The role of social support in reducing the long-term burden of cumulative childhood adversity on adulthood internalising disorder.

PURPOSE: Previous research indicates that social support is protective for the mental health outcomes of exposure to childhood adversity. However, the impact of social support as a protective factor following exposure to cumulative childhood adversity is understudied with prospective longitudinal data. The aim of this present study was to examine how social support mediates the impact of cumulative exposure to childhood adversity on internalising disorder in adulthood. METHODS: The Christchurch Health and Development Study (CHDS) is a general population birth cohort, born in 1977 and representative of Christchurch, New Zealand at the time of the cohort members' birth. The present study used a generalised estimating equations (GEE) framework to analyse direct associations between a cumulative measure of childhood adversity (CA) and internalising disorders (major depression, and any anxiety disorder), and indirect associations through social support. RESULTS: Results indicated a dose-dependent relationship between increased exposure to CA and worsened odds of a diagnosis for major depression and any anxiety disorder, respectively. There was also a significant mediating effect of social support on the direct associations between CA and both major depression (OR (95%CI) =0 .98 (0.97, 0.99), p < 001) and any anxiety disorder (OR (95%CI) = .98 (0.97, 0.99), p < 001). CONCLUSION: The findings indicate that social support reduces the impact of childhood adversity on adult mental health, and is therefore a target for future work examining potential interventions following CA.

The roles of extraversion and neuroticism in the relationship between childhood adversity and adolescent substance misuse.

Although the influences of extraversion and neuroticism on the relationship between childhood adversity and substance misuse have been considered in adults, they are not yet clear and have not been examined among adolescent samples. This study sought to investigate the relationship between childhood adversity and adolescent substance misuse, alongside the influences of extraversion and neuroticism, using data from a longitudinal birth cohort study. Statistical analyses were performed on a longitudinal dataset provided by the Christchurch Health and Development Study (CHDS). After controlling for confounds, childhood adversity was a significant predictor of substance use disorder symptoms in adolescence. Moderation analyses showed that experiences of childhood adversity were most strongly associated with adolescent substance use disorder symptoms at higher levels of extraversion and at higher levels of neuroticism. Among adolescents who have experienced childhood adversity, extraversion and neuroticism may be risk factors for substance use disorder. By encouraging professionals to target adolescent substance misuse intervention and prevention approaches towards those who have experienced childhood adversity and are high in extraversion and/or neuroticism, these findings may help to diminish the prevalence of adolescent substance misuse and improve the health of adolescents.

Modified inverse propensity weighting method to alleviate estimation errors in the model with multiple endogenous variables.

Multiple mental health disorders affect on decisions of people. The disorders are also outcomes of other factors. Health studies commonly follow an inverse propensity weight (IPW) method to address estimation errors associated with the presence of one confounder or covariate number exceeding the recommended sample size. However, approaches of IPW appropriate to alleviate the estimation error associated with multiple confounders distributed unequally in the study samples were not explained in our search literature. This study used longitudinal cohort data from Christchurch Health and Development Study and demonstrated IPW approach to address two confounders with similar natures in terms of etiological process. In our sample, some individuals had no mental health disorder at all, while others had either one of depression or anxiety or both. The methodological step to evaluate a new IPW approach include * Estimated IPWs from all possible combinations of the major depression and anxiety disorder: (a) IPW based on anxiety factor only assuming both mental health problems resulted from the same etiological processes; (b) IPW based on major depression factor only assuming both mental health problems resulted from the same etiological processes; (c) IPW assuming three (independent) categories of etiological processes: neither; either; both of major depression or anxiety disorder, (d) IPW assuming four (independent) categories of etiological processes: neither; major depression only; any anxiety disorder only; both. (e) No IPW or control model (no confounding problem.•Estimated outcome model with one each IPW at a time and one without IPw (control model).•Compared fit statistics of all estimated models.•The IPW derived assuming four categories of etiological processes produced the robust based fit statistics criteria. The study showed significant effects of both mental health problems on investment but the anxiety revealed a stronger effect than that of major depression.

Proximity of alcohol outlets and presentation to hospital by young people after self-harm: A retrospective geospatial study using the integrated data infrastructure.

