Unintentional methadone-related overdose death in New Mexico (USA) and implications for surveillance, 1998-2002

FRANÇAIS :
Entre 1998 et 2002, sur 1120 overdoses observées, 143 étaient liées à la méthadone : 22,4% étaient dues à la méthadone seule, 23,8% à l'association de méthadone/médicaments prescrits, 50,3% à l'association méthadone/drogues illicites et 3,5% à l'association méthadone/alcool. Pour les 79 usagers décédés dont l'origine de la méthadone était connue, 68 l'avait obtenue sur prescription médicale (31 pour traitement de maintenance, 27 contre la douleur et 10 pour une prescription inconnue).
ENGLISH:
Aims To determine death rates from methadone over time, to characterize methadone-related death and to discuss public health surveillance of methadone-related death. Design We analyzed medical examiner data for all unintentional drug overdose deaths in New Mexico, USA, between 1998 and 2002. Measurements Age-adjusted death rates for methadone-related death, logistic regression models for likelihood of methadone-related death among all unintentional drug overdose deaths and bivariate comparisons within methadone-related death. Findings of 1120 drug overdose deaths during this period, there were 143 (12.8%) methadone-related deaths; the death rate decreased over the time period, averaging 1.6 per 100 000. Of 143 methadone-related deaths, 22.4% were due to methadone alone, 23.8% were due to methadone/prescription drugs (no illicit drugs), 50.3% were due to methadone/illicit drugs and 3.5% were due to methadone/alcohol. These groups were significantly different in demographics, health history and circumstances of death. Of 79 decedents (55.2%) with a known source of methadone, 68 obtained methadone through a physician prescription (31 for methadone maintenance treatment (MMT), 27 for managing pain and 10 had unknown reason for prescription). Conclusions Methadone-related death rates and the proportion of methadone-related death among all drug overdose deaths decreased in New Mexico from 1998 to 2002. It is important for surveillance of methadone-related death to assess multiple drug causes, not just underlying cause. Also, methadone for pain management must be examined alongside MMT and when possible, methadone co-intoxication should be described in the context of other drugs causing death. (Author' s abstract)