Polydrug use – prevalence and registration

Espen Walderhaug; Karl Johan Seim-Wikse; Asle Enger; Oleg Milin

doi:10.4045/tidsskr.19.0251

Short report

Polydrug use – prevalence and registration

Norwegian

Espen Walderhaug, Karl Johan Seim-Wikse, Asle Enger, Oleg Milin

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Espen Walderhaug

E-mail: espwal@ous-hf.no

Department of Addiction Treatment

Division of Mental Health and Addiction

Oslo University Hospital

Espen Walderhaug, dr. psychol. and research coordinator.

The author has completed the ICMJE form and declares no conflicts of interest.

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Karl Johan Seim-Wikse

Occupational Health Services

Akershus University Hospital

Karl Johan Seim-Wikse, specialist in child and adolescent psychology and head of department.

The author has completed the ICMJE form and declares no conflicts of interest.

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Asle Enger

Department of Addiction Treatment

Division of Mental Health and Addiction

Oslo University Hospital

Asle Enger, specialist in addiction medicine and infectious diseases, and medical adviser.

The author has completed the ICMJE form and declares no conflicts of interest.

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Oleg Milin

Department of Addiction Treatment

Division of Mental Health and Addiction

Oslo University Hospital

Oleg Milin, specialist in psychiatry and addiction medicine, and senior consultant.

The author has completed the ICMJE form and declares no conflicts of interest.

Abstract

BACKGROUND

Combination of drugs is the main cause of fatal overdose, and polydrug use is associated with greater treatment needs. This study investigates the prevalence and registration of multiple substance dependence.

MATERIAL AND METHOD

Substance dependence diagnoses for 147 inpatients at the Department of Addiction Treatment, Oslo University Hospital were registered and reassessed with a focus on the ICD-10 diagnosis F19 (chaotic intake of multiple substances). The resulting diagnoses were also assessed according to ICD-11.

RESULTS

Altogether 116 (79 %) out of 147 patients were addicted to two or more drugs. Only 22 (15 %) out of 147 were diagnosed with F19, but this figure increased to 52 (35 %) after reassessment. Using ICD-11 we found a prevalence of the diagnosis 6C4F (multiple substance dependence) of 79 %.

INTERPRETATION

We found an underreporting of the ICD-10 diagnosis F19. It is important to use the F19 diagnosis, because polydrug use is underreported, even though it predicts overdose, prognosis and treatment needs.

Article

Introduction

Polydrug use is common, and increases the risk of negative health effects (1). A study that investigated all (N = 194) overdose deaths in Norway in 2012 found an average of 4.9 different drugs per autopsy (2). The study concluded that drugs taken in combination (especially opioids + benzodiazepines) are the main cause of fatal overdose. Mono-intoxication with heroin was not detected in any of the 194 fatal overdoses (2).

Reporting of overdose is largely based on ICD-10, the international statistical classification of diseases and related health problems (3). A single substance, for example heroin, is typically chosen as the main cause of death (2). This gives a wrong impression, because drug-related deaths are rarely caused by one single drug (4). Our impression is that most overdose deaths are due to a pattern characterised by chaotic use of several different drugs. Polydrug use is also associated with poor prognosis, higher rates of comorbidity with other mental disorders (5), and higher demands on the content and length of treatment (1, 5).

Multiple drug dependence can be coded with the ICD-10 diagnosis F19 (3), but the threshold for using this diagnosis appears to be high. The guide for F19 states: 'Only in cases in which patterns of psychoactive substance taking are chaotic and indiscriminate, or in which the contributions of different drugs are inextricably mixed, should code F19.- be used.'. It appears that the strict criteria for diagnosis of multiple substance dependence will be phased out in the future. ICD-11 (6) is scheduled to replace ICD-10 from 2022. According to ICD-11, multiple substance dependence should be coded with 6C4F, regardless of pattern of use.

In normal clinical practice, the F19 diagnosis can be a useful indicator of elevated risk and treatment requirements. However, we had the impression that chaotic drug use occurred more often than it was recorded. This study investigates substance dependence diagnoses in a selection of inpatients that had received specialised, interdisciplinary addiction treatment. The prevalence of ICD-10 diagnosis F19 recorded in the patient records was compared with the prevalence of F19 following a review of the records.

Material and method

We reviewed the patient records of 147 patients that had signed the informed consent form related to the 'Youth Addiction Treatment Evaluation Project' (YATEP). All patients were admitted for inpatient treatment during the period 1 January 2011–31 December 2017 at the Department of Addiction Treatment, Oslo University Hospital. Substance dependence is a requirement for admission, and the usual treatment length is 3 to 6 months. This study was approved by the Regional Committee for Medical and Health Research Ethics (2017/1536 REC South East B) and the Oslo University Hospital (OUS) data protection officer.

