We selected patients by identifying product codes indicating a prescription of OAT and clinical codes indicating a history of illicit opioid use, such as ‘heroin dependence’ (see extended data for a full code list23). We prioritised specificity over sensitivity, aiming to use codes that are only applied to the target population.
We used keywords to search CPRD dictionaries to find Read and SNOMED clinical codes that may illicit opioid use (methadone; buprenorphine; abus; addict; ependen; drug user; heroin; inject; misus*; opiate; opioid; overdose). Our search identified 1,098 Read codes and 1,800 SNOMED codes. Two authors (DL and PP)
screened the codes for relevance, with conflicts resolved through discussion.
Where codes were likely to indicate illicit opioid use, but did not specifically mention opioids, we classified them as ‘probable’. Some clinical codes described prescriptions, tests or adverse reactions relating to methadone and buprenorphine.
Lewer D, Padmanathan P, Qummer ul Arfeen M et al. Healthcare use by people who use illicit opioids (HUPIO): development of a cohort based on electronic primary care records in England [version 1; peer review: awaiting peer review]. Wellcome Open Res 2020, 5:282. 10.12688/wellcomeopenres.16431.1
| Code | Description | Data-base | Read or SNOMED term | Status | Meth/ bupe | Type |
|---|---|---|---|---|---|---|
| x10045241000033110 | Buprenorphine 1mg sublingual tablets sugar free | AURUM | - | Definite | B | Prodcode |
| x10045441000033111 | Buprenorphine 6mg sublingual tablets sugar free | AURUM | - | Definite | B | Prodcode |
| x10045641000033113 | Buprenorphine 4mg sublingual tablets sugar free | AURUM | - | Definite | B | Prodcode |
| x100632 | Methadone therapy | GOLD | xZ1Q6212 | Definite | - | Medcode |
| x10077 | Subutex 2mg sublingual tablets (Indivior UK Ltd) | GOLD | - | Definite | B | Prodcode |
| x101377 | H/O weekly opiate misuse | GOLD | x1TD1.00 | Definite | - | Medcode |
| x103842 | Clinical opiate withdrawal scale | GOLD | x38G1.00 | Probable | - | Medcode |
| x103991 | [X]Mental and behav dis due to use opioids: amnesic syndrome | GOLD | xEu11600 | Definite | - | Medcode |
| x10538 | [X]Drug addiction - opioids | GOLD | xEu11211 | Definite | - | Medcode |
| x106342 | H/O infrequent methadone misuse | GOLD | x1T12.00 | Definite | - | Medcode |
| x106705 | Does not share drug injection equipment | GOLD | x1V3A.00 | Probable | - | Medcode |
| x107780 | Neck injector | GOLD | x1V32.00 | Probable | - | Medcode |
| x108251 | Opioid substitution therapy monitoring | GOLD | x66c4.00 | Definite | - | Medcode |
| x109730 | Drug addiction maintenance therapy - naltrexone | GOLD | x8B23000 | Definite | - | Medcode |
| x109966 | Drug addiction maintenance therapy - lofexidine | GOLD | x8B23100 | Definite | - | Medcode |
| x111551 | Groin injector | GOLD | x1V33.00 | Probable | - | Medcode |
| x11722 | Methadone 10mg/ml oral solution sugar free | GOLD | - | Definite | M | Prodcode |
| x11789141000033119 | Buprenorphine 2mg oral lyophilisates sugar free | AURUM | - | Definite | B | Prodcode |
| x11789241000033114 | Buprenorphine 8mg oral lyophilisates sugar free | AURUM | - | Definite | B | Prodcode |
| x11789341000033116 | Espranor 2mg oral lyophilisates (Martindale Pharmaceuticals Ltd) | AURUM | - | Definite | B | Prodcode |
| x11789441000033110 | Espranor 8mg oral lyophilisates (Martindale Pharmaceuticals Ltd) | AURUM | - | Definite | B | Prodcode |
