PubMed Health⌕ Search

Biomedical subjects

Matthew Hickman

Publications and source records attributed to Matthew Hickman.

At least 19 recordsLinked to original sources
PubMed2007

London audit of drug-related overdose deaths: characteristics and typology, and implications for prevention and monitoring.

OBJECTIVES: To describe the circumstances and draft a typology of drug-related overdose deaths. SETTING: London, 2003. METHODS: An audit of 148 drug overdose deaths (involving heroin, methadone, dihydrocodeine, cocaine, amphetamine or MDMA) investigated by coroners during 2003. Information extracted on toxicology, pathology and circumstances were used to identify drug(s) implicated in the death. RESULTS: Poly- or multiple drug use was detected in the majority of deaths with at least 69 different combinations, including 66% for heroin and 42% for cocaine. Six categories of death were identified involving an opiate (100, 68%); cocaine (14, 9%); other controlled drug (five, 3%); mixed drug overdose (18, 12%); other prescribed drug (five, 3%); and other causes (seven, 5%). A witness was present and the death was not instantaneous in 92 (61%) cases, although evidence in the coronial file suggested that in the majority of cases the overdose went unnoticed until too late to intervene. In all, 15 (one in 10) of the deceased were released from prison within 3 months of death; and 37 (one in four) were reported as in receipt of a methadone prescription. CONCLUSIONS: Perhaps for the first time in the United Kingdom cocaine was detected in more drug overdose deaths than methadone. However, reducing heroin use is central to the prevention of drug-related deaths. We recommend that overdose prevention encompasses strategies to encourage a 'mutual duty of care' among problem drug users, and in the United Kingdom further investigation of the relationship of methadone treatment failures on overall trends in drug-related deaths is merited.

Drug Overdose↗
PubMed2006

Association between availability of heroin and methadone and fatal poisoning in England and Wales 1993-2004.

BACKGROUND: The UK heroin market is the biggest in Europe and approximately 70% of heroin deaths are due to fatal poisoning. Methadone treatment for heroin addiction in the UK, the 'British system', is unique as it is largely provided by General Practitioners. METHODS: The Office for National Statistics provided data on deaths, the Home Office provided law enforcement data on drug seizures and the Department of Health data on prescriptions. For methadone treatment we calculated the death rate per 1000 patient years. We used Spearman's rank correlation to assess the association between illicit drug seizures for heroin and methadone and deaths. RESULTS: Between 1993 and 2004 there were 7072 deaths involving heroin/morphine (86% males) and 3298 deaths involving methadone (83% male). From 1993-1997, directly age-standardized mortality rates for males were similar for both drugs, increasing from approximately 5 to 15 per million. Mortality rates for heroin continued to increase until 2000, subsequently decreasing from 30 to 20 per million by 2003, and rising again to 24 per million in 2004. In contrast, mortality rates for methadone decreased between 1997 and 2004 to just above 1993 levels. Among females the mortality rate for both drugs was lower than for males throughout the study period, remaining relatively stable. Methadone deaths per 1000 patient years remained similar between 1993 and 1997, after which they fell by three quarters. For both heroin/morphine and methadone, deaths were strongly associated with seizures (Spearmans' coefficient for males: heroin, P = 0.95, P < 0.001 and methadone, P = 0.83, P = 0.0013). CONCLUSIONS: Our study suggests the 'British System' can deliver substantial expansion of treatment without increased mortality risk. The fall in heroin/morphine deaths since 2000 may also be an indication of success of increasing methadone treatment. Data on mortality risk is needed to determine whether increased methadone treatment has reduced drug-related deaths.

Administration, Oral↗
PubMed2006

Methods to recruit hard-to-reach groups: comparing two chain referral sampling methods of recruiting injecting drug users across nine studies in Russia and Estonia.

