Future versions of icd will drop
the icd_ prefix. For example, charlson should be used in
favor of icd_charlson. To distinguish icd function calls,
consider using the prefix icd:: instead, e.g., icd::charlson.
Functions which specifically operate on either ICD-9 or ICD-10 codes or
their sub-types will retain the prefix. E.g.
icd9_comorbid_ahrq. icd specific classes also retain
the prefix, e.g., icd_wide_data.