Home Affairs Committee - Drugs: Breaking the CycleWritten evidence submitted by Sheila M Bird OBE MA PhD CStat FFPH, Medical Research Council Biostatistics Unit, Cambridge (DP139)

Executive Summary

Because harms are drug-specific, policy likewise should be drug-specific: drugs, not drug, are at issue as the title of the Home Affairs Select Committee Inquiry rightly recognises.

The Medical Research Council has funded a series of addictions research clusters, one of which, NIQUAD, is focused on developing record-linkage and biostatistical methods for evidence-synthesis of the available surveillance, criminal justice and epidemiological information (see Appendix). NIQUAD is comprised of the MRC Biostatistics Unit, Cambridge (Bird, De Angelis), and Universities of Bristol (Ades, Hickman), York (Godfrey), Strathclyde (Bird & Hutchinson), and Manchester (led by Millar), was one of the 11 successful applications, see Appendix. NIQUAD aims to answer public health questions about addiction by:

Improving, integrating, and harmonizing the information base.

Assessing the quality, precision, validity and consistency of available information.

Making data accessible to a wider range of expertise.

Developing methods to better exploit existing/new information sources.

This requires parallel work on developing record linkage and evidence synthesis of available information. Record-linkage of administrative and research data at the individual case level can create statistically powerful “virtual” cohorts that track pathways in and out of treatment, criminal justice, and healthcare, and the sequencing of key events. Evidence synthesis will develop models that link all the available evidence to link and test its consistency and to examine the relationships between parameters.

NIQUAD includes: key experts in surveillance and substance use epidemiology; non-addiction scientists with high-level skills in relevant statistical, mathematical modelling and health economic techniques; and health informatics experts to support the development of data resources to fuel the planned work.

Different policy responses—which range from banning through watchful-waiting to taxation and decriminalisation or legalisation—may be rational and evidence-based for cannabis, an essentially non-lethal, highly-prevalent drug; a novel “legal high” for which the public health priority is to quantify initially its short-term risks; and heroin use by injection.

Public health sciences are insufficiently recognised in the Government’s 2010 Drug Strategy. The introductory sections “Where are we now?” and “Patterns in age and usage” make no explicit mention of the added dangers from heroin-use by injection. Dangers include blood-borne viruses (not just HIV but vaccine-preventable Hepatitis A & B and vaccine-lacking Hepatitis C virus); bacteriological infections; and fatal opiate-overdose.

Secondly, the 2010 Drug Strategy offers a serious under-count (50,000) of last-year-users of opiates (heroin, methadone) by basing its estimate on the British Crime Survey, a household-based survey and, as such, particularly unsuitable—by its own acknowledgement—for estimation of the number of injectors or of heroin-users.

Thirdly, drugs-related deaths (DRDs) are a non-recoverable harm. The criteria used by the government to measure the efficacy of its policies on drugs must include DRDs, and must address England’s lack of a national toxicological protocol to be followed at forensic autopsies on suspect DRDs.

Home Office has responsibility for England’s registration of deaths, and Ministry of Justice for coroners. Legislation is long overdue which requires the registration of all deaths in England within 8 days of death having been ascertained (as applies in Scotland).

Shockingly for the 21st century, the Office for National Statistics (ONS) continues in ignorance, for months, about the fact of death for most individuals whose death is eventually coded as drugs-related. The reason is that deaths are referred to coroners and can evade registration until an inquest-verdict on cause is reached.

Due to this registration-lacuna, to which the Royal Statistical Society has previously drawn attention, there are ongoing major time-delays in the ability of Public Health England to monitor the impact the Government’s 2010 recovery agenda on the mortality: for example, of erstwhile NTA-clients, or of drugs-dependent ex-prisoners.1

Fourthly, England lacks a national protocol for the conduct and reporting of toxicological studies on suspect DRDs. For example, although the more common opiate-substitute methadone is routinely tested for, buprenorphine is not. Thus, few buprenorphine-related deaths per 1,000,000 recommended daily doses of buprenorphine may be due to absence of evidence, rather than evidence of a low fatality-rate.