The admission notes and discharge reports were reviewed in detail by a specialist in medicine and a specialist in psychology. Substance dependence diagnoses in ICD-10 (F10 – F19, except for tobacco (F17)) were recorded for each participant as they appeared in patient records. This was followed by a reassessment that recorded which patients conformed a strict understanding of the F19 diagnosis.

Results

The sample consisted of 93 (63 %) men and 54 (37 %) women. The participants were on average 23.6 (SD = 2.9) years of age and had completed 10.8 (SD = 1.5) years of education (Table 1).

Table 1

Prevalence of ICD-10 substance dependence diagnoses in the admission notes and discharge reports at the Department of Addiction Treatment, Oslo University Hospital. The patients were admitted to inpatient treatment during the period 1 January 2011–31 December 2017.

	Number (cumulative per cent)
F19 recorded in the patient record	22 (15 %)
F19 following reassessment¹	52 (35 %)
≥3 substance dependence diagnoses	87 (61 %)
≥2 substance dependence diagnoses	116 (79 %)
≥1 substance dependence diagnoses	147 (100 %)

¹F19 coded retrospectively by two specialists

The ICD-10 code F19 was recorded on 22 (15 %) of patients in the patient records, but this number increased to 52 (35 %) following reassessment by two specialists in consensus. A total of 116 out of 147 (79 %) patients had two or more substance dependence diagnoses. That is, 79 % of the sample classified for the ICD-11 definition of multiple substance dependence (6C4F).

Discussion

In view of the documentation above, we found that the ICD-10 code F19 was underreported. Clinicians seem to record several separate substance dependence diagnoses in preference to coding F19 when this would have been most appropriate. This can partly be explained by the notion that F19 is perceived as inaccurate, rather than a correct description of chaotic drug use. It is a valid point that the F19 diagnosis alone does not indicate which substances the patient struggles with. This can be solved by coding the F19, followed by the diagnoses of the individual substances included in the addiction disorder. This would also be a useful adoption for the future ICD-11 guidelines for classification. We hope that the ICD-11 code for multiple substance dependence (6C4F) will have an efficient system for 'post-coordination', where the specific substances involved can be recorded. We also hope that ICD-11 can facilitate a shift in focus for current practice, towards combinations of drugs as a major risk factor for fatal drug overdose (4).

This study is limited as it relies on information from the patient records, and the sample is not necessarily representative for this patient group. Furthermore, the ICD-11 codes on substance dependence could change in the period before implementation. Divergent practice and deficient registration of F19 is not a local phenomenon, but occurs throughout Europe (7). Preliminary figures show that patients seeking treatment for substance dependence report a prevalence of polydrug use ranging from more than 95 % (Cyprus and Poland) to less than 5 % (Malta and Slovenia). Figures from Norway are not included in this dataset, due to an insufficient recording of polydrug use (7). Future research should increase its efforts to investigate the prevalence and consequence of polydrug use, and utilise data from the Norwegian Patient Registry. Clinical practice for coding of multiple substance dependence should be harmonised and quality controlled. Polydrug use is probably an increasing trend, and 6C4F may become the most common substance dependence diagnosis in future multidisciplinary, specialised drug addiction treatment.

The article has been peer-reviewed.

Literature

1.
Selected issue on polydrug use: patterns and responses. Lisbon: European Monitoring Centre for Drugs and Drug Addiction, 2009. http://www.emcdda.europa.eu/system/files/publications/534/EMCDDA_SI09_polydrug_use_187893.pdf Lest 3.6.2019.
2.
Edvardsen HE, Tverborgvik T, Frost J et al. Differences in combinations and concentrations of drugs of abuse in fatal intoxication and driving under the influence cases. Forensic Sci Int 2017; 281: 127–33. [PubMed][CrossRef]
3.
The ICD-10 Classification of Mental and Behavioural Disorders – Diagnostic Criteria for Research. Geneva: World Health Organization, 1993.
4.
Simonsen KW, Edvardsen HME, Thelander G et al. Fatal poisoning in drug addicts in the Nordic countries in 2012. Forensic Sci Int 2015; 248: 172–80. [PubMed][CrossRef]
5.
McCabe SE, West BT. The three-year course of multiple substance use disorders in the United States: A national longitudinal study. J Clin Psychiatry 2017; 78: e537–44. [PubMed][CrossRef]
6.
World Health Organization. International statistical classification of diseases and related health problems (11th Revision). https://icd.who.int/browse11/l-m/en Lest 3.6.2019.
7.
Montanari L, Guarita B. Polydrug use among drug treatment clients in Europe. What implications for treatment? Presentation at EMCDDA technical conference, Lisboa, 22.09.2015. http://www.emcdda.europa.eu/attachements.cfm/att_243617_EN_01.%20LM%20-%20Polydrug%20use%20TDI.pdf Lest 3.6.2019.

