refill_gap: Determine Drug Persistence with Refill Gap Only

In amarshall1/prescribeR: Quantify Exposure Based On Routine Prescribing Data

Description

This function determines periods of persistent use of the drug of interest based on the gaps between prescriptions. Gaps which exceed the selected allowable gap length result in discontinuation points, and the function returns patient ID's and periods of exposure that are over the selected minimum length.

Usage

refill_gap(df, drug, gap, threshold = 0, summary = FALSE,
  patient_id_col = "patient_id", drug_id_col = "drug_id",
  presc_date_col = "presc_date_x", date_format)

Arguments

df	a data frame containing prescribing records to be analysed - records must contain at least a paitent ID, drug ID and a 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
gap	a number, the length of the allowable gap in days between two prescriptions before the patient is considered to have discontinued use of the drug
threshold	a number, the minimum length of period of exposure, in days, to be included in the results
summary	a logical, if true the function will return a summary of all exposure periods instead of the individual periods
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 prescption date
date_format	a string, the format of the dates in df

Value

a data frame containing patient IDs and corresponding periods of exposure (consisting of first and last prescriptions, number of prescriptions and lengths of exposure) which match the chosen refill gap and minimum length

Examples

refill_gap(synth_presc, drug = "SIMVASTATIN", gap = 30,
drug_id_col = "approved_name", presc_date_col = "presc_date",
date_format = "%d/%m/%Y")
refill_gap(synth_presc, drug = "103050", gap = 30, threshold = 60, summary = TRUE,
drug_id_col = "bnf_paragraph", presc_date_col = "presc_date",
date_format = "%d/%m/%Y")

amarshall1/prescribeR documentation built on May 20, 2020, 2:34 p.m.