Fifthly, I note that the Advisory Council on the Misuse of Drugs (ACMD) lacks statistician-membership, an issue that, as then-chair of the Home Office’s Surveys, Design and Statistics Subcommittee (SDSSC), I raised in the aftermath of ACMD’s report on ecstasy. With the impending dissolution of SDSSC, ACMD can no longer call on its independent good offices.

Specific Remarks

1. The Government’s 2010 drug strategy cannot be adequately grounded in public health science until the Home Office addresses its dual problems of England’s delayed registration of coroner-referred deaths and the absence of a national protocol for the conduct and reporting of toxicological studies in respect of suspect drugs-related deaths (DRDs).

2. The criteria used by government to measure the efficacy of its drugs policies should include a greater use of randomized controlled trials to obtain objective evidence on the efficacy of its criminal justice, policing and other policy interventions.2 , 3 , 4

3. The criteria used by government to measure the efficacy of its drugs policies should also adhere to the recommendations in 2000 on drugs-related deaths of the Advisory Council on the Misuse of Drugs that the number of drug-specific fatalities (numerator) needed to be related to the number of prevalent drug-specific-users (denominator).5 See Straight Statistics for examples of the relevant synthesis using: (i) British Crime Survey estimates of past-year users of cocaine by age, (ii) capture-recapture estimate of injecting drug-users and (iii) NTA-estimates of methadone-clients by gender.6 Our evidence synthesis was, however, confounded to an extent by reliance on drug-specific deaths that were reported by year of registration, not by year of death; and needs to be updated accordingly.

4. Delays in England’s death-registration7 meant that not until after August 2011 was it possible to demonstrate that there had been a decrease in cocaine-related deaths in 20098 which was commensurate with (a) the timing and (b) the extent of switch from cocaine to mephedrone that were revealed respectively by (a) compulsory drugs testing in the British Army9 and (b) British Crime Survey respondents’ past-year use of specific-drugs, such as cocaine, ecstasy and mephedrone.10

5. The independence and quality of expert advice on quantitative aspects of specific drugs might be better demonstrated if, for each specific drug, there was a short standard-design, scientific pamphlet which set out the key data-sources, how they are combined, what inferences (with associated uncertainty) have been drawn, and which most salient pieces of evidence-jigsaw are missing that research should concentrate on remedying. After all, this is how statistical science and epidemiology work in other, less politicised arenas. Statistician-membership of Advisory Council on the Misuse of Drugs is lacking, however.

6. The Medical Research Council has funded a number of addictions clusters, one of which I am associated with (NIQUAD, see Appendix) because it was specifically designed to enhance quantitative understanding of drugs harms on a nationally-integrated basis: for Scotland or for England as approved record-linkages across quality-assured databases permit (because they are for the public good) and methodological developments enable, see http://www.rss.org.uk/uploadedfiles/userfiles/files/Royal-Society-Science-as-a-public-enterprise-Royal-Statistical-Society-response.pdf

7. The UK has invested in, and been successful at, measuring the prevalence of past-year use of specific drugs; and hence in tracking how age- and gender-specific prevalence has changed over time. In general, we have been less successful in being able to ascribe any noted changes to specific policies, but there are exceptions, such as the universal offering of hepatitis B immunization to Scottish prisoners from 199911 , 12 and the impact—in terms of reduced methadone-related deaths per 1,000,000 recommended daily doses—of quality-assurance in methadone prescribing.13

8. Part of the reason for our uncertainty about the impact of specific policies is that UK has shied away from randomized controlled trial of court-based14 , 15 or policing-based policies16 in respect of drugs-dependent offenders, see also recommendations by Royal Statistical Society’s Working Party on Performance Monitoring in the Public Services.17