OBJECTIVES: There is a well-established association between alcohol use, misuse, intoxication and self-harm, the latter of which is associated with suicide. This study aimed to better understand the association between proximity to alcohol outlets and the likelihood of young people presenting to hospital following self-harm. METHODS: This was a nationwide retrospective geospatial study using data from the New Zealand Integrated Data Infrastructure using population-level data for 10-29-year-olds for the 2018 and 2017 calendar years. Presentations to hospital following self-harm were identified using the national minimum data set. Proximity to alcohol outlets was defined in road network distance (in kilometres) and ascertained using Integrated Data Infrastructure geospatial data. Alternative measures of proximity were employed in sensitivity analyses. Complete-case two-level random intercept logistic regression models were used to estimate the relationship between alcohol outlet proximity and hospital presentation for self-harm. Adjusted models included sex, age, ethnicity, area-level deprivation, urbanicity and distance to nearest medical facility. Analyses were also stratified by urbanicity. RESULTS: Of the 1,285,368 individuals (mean [standard deviation] age 20.0 [5.9] years), 7944 (0.6%) were admitted to hospital for self-harm. Overall, the odds of presenting to hospital for self-harm significantly decreased as the distance from the nearest alcohol outlet increased, including in adjusted models (adjusted odds ratio 0.980; 95% confidence interval = [0.969-0.992]); the association was robust to changes in the measure of alcohol proximity. The effect direction was consistent across all categorisations of urbanicity, but only statistically significant in large urban areas and rural areas. CONCLUSIONS: The findings of this study show a clear association between young people's access to alcohol outlets and presentation to hospital for self-harm and may provide a mandate for government policies and universal interventions to reduce young people's access to alcohol outlets. Further research regarding causative mechanisms is needed.

Toku Oranga: the subjective wellbeing and psychological functioning of postgraduate and medical students in Otautahi Christchurch.

AIMS: Postgraduate and medical students are at risk of psychological distress and burnout, which can cause significant functional and occupational impairment. We aimed to report subjective wellbeing, psychological distress and burnout in postgraduate and medical students in Otautahi Christchurch, Aotearoa (New Zealand), and identify any associations between participant and course information and outcome measures including exposure to major earthquakes in 2010/2011 and the 2019 terrorist attack. METHODS: A self-report online survey was completed by 140 students between November 2019 and March 2020. Life satisfaction, psychological distress and burnout were primary outcomes. Data were analysed using univariate and multivariable analysis. RESULTS: High levels of psychological distress were present in both student groups. Burnout was reported by 78% of respondents. There were no significant associations found between exposure to the Christchurch earthquakes or terrorist attack with primary outcomes. Personality factors, resilience and perceived support and success were weakly associated with wellbeing, distress and burnout. CONCLUSIONS: Postgraduates and medical students reported high levels of psychological distress and burnout. The earthquakes and terrorist attack do not appear to be associated with negative effects in these cohorts. Personality and resilience characteristics may assist in predicting students at risk of morbidity and evaluating potentially relevant interventions.

Intervention targets for reducing mortality between mid-adolescence and mid-adulthood: a protocol for a machine-learning facilitated systematic umbrella review.

INTRODUCTION: A rise in premature mortality-defined here as death during the most productive years of life, between adolescence and middle adulthood (15-60 years)-is contributing to stalling life expectancy in high-income countries. Causes of mortality vary, but often include substance misuse, suicide, unintentional injury and non-communicable disease. The development of evidence-informed policy frameworks to guide new approaches to prevention require knowledge of early targets for intervention, and interactions between higher level drivers. Here, we aim to: (1) identify systematic reviews with or without meta-analyses focused on intervention targets for premature mortality (in which intervention targets are causes of mortality that can, at least hypothetically, be modified to reduce risk); (2) evaluate the review quality and risk of bias; (3) compare and evaluate each review's, and their relevant primary studies, findings to identify existing evidence gaps. METHODS AND ANALYSIS: In May 2023, we searched electronic databases (MEDLINE, PubMed, Embase, Cochrane Library) for peer-reviewed papers published in the English language in the 12 years from 2012 to 2023 that examined intervention targets for mortality. Screening will narrow these papers to focus on systematic reviews with or without meta-analyses, and their primary papers. Our outcome is death between ages 15 and 60 years; with potential intervention targets measured prior to death. A MeaSurement Tool to Assess systematic Reviews (AMSTAR 2) will be used to assess quality and risk of bias within included systematic reviews. Results will be synthesised narratively due to anticipated heterogeneity between reviews and between primary studies contained within included reviews. ETHICS AND DISSEMINATION: This review will synthesise findings from published systematic reviews and meta-analyses, and their primary reviewed studies, meaning ethics committee approval is not required. Our findings will inform cross-cohort consortium development, be published in a peer-reviewed journal, and be presented at national and international conferences. PROSPERO REGISTRATION NUMBER: CRD42022355861.

