README.md

Drug code sets for Electronic Health Record research

⚠️ UK Biobank guidance highlights issues including incomplete and/or inconsistently formatted BNF codes, missing Read v2 codes and missing drug names. The ukbb-ehr-data repository includes example code to handle these issues and identify periods of prescriptions using the code sets below.

Drug coding

prescriptions.rds is a named "list of lists" for the following drug categories:

Drug category	Name
Anti-diabetes drugs	diabetes
Anti-hypertensives	hypertension
Atypical anti-psychotics	antipsychotic
Steroids	steroids
Statins	statins

For each drug category the following codes are provided:

Name	Description
read	Read v2 codes for the drug category. Partial matching should be used e.g. bxi means select all Read v2 codes starting bxi (those matching the regular expression ^bxi).
bnf	BNF codes for the drug category. Partial matching should be used e.g. 0212000AA means select all Read v2 codes starting 0212000AA (those matching the regular expression ^0212000AA).
search	Search terms that can be used to identify drugs based on the drug_name field. E.g. statin means select any drug matching the regular expression statin (case insensitive).

Search terms aim to cover all potential generic and brand names for drugs in each category. Results should be carefully reviewed when using these terms.

Anti-diabetes drugs

Codes are provided for:

Drug category	Name
Any anti-diabetes drug	all
Insulin	insulin
All anti-diabetic drugs excluding insulin	non_insulin
Metformin	metformin

For the avoidance of doubt, metformin codes are included under non_insulin.

For example, the following returns BNF codes for anti-diabetes drugs:

drug_codes <- readRDS("drugs/prescriptions.rds")
drug_codes$diabetes$all$bnf  # codes for all anti-diabetes drugs
drug_codes$diabetes$insulin$bnf  # codes for insulin only

Anti-hypertensives

Codes are provided for:

Drug category	Name
Any anti-hypertensive	all
Thiazides and related diuretics	thiazides
Potassium-sparing diuretics and aldosterone antagonists	potassium_aldosterone
Potassium sparing diuretics and compounds	potassium_compounds
Beta adrenoceptor blocking drugs	beta_blockers
Vasodilator antihypertensive drugs	vasodilator
Centrally-acting antihypertensive drugs	centrally_acting
Adrenergic neurone blocking drugs	adrenergic_blockers
Alpha-adrenoceptor blocking drugs	alpha_blockers
Renin-angiotensin system drugs	renin_system
Calcium-channel blockers	calcium_blockers

For example, the following returns Read v2 codes for anti-hypertensives:

drug_codes <- readRDS("drugs/prescriptions.rds")
drug_codes$hypertension$all$read  # codes for all anti-hypertensives
drug_codes$hypertension$vasodilator$read  # codes for vasodilators only

Atypical anti-psychotics

The following returns the search terms for all atypical anti-psychotics including depot injections:

drug_codes <- readRDS("drugs/prescriptions.rds")
drug_codes$antipsychotic$all$search

Steroids

The following returns BNF codes for all steroids including depot injections:

drug_codes <- readRDS("drugs/prescriptions.rds")
drug_codes$steroids$all$bnf

Statins

The following returns Read v2 codes for all statins:

drug_codes <- readRDS("drugs/prescriptions.rds")
drug_codes$statins$all$read