9. The National Institute for Health and Clinical Excellence (NICE) has tried to address the cost-effectiveness of treatment or public health policies for opiate-users or injection drug users. Criminal justice and policing initiatives have not been similarly scrutinised as far as I am aware. Even NICE faced difficulties and required to make expert judgements, because follow-up in most randomized controlled trials (RCT) of opiate-substitution therapy had been for less than one year and no RCT was large enough to demonstrate reduction in mortality or in Hepatitis C virus seroconversions. Nor was there evidence about the extent to which needle and syringe exchanges may prolong injecting careers (and hence the risk of opiate-overdose fatality)—if they do. Nor was there extensive evidence about the quality of life (eg EQ-5D scores) of injecting drug users. An important contribution of NICE’s cost-effectiveness studies is their transparency: on both the structure of the decision-model and the data-sources used as inputs to cost-effectiveness modelling.18

10. It is essential that public health considerations play a leading role in developing drugs policy because—if we get it wrong—young people may die unnecessarily. It is worth recalling that Scotland has had more than twice as many drugs-related deaths in the first decade of the 21st century (3,994) than she has had fatalities from HIV/AIDS since 1980. The medical sciences, among them biostatistics, need to tackle the fatalities from UK’s injector epidemics as rigorously as we did those from injection-related HIV disease. Attention should therefore focus on measuring, and further reducing, injector-incidence, with public health messages designed to dissuade habitués from initiation of others into injecting.19

11. The Home Affairs Select Committee is wise to focus on the inter-relationship between use of specific drugs (heroin, methadone, alcohol, benzodiazepines, for example; or alcohol and cocaine/ecstasy/mephedrone as another) and on the possible transition from one form of dependency to another (heroin to alcohol, say). In 21st Century Drugs and Statistical Science, we suggested that British Crime Survey might pool data across survey-years to enable past-year use of specific combinations of drugs to be investigated.20 , 21 Heavy alcohol use is associated with faster progression to liver disease for carriers of the Hepatitis C virus (HCV) and so moderation of alcohol use is important for older former injectors, a high proportion of whom (around half) will have become HCV-carriers through shared injecting.

12. Smoking apart, more detailed study than hitherto is needed on the health and social harms (to users and to others) of specific drugs—because they differ between drugs and also by route of administration and in whether they manifest in the short-term (acquisitive crime; alcohol-related violence) or after a decade or more (HCV-related liver disease; alcohol-related liver disease).

13. It is important to recognise that “drug-related offences”, as reported in national statistics, do not encompass many of “acquisitive crimes” committed by drugs-users and that the majority of “acquisitive crime” is not perpetrated by drugs-users. Just as pseudonymised record-linkage studies in Scotland have helped to reveal the extent of cause-specific hospitalisations and mortality for drug-treatment clients, Home Office and others’ initiatives on linkage of NTA-clients to Police National Computer records and to deaths records in England are helping to reveal the extent of their detected criminal-justice “morbidities”.22

14. It is notable that the Treasury receives substantial taxes in respect of the sale of both cigarettes and alcohol but Treasury currently gains little tax from the purchases made by drugs-users from dealers in illegal drugs. Questions on legalisation or decriminalisation are better addressed drug-specifically and, because the issues are technically complex, initially for some—not necessarily all—currently-illegal drugs.

15. The transfer of NTA’s functions, including its quality-assurance and data-registration roles, and the Government’s sharper focus on recovery are confounded to an extent because the changes coincide more or less. It is essential, therefore, that record-linkable database of erstwhile NTA-clients is maintained and that linkage to the deaths-register is enabled so that the mortality of clients of the variously-commissioned treatment-providers can be notified to them, and monitored nationally.

