Numbers registry
Every threshold in the Step 1 review book, alphabetically.
| Threshold | Value |
|---|---|
| 2-hour OGTT glucose | ≥200 mg/dL |
| 5-year survival | ~10% |
| AAA definition | ≥3 cm aortic diameter |
| Accreta (attachment only) | ~75% of the spectrum |
| AFE mortality | 20–40% |
| Alcohol withdrawal seizures | 12–48 h after last drink |
| ALF mortality without transplant | ~40–50% |
| Alpha-globin gene copies | 4 |
| alteplase window | ≤4.5 h |
| Amiodarone half-life | ~40–55 days |
| Annual progression risk to adenocarcinoma | ~0.2–0.5%/year |
| Anti-AChR sensitivity | ~85% |
| Anti-CCP specificity for RA | ~95–98% |
| Apnea definition | ≥10 seconds airflow cessation |
| Apnea test threshold | ≥60 mmHg and ≥20 mmHg above baseline |
| APP locus | chromosome 21 |
| artery of Adamkiewicz level | T9–L2 |
| Atherosclerotic RAS share | ~90% |
| ATP from complete palmitate oxidation | ~106 ATP |
| ATP yield per glucose | ~30–32 ATP |
| Atrial flutter rate | ~300/min atrial, ~150/min ventricular with 2:1 block |
| Autoregulation range | 80–180 mmHg MAP |
| Average age at menopause | ~51 years |
| BNP rule-out threshold | <100 pg/mL |
| CD4 threshold for cryptococcal meningitis risk | <100 cells/µL |
| Cecal diameter perforation risk | >12 cm |
| Cerebral autoregulation curve | shifted right in chronic hypertension |
| Cerebral autoregulation range | MAP 60–160 mmHg |
| Chiari I tonsillar descent | >5 mm below foramen magnum |
| Coarctation-BAV association | ~50% |
| COHb half-life, room air | ~5 hours |
| Colesevelam TG contraindication | >500 mg/dL |
| Compartment pressure threshold | ≥30 mmHg |
| Complete mole choriocarcinoma risk | ~2–3% |
| COPD O2 target | 88–92% SpO2 |
| Cord separation delay | >30 days |
| CSF/serum glucose ratio threshold | <0.4 |
| Cup-to-disc ratio | >0.5 |
| Cystic fibrosis carrier frequency | ~1/25 |
| Cystic fibrosis incidence | ~1/2500 |
| Delirium tremens | 48–96 h |
| Delirium tremens mortality (untreated) | up to 5–15% |
| DMD creatine kinase | >10,000 IU/L |
| DMD onset | before age 5 years |
| Down syndrome AD pathology | by ~age 40 |
| Dressler syndrome window | weeks 2–6 |
| Early noncontrast CT sensitivity for nontraumatic SAH | very high within 6 h |
| EDH source | middle meningeal artery |
| Empirical rule | 68% / 95% / 99.7% |
| Eruptive xanthoma trigger | >1000 mg/dL triglycerides |
| Exercise heart rate | 70→180/min |
| Exercise stroke volume | 70→130 mL |
| F:M ratio | 2–3:1 |
| Fasting plasma glucose | ≥126 mg/dL |
| Filtration fraction | ~20% |
| First-degree AV block PR interval | >0.20 s |
| Flare duration | 1–2 weeks |
| FMD share | ~10% |
| FRC | ≈2400 mL |
| Free wall/septal/papillary rupture window | days 3–14 |
| FTD onset age | 45–65 y |
| Full-penetrance repeats | ≥40 |
| GFR | ~120 mL/min |
| GFR increase | 40–65% |
| GTN risk after complete mole | 15–20% |
| Hb-bound O2 share | >98% |
| HCC tumor marker | AFP |
| Hemoglobin A1C | ≥6.5% |
| Hepatic B12 stores | 3–5 years |
| HEV third-trimester mortality | up to 20–25% |
| HFpEF cutoff | ≥50% |
| HFrEF cutoff | ≤40% |
| HIT platelet fall onset | 5–10 days |
| HLA-B27 in AS | >90% |
| HPV 16/18 attributable fraction | ~70% |
| HSV encephalitis mortality | ~70% untreated vs ~20% with early acyclovir |
| HTT CAG repeat threshold | ≥36 repeats |
| Hypernatremia correction | ≤10–12 mEq/L per 24 h |
| Hypertriglyceridemia threshold | >1000 mg/dL |
| Hyperuricemia threshold | 6.8 mg/dL |
| Intermediate repeats | 27–35 |
| Klinefelter breast cancer risk | ~20× |
| L:S ratio maturity | ≥2.0 |
| Lecithin:sphingomyelin ratio, mature | ≥2.0 |
| LEMS-SCLC association | ~60% |
| Lipase diagnostic threshold | ≥3× upper limit of normal |
| Lithium maintenance level | 0.6–1.2 mEq/L |
| Low tidal volume ventilation | 6 mL/kg predicted body weight, plateau <30 cmH2O |
| Luteal phase length | ~14 days |
