new_users_fixed: Determine New vs. Ongoing Use of a Drug of Interest, Fixed...
In amarshall1/prescribeR: Quantify Exposure Based On Routine Prescribing Data

Description Usage Arguments Value Examples

Classifies patients as new or ongoing users of the drug(s) of interest based on whether or not they have prescriptions within a lookback period based on a standardised start date for all patients

new_users_fixed(df, drug, start_date = NULL, timeframe = 0,
  return_all = TRUE, patient_id_col = "patient_id",
  drug_id_col = "drug_id", presc_date_col = "presc_date_x",
  date_format)

`df`	a data frame containing prescription records to be analysed - records must contain at least a patient ID, drug ID and prescription date
`drug`	a string containing a drug ID to be used to limit the prescribing data to the drug(s) of interest, accepts regular expressions
`start_date`	a string containing the date to start follow-up - any prescriptions before this date are used to indicate ongoing use
`timeframe`	a number representing the length, in days, of the timeframe before the start date to check for previous prescriptions
`return_all`	a logical, if TRUE the function will return data for all patients as well as flags indicating if they were exposed during follow-up and if they are new users. If FALSE, returns only new users exposed during follow-up
`patient_id_col`	a string, the name of the column in `df` containing the patient IDs
`drug_id_col`	a string, the name of the column in `df` containing the drug IDs
`presc_date_col`	a string, the name of the column in `df` containing the prescription date
`date_format`	a string, the format of the dates contained in `df` and the start_date argument

A data frame containing patient IDs, flags indicating if the patient was a new user at the start date and if they were exposed during follow-up, and where applicable the date of the first prescription during follow-up

1 2	new_users_fixed(synth_presc, drug = "SIMVASTATIN", start_date = "2021-01-01", timeframe = 90, presc_date_col = "presc_date", drug_id_col = "approved_name")