Funding for this research was provided by:
National Institute on Drug Abuse (R01DA025555)
Received: 26 February 2020
Accepted: 30 November 2020
First Online: 6 January 2021
Ethics approval and consent to participate
: No participants in this study, data extraction form was developed to extract data from existing articles.
: All authors provide <i>Health Economics Review</i>, Biomed Central, consent for publication.
: No competing interests to declare.