**9. Methodology for identifying potential mephedrone-related fatalities**

In the UK and Islands all sudden, unexpected or violent deaths - as well as deaths in custody - are formally investigated by Coroners (or their equivalent in the Islands), or Procurators Fiscal in the case of Scotland. Most drug-related deaths are subject to these processes, typically by way of a coronial inquest (Corkery, 2002).

Since its establishment in 1997, the National Programme on Substance Abuse Deaths (np-SAD) has been regularly receiving coroners' information on drug-related deaths amongst both addicts and non-addicts in the UK, the Channel Islands and the Isle of Man. The average annual response rate from coroners in England and Wales to np-SAD has been between 89% and 95% (Ghodse et al., 2010). Since 2004, information has also been received from the Scottish Crime &Drug Enforcement Agency and the General Register Office for Northern Ireland. To date, details of some 25,000 deaths have been received. The information reported here on deaths associated with mephedrone consumption are based on all relevant cases recorded in the Special Mortality Register of the np-SAD based at St George's Hospital Medical School, University of London.

To be recorded in the np-SAD database as a drug-related death, at least one of the following criteria must be met: (a) presence of one or more psychoactive substances directly implicated in death; (b) history of dependence or abuse of drugs; and (c) presence of controlled drugs at post-mortem. Full details of the np-SAD data collection form and its surveillance work can be found in the Programme's annual report (Ghodse et al., 2010). Ethical approval is not required in the UK for studies whose subjects are deceased. However, confidentiality arrangements are in place with each of the respective data providers.

A range of documents are contained in coronial inquest files, although the variety differs from case to case. Typically, the coroner has access to: statements from witnesses, family and friends; General Practitioner records (if the deceased is registered with one); reports from ambulance, police or other emergency services; hospital Emergency Department and clinical ward reports; psychiatric and substance abuse team reports; as well as post mortem and toxicology reports. Internet searches of toxicological as well as newspaper and other media websites revealed information on further cases. The media reports available for some cases were used to supplement the information provided on the np-SAD data collection form, especially where access to the full coronial files was not possible.

In addition to its routine surveillance activities, the Programme also provides real-time information on the emergence of novel substances or new ways of taking existing substances to the UK Early Warning System and the Advisory Council on the Misuse of Drugs (ACMD). This information comes both from notifications of deaths and from 'alerts' or other information provided by the various agencies and networks, national and international, with which the Programme maintains contacts. Regular searches of media reports are also undertaken.

Through these channels (including coroners, forensic toxicologists – principally the London Toxicology Group, Drug & Alcohol Action Teams, and the Scottish Crime & Drug Enforcement Agency) the Programme became aware of the emerging issue of the use of methcathinones, especially mephedrone, and similar substances (including chemicals), and of their potential adverse health consequences. It was decided to take a pro-active approach to monitor the situation especially in respect of the potential role of these new substances in causing or contributing to death. For those cases not formally reported to the Programme, contact was made with the relevant coroners to request the submission of an np-SD form so as to obtain the appropriate information. Information on these cases was added to the database when forms were received by the Programme team.

The np-SAD database was searched using the terms 'mephedrone' and '4 methylmethcathinone' to identify potentially relevant cases. The database fields searched were those holding data on: drugs present at post-mortem; drugs implicated; cause(s) of death; accident details; and 'other relevant information'. The data presented here relate to all concluded cases for which forms had been submitted to the Programme by 31 August 2011. Details of some of these cases have previously been published (Torrance & Cooper, 2010; Wood et al., 2010b; Maskell et al., 2011; EMCDDA, 2011:78-85).

Analyses were performed using IBM® SPSS® Statistics, version 18 for Windows™. Demographic details, risk factors, and categorical data were expressed as frequencies and percentages within groups; ages were compared using Levene's Test for Equality of Variances (two-tailed). The results for statistical tests were regarded as significant at or below the 5% probability level.
