To help to integrate traditional Asian medicine with Western medicine (S. Cameron et al. Nature 482, 35; 2012), the World Health Organization (WHO) is developing common systems for collecting statistics from both. This information — known as the International Classification of Traditional Medicine (see go.nature.com/mv3iux) — is being incorporated into a revision of the WHO International Classification of Diseases, to be released in 2015.

Clean, standardized data from several countries will allow proper comparison of the effectiveness, cost and safety of the different approaches.