Protective factors for psychosocial outcomes following cumulative childhood adversity: systematic review.

BACKGROUND: The long-term cumulative impact of exposure to childhood adversity is well documented. There is an increasing body of literature examining protective factors following childhood adversity. However, no known reviews have summarised studies examining protective factors for broad psychosocial outcomes following childhood adversity. AIMS: To summarise the current evidence from longitudinal studies of protective factors for adult psychosocial outcomes following cumulative exposure to childhood adversity. METHOD: We conducted a formal systematic review of studies that were longitudinal; were published in a peer-reviewed journal; examined social, environmental or psychological factors that were measured following a cumulative measure of childhood adversity; and resulted in more positive adult psychosocial outcomes. RESULTS: A total of 28 studies from 23 cohorts were included. Because of significant heterogeneity and conceptual differences in the final sample of articles, a meta-analysis was not conducted. The narrative review identified that social support is a protective factor specifically for mental health outcomes following childhood adversity. Findings also suggest that aspects of education are protective factors to adult socioeconomic, mental health and social outcomes following childhood adversity. Personality factors were protective for a variety of outcomes, particularly mental health. The personality factors were too various to summarise into meaningful combined effects. Overall GRADE quality assessments were low and very low, although these scores mostly reflect that all observational studies are low quality by default. CONCLUSIONS: These findings support strategies that improve connection and access to education following childhood adversity exposure. Further research is needed for the roles of personality and dispositional factors, romantic relationship factors and the combined influences of multiple protective factors.

Validation of a Bayesian learning model to predict the risk for cannabis use disorder.

BACKGROUND: Cannabis use disorder (CUD) is a growing public health problem. Early identification of adolescents and young adults at risk of developing CUD in the future may help stem this trend. A logistic regression model fitted using a Bayesian learning approach was developed recently to predict the risk of future CUD based on seven risk factors in adolescence and youth. A nationally representative longitudinal dataset, Add Health was used to train the model (henceforth referred as Add Health model). METHODS: We validated the Add Health model on two cohorts, namely, Michigan Longitudinal Study (MLS) and Christchurch Health and Development Study (CHDS) using longitudinal data from participants until they were approximately 30 years old (to be consistent with the training data from Add Health). If a participant was diagnosed with CUD at any age during this period, they were considered a case. We calculated the area under the curve (AUC) and the ratio of expected and observed number of cases (E/O). We also explored recalibrating the model to account for differences in population prevalence. RESULTS: The cohort sizes used for validation were 424 (53 cases) for MLS and 637 (105 cases) for CHDS. AUCs for the two cohorts were 0.66 (MLS) and 0.73 (CHDS) and the corresponding E/O ratios (after recalibration) were 0.995 and 0.999. CONCLUSION: The external validation of the Add Health model on two different cohorts lends confidence to the model's ability to identify adolescent or young adult cannabis users at high risk of developing CUD in later life.

Change in the food environment and measured adiposity in adulthood in the Christchurch Health and development birth cohort, Aotearoa, New Zealand: A birth cohort study.

This study investigated associations between change in the food environment and change in measured body mass index (BMI) and waist circumference (WC) in the Christchurch Health and Development Study (CHDS) birth cohort. Our findings suggest that cohort members who experienced the greatest proportional change towards better access to fast food outlets had the slightly larger increases in BMI and WC. Contrastingly, cohort members who experienced the greatest proportional change towards shorter distance and better access to supermarkets had slightly smaller increases in BMI and WC. Our findings may help explain the changes in BMI and WC at a population level.

Predictors of methamphetamine use in a longitudinal birth cohort.