| macroalbuminuria | >300 mg/day |
| MAP vasopressor threshold | <65 mmHg |
| MASLD (formerly NAFLD) prevalence | ~30% |
| Maximum tensile strength | ~80% |
| Measles herd immunity threshold | 92–95% |
| Measles R0 | 12–18 |
| Medullary osmolality | ~1200 mOsm/kg |
| Medullary osmolality at papilla | ~1200 mOsm/kg |
| Melanoma diameter threshold | >6 mm |
| Menopause definition | 12 consecutive months |
| Microalbuminuria | 30–300 mg/day |
| microalbuminuria | 30–300 mg/day |
| Minimum core temperature | ≥36°C |
| Most common cardiomyopathy | Dilated |
| Most specific IDA marker | ↓Ferritin |
| MS oligoclonal bands | positive in >90% |
| MS onset age | 20–40 y |
| Normal A-a | 5–15 mmHg |
| Normal cardiac output | ~5 L/min |
| Normal CO | ~5 L/min |
| Normal compartment pressure | <10 mmHg |
| Normal EF | 55–70% |
| Normal ejection fraction | 55–70% |
| Normal HTT CAG repeats | <27 |
| Normal intraocular pressure | 10–21 mmHg |
| Normal IOP | 10–21 mmHg |
| Normal MAP | 70–105 mmHg |
| Normal PO4 | 2.5–4.5 mg/dL |
| Normal PTH | 10–65 pg/mL |
| Normal serum Ca2+ | 8.5–10.2 mg/dL |
| Normal serum osmolality | 280–295 mOsm/kg |
| Normal V/Q | ≈0.8 |
| OCB sensitivity | >90% |
| Ovulation timing | ~36 hours after LH surge onset |
| PaO2/FiO2 mild | >200 to ≤300 |
| PaO2/FiO2 severe | ≤100 |
| PCWP cutoff | ≤18 mmHg |
| Peak incidence | 15–35 years |
| Pembrolizumab target | PD-1 on T cells |
| Pertussis lymphocytosis | WBC 20,000–50,000/µL |
| PKD1 share | ~85% |
| Plasma metanephrine sensitivity | ~97% |
| PPV formula | PPV = (Sn×Prev)/[(Sn×Prev)+(1−Sp)(1−Prev)] |
| Preeclampsia BP threshold | SBP ≥140 or DBP ≥90 mmHg |
| Prevalence formula | Prevalence ≈ Incidence × Duration |
| Primary ovarian insufficiency | <40 years |
| Progression to SCC | 1–10% |
| Prolactin suggesting prolactinoma | >200 ng/mL |
| Proximal Na+/water reabsorption | 65–70% |
| PSA in BPH | normal to mildly elevated |
| PSEN1 locus | chromosome 14 |
| Pulsus paradoxus threshold | >10 mmHg inspiratory SBP drop |
| Radiographic delay | 10–14 d |
| Reduced-penetrance repeats | 36–39 |
| Resting O2 extraction | ~75% |
| Reynolds pentad | Charcot triad + altered mental status + hypotension |
| Rule of 2's | 2% prevalence, 2 ft from ileocecal valve, 2 in long, symptomatic by age 2 |
| SAAG threshold for portal hypertension | ≥1.1 g/dL |
| SBP diagnostic threshold | ≥250 PMN/µL |
| SCFE bilaterality | 20–40% |
| SDH source | bridging veins |
| Secondary amenorrhea threshold | ≥3 months |
| Severe AHI | ≥30 events/hour |
| Severe hypophosphatemia threshold | <1.0 mg/dL |
| Severe thrombocytopenia threshold | <100,000/µL |
| Severe-range BP | SBP ≥160 or DBP ≥110 mmHg |
| Severely increased albuminuria | >300 mg/day |
| Spermatogenesis duration | ~64 days |
| ST-elevation lead groups | V1–V4 anterior (LAD) |
| Status epilepticus definition | ≥5 minutes |
| Status epilepticus duration | ≥5 min continuous, or ≥2 seizures without recovery |
| Surfactant maturity threshold | ~35 weeks gestation |
| Sweat chloride diagnostic | ≥60 mmol/L |
| Sweat chloride diagnostic threshold | ≥60 mmol/L |
| Synovial WBC threshold, native joint | >50,000/μL |
| Target SpO2 in exacerbation | 88–92% |
| Tensile strength at 1 week | ~10% |
| Testosterone:DHT ratio | markedly elevated, often >20:1 |
| TG pancreatitis risk threshold | >500 mg/dL |
| Toxic megacolon threshold | >6 cm |
| Transferrin saturation cutoff | <20% |
| Trisomy 18 median survival | 5–15 days |
| Trisomy 18 one-year survival | <10% |
| Trisomy 21 risk, maternal age 20 vs 40 | ~1/1500 → ~1/100 |
| Tubular adenoma malignancy risk | ~5% |
| TV | ≈500 mL |
| Urate-lowering target | <6 mg/dL |
| VF risk window | <48 h |
| Villous adenoma malignancy risk | ~40% |
| VT rate | usually 150–250/min |
| Whipple triad glucose | <55 mg/dL |
| xanthochromia delay | ≥6–12 h |