Comments ( 2 )

Dette kommentarfeltet modereres, men kommentarer blir ikke redaksjonelt behandlet ut over å sikre at de følger retningslinjer for vårt kommentarfelt.

30.09.2019:

Det er positivt at Walderhaug et al (1) reiser søkelyset på diagnosen skadelig bruk og/eller avhengighet av flere rusmidler samtidig og hvordan man diagnostiserer disse.

”Blandingsmisbruk” er et begrep som er lett forståelig og brukes mye i praksis, men finnes ikke i diagnosemanualen ICD-10 (2). Det korrekte er psykiske lidelser og atferdsforstyrrelser som skyldes bruk av flere stoffer.

Praksis i diagnostisering av tilstanden varierer, men det foreligger neppe nasjonal underrapportering. F19 er en sekkepost, som man bare benytter når man ikke klarer å diagnostisere spesifikt de rusmidler som pasienten er avhengig av. Jo nøyere man har spesifisert de forskjellige rusmidler som inngår i rusmiddelavhengigheten, desto lavere vil bruken av diagnosen F19 være. For å få et rett bilde er det bare å summere de som har flere enn to F 10-19 rusmiddeldiagnoser.
Tidligere brukte vi ofte F19 når pasienten var avhengig av to eller flere rusmidler. Internt i avdelingen ble dette påpekt å være ukorrekt. Det korrekte var å oppgi spesifikt alle rusmiddeldiagnoser pasienten hadde ved skadelig bruk eller avhengighet av flere rusmidler og reservere F19 bare til tilfeller der mønsteret for stoffinntaket er kaotisk og tilfeldig, eller der man ikke kan skille effekten av forskjellige psykoaktive stoffer fra hverandre (2).

I dag dominerer bruk og avhengighet av flere rusmidler russcenen dersom man tar utgangspunkt i innleggelser i Tverrfaglig spesialisert rusbehandling (TSB). Norske studier viser at prevalensen blant slike innleggelser i avrusningsavdelinger ligger mellom 70 og 80 % og har vært stadig økende siden tidlig på 1990 tallet (3, 4). En personlig opptelling i 1987 blant 400 innlagte i Avrusningsavdelingen i Kristiansand (senere Avdeling for rus og avhengighetsbehandling, Sørlandet Sykehus) viste bruk/avhengighet av to rusmidler eller flere hos 40 %. Alkohol kombinert med benzodiazepiner dominerte. I 2013 utgjorde blandingsgruppen 71% av 400 innleggelser. Gjennomsnittsalderen var 39 år (18-70 år) og 75 % var menn (4). Det ble påvist et gjennomsnitt på 3,2 forskjellige rusmiddeldiagnoser og 32 forskjellige blandingskombinasjoner bekreftet ved journalgjennomgang og laboratorieprøver. Kombinasjonen alkohol og benzodiazepiner var hyppigst forekommende, etterfulgt av kombinasjonen benzodiazepiner, cannabis, opiater og amfetamin (4).

ICD-11 blir neppe klassifiseringssystem i Norge før 2027 (5) og det er vel tvilsomt om koden 6C4F vil tilføre oss så mye nytt. Fokus på blandingsrus er likevel viktig.

Litteratur

1. Walderhaug E, Seim-Wikse K J, Enger A et al. Blandingsmisbruk – forekomst og registrering. Tidsskrift Nor Legeforen 2019;139:1279-81.

2. ICD-10 Den internasjonale statistiske klassefikasjonen av sykdommer og beslektede helseproblemer. Norsk utgave. Statens helsetilsyn 1996.

3. Hobbesland Å. Undersøkelse av avgiftningsbehandling ved seks avgiftningsavdelinger i helse-region sør. Skien: Borgestadklinikken, 2006.

4. Dunsæd F, Kristensen Ø, Vederhus JK et al. Standardisert avrusning ved blandingsmisbruk. Tidsskr Nor Legeforen, 2016;135:1639-42.