BACKGROUND: Identifying predictors of methamphetamine use can inform population prevention strategies. METHODS: Participants (n = 1265) born in Christchurch, New Zealand were followed from birth to age 40. Methamphetamine outcomes (any use since the last interview, and regular use, defined as any period of at least weekly use) were ascertained by self-report at six interviews from age 18 to 40. Predictors with plausible associations with methamphetamine use were extracted from the study database. These were grouped into early predictors (age 0-16), comprising childhood, familial and individual characteristics; and later time-dynamic correlates of methamphetamine use in adulthood (ages 16-40). Generalised estimating equation models were fitted to identify predictors of methamphetamine use outcomes. RESULTS: In adjusted models, paternal overprotectiveness and childhood anxious / withdrawn behavior were associated with any use of methamphetamine, but not regular use. Conversely, childhood conduct problems and parental illicit drug were associated with regular use but not any use. Male sex, high novelty seeking and deviant peer affiliations were associated with both any use and regular use in adjusted models. The strongest correlates of methamphetamine use in adulthood were unemployment, life stress and other substance use disorders (cannabis, nicotine, and alcohol). CONCLUSION: Markers of externalizing problems in childhood and adolescence (conduct problems, high novelty seeking, parental illicit substance use, and deviant peer affiliations) are the strongest predictors of regular methamphetamine use in adulthood.

Childhood anxious/withdrawn behaviour and later anxiety disorder: a network outcome analysis of a population cohort.

BACKGROUND: Several previous studies have identified a continuity between childhood anxiety/withdrawal and anxiety disorder (AD) in later life. However, not all children with anxiety/withdrawal problems will experience an AD in later life. Previous studies have shown that the severity of childhood anxiety/withdrawal accounts for some of the variability in AD outcomes. However, no studies to date have investigated how variation in features of anxiety/withdrawal may relate to continuity prognoses. The present research addresses this gap. METHODS: Data were gathered as part of the Christchurch Health and Development Study, a 40-year population birth cohort of 1265 children born in Christchurch, New Zealand. Fifteen childhood anxiety/withdrawal items were measured at 7-9 years and AD outcomes were measured at various interviews from 15 to 40 years. Six network models were estimated. Two models estimated the network structure of childhood anxiety/withdrawal items independently for males and females. Four models estimated childhood anxiety/withdrawal items predicting adolescent AD (14-21 years) and adult AD (21-40 years) in both males and females. RESULTS: Approximately 40% of participants met the diagnostic criteria for an AD during both the adolescent (14-21 years) and adult (21-40 years) outcome periods. Outcome networks showed that items measuring social and emotional anxious/withdrawn behaviours most frequently predicted AD outcomes. Items measuring situation-based fears and authority figure-specific anxious/withdrawn behaviour did not consistently predict AD outcomes. This applied across both the male and female subsamples. CONCLUSIONS: Social and emotional anxious/withdrawn behaviours in middle childhood appear to carry increased risk for AD outcomes in both adolescence and adulthood.

Methamphetamine use and psychotic symptoms: findings from a New Zealand longitudinal birth cohort.

BACKGROUND: This study examined the association between methamphetamine use and psychotic symptoms in a New Zealand general population birth cohort (n = 1265 at birth). METHODS: At age 18, 21, 25, 30, and 35, participants reported on their methamphetamine use and psychotic symptoms in the period since the previous interview. Generalized estimating equations modelled the association between methamphetamine use and psychotic symptoms (percentage reporting any symptom, and number of symptoms per participant). Confounding factors included childhood individual characteristics, family socioeconomic circumstances and family functioning. Long term effects of methamphetamine use on psychotic symptoms were assessed by comparing the incidence of psychotic symptoms at age 30-35 for those with and without a history of methamphetamine use prior to age 30. RESULTS: After adjusting for confounding factors and time-varying covariate factors including concurrent cannabis use, methamphetamine use was associated with a modest increase in psychosis risk over five waves of data (adjusted odds ratio (OR) 1.33, 95% confidence interval (CI) 1.03-1.72 for the percentage measure; and IRR 1.24, 95% CI 1.02-1.50 for the symptom count measure). The increased risk of psychotic symptoms was concentrated among participants who had used at least weekly at any point (adjusted OR 2.85, 95% CI 1.21-6.69). Use of methamphetamine less than weekly was not associated with increased psychosis risk. We found no evidence for a persistent vulnerability to psychosis in the absence of continuing methamphetamine use. CONCLUSION: Methamphetamine use is associated with increased risk of psychotic symptoms in the general population. Increased risk is chiefly confined to people who ever used regularly (at least weekly), and recently.

