required":true,"min":0.5,"max":20,"description":"International normalised ratio. Values below 1 are set to 1.","example":1.5},{"name":"creatinine_mg_dl","label":"Creatinine","type":"number","unit":"mg/dL","required":true,"max":30,"exclusive_min":0,"description":"Serum creatinine in mg/dL (µmol/L ÷ 88.4). Bounded to 1–4.","example":1.2},{"name":"sodium_mmol_l","label":"Sodium","type":"number","unit":"mmol/L","required":false,"min":100,"max":200,"description":"Optional serum sodium; enables MELD-Na (bounded to 125–137).","example":135},{"name":"dialysis_twice_past_week","label":"Dialysis ≥2 times in past 7 days (or 24 h CVVHD)","type":"boolean","required":false,"default":false,"description":"If true, creatinine is set to 4.0 mg/dL as in the OPTN policy.","example":false}],"outputs":[{"name":"meld_score","label":"MELD","type":"integer","decimals":4,"description":"MELD(i) without sodium, rounded and bounded to 6–40."},{"name":"meld_na_score","label":"MELD-Na","type":"integer","decimals":4,"description":"2016 OPTN MELD-Na (only when sodium_mmol_l is given), bounded to 6–40."},{"name":"three_month_mortality_percent","label":"Observed 3-month mortality","type":"number","unit":"%","decimals":1,"description":"Wiesner 2003 band for MELD-Na when available, otherwise MELD."},{"name":"mortality_band","label":"Mortality band","type":"string","decimals":4,"description":"Score band and observed mortality from Wiesner et al. 2003."},{"name":"values_used","label":"Bounded values","type":"string","decimals":4,"description":"Laboratory values after the OPTN bounds were applied."}],"input_schema":{"type":"object","properties":{"bilirubin_mg_dl":{"description":"Serum total bilirubin in mg/dL (µmol/L ÷ 17.1). Values below 1 are set to 1. Unit: mg/dL.","type":"number","maximum":100,"exclusiveMinimum":0,"examples":[2],"x-unit":"mg/dL"},"inr":{"description":"International normalised ratio. Values below 1 are set to 1.","type":"number","minimum":0.5,"maximum":20,"examples":[1.5]},"creatinine_mg_dl":{"description":"Serum creatinine in mg/dL (µmol/L ÷ 88.4). Bounded to 1–4. Unit: mg/dL.","type":"number","maximum":30,"exclusiveMinimum":0,"examples":[1.2],"x-unit":"mg/dL"},"sodium_mmol_l":{"description":"Optional serum sodium; enables MELD-Na (bounded to 125–137). Unit: mmol/L.","type":"number","minimum":100,"maximum":200,"examples":[135],"x-unit":"mmol/L"},"dialysis_twice_past_week":{"description":"If true, creatinine is set to 4.0 mg/dL as in the OPTN policy.","type":"boolean","default":false,"examples":[false]}},"additionalProperties":false,"required":["bilirubin_mg_dl","inr","creatinine_mg_dl"]},"output_schema":{"type":"object","properties":{"meld_score":{"description":"MELD(i) without sodium, rounded and bounded to 6–40.","type":"integer"},"meld_na_score":{"description":"2016 OPTN MELD-Na (only when sodium_mmol_l is given), bounded to 6–40.","type":"integer"},"three_month_mortality_percent":{"description":"Wiesner 2003 band for MELD-Na when available, otherwise MELD. Unit: %.","type":"number","x-unit":"%"},"mortality_band":{"description":"Score band and observed mortality from Wiesner et al. 2003.","type":"string"},"values_used":{"description":"Laboratory values after the OPTN bounds were applied.","type":"string"}}},"formula":"MELD(i) = 0.957 × ln(creatinine) + 0.378 × ln(bilirubin) + 1.120 × ln(INR) + 0.643, rounded to one decimal and multiplied by 10 (values < 1 set to 1; creatinine capped at 4 or set to 4 with dialysis). If MELD(i) > 11: MELD-Na = MELD(i) + 1.32 × (137 − Na) − 0.033 × MELD(i) × (137 − Na), Na bounded 125–137. Final scores rounded and bounded to 6–40.","method":"Kamath 2001 