Predictors of death for methadone maintenance patients in Croatia

Croat Med J. 2013 Feb 15;54(1):42-8.

Risk factors for fatal outcome in patients with opioid dependence treated with methadone in a family medicine setting in Croatia.

Cerovecki V, Tiljak H, Ozvacic Adzic Z, Krizmaric M, Pregelj P, Kastelic A.

The authors report on 287 patients treated with methadone maintenance by Croatian family doctors between 1995 and 2007.  It unclear to what extent doses were observed.  They note 16.7% self-administered methadone, 9.8% were administered methadone by someone else, 73.5% used "a combined model".

During the 12 years 8% or 23 patients died for an annual mortality of 0.7%.  The greatest risk factor was previous failure of methadone treatment Odds Ratio 19, loss of continuity of care OR 12, unstable family relationships OR 9, an intention for maintenance vs detox (presumably reflecting a more chronic opiate addiction) OR 3 

It wasn't stated but implied that overdose is the cause of much of this mortality.  The maximum dose allowed in this setting was 50 mg methadone daily and it appears that patients likely to use additional substances or to take methadone erratically were at the highest risk of death.

This may not apply in the US context where methadone doses are higher and daily observed dosing is the norm, but it suggests that previous failures at methadone maintenance or unstable family relationships may be an indication for more careful monitoring.