 The study examined the positive predictive value, PPV, of international classification of diseases, 10th revision, ICD, 10, diagnostic coding in the Danish National Registry of Patients, NRP, for 19 Charlson conditions and found that the overall PPV was 98% with a range from 82.0% to 100%. This article was authored by Lash Timothy L, Christensen Stefan, Christians in Christian F, and others.