| x1220925010 | Heroin poisoning | AURUM | x13187008 | Probable | - | Medcode |
| x13031 | Subutex 0.4mg sublingual tablets (Indivior UK Ltd) | GOLD | - | Definite | B | Prodcode |
| x1485129010 | Failed heroin detoxification | AURUM | x391102000 | Definite | - | Medcode |
| x16243 | Opioid type drug dependence | GOLD | xE240.00 | Definite | - | Medcode |
| x16374 | Methadone dependence | GOLD | xE240.12 | Definite | - | Medcode |
| x1655941000033119 | Methadone 10mg/ml oral solution sugar free | AURUM | - | Definite | M | Prodcode |
| x1656041000033112 | Methadone 20mg/ml oral solution sugar free | AURUM | - | Definite | M | Prodcode |
| x1715481000000114 | Drug addiction maintenance therapy - naltrexone | AURUM | x768691000000103 | Definite | - | Medcode |
| x1715521000000114 | Drug addiction maintenance therapy - lofexidine | AURUM | x768711000000101 | Definite | - | Medcode |
| x174241000033111 | Buprenorphine 400microgram sublingual tablets sugar free | AURUM | - | Definite | B | Prodcode |
| x1772531000006119 | Clinical Opiate Withdrawal Scale | AURUM | x1772531000006103 | Probable | - | Medcode |
| x1774961000000119 | Clinical opiate withdrawal scale | AURUM | x763699005 | Probable | - | Medcode |
| x1835341000033111 | Buprenorphine 2mg sublingual tablets sugar free | AURUM | - | Definite | B | Prodcode |
| x1835441000033117 | Buprenorphine 8mg sublingual tablets sugar free | AURUM | - | Definite | B | Prodcode |
| x1835541000033116 | Subutex 0.4mg sublingual tablets (Indivior UK Ltd) | AURUM | - | Definite | B | Prodcode |
| x1835641000033115 | Subutex 2mg sublingual tablets (Indivior UK Ltd) | AURUM | - | Definite | B | Prodcode |
| x1835741000033112 | Subutex 8mg sublingual tablets (Indivior UK Ltd) | AURUM | - | Definite | B | Prodcode |
| x1880021000006116 | Opioid substitution therapy monitoring | AURUM | x1880021000006100 | Definite | - | Medcode |
| x1971421000006118 | Mental and behav dis due to use opioids: withdrawal state, uncomplicated | AURUM | x1971421000006102 | Definite | - | Medcode |
| x1971441000006113 | Mental and behav dis due to use opioids: withdrawal state, with convulsions | AURUM | x1971441000006109 | Definite | - | Medcode |
| x1971451000006110 | Men & behav dis due opioid: withdrawl state with delirium, without convulsions | AURUM | x1971451000006106 | Definite | - | Medcode |
| x1971461000006112 | Men & behav dis due opioid: withdrawl state with delirium, with convulsions | AURUM | x1971461000006108 | Definite | - | Medcode |
| x1971471000006117 | Mental & behav dis due to use opioids: psychotic disorder, schizophrenia-like | AURUM | x1971471000006101 | Definite | - | Medcode |
| x1971501000006112 | Mental & behav dis due to use opioids: psychotic disorder, predominantly delusional | AURUM | x1971501000006108 | Definite | - | Medcode |
| x1971521000006119 | Mental & behav dis due to use opioids: psychotic disorder, predominantly hallucinatory | AURUM | x1971521000006103 | Definite | - | Medcode |
| x1971531000006116 | Mental & behav dis due to use opioids: psychotic disorder, predominantly polymorphic | AURUM | x1971531000006100 | Definite | - | Medcode |
| x1971571000006118 | Mental & behav dis due to use opioids: psychotic disorder, predominantly depressive symptoms | AURUM | x1971571000006102 | Definite | - | Medcode |
| x1971601000006113 | Mental & behav dis due to use opioids: psychotic disorder, predominantly manic symptoms | AURUM | x1971601000006109 | Definite | - | Medcode |
