The main objective of our study was to assess whether PWUDs would be willing to use a DCR in Lyon, France, and to explore the factors associated with the use of such facility. Overall, our study found that almost two-thirds of the PWUDs surveyed would be willing to use a DCR if it was opened in the city. To our knowledge, very few French studies had ever assessed whether PWUDs would be interested in using a DCR. A survey conducted prior to the opening of the Paris DCR included 156 participants, but only 30 were PWUDs [16]. In addition, another study was conducted from the COSINUS cohort survey with a subsample focused on Marseille among 195 participants, a city without a DCR found that more than half (57%) of participants who were ready to use a DCR [17], compared to three-quarters (73%) in our survey conducted in another city without a DCR.

Regarding the main results of our study, we found that almost two-thirds of the interviewees were willing to use a potential DCR in Lyon. The results obtained from our survey conducted in Lyon are higher compared to other French studies [17] and quite similar or below compared to those found in similar international surveys, which found a range between 68.5% and 89.0 [18–22]. A possible explanation for our lower rate could be that part of our sample consisted of treatment-seeking PWUDs who were recruited in treatment centers, whereas other surveys recruited only PWUDs who were not seeking treatment. This hypothesis is supported by the results of the multivariable analyses, which show that participants recruited in an addiction treatment center unit were significantly less willing to use a DCR than those recruited in a harm reduction center. Despite these main limitations, our results are relatively in line with national and, when applicable, international findings on the main points, even if international comparisons should remain careful, as, in other surveys, the target population was more people who inject drugs than PWUDs [21–23].

Similarly, features of precariousness and social isolation, including living alone or benefiting from the social security coverage for precarious people, were also predictive of intending to use a DCR. This is particularly important, insofar as some DCRs offer referral to health and social services [1], and may thus participate in the overall improvement of the health and social conditions of PWUDs.

Past or current HCV contamination, as well as drug injection practices, public space consumption and material sharing habits, were associated with an increased intention to use a DCR. Moreover, having experienced problems with police forces or with residents were also associated with being willing to use a DCR. This might be related to the fact that DCR implementation also implies a memorandum of understanding with local police to avoid clients having adverse police interactions in and around the DCR.

A notable last finding was that crack use was significantly associated with being willing to use a DCR, while heroin use was not. A possible explanation for this finding could be that France currently faces an increasing crack problem, in particular in the most precarious populations [23, 24], which are those who are the most attracted by using a DCR.

All these findings are consistent with recent literature, which found that DCRs aim to attract the most marginalized fringe of PWUDs, i.e., the most precarious ones and those actively using drugs in the public space [1, 2]. This suggests that, in Lyon, as in other cities where DCRs have opened or are planned to be opened, a substantial proportion of PWUDs would benefit from such type of services. A more original finding of our survey was that a substantial part of the PWUDs surveyed were correctly handling their used materials; it is thus possible that a DCR was perceived as a useful means to achieve a clean handling of waste related to drug use. Overall, our results are in line with similar surveys, as we found that the PWUDs willing to attend a DCR were the most precarious people [21, 22], as it is one of the main aims of DCRs to offer such the public a venue for safer and quieter drug use [1, 2].

Our survey had several limitations. The sample combined treatment-seeking and non-treatment-seeking PWUDs was a strategy of recruitment differing from many similar studies, in which only non-treatment-seeking PWUDs were interviewed. Since treatment-seeking PWUDs are less likely to use a DCR, our main results may thus have been biased against the use of a DCR, but, despite this, it remained clear that a large majority of PWUDs were willing to use such a facility. A second limitation was that we did not interview PWUDs who could not answer the questionnaire, in particular those whose command of the French language was insufficient. Although it is difficult to assess the proportion of non-French-speaking PWUDs in Lyon, we can assume that a substantial part of local PWUDs could have been overlooked, with their opinion not taken into account. A last limitation is that it would have been interesting to add a qualitative study on the needs, obstacles and levers for the use of a DCR in Lyon, as it has been done in another studies.

In Lyon, approximately two-thirds of local PWUDs declared willingness to use a DCR if such a facility was to be opened. The most interested PWUDs were those not seeking treatment, living alone, receiving a social insurance benefit for precarious people, seropositive for HCV, using cannabis or crack, and reporting previous problems with residents or police forces. These findings are in line with previous similar studies, but we also show that DCRs attract the most marginalized and precarious PWUDs even in a city such as Lyon, in which street drug use is widespread and not really concentrated in specific open scenes.