The long-term impacts of the Canterbury earthquakes on the mental health of the Christchurch Health and Development Study cohort.

OBJECTIVE: Long-term studies following disasters are rare. It is important to quantify long-term effects of disasters to determine impacts on populations over time. We therefore aim to report the long-term associations between exposure to the Canterbury earthquakes and common mental disorders, taking into account potential confounding factors. METHODS: The Christchurch Health and Development Study is a 40-year longitudinal study of a birth cohort of New Zealand children (635 males and 630 females). The Christchurch Health and Development Study includes 884 participants with data on earthquake exposure and mental health outcomes at ages 34 and 40 years. Rates of Diagnostic and Statistical Manual of Mental Disorders (4th ed.) disorders were measured categorically and using an expanded definition that included sub-syndromal symptoms. The current impact of the earthquakes is reported using 12-month prevalence data 7 years after the earthquakes. The cumulative impact of the earthquakes over the 7 years since onset is also reported. RESULTS: There was a linear trend towards increasing rates of disorder with increasing exposure to the earthquakes. After adjusting for covariates, the 12-month prevalence of anxiety disorder symptoms was significantly increased (p = 0.003). The earthquakes were also associated with cumulative increases in symptoms of post-traumatic stress disorder (p < 0.001), anxiety disorder (p = 0.016), nicotine dependence (p = 0.012), and the total number of disorders (p = 0.039). CONCLUSION: The Canterbury earthquakes were associated with persistent increases in Anxiety Disorder symptoms 7 years after their onset. The earthquakes were also associated with cumulative increases in symptoms of common psychiatric disorders. The magnitude of these effects is small, may no longer be clinically significant and has decreased over time.

Critically ill septic patients have elevated oxidative stress biomarkers: lack of attenuation by parenteral vitamin C.

Patients with septic shock are under an intense inflammatory burden, which is closely associated with increased oxidative stress and depletion of antioxidants such as vitamin C. We hypothesized that patients with septic shock would present with elevated oxidative stress (assessed as F2-isoprostanes) and that administration of parenteral vitamin C to these patients would attenuate F2-isoprostane concentrations. We recruited 40 critically ill patients with septic shock into a randomized placebo-controlled trial and assessed the effect of short-term (4-day) parenteral vitamin C administration (100 mg/kg/d) on 8-isoprostane F2α concentrations, which were measured using enzyme-linked immunosorbent assays. Sources of sepsis and intensive care unit severity scores were recorded. Smokers (n = 20) and nonsmoking controls (n = 50) were assessed for comparison. The median baseline 8-isoprostane F2α concentration in the septic patients was 3.95 (interquartile range [Q1, Q3] 2.1, 6.63) ng/mg creatinine; this was higher than smokers 1.61 [1.25, 2.82] P = .007 ng/mg creatinine; P = .005) and nonsmoking controls 1.12 [0.76, 1.57] ng/mg creatinine; P < .0001). The 8-isoprostane F2α concentrations in the placebo group did not vary significantly over the duration of the study. Although parenteral vitamin C administration significantly increased the vitamin C status of the patients within 24 hours, this did not affect their 8-isoprostane F2α concentrations. In conclusion, patients with septic shock have elevated 8-isoprostane F2α excretion, which short-term parenteral vitamin C administration is unable to attenuate. If vitamin C is to work by antioxidant mechanisms, then early administration, before the development of shock, may be required. This trial was registered at anzctr.org.au (ACTRN12617001184369).

Cannabis use and patterns of psychotic symptomatology in a longitudinal birth cohort.

AIM: Research has established associations between regular cannabis use and psychotic symptomatology in young people. However, there has been little previous research on whether the experience of psychotic symptomatology differs between non-users and regular users of cannabis. METHOD: Data were from the Christchurch Health and Development Study (CHDS), a longitudinal cohort born in 1977. Data on frequency of cannabis use and (past month) psychotic symptomatology were obtained at the age 18, 21 and 25 waves of assessment. Symptoms were rank ordered by the number of affirmative responses over the three assessments, and the symptom profile of non-users and regular users were compared using a non-parametric Mann-Whitney U test. RESULTS: Among non-users and regular users, the commonly reported symptoms of psychosis were those that would be considered "mild". More severe symptoms were not commonly reported. A comparison of the symptom profile across the two groups showed no significant differences. CONCLUSION: There was no evidence of qualitative differences in the pattern of psychotic symptomatology reported by non-cannabis users and regular cannabis users. Although regular cannabis users tend to report a greater number of symptoms, these symptoms did not tend to be severe, and were unlikely to be indicative of psychotic illness.