| x1971631000006117 | Mental & behav dis due to use opioids: psychotic disorder, mixed | AURUM | x1971631000006101 | Definite | - | Medcode |
| x1971651000006112 | Mental & behav dis due to use opioids: resid & late-onset psychot dis, flashbacks | AURUM | x1971651000006108 | Definite | - | Medcode |
| x1971671000006119 | Mental & behav dis due to use opioids: resid & late-onset psychot dis, personality or behaviour disorder | AURUM | x1971671000006103 | Definite | - | Medcode |
| x1971681000006116 | Mental & behav dis due to use opioids: resid & late-onset psychot dis, residual affective disorder | AURUM | x1971681000006100 | Definite | - | Medcode |
| x1971701000006118 | Mental & behav dis due to use opioids: resid & late-onset psychot dis, dementia | AURUM | x1971701000006102 | Definite | - | Medcode |
| x1971711000006115 | Mental & behav dis due to use opioids: resid & late-onset psychot dis, other persisting cognitive impairment | AURUM | x1971711000006104 | Definite | - | Medcode |
| x1971741000006116 | Mental & behav dis due to use opioids: resid & late-onset psychot dis, late-onset psychotic disorder | AURUM | x1971741000006100 | Definite | - | Medcode |
| x1976281000006111 | Mental & behav dis due to use opioids: acute intoxication, uncomplicated | AURUM | x1976281000006107 | Definite | - | Medcode |
| x1976301000006110 | Mental & behav dis due to use opioids: acute intoxication, with trauma or other bodily injury | AURUM | x1976301000006106 | Definite | - | Medcode |
| x1976331000006119 | Mental & behav dis due to use opioids: acute intoxication, with other medical complications | AURUM | x1976331000006103 | Definite | - | Medcode |
| x1976351000006114 | Mental & behav dis due to use opioids: acute intoxication, with delirium | AURUM | x1976351000006105 | Definite | - | Medcode |
| x1976421000006111 | Mental & behav dis due to use opioids: acute intoxication, with perceptual distortions | AURUM | x1976421000006107 | Definite | - | Medcode |
| x1976441000006116 | Mental & behav dis due to use opioids: acute intoxication, with coma | AURUM | x1976441000006100 | Definite | - | Medcode |
| x1976471000006112 | Mental & behav dis due to use opioids: acute intoxication, with convulsions | AURUM | x1976471000006108 | Definite | - | Medcode |
| x1976501000006117 | Mental and behav dis due to use opioids: dependence syndr, currently abstinent | AURUM | x1976501000006101 | Definite | - | Medcode |
| x1976531000006113 | Mental and behav dis due to use opioids: dependence syndr, currently abstinent, but in a protected environment | AURUM | x1976531000006109 | Definite | - | Medcode |
| x1976551000006118 | Mental and behav dis due to use opioids: dependence syndr, currently on a clinically supervised maintenance or replacement regime [controlled dependence] | AURUM | x1976551000006102 | Definite | - | Medcode |
| x1976581000006114 | Mental and behav dis due to use opioids: dependence syndr, currently abstinent, but receiving treatment with aversive or blocking drugs | AURUM | x1976581000006105 | Definite | - | Medcode |
| x1976591000006112 | Mental and behav dis due to use opioids: dependence syndr, currently using the substance [active dependence] | AURUM | x1976591000006108 | Definite | - | Medcode |
| x1976611000006118 | Mental and behav dis due to use opioids: dependence syndr, continuous use | AURUM | x1976611000006102 | Definite | - | Medcode |
| x1976621000006114 | Mental and behav dis due to use opioids: dependence syndr, episodic use [dipsomania] | AURUM | x1976621000006105 | Definite | - | Medcode |
