Busch, M., Klein, C., Uhl, A., Haltmayer, H., Cabanis, M., Westenberg, J. N., Vogel, M., & Krausz, R. M. (2021). Retention in the Austrian opioid agonist treatment system: a national prospective cohort study. Harm Reduction Journal, 18, Article number 25.

The full arcticle is available here: 
doi: 10.1186/s12954-021-00473-9