5. Malt UF. ICD-11 – en statusrapport. Psykiateren 2018;4:6-7.

03.10.2019:

Øistein Kristensen kjenner fagfeltet godt, og skriver en kommentar til vår artikkel med mye viktig og riktig informasjon. Vi er enige om at dagens Tverrfaglige spesialiserte rusbehandling (TSB) domineres av pasienter med bruk og avhengighet av flere stoffer. Kristiansen dokumenterer også at dette problemet er stort, og har vært økende siden 1990 tallet. Å sette diagnose på avhengighet av flere stoffer ut i fra ICD-10 er vanskelig, og det har utviklet seg en praksis der man i prioritert rekkefølge lister opp en diagnose for hver stoffgruppe pasienten er avhengig av. Kristensen påpeker selv at F19 i denne sammenhengen ofte blir oppfattet som en sekkepost. Vårt spørsmål blir da: Hvilken diagnose skal man gi en pasient med et mønster der stoffinntaket er kaotisk og tilfeldig, eller man ikke kan skille effekten av forskjellige psykoaktive stoffer fra hverandre? Skal man følge lokal klinisk praksis, eller det som står skrevet i ICD-10?

Vi deler Kristensens syn på at «praksis i diagnostisering av tilstanden varierer», men vi kan ikke si oss enige i at «det foreligger neppe nasjonal underrapportering». Hva skal vi tenke om kvaliteten på nasjonale data som er basert på varierende praksis i diagnostisering? Tar vi utgangspunkt i «Aktivitetsdata for psykisk helsevern for voksne i tverrfaglig spesialisert rusbehandling 2018», kan vi se at F19 er innrapportert som hovedtilstand i 8,8 % av døgnpasientene nasjonalt i TSB (1, s. 19). I vår studie fant vi en forekomst av F19 på 35 % (2). Denne forskjellen kan forklares ved at det foreligger en nasjonal underrapportering.

Der statistikken tar utgangspunkt i en enkelt hovedtilstand kan man forvente en underrapportering av blandingsmisbruk. Det gjelder for statistikk over overdosedødsfall (3), og de ledende rapporteringssystemene for behandlingsdata i Europa og USA (4). Den nye protokollen for «treatment demand indicator (3.0)» ble derfor endret av European Monitoring Centre for Drugs and Drug Addiction (EMCDDA), slik at det var mulig å kode blandingsmisbruk (polydrug use) som en komplementær tilleggs-variabel (4). Det er i lys av dette vi håper den nye ICD-11 får et velfungerende system for registrering av bruk og avhengighet av flere stoffer. Vi trenger et system som både tilfredsstiller behovene i klinisk praksis, og behovet for korrekt statistikk om denne tilstanden.

Litteratur:

1. Aktivitetsdata for psykisk helsevern for voksne i tverrfaglig spesialisert rusbehandling 2018. Rapport IS-2819. Trondheim: Helsedirektoratet, 2019. https://www.helsedirektoratet.no/rapporter/aktivitetsdata-for-psykisk-helsevern-for-voksne-og-tverrfaglig-spesialisert-rusbehandling Lest 1.10.2019.
2. Walderhaug E, Seim-Wikse K J, Enger A et al. Blandingsmisbruk – forekomst og registrering. Tidsskrift Nor Legeforen 2019;139:1279-81.
3. Edvardsen HE, Tverborgvik T, Frost J et al. Differences in combinations and concentrations of drugs of abuse in fatal intoxication and driving under the influence cases. Forensic Sci Int 2017; 281: 127–33.
4. Maffli E, Astudillo M. Multiple substance use among patients attending treatment for substance-related problems in Switzerland. Drugs and Alcohol Today 2018; 18: 178-87.

This article was published more than 12 months ago and we have therefore closed it for new comments.

Published: 23 September 2019

Tidsskr Nor Legeforen 23 September 2019 Vol. 139.

doi:

10.4045/tidsskr.19.0251

Received 25.3.2019, first revision submitted 16.5.2019, accepted 18.6.2019.

Published: 23 September 2019

Tidsskr Nor Legeforen 2019 Vol. 139.

doi: 10.4045/tidsskr.19.0251

Received 25.3.2019, first revision submitted 16.5.2019, accepted 18.6.2019.

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Polydrug use – prevalence and registration

BACKGROUND

MATERIAL AND METHOD

RESULTS

INTERPRETATION

MAIN MESSAGE

Material and method

Results

Table 1

Discussion

Conclusion

Blandingsmisbruk – prevalens og registrering

Walderhaug og medforfattere svarer

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