| x2000491000006110 | Does not use opioids on top of substitution therapy | AURUM | x2000491000006106 | Definite | - | Medcode |
| x2000501000006119 | Uses other opioids on top of substitution therapy | AURUM | x2000501000006103 | Definite | - | Medcode |
| x2003041000033115 | Methadone 1mg/ml oral solution sugar free | AURUM | - | Definite | M | Prodcode |
| x20458 | Heroin poisoning | GOLD | xSL50100 | Probable | - | Medcode |
| x2052541000033112 | Methadone Hydrochloride Diluent Oral Solution Sugar Free | AURUM | - | Definite | M | Prodcode |
| x20962 | Episodic opioid dependence | GOLD | xE240200 | Definite | - | Medcode |
| x21562 | Physeptone 1mg/ml oral solution sugar free (Martindale Pharmaceuticals Ltd) | GOLD | - | Definite | M | Prodcode |
| x22059 | Morphine dependence | GOLD | xE240.13 | Definite | - | Medcode |
| x22079 | Injecting drug user | GOLD | x13c0.00 | Probable | - | Medcode |
| x2267741000033115 | Methadone Hydrochloride Oral Solution, Sugar Free, Tartrazine Free 1 mg/1 ml | AURUM | - | Definite | M | Prodcode |
| x2296901000000113 | Opioid substitution therapy monitoring | AURUM | x891951000000109 | Definite | - | Medcode |
| x24441 | Opioid drug dependence NOS | GOLD | xE240z00 | Definite | - | Medcode |
| x2474734017 | [V]Personal history of drug abuse by injection | AURUM | x371435006 | Probable | - | Medcode |
| x2548992019 | Previously injecting drug user | AURUM | x416479009 | Probable | - | Medcode |
| x2549886016 | Abstinent from drug misuse on maintenance replacement | AURUM | x712545004 | Probable | - | Medcode |
| x25527 | [X]Cold turkey, opiate withdrawal | GOLD | xEu11311 | Definite | - | Medcode |
| x26061 | Combined opioid with other drug dependence | GOLD | xE248.00 | Definite | - | Medcode |
| x26277 | Physeptone 1mg/ml mixture (Martindale Pharmaceuticals Ltd) | GOLD | - | Definite | M | Prodcode |
| x2639961000000113 | Opioid analgesic dependence | AURUM | x1047881000000106 | Probable | - | Medcode |
| x26831 | Nondependent opioid abuse | GOLD | xE255.00 | Definite | - | Medcode |
| x27652 | [X]Men & beh dis due opioids: resid & late-onset psychot dis | GOLD | xEu11700 | Definite | - | Medcode |
| x27960 | Opioid dependence in remission | GOLD | xE240300 | Definite | - | Medcode |
| x28710 | [X]Overdose - heroin | GOLD | xU205.11 | Probable | - | Medcode |
| x28976 | Drug addiction detoxification therapy - methadone | GOLD | x8B2N.00 | Definite | - | Medcode |
| x295153014 | Unspecified opioid dependence | AURUM | x75544000 | Definite | - | Medcode |
| x295154015 | Continuous opioid dependence | AURUM | x191819002 | Definite | - | Medcode |
| x295155019 | Episodic opioid dependence | AURUM | x191820008 | Definite | - | Medcode |
| x295156018 | Opioid dependence in remission | AURUM | x191821007 | Definite | - | Medcode |
| x295157010 | Opioid drug dependence NOS | AURUM | x75544000 | Definite | - | Medcode |
| x2952 | Methadone 1mg/ml oral solution | GOLD | - | Definite | M | Prodcode |
| x295228015 | Combined opioid with other drug dependence | AURUM | x191865004 | Definite | - | Medcode |
| x295229011 | Combined opioid with other drug dependence, unspecified | AURUM | x191865004 | Definite | - | Medcode |
| x295230018 | Combined opioid with other drug dependence, continuous | AURUM | x191867007 | Definite | - | Medcode |
| x295231019 | Combined opioid with other drug dependence, episodic | AURUM | x191868002 | Definite | - | Medcode |
