Marie Jauffret-Roustide is a Sociologist, Research Fellow at the French National Institute of Health and Medical Research in Paris. She leads an international comparative research program on harm reduction including the evaluation of drug consumption rooms, and ethnographic research on cocaine crack, gender and racial issues in drug policies.

Background
Compared to other European countries, France was late in implementing drug consumption rooms (DCRs), due to political controversy. Two DCRs opened in Paris and Strasbourg in 2016. Their effectiveness has been evaluated using the COSINUS cohort, a scientific evaluation requested by the French government.

Methods
COSINUS is a 12-month prospective cohort study of 665 PWID in France studying DCR effectiveness on PWID health and public order. We collected data from face-to-face interviews at enrolment, and at 6 and 12 months follow-up. PWID were recruited in two cities with a DCR (Paris and Strasbourg) and two other without DCRs (Bordeaux and Marseille). After adjusting for other correlates (p-value<0.05), the impact of DCR exposure on each outcome was assessed using a two-step Heckman mixed-effects probit model, allowing us to take into account the correlation between repeated measures and to adjust for potential bias due to non-randomization between the DCR-exposed and DCR-unexposed groups.

Results
Multivariable models found that DCR-exposed participants were less likely to report overdoses (adjusted coefficient [95%CI]: -0.47, [-0.88;-0.07], p=0.023) ; as well as injection equipment sharing ([95%CI]: =-1.14 [-1.91;-0.36]) ; abscesses (-0.74 [-1.11;-0.37], p<0.001) ; and Emergency Departments visits (-0.74 [-1.27;-0.20], p=0.007).
Regarding public order, DCR-exposed participants report significantly less injecting mainly in public spaces ([-0.56 [0.88; -0.24], p<0.001) and less likely to have committed a crime in the past month (-1.10 [-1.93;-0.27], p=0.007).

Conclusion
This is the first time in Europe and worldwide that DCRs effectiveness has been evaluated by using a control group. Our findings show that DCRs are highly effective to improve the health of PWID and the public peace for DCR’s residents. The design of our French DCR evaluation may be helpful for other European countries to implement evidence-based policies in the harm reduction area.