{"id":2078,"slug":"knapp-2004-eu-verbal-misinterpret","title":"Knapp et al. 2004 — EU verbal frequency labels cause dramatic overestimation of medical risk","kind":"reference","scope":"business","status":"current","audiences":["kevin","candid-team"],"topics":["verbal-label-misinterpretation"],"reference_body":"**Claim:** Knapp, Raynor & Berry (2004, *Quality & Safety in Health Care* 13(3):176-180) found a side effect labeled \"rare\" (true ~0.01-0.1%) was estimated at **~18%** by the verbal group vs ~2.1% by the numeric group; \"common\" constipation was estimated at **34.2%** (verbal) vs **8.1%** (numeric).\n\nBüchter et al. (2014, *BMC Medical Informatics & Decision Making* 14:76, **meta-analysis of 10 RCTs**) found verbal descriptors led to systematic overestimation of absolute risk (range of means 3%-54%) vs smaller overestimation for numbers (2%-20%). Bal et al. (2021, *JGIM*, systematic review): average interpretations of \"rare\" ranged 7-21% and \"common\" ranged 34-71% across studies.\n\n**Source:** Knapp et al. 2004; Büchter et al. 2014 meta-analysis; Bal et al. 2021 systematic review.\n\n**Confidence:** Verified — peer-reviewed + meta-analysed + systematic-reviewed.\n\n**Why this matters for Candid:** Independent corroboration of [[budescu-2009-2014-ipcc-verbal-mistinterpret]] from a different domain. The convergence (climate + medicine) is unusually strong. Anchor every widget tier word.","rationale_body":null,"metadata":null,"links":{"outgoing":[{"slug":"eu-smpc-frequency-bands","title":"EU Summary of Product Characteristics — defined frequency bands as a tier convention","kind":"reference","scope":"business","link_type":"relates-to"}],"incoming":[{"slug":"research-brief-smb-widget-presenting-tiers-june-2026","title":"Research brief: SMB widget presentation layer — tiered results without overclaiming (June 2026)","kind":"reference","scope":"business","link_type":"relates-to"},{"slug":"bal-2021-systematic-review-verbal-labels","title":"Bal et al. 2021 (JGIM systematic review) — \"rare\" interpretations 7-21%, \"common\" 34-71%","kind":"reference","scope":"business","link_type":"relates-to"}]},"created_at":"2026-06-23T19:16:03.443Z","updated_at":"2026-06-23T19:16:03.443Z"}