| x295232014 | Combined opioid with other drug dependence in remission | AURUM | x191869005 | Definite | - | Medcode |
| x295233016 | Combined opioid with other drug dependence NOS | AURUM | x191865004 | Definite | - | Medcode |
| x295290016 | Nondependent opioid abuse | AURUM | x191909007 | Definite | - | Medcode |
| x295293019 | Nondependent opioid abuse, unspecified | AURUM | x191909007 | Definite | - | Medcode |
| x295295014 | Nondependent opioid abuse, continuous | AURUM | x191912005 | Definite | - | Medcode |
| x295296010 | Nondependent opioid abuse, episodic | AURUM | x191913000 | Definite | - | Medcode |
| x295297018 | Nondependent opioid abuse in remission | AURUM | x191914006 | Definite | - | Medcode |
| x2957141000033113 | Physeptone 1mg/ml oral solution sugar free (Martindale Pharmaceuticals Ltd) | AURUM | - | Definite | M | Prodcode |
| x2957241000033118 | Physeptone 1mg/ml mixture (Martindale Pharmaceuticals Ltd) | AURUM | - | Definite | M | Prodcode |
| x295803018 | [X]Mental and behavioural disorders due to use of opioids | AURUM | x14784000 | Definite | - | Medcode |
| x298101000000113 | Buprenorphine maintenance therapy | AURUM | x198021000000102 | Definite | - | Medcode |
| x30251 | Intravenous drug user | GOLD | x13c1.00 | Probable | - | Medcode |
| x302981000000113 | Drug addiction detoxification therapy - methadone | AURUM | x200021000000100 | Definite | - | Medcode |
| x303011000000111 | Drug addiction maintenance therapy - methadone | AURUM | x200031000000103 | Definite | - | Medcode |
| x30565 | Failed heroin detoxification | GOLD | x146C.00 | Definite | - | Medcode |
| x30598 | Opiate dependence detoxification | GOLD | x8BAd.00 | Definite | - | Medcode |
| x3064 | Buprenorphine 400microgram sublingual tablets sugar free | GOLD | - | Definite | B | Prodcode |
| x30694 | Drug addiction maintenance therapy - methadone | GOLD | x8B2P.00 | Definite | - | Medcode |
| x30711 | [V]Personal history of drug abuse by injection | GOLD | xZV11500 | Probable | - | Medcode |
| x309921000000119 | Heroin misuse | AURUM | x202991000000100 | Definite | - | Medcode |
| x314821000000113 | Opiate dependence detoxification | AURUM | x205231000000102 | Definite | - | Medcode |
| x316901000000118 | Drug addiction maintenance therapy - buprenorphine | AURUM | x206121000000104 | Definite | - | Medcode |
| x316931000000112 | Drug addiction detoxification therapy - buprenorphine | AURUM | x206131000000102 | Definite | - | Medcode |
| x32709 | Previously injecting drug user | GOLD | x13cJ.00 | Probable | - | Medcode |
| x32804 | Opium dependence | GOLD | xE240.14 | Definite | - | Medcode |
| x328544015 | Accidental poisoning by heroin | AURUM | x216463005 | Probable | - | Medcode |
| x33068 | Methadone 10mg/1ml solution for injection ampoules | GOLD | - | Definite | M | Prodcode |
| x33832 | Methadone 1mg/ml oral solution (Martindale Pharmaceuticals Ltd) | GOLD | - | Definite | M | Prodcode |
| x339576014 | Injecting drug user | AURUM | x226034001 | Probable | - | Medcode |
| x342465012 | Intravenous drug user | AURUM | x228388006 | Probable | - | Medcode |
| x342466013 | Groin injector | AURUM | x228389003 | Probable | - | Medcode |
| x342468014 | Drug injection behaviour | AURUM | x228391006 | Probable | - | Medcode |
| x342473015 | Sharing of drug injecting equipment | AURUM | x228395002 | Probable | - | Medcode |
| x342474014 | Does not share drug injection equipment | AURUM | x228396001 | Probable | - | Medcode |
