# Cancer Cachexia Prevalence Is Underestimated in Medical Records of Patients in a Regional Tertiary Hospital

## TL;DR

This study shows that cancer cachexia is underdiagnosed and underreported in medical records, leading to an underestimated prevalence.

## Contribution

The study demonstrates that ICD coding and structured data significantly underestimate cachexia prevalence, while unstructured data reveals additional cases.

## Key findings

- Standard ICD code searching underestimated cachexia prevalence in cancer patients.
- Many cachexia cases were not diagnosed despite objective weight data indicating their presence.
- Unstructured clinical narratives identified additional cachexia cases not captured by structured data.

## Abstract

Widespread lack of awareness and limited real‐world prevalence evidence have impeded cachexia care and research. We hypothesized that healthcare professionals may identify the term cachexia, leading to International Classification of Diseases (ICD) coding for this term, with or without records of body weight loss for diagnosing cancer cachexia, and that frequently, ICD coding does not accurately reflect weight data.

We assessed cachexia prevalence in patients diagnosed with cancer, using the Clinical Data Warehouse of a French hospital containing two types of real‐world digitized data: (a) ‘structured’: coded diagnoses and electronic records; (b) ‘unstructured’: uncoded clinical narratives/reports: discharge summaries, procedure results, letters. Two sequential searches covering 2018–2023 (1) determined the prevalence of cachexia in all patients with a diagnosis of cancer using ICD‐10 code R64 (cachexia), electronic records of body weight and unstructured narrative data; and (2) examined data of cancers of high‐prevalence cachexia: colorectal, pancreatic and bronchial/lung cancers, determining (a) prevalence of cachexia by these criteria; (b) extent to which a diagnosis of cachexia was supported by weight loss data; and (c) extent to which the diagnosis of cachexia was not made despite objective weight data indicating its presence.

A total of 76 547 of 737 906 patients had cancer of any primary type; 1856 (2.42%) of these had a cachexia diagnosis: 620 identified by ICD code, 1507 by unstructured data, including 271 by both. Of 6946 patients with colorectal, pancreatic or bronchial/lung cancer, 2033 patients (29.3%) were identified with cachexia by structured and/or unstructured data; both approaches were required to discover cachexia cases. From structured data an ICD‐R64 search found only 254 patients described by the term cachexia, of which 127 had weight data supporting the diagnosis in the electronic medical record. An additional 1340 patients with BMI < 20 kg/m2 or weight loss > 5% were not coded as cachectic. Unstructured data for the three cancers identified 439 additional cachexic patients.

(1) Standard ICD code‐searching underestimated cachexia prevalence in all patients and those with high‐prevalence‐cachexia cancers; (2) Many cachexia cases were not diagnosed, although data indicated its presence; (3) Many cachexia cases diagnosed by judgement were not supported by data; (4) Increasing provider awareness of cancer cachexia definitions would likely improve cachexia care and research.