Erratum to “A syndemic of psychiatric morbidity, substance misuse, violence, and poor physical health among young Scottish men with reduced life expectancy” [SSM - Population Health 15(2021) 100858] (SSM - Population Health (2021) 15, (S2352827321001336), (10.1016/j.ssmph.2021.100858))

The authors regret errors in the coding and description of the analysis in the original manuscript. In summary, a portion of the analysis as described in the published article was incorrect: we reported the estimates as odds ratios when we should have used linear regression with robust standard errors. The direction and statistical significance of most of the estimates remained qualitatively similar, with one exception: the product term for violence and substance misuse, which was of marginal statistical significance in the original manuscript, was not statistically significant in the revised analysis. With no syndemic interaction between violence and the other components, this necessitated slight changes to the conceptual model (Figure 3), discussion, and conclusion. Details are as follows. In the statistical analysis section of the original manuscript, we wrote: “In order to test for syndemic effects between violence, psychiatric morbidity and substance misuse, and physical health risks on poor physical health/long-standing conditions (outcome), we estimated interaction terms using logistic regression” (p.4). This description was incorrect and should have read instead: “In order to test for syndemic effects between standardized factor scores of violence, psychiatric morbidity and substance misuse, and physical health risks on poor physical health/long-standing conditions (outcome), we estimated interaction terms using linear regression with robust standard errors.” In the results section of the original manuscript, we wrote: “Table 3 shows evidence of multiplicative interaction between violence and substance misuse, physical health risks and mental health problems, physical health risks and substance misuse, and mental health problems and substance misuse” (p.6). This description was incorrect and should have read instead: “Table 3 shows evidence of additive interaction between physical health risks and mental health problems, physical health risks and substance misuse, and mental health problems and substance misuse.” In Table 3 of the original manuscript, we presented the results of this analysis as follows: [Table presented] The estimates as presented in Table 3 were incorrect and should have instead been presented as: [Table presented] In Figure 3 of the original manuscript, we presented a hypothetical model as follows: [Figure presented] Given the revised estimates in Table 3, the proposed model was incorrect and should have been presented as follows: [Figure presented] In the discussion section of the original manuscript, we wrote: “In this second pathway, syndemic interactions between multiple morbidities of poor mental health, substance misuse, violence, and a diathesis of biological/behavioural risk lead to this intermediary stage along the pathway consisting of early adult precursors of what will become a range of diseases in mid- and later-life” (p.8). Given the revised estimates in Table 3, this description was incorrect and should have read instead: “In this second pathway, syndemic interactions between multiple morbidities of poor mental health, substance misuse, and a diathesis of biological/behavioural risk lead to this intermediary stage along the pathway consisting of early adult precursors of what will become a range of diseases in mid- and later-life.” Finally, in the conclusion of the abstract, we wrote: “Syndemic effects from synergistic interactions were confirmed between psychiatric morbidity, substance misuse, violence, and biological/behavioural risk for physical health” (p.1). Given the revised estimates in Table 3, this description was incorrect and should have read instead: “Syndemic effects from synergistic interactions were confirmed between psychiatric morbidity, substance misuse, and biological/behavioural risk for physical health.” The authors sincerely apologize for the errors in the original manuscript.