Table 1 Inclusion and exclusion criteria

Population

People who are dependent on non-prescription opioids and who are receiving opioid agonist therapy or maintenance therapy for opioid dependency

Intervention

Pharmacological maintenance therapy, monotherapy or combination

 Morphine/morphine sulphate/diacetylmorphine/diamorphine (DIA)

 Buprenorphine (BUP)

 Methadone (METH)

 Codeine, dihydrocodeine

 Naloxone, naltrexone (NAL)

 Buprenorphine/naloxone (BUP/NAL)

Note naloxone may be used in combination with other treatments (morphine + naloxone)

The following operational definition will be employed for “maintenance” treatment: the treatment approach does not include a reduction or cessation of one of the above treatments as part of the approach

Comparators

Any comparator regime used in maintenance therapy (including no therapy or placebo)

Outcomes

Health economic models (any type including Markov, dynamic, Monte-Carlo, simulations, decision-trees etc)

Study types

Cost-effectiveness (CEA), cost-utility (CUA), cost-minimisation (CMA), cost-benefit (CBA), budget impact (BIM), cost-consequence (CC)

Language

English language abstracts

Timeframe

Last 20 years (1995–2015)

Exclusions

Studies indexed as case reports, case series, editorials and letters

English language title and abstracts only

Economic studies that do not employ modelling techniques (studies describing extrapolation of data beyond the primary clinical evidence time horizon were considered to include modelling techniques. Studies based only on cost and outcomes during the course of a trial were excluded)