16. Prospectively, to do the above monitoring in a timely manner requires, inter alia, legislation to mandate the registration of all deaths in England within 8 days of the death having been ascertained. This would put an end to the long registration-delays that are currently permitted for coroner-referred deaths, see also Royal Statistical Society’s evidence House of Commons Science and Technology Select Committee’s Inquiry into Scientific Advice in Emergencies.23

17. In advance of changes in the Government’s 2010 Drug Strategy, Strang et al published in the British Medical Journal a methodology by which the quality of methadone prescribing in the past could be, and recently was, assessed.24 The same methodology can be applied prospectively to appraise the quality of methadone prescribing in 2011–2014. The hidden danger in a recovery agenda is that clients may be “moved on” from opiate substitution therapy sooner than they can cope with, subsequently relapse, and are then at higher risk of fatal heroin overdose.

18. The quintessential challenge presented by new “legal highs” is the lack of an evidence-base on their benefits and harms—in the short-term, let alone longer term. Making them illegal criminalises or conceals their usage, rather than according them a provisionally-legal “watchful waiting” status which, in effect, warns users that they themselves are responsible for the still-unknown risks they run.

19. Usage of a new “legal high” (H1, say) may turn out to be less harmful than use of drug X which H1 partially displaced—as may have occurred in respect of cocaine and mephedrone. Making H1 illegal is also likely to lead to the creation of a string of others (H2, H3, H4, …), some of which may be yet more harmful than H1 was.

20. Impending dissolution of the Home Office’s Surveys, Design and Statistics Subcommittee means that the Advisory Council on Misuse of Drugs cannot call on its independent good offices for statistical input.

January 2012

APPENDIX

Nationally Integrated Quantitative Understanding of Addiction Harms (NIQUAD)

NIQUAD is an MRC-funded addictions cluster comprised of the MRC Biostatistics Unit, Cambridge (Bird, De Angelis), and Universities of Bristol (Ades, Hickman), York (Godfrey), Strathclyde (Bird & Hutchinson), and Manchester (led by Millar), and was one of the 11 successful applications.

NIQUAD aims to answer public health questions about addiction by:

Improving, integrating, and harmonizing the information base.

Assessing the quality, precision, validity and consistency of available information.

Making data accessible to a wider range of expertise.

Developing methods to better exploit existing/new information sources.

This requires parallel work on developing record linkage and on statistical method for evidence synthesis of available information. Record-linkage of administrative and research data at the individual case level can create statistically powerful “virtual” cohorts that track pathways in and out of treatment, criminal justice, and healthcare, and the sequencing of key events. Evidence synthesis will develop models that link all the available evidence to link and test its consistency and to examine the relationships between parameters.

NIQUAD includes: key experts in surveillance and substance use epidemiology; non-addiction scientists with high-level skills in relevant statistical, mathematical modelling and health economic techniques; and health informatics.

1 www.rss.org.uk/site/cms/contentviewarticle.asp?article=1198

2 Bird S M. Prescribing sentence: time for evidence-based justice. Lancet 2004; 364: 1457–1459.

3 Bird S M, Merrall E L C. Serial offending: evaluation of drugs courts. Lancet 2009; 373: 1231–1233.

4 Bird S M, Goldacre B, Strang J. We should push for evidence based sentencing in criminal justice. British Medical Journal 2011; 341: 612 (d612. doi: 10.1136/bmj.d612).

5 Advisory Council on the Misuse of Drugs (chair: Professor Sir Michael Rawlins). Reducing Drug Related Deaths. Home Office, London: 2000.

6 Bird S M, Robertson J R, Strang J. Delving deeper into a decade of drug-related deaths. Straight Statistics 2010: 1 November. See www.straightstatistics.org/article/delving-deeper-decade-drug-related-deaths.

7 Bird S M. Drugs deaths in England and Wales—a wake-up call to the Registrar General. Straight Statistics 2011: 24 August. See www.straightstatistics.org/article/drugs-deaths-england-and-wales-wake-call-registrar-general. Also Decrease in cocaine-related deaths was in 2009, not 2010. See
www.straightstatistics.org/article/decrease-cocaine-related-deaths-was-2009-not-2010.

8 Ibid.

9 Bird S M. More insights on mephedrone from the British Crime Survey. Straight Statistics 2011: 7 September. See www.straightstatistics.org/article/more-insights-mephedrone-british-crime-survey.

