The psychoactive drug use was measured using a blunt measure, which asked the participants if they had used any psychoactive drug in the past year and this might have hindered the detection of an association with RTIs. Additionally, this study may lack the statistical power to detect a potential association between marijuana use and RTIs, considering confounders. In spite of these limitations, the strength of our study lies in the ability to use population-based controls rather than hospitalbased controls. Population-based controls are preferred due to their representativeness of the source population as compared with control selected from hospital- which may share similar essential exposures with cases and hence leading to overmatching . Additionally, we have used a validated AUDIT questionnaire, which has been pre-tested in Tanzania among trauma patients and has shown an acceptable validity and reliability . Face-to-face structured questionnaire were used in data collection, which provides an advantage of making clarifications of difficult questions if needed and ideal in population with low literacy. A further strength is that our study was able to adjust for risky driving behaviour as well as important workrelated factors, which has been shown to be common among commercial motorcyclists . Based on individual-level self-concept theory and previous research , identification as a substance user is a risk factor for deleterious substance use. A drinking/marijuana identity, for example, reflects the extent to which alcohol/marijuana use is an integral part of how one sees one’s self. Identity is viewed in the current study from the perspective of one’s personal identity which emphasizes aspects of the selfthat are independent of group or role identities .
Less clearly understood are factors that might mediate the relationship between identity and alcohol/marijuana-related outcomes . Given that past research has examined protective behavioral strategies and their use as a harm reduction strategy with PBS defined as “strategies employed before, during, or after drinking [or marijuana use] that reduce alcohol [marijuana] use, intoxication, and/or alcohol [marijuana] related harm”.PBS more broadly may be a mediator of the relationship between identity and outcomes. The current study focuses on the extent that PBS mediate the relationship between drinking/marijuana identity and alcohol/marijuana-related outcomes. Research indicates that drinking identity is positively associated with past-month alcohol frequency , typical quantity , and alcohol-related consequences . Studies have evaluated and confirmed a similar relationship between identity and alcohol-related outcomes in more diverse populations . Studies have also reported that marijuana identity is positively associated with marijuana use-related outcomes .Elucidating mediators of the identity-outcome association has the potential to identify factors that could be targeted in future interventions. Alcohol PBS have generally been negatively associated with alcoholrelated outcomes . Further, specific alcohol PBS have been found to be negatively associated with quantity and consequences . With respect to cannabis grow system, marijuana PBS have generally been found to be negatively associated with marijuana frequency , quantity and consequences . Less well understood is whether an association between identity and PBS exists, as well as whether PBS are a mediator of identity-outcome association in college student and community-based samples. Individuals may be using PBS in order to maximize the perceived benefits of substance use while also mitigating the risk associated with substance use . However, individuals with a high level of drinking/marijuana identity may be less inclined to use strategies that would limit their engagement in identity-consistent behavior. Therefore, identity may be negatively associated with PBS. In terms of clinical implications of the examination of PBS as a mediator of the identity-outcome relationship, identity-based and PBS-based interventions that attempt to decrease an individual’s level of drinking/marijuana identification or increase an individual’s use of PBS may help to reduce/attenuate the identity-outcome association.
In the current study, PBS were hypothesized to mediate the relationship between drinking/marijuana identity and alcohol/marijuana-related outcomes . In the cross-sectional studies, PBS were found to mediate the relationship between identity and outcomes. With respect to alcohol, mediation findings were limited to MOD PBS and specific to two alcohol-related outcomes evaluated. In the longitudinal study, across the three models, limited support for PBS as mediator was observed. With respect to marijuana, marijuana PBS were found to mediate the relationship between marijuana identity and all three of the marijuana-related outcomes evaluated . These findings represent an important scientific contribution to the existing substance use identity and PBS literature because they support the existence of a relationship between identity and PBS, a relationship that could be targeted in prevention/intervention work. First, to our knowledge, no published studies have reported on the relationship between drinking identity and alcohol PBS. In the current study, drinking identity was consistently found to be negatively associated with MOD PBS, followed to a lesser extent by LSD PBS and SHR PBS. In addition, drinking identity was found to be predictive of change in MOD and SHR PBS although the change in PBS from baseline to 3- months in Study 1 was not found to be statistically significant . Second, similar to past PBS mediation investigations, MOD PBS was a statistically significant mediator. For example, MOD PBS have been found to mediate the relationship between college-related alcohol beliefs and alcohol-related outcomes , preparty-specific motives and event-level preparty drinking , and in the current study, drinking identity and alcohol-related outcomes. MOD PBS include drinking slowly and the avoidance of drinking games, shots of liquor, and mixing different types of alcohol. Although speculative, research indicates that individuals drink to have a good time with friends , and individuals with a higher level identification as a drinker may be reluctant to use MOD PBS because these strategies may reduce engagement in activities that facilitate having a good time. Another explanation for the MOD PBS mediation findings is that an individual whose identity is strongly linked with using alcohol may be less inclined to use MOD PBS because these strategies may limit the ability to convey important identity-related information to others when drinking . Taken together, these findings indicate that an individual with a high level of drinking identity is likely to not use strategies that limit participation in drinking games or the consumption of shots and that the lack of use of these strategies may lead to the consumption of higher quantities of alcohol and the experiencing of alcohol-related consequences.
