CrCl and ECOG↔Karnofsky at Screening — Without Slowing the Visit

Screening visits stack eligibility math on top of consent and scheduling. Creatinine clearance thresholds appear in protocols with little patience for arithmetic debates. Performance status shows up as ECOG in one place and Karnofsky in another. Someone pulls a web calculator of unknown formula pedigree, or converts scales from memory, and the visit slows while numbers get rechecked.

Weight basis adds confusion: actual vs ideal vs adjusted body weight changes Cockcroft-Gault results. If height is missing, staff guess or skip IBW/AdjBW options and only notice the mismatch when the sponsor’s IWRS rejects the value.

These are reference calculations for logistics and eligibility conversation — not a place to store charts. Typing names or MRNs into a convenience calculator creates a PHI habit the site does not need.

Unit mistakes stall screening too. Creatinine reported in mg/dL versus µmol/L, weight in kg versus lb — a transposed unit produces a clearance number that looks plausible until medical review catches it.

Performance status source documents disagree. A prior note lists Karnofsky 80; the protocol table expects ECOG. Converting from memory without a reference band invites a one-grade swing that matters at the eligibility cutoff.

Screening backlogs amplify every delay. When three consents stack on one morning, a five-minute formula hunt becomes a room full of waiting people. Reference tools should remove debate, not add another tab to manage.

Protocols specify formulas and thresholds; sponsor IWRS/EDC calculators and investigator judgment govern decisions. Site tools that mirror common equations (Cockcroft-Gault; ECOG↔Karnofsky bands) are administrative aids so coordinators can prepare numbers quickly and verify against the protocol-specified method.

CRC Toolbox renal/performance helpers are ephemeral and Zero-PHI by design: numeric inputs only, nothing uploaded, nothing retained as a patient file.

Renal eligibility is often a gate before randomization. The site calculation is a preview — sponsor systems and investigator assessment confirm. Document final eligibility in the systems of record, not in the browser helper.

ECOG and Karnofsky are not linear conversions in every clinical context; paired-band reference maps common equivalents for screening conversation. Investigator assessment still governs what goes on the CRF.