Evidence suggests rapid diffusion of injecting drug use and associated outbreaks of HIV among injecting drug users (IDUs) in the Russian Federation and Eastern Europe. There remains a need for research among non-treatment and community-recruited samples of IDUs to better estimate the dynamics of HIV transmission and to improve treatment and health services access. We compare two sampling methodologies "respondent-driven sampling" (RDS) and chain referral sampling using "indigenous field workers" (IFS) to investigate the relative effectiveness of RDS to reach more marginal and hard-to-reach groups and perhaps to include those with the riskiest behaviour around HIV transmission. We evaluate the relative efficiency of RDS to recruit a lower cost sample in comparison to IFS. We also provide a theoretical comparison of the two approaches. We draw upon nine community-recruited surveys of IDUs undertaken in the Russian Federation and Estonia between 2001 and 2005 that used either IFS or RDS. Sampling effects on the demographic composition and injecting risk behaviours of the samples generated are compared using multivariate analysis. Our findings suggest that RDS does not appear to recruit more marginalised sections of the IDU community nor those engaging in riskier injecting behaviours in comparison with IFS. RDS appears to have practical advantages over IFS in the implementation of fieldwork in terms of greater recruitment efficiency and safety of field workers, but at a greater cost. Further research is needed to assess how the practicalities of implementing RDS in the field compromises the requirements mandated by the theoretical guidelines of RDS for adjusting the sample estimates to obtain estimates of the wider IDU population.

Data Collection↗
PubMed2006

Estimating prevalence of injecting drug use: a comparison of multiplier and capture-recapture methods in cities in England and Russia.

We consider the question of what method should be recommended to estimate the prevalence of injecting drug use (IDU); and compare multiplier and capture-recapture (CRC) methods of estimating prevalence of injecting drug use (IDU). The prevalence of injecting drug use in four cities (Brighton, Liverpool, London and Togliatti) was estimated using similar methods: covariate capture-recapture (CRC) and multipliers. The multipliers, generated either from a community recruited survey or historical/literature-based, were applied to a range of 'benchmarks': specialist drug treatment, arrests, accident and emergency department (A&E), syringe exchange, HIV tests and opiate overdose deaths. The CRC estimates were assumed to be 'preferred/gold standard' [2,304 (95% confidence interval 1,514 - 3,737) in Brighton, 2,910 (2,546 - 4,977) in Liverpool, 16,782 (13,793 - 21,620) in 12 London boroughs and 15,039 (12,696 - 18,515) male IDU in Togliatti]. The ranges given by the multiplier estimates obtained through the community survey varied from 200 to 770 in Brighton, 530 to 1,300 in Liverpool, 2,900 to 10,600 in London and 12,400 to 91,000 in Togliatti. Several multipliers gave implausible results, lower than the observed data collected for another benchmark, and in the three English cities all these multiplier estimates were below the lower 95% confidence interval of the CRC estimate. In Togliatti, only one multiplier estimate was close to the preferred CRC estimates, with the rest implausibly high. The multiplier estimates based on historical/literature multipliers also ranged widely from 390 to 4,800 for Brighton, from 1,645 to 2,800 in Liverpool, from 4,650 to 12,600 in the 12 London boroughs and 12,800 to 32,000 in Togliatti. In the three UK cities the mortality multiplier estimates were closest to the capture-recapture estimates. The study was a practical demonstration comparing a range of multiplier estimates with a single CRC study. In almost all the individual comparisons the multiplier estimates performed poorly. CRC methods should be preferred as the means of estimating numbers of drug users with multiplier methods being used with caution and only where CRC is not possible.

AIDS Serodiagnosis↗
PubMed2006

Model projections on the required coverage of syringe distribution to prevent HIV epidemics among injecting drug users.

BACKGROUND: Although syringe distribution is effective in preventing HIV transmission among injecting drug users (IDUs), there is little evidence on the required coverage to substantially reduce HIV transmission. METHODS: A mathematical model is developed to explore the relationship between the endemic HIV prevalence among IDUs and the coverage of syringe distribution. Data from IDU populations in the United Kingdom and Belarus are used to explore the implications of increasing coverage and the effect of changes in other behaviors. RESULTS: Projections suggest that there is a coverage threshold, which, if reached, could lead to substantial decreases in HIV prevalence. The threshold largely depends on the frequency that IDUs inject and (safely) reuse their syringes, and corresponds to less than 4 syringe-sharing events per IDU per month. Other factors, such as the injecting cessation rate and efficacy of syringe cleaning, only have substantial impact near threshold coverage levels. CONCLUSIONS: Our results support a policy of increasing the coverage of syringe distribution but highlight the difficulty in producing a universal coverage target. Great public health benefit could be conferred by encouraging the safe reuse of an IDU's own syringes and small stable injecting groups. Policies that discourage this will negate the impact of syringe distribution interventions.