Future research in this area is needed to identify why individuals who report a high level of identification as a drinker may report not using specific alcohol PBS. Third, MOD PBS were found to be a statistically significant mediator in both the college and community-based samples, findings that tentatively support the generalizability of these mediation effects beyond college student populations. Across all studies, LSD PBS and SHR PBS did not mediate the relationship between drinking identity and outcomes. From a conceptual standpoint, it is unclear why drinking identity is differentially related to different forms of PBS and mixed method research is needed to elucidate these findings. However, as an example, it has been argued that some LSD PBS may not serve a protective function that helps individuals reduce alcohol use and consequences . Thus, lack of support for mediation could be a function of a weak association between specific PBS and outcomes. When alcohol quantity and consequences served as the alcohol-related outcome in the mediation models, the statistically significant cross-sectional mediation effect with MOD PBS was replicated longitudinally in Study 1 data. However, mediation effects were not replicated in the other two longitudinal models. The lack of statistical mediation in the other two models were likely due to the intervention not specifically targeting drinking identity or PBS directly. Identity and MOD PBS were not found to have significantly changed in either the control or intervention group between baseline and 3-month follow-up; thus, controlling for baseline PBS use potentially left little variability for identity to explain in MOD PBS at 3 months. Future identity-based interventions are needed to examine whether reductions in identification as a drinker are associated with greater PBS use. Future PBS-based interventions would also benefit from examining whether increased PBS use is associated with decreased identification as a drinker. Similar intervention approaches are needed to better test whether PBS mediate the association between marijuana identity and outcomes. Participants with a high level of identification as a marijuana user reported the use of fewer marijuana PBS, findings that add to the emergent literature on the relationship between marijuana identity and marijuana PBS . Similar to reasons for alcohol use, research indicates that individuals use marijuana to have a good time with friends , and it may be that the use of marijuana PBS that limit an individual’s ability to have a good time may be strategies infrequently used by individuals with a high level of cannabis grow lights identity . Additional research is needed to clarify the role marijuana PBS play as a mediator in non-college populations.Based on these findings, there may be two potential targets to reduce alcohol quantity and consequences: increase an individual’s use of MOD PBS and/or decrease an individual’s level of identification as a drinker. For the first, although the evidence base for PBS interventions is mixed , recent adaptions of PBS interventions have been found to be more efficacious, particularly when targeting MOD PBS . These new PBS interventions may be particularly well-suited to reduce the influence that identity has on alcohol/marijuana-related outcomes given that the message framing of PBS normative feedback within these interventions is tailored based on how common others are perceived to be using PBS. Based on findings from the current study, it would appear that an alcohol PBS intervention that attempts to increase a participant’s level of MOD PBS may help to reduce the effect that identifying as drinker may have on both the quantity of alcohol consumed and the number of alcohol-related consequences experienced.
With respect to marijuana PBS interventions, there is less specificity in terms of which specificmarijuana PBS to target. Additional research is needed to identify marijuana PBS that individuals are willing to use and which are effective at reducing marijuana use-related outcomes. It is unclear the extent to which interventions can directly target drinking identity, and relatedly, marijuana identity. Given the difficulty inherent in experimentally manipulating an individual’s level of substance use identity, it may be more feasible to target specific PBS at the current time. Research is needed to evaluate novel approaches that may be effective at changing an individual’s level of identity as well as their PBS use, particularly for individuals who strongly identify as an alcohol/marijuana user. Findings from the current study should be considered within the context of certain study limitations. For example, the questions as well as the time frame for reporting retrospective PBS use and outcomes sometimes varied across studies. Although this is a limitation in the current study, demonstrating that MOD PBS were a statistically significant mediator and that this finding was observed despite different assessment approaches is also a notable strength. In addition, low levels of internal consistency were observed in the measurement of PBS in Study 1 thus limiting confidence in the extent that subscale items reflected different forms of PBS. Although PBS mediation effects were examined cross-sectionally/ longitudinally, the analytic approach was still correlational. Additional experimental studies are needed to disentangle the causal sequencing of the relationship between identity, PBS, and the outcomes. In Study 3, there were a sizable number of participants who were currently attending college. Caution should be exercised about the extent to which findings from Study 3 truly reflect data from non-college attending adult populations. Global health experts have raised substantial concern regarding the impact of the COVID-19 pandemic on substance use due to increased social isolation and elevated stress . Yet, the impact of the pandemic is unclear given the reduction in social gatherings where substances are commonly consumed and the potential difficulty physically obtaining or financially affording substances . The pandemic may also impact the severity of substance use disorders due to changes in frequency of substance use and the disruption of substance use treatment .