coefficients (3.78, 11.2, 9.57, 6.43 in the ×10 form); mortality bands are the 3-month waiting-list mortality observed by Wiesner 2003 (≤9: 1.9%, 10–19: 6.0%, 20–29: 19.6%, 30–39: 52.6%, 40: 71.3%). Results are informational only and not a substitute for clinical judgement or medical advice.","sources":[{"name":"Kamath PS et al. (2001) A model to predict survival in patients with end-stage liver disease, Hepatology 33:464-470","url":"https://pubmed.ncbi.nlm.nih.gov/11172350/","type":"peer_reviewed","retrieved_at":"2026-09-24"},{"name":"Wiesner R et al. (2003) Model for end-stage liver disease (MELD) and allocation of donor livers, Gastroenterology 124:91-96","url":"https://pubmed.ncbi.nlm.nih.gov/12512033/","type":"peer_reviewed","retrieved_at":"2026-09-24"},{"name":"OPTN/HRSA policy notice – Improving liver allocation: MELD, PELD, Status 1A, Status 1B (MELD-Na formula)","url":"https://www.hrsa.gov/sites/default/files/hrsa/optn/policy-guid-change_impr-liv-alloc-meld-peld-sta-1a-sta-1b_liv.pdf","type":"government","retrieved_at":"2026-09-24"}],"freshness":{"type":"static","max_age_seconds":null,"note":"Deterministic formula with fixed constants; results never go stale. Inputs supplied by the caller determine the output."},"examples":[{"name":"Bilirubin 2.0, INR 1.5, creatinine 1.2, Na 135","inputs":{"bilirubin_mg_dl":2,"inr":1.5,"creatinine_mg_dl":1.2,"sodium_mmol_l":135},"expected":{"meld_score":15,"meld_na_score":17,"three_month_mortality_percent":6},"url":"https://tttkmbb.com/api/v1/calculate/meld-score?bilirubin_mg_dl=2&inr=1.5&creatinine_mg_dl=1.2&sodium_mmol_l=135"},{"name":"Bilirubin 5.0, INR 2.5, creatinine 2.0, Na 128","inputs":{"bilirubin_mg_dl":5,"inr":2.5,"creatinine_mg_dl":2,"sodium_mmol_l":128},"expected":{"meld_score":29,"meld_na_score":32,"three_month_mortality_percent":52.6},"url":"https://tttkmbb.com/api/v1/calculate/meld-score?bilirubin_mg_dl=5&inr=2.5&creatinine_mg_dl=2&sodium_mmol_l=128"},{"name":"Bilirubin 0.8, INR 1.0, creatinine 0.9 (all bounded to 1)","inputs":{"bilirubin_mg_dl":0.8,"inr":1,"creatinine_mg_dl":0.9},"expected":{"meld_score":6,"three_month_mortality_percent":1.9},"url":"https://tttkmbb.com/api/v1/calculate/meld-score?bilirubin_mg_dl=0.8&inr=1&creatinine_mg_dl=0.9"}],"faq":[{"q":"Why is my score different from an older calculator?","a":"Pre-2016 calculators used the un-rounded Kamath formula or omitted sodium; this one follows the OPTN rounding (MELD(i) to one decimal × 10) and adds the sodium term only when MELD(i) exceeds 11."},{"q":"Are the mortality percentages predictions for an individual?","a":"No. They are the mortality observed in waiting-list cohorts in 2003 for each score band; individual prognosis depends on complications and treatment."}],"tags":["meld score","meld-na","liver disease","cirrhosis","transplant","bilirubin inr creatinine"],"related":[{"calculator_id":"egfr","reason":"Kidney function is a MELD component."},{"calculator_id":"anion-gap","reason":"Electrolyte assessment in decompensated cirrhosis."}],"links":{"html":"https://tttkmbb.com/medical/meld-score","markdown":"https://tttkmbb.com/medical/meld-score.md","json":"https://tttkmbb.com/medical/meld-score.json","api":"https://tttkmbb.com/api/v1/calculate/meld-score","schema":"https://tttkmbb.com/api/v1/calculators/meld-score","openapi":"https://tttkmbb.com/openapi.json","mcp":"https://tttkmbb.com/mcp"},"version":"v1","updated_at":"2026-09-24"},"timestamp":"2026-09-24T01:48:13Z","next_actions":[{"tool":"run_calculator","calculator_id":"meld-score","reason":"Run MELD Score Calculator with the inputs above."}],"links":{"markdown":"https://tttkmbb.com/medical/meld-score.md"}}