Just because you can does not mean you should: an examination of efficacy and potential harms from non-prescribed supplements taken by members of the Christchurch Health and Development Study at age 40.

Nil.

Childhood maltreatment and the menopause transition in a cohort of midlife New Zealand women.

OBJECTIVE: Knowledge surrounding the link between childhood adversity and reproductive outcomes at midlife is limited. The present study examined the relationship between childhood maltreatment (childhood sexual abuse [CSA], childhood physical punishment [CPP]), and menopause status at age 40. METHODS: Data were gathered from female members of the Christchurch Health and Development Study, a longitudinal birth cohort of 1,265 individuals (630 females) born in Christchurch, New Zealand in 1977. Menopause status was defined by categorizing the female cohort at age 40 as either: 1) premenopausal, or 2) peri/ postmenopausal. Retrospective reports of CSA (<16 y) and CPP (<16 y) were obtained at ages 18 and 21 years. RESULTS: The analysis sample comprised n = 468 women with data recorded on both their menopause status at age 40 and history of maltreatment (<16 y), of whom 22% (n = 104) were classified as peri/postmenopausal. A statistically significant association was found between and severity of CSA and menopause status, but not between CPP and menopause status. The association with CSA was robust to control for both childhood confounding factors (<16 y) and intervening adult factors (18-40 y) associated with the menopause transition. In the fully adjusted model, women who had experienced severe CSA involving attempted/completed sexual penetration had twice the rate of entering peri/postmenopause compared with those who reported no CSA (39.0% vs 18.8%). CONCLUSIONS: Severity of CSA exposure was associated with earlier menopausal transition in this female cohort. These findings are consistent with the emerging literature on the long-term health and developmental impacts of CSA.

Acute alcohol use and suicide deaths: an analysis of New Zealand coronial data from 2007-2020.

AIMS: Acute alcohol use is a proximal risk factor for suicide. However, the proportion of suicide deaths involving acute alcohol use has not been quantified in New Zealand. We sought to quantify and characterise the association between acute alcohol use and suicide. METHODS: Data for all suicides (≥15 years) between July 2007 and December 2020 were drawn from the National Coronial Information System. Acute alcohol use was defined as blood alcohol concentration (BAC) >50mg/100mL. Logistic regression was used to compare characteristics between suicide deaths with and without acute alcohol use. RESULTS: Twenty-six point six percent of suicide deaths involved acute alcohol use. No difference in the association was found by sex (male AOR: 0.87 (95%CI: 0.74,1.02)). Ethnicity differences were identified (Maori AOR: 1.20 (95%CI: 1.01,1.42), Pacific AOR: 1.46 (95%CI: 1.10,2.00)). Those aged 15-54 years had similar risks of suicide involving acute alcohol use, with a lower association in older age groups. CONCLUSIONS: Acute alcohol use was identified in approximately one quarter of suicides, with stronger associations in those of Maori and Pasifika ethnicity, and those aged <55 years. Acute alcohol use is a significant but modifiable risk factor for suicide in New Zealand.

Measuring drug harm in New Zealand: a stocktake of current data sources.

AIMS: The availability of legal and illegal drugs is widespread across New Zealand. All drugs have the potential to cause harm to those who use them, and to others. Understanding the nature and extent of these harms depends upon the ongoing and systematic collection of relevant data, which is crucial in achieving the current national policy goal of minimising drug harm. Thus, we aim to describe how information on drug harm is currently collected and measured in New Zealand. METHODS: This article maps and evaluates harm data within New Zealand, explores data collection methods and timing, and identifies the substances and types of harm assessed to date. We review large and predominantly administrative datasets that provide a measure of harm, which are collected more than once and/or are updated periodically. RESULTS: We highlight a number of key gaps and limitations that exist within the current data landscape, and outline barriers to ensuring greater utilisation. We recommend more frequent data collection, including improved data on harms to others, and inclusion of a wider range of drugs. CONCLUSIONS: Implementation of these recommendations will improve the understanding of comprehensive drug harm in New Zealand, to guide effective local harm reduction policies and interventions.