10 Bird S M, Mercer P. Mephedrone and cocaine: clues from Army testing. Straight Statistics 2011: 11 February. See www.straightstatistics.org/article/mephedrone-and-cocaine-clues-army-testing.

11 Hutchinson S J, Wadd S, Taylor A, Bird S M, Mitchell A, Morrison D S, Ahmed S, Goldberg D J. Sudden rise in uptake of Hepatitis B among injecting drug users associated with a universal vaccine programme in prisons. Vaccine 2004; 23: 210–214.

12 Allen E, Taylor A, Palmateer N, Hutchinson S, Rees C, Johnston L, Vitrano G, Cameron S, Goldberg D. The Needle Exchange Surveillance Initiative (NESI): prevalence of HCV and injecting risk behaviours among injecting drug users attending needle exchanges in Scotland, 2008/2009. University of the West of Scotland, April 2010. (see
http://forthvalleysat.co.uk/v2/index2.php?option=com_docman&task=doc_view&gid=611&Itemid=68)

13 Strang J, Hall W, Hickman M, Bird S M. Impact of supervision of methadone consumption on deaths related to methadone overdose (1993-2008): analyses using OD4 index in England and Scotland. British Medical Journal 2010; 341:640 (pico) and British Medical Journal 2010; 341:c4851 (doi:10.1136/bmj.c4851 for 7 pages).

14 Bird S M. Prescribing sentence: time for evidence-based justice. Lancet 2004; 364: 1457–1459.

15 Bird S M, Merrall E L C. Serial offending: evaluation of drugs courts. Lancet 2009; 373: 1231–1233.

16 Bird S M, Goldacre B, Strang J. We should push for evidence based sentencing in criminal justice. British Medical Journal 2011; 341: 612 (d612. doi: 10.1136/bmj.d612).

17 Royal Statistical Society Working Party on Performance Monitoring in the Public Services (chair: Professor Sheila M. Bird). Performance Indicators: Good, Bad, and Ugly. London: Royal Statistical Society, 23 October 2003 (see Reports at www.rss.org.uk).

18 Vickerman P, Miners A, Williams J. Assessing the cost-effectiveness of interventions linked to needle and syringe programmes for injecting drug users: an economic modelling report. See
www.nice.org.uk/nicemedia/live/12130/43370/43370.pdf

19 Surveys, Design and Statistics Subcommittee (then-chair: Professor Sheila M Bird) of Home Office’s Scientific Advisory Committee. 21st Century Drugs and Statistical Science. Home Office, 15 December 2008. (See http://www.homeoffice.gov.uk/documents/science-advisory-committee/21st-century-drugs-stats?view=Binary).

20 Bird S M. More insights on mephedrone from the British Crime Survey. Straight Statistics 2011: 7 September. See www.straightstatistics.org/article/more-insights-mephedrone-british-crime-survey.

21 Surveys, Design and Statistics Subcommittee (then-chair: Professor Sheila M Bird) of Home Office’s Scientific Advisory Committee. 21st Century Drugs and Statistical Science. Home Office, 15 December 2008. (See http://www.homeoffice.gov.uk/documents/science-advisory-committee/21st-century-drugs-stats?view=Binary).

22 Merrall E L C, Bird S M, Hutchinson S J. Mortality of those who attended drug services in Scotland 1996-2006: record linkage study. International Journal of Drug Policy 2011 [29 June 2011 Epub ahead of print].

23 www.rss.org.uk/site/cms/contentviewarticle.asp?article=1198

24 Strang J, Hall W, Hickman M, Bird S M. Impact of supervision of methadone consumption on deaths related to methadone overdose (1993–2008): analyses using OD4 index in England and Scotland. British Medical Journal 2010; 341:640 (pico) and British Medical Journal 2010; 341:c4851
(doi:10.1136/bmj.c4851 for 7 pages).

Prepared 8th December 2012