HIV Infections↗
PubMed2006

Prevalence of HIV, hepatitis C and syphilis among injecting drug users in Russia: a multi-city study.

OBJECTIVES: To estimate the prevalence of HIV, hepatitis C virus (HCV) and syphilis in injecting drug users (IDUs) in Russia. METHODS: Unlinked anonymous cross-sectional survey of 1473 IDUs recruited from non-treatment settings in Moscow, Volgograd and Barnaul (Siberia), with oral fluid sample collection for HIV, HCV antibody (anti-HIV, anti-HCV) and syphilis testing. RESULTS: Prevalence of antibody to HIV was 14% in Moscow, 3% in Volgograd and 9% in Barnaul. HCV prevalence was 67% in Moscow, 70% in Volgograd and 54% in Barnaul. Prevalence of positive syphilis serology was 8% in Moscow, 20% in Volgograd and 6% in Barnaul. Half of those HIV positive and a third of those HCV positive were unaware of their positive status. Common risk factors associated with HIV and HCV infection across the cities included both direct and indirect sharing of injecting equipment and injection of home-produced drugs. Among environmental risk factors, we found increased odds of anti-HIV associated with being in prison in Moscow, and some association between official registration as a drug user and anti-HIV and anti-HCV. No associations were found between sexual risk behaviours and anti-HIV in any city. CONCLUSIONS: HIV prevalence among IDUs was markedly higher than city routine surveillance data suggests and at potentially critical levels in terms of HIV prevention in two cities. HCV prevalence was high in all cities. Syphilis prevalence highlights the potential for sexual risk and sexual HIV transmission. Despite large-scale testing programmes, knowledge of positive status was poor. The scaling-up of harm reduction for IDUs in Russia, including sexual risk reduction, is an urgent priority.

Adolescent↗
PubMed2006

Antiretroviral treatment for injecting drug users in developing and transitional countries 1 year before the end of the "Treating 3 million by 2005. Making it happen. The WHO strategy" ("3 by 5").

OBJECTIVE: To describe and estimate the availability of antiretroviral treatment (ART) to injecting drug users (IDUs) in developing and transitional countries. METHODS: Literature review of grey and published literature and key informants' communications on the estimated number of current/former injecting drug users (IDUs) receiving ART and the proportion of human immunodeficiency virus (HIV) attributed to injecting drug use (IDU), the number of people in ART and in need of ART, the number of people living with HIV/acquired immunodeficiency syndrome (AIDS) (PLWHA) and the main source of ART. RESULTS: Data on former/current IDUs on ART were available from 50 countries (in 19 countries: nil IDUs in treatment) suggesting that approximately 34 000 IDUs were receiving ART by the end of 2004, of whom 30 000 were in Brazil. In these 50 countries IDUs represent approximately 15% of the people in ART. In Eastern European and Central Asia IDU are associated with > 80% of HIV cases but only approximately 2000 (14%) of the people in ART. In South and South-East Asia there were approximately 1700 former/current IDUs receiving ART ( approximately 1.8% of the people in ART), whereas the proportion of HIV cases associated to IDU is > 20% in five countries (and regionally ranges from 4% to 75%). DISCUSSION: There is evidence that the coverage of ART among current/former IDUs is proportionally substantially less than other exposure categories. Ongoing monitoring of ART by exposure and population subgroups is critical to ensuring that scale-up is equitable, and that the distribution of ART is, at the very least, transparent.

Antiretroviral Therapy, Highly Active↗
PubMed2006

Public injecting and the need for 'safer environment interventions' in the reduction of drug-related harm.

BACKGROUND: One key structural dimension in the distribution of drug-related harm associated with injecting drug use is the injecting environment. Epidemiological evidence associates elevated blood-borne viral risk with injecting in 'public' and 'semipublic' environments. Yet the quality of evidence on public injecting and related viral risk is variable, and is lacking in many countries such as the United Kingdom. AIM: This commentary considers the micro-injecting environment as a critical dimension of risk, exploring the need for 'safer injecting environment interventions'. METHODS: We draw upon published research evidence and qualitative case examples. RESULTS: We note the limits in epidemiological evidence on public injecting and emphasize the need for ethnographic research to determine the 'social relations' of how drug users and risk practices interact with injecting environments. We identify three main forms of 'safer environment intervention': purpose-built drug consumption rooms; interventions within existing spatial relations; and spatial programming and urban design. While drug consumption rooms find evidence-based support, they are not a panacea. We emphasize the potential of interventions embedded within existing spatial and social relations. These include low-cost pragmatic interventions enhancing facilities and safety at public and semipublic injecting sites and, primarily, peer-based interventions, including peer-supervised injecting sites. We caution against spatial programming and urban design interventions which can cause the displacement of socially marginalized populations and the redistribution of harm. CONCLUSIONS: Public health interventions in the addictions field have in the past focused upon individual behavioural change at the cost of social interventions and environmental change. We wish to focus greater attention on reducing risks related to public injecting and encourage greater debate on 'safer environment interventions' in harm reduction.

