Create a unique patient level id (if it does not already exist)

The patient identifier is derived from the record number or the first record number (ensuring it matches) an entry in the record number. This deals with multiple admissions in the data set. In the patient identifiable NHS data this is the NHS number.

Usage

derive_patient_identifier(df, v)

Arguments

df

the dataframe.

v

the value set. usually precomputed by the augment framework the value set can be explicitly supplied with v = get_value_sets(df)

Value

a dataframe