| x34249 | [X]Mental and behav dis due to use opioids: dependence syndr | GOLD | xEu11200 | Definite | - | Medcode |
| x346947018 | Heroin dependence | AURUM | x231477003 | Definite | - | Medcode |
| x346949015 | Methadone dependence | AURUM | x231478008 | Definite | - | Medcode |
| x346950015 | Morphine dependence | AURUM | x231479000 | Definite | - | Medcode |
| x346951016 | Opium dependence | AURUM | x231480002 | Definite | - | Medcode |
| x35169 | Suboxone 8mg/2mg sublingual tablets (Indivior UK Ltd) | GOLD | - | Definite | B | Prodcode |
| x35170 | Suboxone 2mg/500microgram sublingual tablets (Indivior UK Ltd) | GOLD | - | Definite | B | Prodcode |
| x35681 | Buprenorphine 2mg / Naloxone 500microgram sublingual tablets sugar free | GOLD | - | Definite | B | Prodcode |
| x35682 | Buprenorphine 8mg / Naloxone 2mg sublingual tablets sugar free | GOLD | - | Definite | B | Prodcode |
| x361941000006116 | [X]Accidental poisoning with heroin | AURUM | x216463005 | Probable | - | Medcode |
| x36241 | [X]Mental and behav dis due to use opioids: withdrawal state | GOLD | xEu11300 | Definite | - | Medcode |
| x371181000006118 | [X]Cold turkey, opiate withdrawal | AURUM | x87132004 | Definite | - | Medcode |
| x37527 | Adverse reaction to heroin, diamorphine | GOLD | xTJ50.00 | Probable | - | Medcode |
| x37568 | [X]Mental and behav dis due to use of opioids: harmful use | GOLD | xEu11100 | Definite | - | Medcode |
| x379281000006110 | [X]Drug addiction - opioids | AURUM | x75544000 | Definite | - | Medcode |
| x38034 | Unspecified opioid dependence | GOLD | xE240000 | Definite | - | Medcode |
| x388831000006113 | [X]Heroin addiction | AURUM | x75544000 | Definite | - | Medcode |
| x397161000006110 | [X]Men & beh dis due opioids: resid & late-onset psychot dis | AURUM | x943071000000104 | Definite | - | Medcode |
| x397231000006112 | [X]Men & behav dis due opioid: withdrawl state with delirium | AURUM | x91388009 | Definite | - | Medcode |
| x397261000006115 | [X]Men & behav dis due to use opioids: oth men & behav dis | AURUM | x14784000 | Definite | - | Medcode |
| x397451000006116 | [X]Ment & behav dis due use opioids: unsp ment & behav dis | AURUM | x91388009 | Definite | - | Medcode |
| x397651000006119 | [X]Mental & behav dis due to use opioids: acute intoxication | AURUM | x77721001 | Definite | - | Medcode |
| x397661000006117 | [X]Mental & behav dis due to use opioids: psychotic disorder | AURUM | x943071000000104 | Definite | - | Medcode |
| x397901000006111 | [X]Mental and behav dis due to use of opioids: harmful use | AURUM | x5602001 | Definite | - | Medcode |
| x397921000006118 | [X]Mental and behav dis due to use opioids: amnesic syndrome | AURUM | x91388009 | Definite | - | Medcode |
| x397931000006115 | [X]Mental and behav dis due to use opioids: dependence syndr | AURUM | x75544000 | Definite | - | Medcode |
| x397941000006113 | [X]Mental and behav dis due to use opioids: withdrawal state | AURUM | x87132004 | Definite | - | Medcode |
| x4010641000033111 | Buprenorphine 2mg / Naloxone 500microgram sublingual tablets sugar free | AURUM | - | Definite | B | Prodcode |
| x4010741000033119 | Buprenorphine 8mg / Naloxone 2mg sublingual tablets sugar free | AURUM | - | Definite | B | Prodcode |
| x4010841000033112 | Suboxone 2mg/500microgram sublingual tablets (Indivior UK Ltd) | AURUM | - | Definite | B | Prodcode |
| x4010941000033116 | Suboxone 8mg/2mg sublingual tablets (Indivior UK Ltd) | AURUM | - | Definite | B | Prodcode |
| x40536 | Nondependent opioid abuse, unspecified | GOLD |