Environment↗
PubMed2006

Trends in deaths related to drug misuse in England and Wales, 1993-2004.

In this article we report trends in deaths related to drug misuse in England and Wales from 1993 to 2004, looking particularly at the period between 1999 and 2004, for which there was a Government target to reduce these deaths by 20 per cent. Although there was an overall decline in deaths related to drug misuse between 1999 and 2004, the percentage reduction, at 9 per cent, was less than the Government target. There was an increase in deaths between 2003 and 2004, largely accounted for by deaths involving heroin/methadone and morphine. Mortality rates were highest in young adults and an increase in mortality rates within this group appears to have been the driver behind rising mortality trends during the 1990s.

Adolescent↗
PubMed2005

Drug-related mortality and its impact on adult mortality in eight European countries.

OBJECTIVE: To estimate the mortality rates from drug-related deaths and other causes among problem drug users and population attributable risk of death due to opiate use in eight study sites in Europe. METHODS: Opiate users were recruited from drug treatment centres during the period 1990-1998 and deaths followed up through national or local mortality registries. Gender-specific overall mortality rate, proportion of deaths by cause (drug-related, HIV, other), standardized mortality ratios (SMRs), and the attributable risk fraction (ARF) were estimated. RESULTS: Crude mortality rates varied from 1 per 100 person-years in the Dublin and London cohorts to 3.8 per 100 person-years in Barcelona. The highest drug-related mortality rate was 10 per 1,000 person-years in Barcelona; the rates were approximately 7 per 1,000 person-years in Denmark, London, Rome, and Vienna, and <3.5 per 1,000 person-years for the others cohorts. The mortality rate for AIDS was <2 per 1,000 person-years in all the cohorts except Lisbon, Rome, and Barcelona, for which it was approximately 6 per 1,000 person-years. The highest SMR among males was 21.1 in Barcelona, and among females the highest SMRs were 53.7 and 37.7 in Barcelona and Rome, respectively. In Denmark the ARF was 5%, whereas it was >10% in all other study sites and 24% in Barcelona. CONCLUSION: Cohort mortality studies, especially in combination with estimates of prevalence, provide useful insights into the impact of opiate use on mortality across European countries and emphasize how preventing overall and drug-related deaths among opiate users can significantly improve the health of the population.

Adolescent↗
PubMed2005

HIV prevalence among injecting drug users in England and Wales 1990 to 2003: evidence for increased transmission in recent years.

OBJECTIVE: To describe trends in HIV prevalence among injecting drug users in England and Wales between 1990 and 2003. METHODS: Analysis of surveillance data from voluntary unlinked anonymous cross-sectional surveys collecting oral fluid samples and behavioural information from injecting drug users recruited from both drug agency (n = 24,304) and community settings (n = 3628). RESULTS: HIV prevalence in England and Wales declined from 5.9% in 1990 to 0.6% in 1996 and then remained stable until 1999, after which it increased to 1.4% in 2003. Few HIV infections were detected among short-term injectors between 1994 and 1999, but in recent years prevalence among this group has increased. Other factors associated with higher odds of HIV infection were being recruited in London and from community settings, and ever having had a voluntary confidential HIV test. Incidence estimated through a force of infection model was 2.8% per annum among those injecting for less than a year in London between 1998 and 2003. CONCLUSIONS: These data suggest that incidence and prevalence of HIV may have increased, whereas other indicators suggest an increase in risk behaviour. It is critical that harm reduction measures are reinvigorated, and evolve in response to changes in drug use risk behaviours and policy.

Adolescent↗
PubMed2005

Capturing crack cocaine use: estimating the prevalence of crack cocaine use in London using capture-recapture with covariates.

AIM: To estimate the prevalence of crack cocaine use in 12 London Boroughs (and London as a whole). SETTING: Twelve London Boroughs, 2000-01. METHODS: (1) Covariate capture-recapture techniques applied to three data sources of subjects reporting crack cocaine use: specialist drug treatment (2905), arrest referral (1188) and accident and emergency and community survey (531); and (2) ratio-estimation multiplier, using an estimate of number of injecting drug users and proportion that use crack cocaine. FINDINGS: After matching, 4117 individuals aged 15-44 were identified. The best-fitting model estimated 16 855 unobserved crack cocaine users, giving an overall estimate of approximately 21 000 [95% confidence interval (CI) 13 000-43,000] and a prevalence of 1.5% (95% CI 1.0-3.2%). Prevalence of crack cocaine use was 2.4% (95% CI 1.5-5.0%) among men and 0.7% (95% CI 0.5-1.0%) among women, and similar by age groups 15-29 and 30-44 years. Overall, approximately 11 900 (57%) of the estimated number of crack cocaine users were also opiate users. In London as a whole there may be 46,000 (1.3%) crack cocaine users aged 15-44 years, with 28 000 (1.9%) in inner London-four times higher than estimates from population surveys. Some corroboration was provided by the ratio-estimation method, which estimated 23 000 users in the 12 Boroughs. CONCLUSIONS: Capture-recapture can be applied to crack cocaine and obtain better estimates than population surveys. The size of the crack cocaine-using population in London is large, although currently the majority are also opiate users. Given that half of current users are under 30 the problems associated with crack cocaine use are likely to increase in the future.

Adolescent↗
PubMed2005

Hepatitis C virus infection, HIV co-infection, and associated risk among injecting drug users in Togliatti, Russia.

The objective of this study was to estimate the prevalence of hepatitis C virus (HCV) infection and co-infection with HIV among injecting drug users (IDUs) in Togliatti City, Russia. Unlinked anonymous cross-sectional survey of IDUs recruited from community settings, with oral fluid sample collection for HCV and HIV antibody (anti-HCV, anti-HIV) testing, was carried out. The anti-HCV prevalence was 87% (357/411), anti-HIV prevalence 56% (234/418), and 93% (214/230) of HIV-positive IDUs were co-infected with HCV. Only 23% (94/411) of those HCV positive self-reported as such. In an adjusted model, increased odds of HCV positivity were associated with needle and syringe, as well as injecting paraphernalia sharing in the last four weeks. IDUs injecting more than once with the same needle also had raised odds. There were no marked associations between HCV positivity and the duration of injecting or age group. Almost all IDUs were HCV positive, and almost all HIV-positive IDUs were HCV co-infected. There is an urgent need to maximize syringe distribution coverage, develop health promotion targeting HCV prevention for IDUs, and improve access among IDUs to treatments for HIV and HCV infection.

Adult↗
PubMed2004

Global overview of injecting drug use and HIV infection among injecting drug users.

OBJECTIVE: To provide global estimates of the prevalence of injecting drug use (IDU) and HIV prevalence among IDU, in particular to provide estimates for developing and transitional countries. METHODS: Collation and review of existing estimates of IDU prevalence and HIV prevalence from published and unpublished documents for the period 1998-2003. The strength of evidence for the information was assessed based on the source and type of study. RESULTS: Estimates of IDU prevalence were available for 130 countries. The number of IDU worldwide was estimated as approximately 13.2 million. Over ten million (78%) live in developing and transitional countries (Eastern Europe and Central Asia, 3.1 million; South and South-east Asia, 3.3 million; East-Asia and Pacific, 2.3 million). Estimates of HIV prevalence were available for 78 countries. HIV prevalence among IDU of over 20% was reported for at least one site in 25 countries and territories: Belarus, Estonia, Kazakhstan, Russia, Ukraine, Italy, Netherlands, Portugal, Serbia and Montenegro, Spain, Libya, India, Indonesia, Malaysia, Myanmar, Nepal, Thailand, Viet Nam, China, Argentina, Brazil, Uruguay, Puerto Rico, USA and Canada. CONCLUSIONS: These findings update previous assessments of the number of countries with IDU and HIV-infected IDU, and the previous quantitative global estimates of the prevalence of IDU. However, gaps remain in the information and the strength of the evidence often was weak.

Adolescent↗