The experience of physiological and psychosocial alcohol-related harms across adolescence and its association with alcohol use disorder in early adulthood: A prospective cohort study.

BACKGROUND: Different forms of alcohol-related harm (e.g., hangovers, fighting) may confer differential risk of clinically relevant alcohol problems. We examine: (i) patterns of transition in experiencing alcohol-related harms across adolescence; (ii) whether factors in early adolescence predict transition patterns; and (iii) whether transition patterns predict later alcohol use disorder (AUD) symptoms. METHODS: We used a longitudinal Australian cohort (n = 1828) to model latent class transition patterns of alcohol-related harms across three timepoints (Mage  = 13.9, 16.8, 18.8 years). Regression models assessed whether child, peer, and parent factors in early adolescence (Mage  = 12.9) predicted harms transition patterns and whether these patterns predicted AUD symptoms in early adulthood (Mage  = 19.8). RESULTS: Five transition patterns characterized most of the cohort (n ≈ 1609, 88.0%): (i) minimal harms (n ≈ 381, 20.8%); (ii) late physiological harms (n ≈ 702, 38.4%); (iii) early physiological harms (n ≈ 226, 12.4%); (iv) late all harms (n ≈ 131, 7.2%); and (v) gradual all harms (n ≈ 169, 9.2%). With late physiological harms as the reference, females had increased risk of experiencing early physiological harms (relative risk [RR]: 2.15; 99.5% CI: 1.19, 3.90). Late all harms (RR: 1.71; CI: 1.19, 2.47) and gradual all harms (RR: 1.84; CI: 1.37, 2.47) were each associated with increased odds of meeting criteria for AUD, even when patterns of alcohol consumption are considered. CONCLUSIONS: Adolescents display heterogeneous transition patterns across physiological and psychosocial alcohol-related harms. Females are at greater risk of experiencing early physiological harms. Experience of both physiological and psychosocial harms in late adolescence is an important and potentially modifiable precursor to clinically relevant alcohol problems in early adulthood.

Characteristics, toxicology and major organ pathology of deaths due to acute alcohol toxicity in Australia, 2011-2022.

INTRODUCTION: Acute alcohol toxicity is a significant component of alcohol-related mortality. The study aimed to: (i) determine the circumstances of death and characteristics of fatal alcohol toxicity cases, 2011-2022; (ii) determine their toxicological profile and major autopsy findings; and (iii) determine trends in population mortality rates. METHODS: Retrospective study of acute alcohol toxicity deaths in Australia, 2011-2022, retrieved from the National Coronial Information System. RESULTS: A total of 891 cases were identified, with a mean age of 49.2 years, 71.0% being male. Alcohol use problems were noted in 71.3%. In 57.5% death was attributed solely to acute alcohol toxicity, and combined acute alcohol toxicity/disease in 42.5%. There was evidence of sudden collapse in 24.9% of cases. The mean BAC was 0.331 g/100 mL (range 0.107-0.936), and spirits were the most commonly reported beverages (35.8%). Cases of combined toxicity/disease had significantly lower BACs than those attributed solely to alcohol toxicity (0.296 vs. 0.358 g/100 mL). Cardiomegaly was diagnosed in 32.5%, and severe coronary artery disease in 22.1%. Aspiration of vomitus was noted in 18.0%, and chronic obstructive pulmonary disease in 19.6%. Severe liver steatosis was present in 33.4% and 13.6% had cirrhosis. There was an average annual percentage increase in deaths of 7.90. DISCUSSION AND CONCLUSIONS: The 'typical' case was a long-standing, heavy spirits drinker. BACs showed enormous variation and no arbitrary concentration may be deemed lethal. Clinically significant disease was associated with death at a lower BAC and people with such disease may be at increased risk of alcohol poisoning.

Transitions to polysubstance use: Prospective cohort study of adolescents in Australia.

BACKGROUND AND AIMS: Adolescent polysubstance use has been associated with adverse social and health outcomes. Our aim was to measure rates and transitions to polysubstance use during adolescence and identify factors associated with initiation and discontinuation of polysubstance use. DESIGN: Prospective cohort study. Multistate Markov modelling was used to estimate rates and identify correlates of transitions between substance use states. SETTING AND PARTICIPANTS: Adolescent-parent dyads (n = 1927; adolescents in grade 7, age ≈13 years) were recruited from Australian schools during 2010/11 (Wave 1). Adolescents were surveyed annually until 2016/17 (n = 1503; age ≈19 years; Wave 7) and parents were surveyed annually until 2014/15 (Wave 5). MEASUREMENTS: Alcohol, tobacco, cannabis and 3,4-methylenedioxymethamphetamine (MDMA) use outcomes were collected at Waves 3-7. Potential confounders were collected at Waves 1-6 and consisted of sex, anxiety and depression symptoms and externalizing problems, parental monitoring, family conflict and cohesion, parental substance use and peer substance use. Covariates were age and family socioeconomic status. FINDINGS: Few adolescents engaged in polysubstance use at earlier waves (Wave 3: 5%; Wave 4: 8%), but proportions increased sharply across adolescence (Waves 5-7: 17%, 24%, 36%). Rates of transitioning to polysubstance use increased with age, with few (<9%) adolescents transitioning out. More externalizing problems (odds ratio [OR] = 1.10; 99.6% confidence interval [CI] = 1.07-1.14), parental heavy episodic drinking (OR = 1.22; 99.6% CI = 1.07-1.40), parental illicit substance use (OR = 3.56; 99.6% CI = 1.43-8.86), peer alcohol use (OR = 5.68; 99.6% CI = 1.59-20.50) and peer smoking (OR = 4.18; 99.6% CI = 1.95-8.81) were associated with transitioning to polysubstance use. CONCLUSIONS: Polysubstance use in Australia appears to be rare during early adolescence but more common in later adolescence with low rates of transitioning out. Externalizing problems and greater parental and peer substance use are risk factors for adolescent polysubstance use that may be suitable intervention targets.

The key role of specific DSM-5 diagnostic criteria in the early development of alcohol use disorder: Findings from the RADAR prospective cohort study.

BACKGROUND: Prevention and early intervention of alcohol use disorder (AUD) is a public health priority, yet there are gaps in our understanding of how AUD emerges, which symptoms of AUD come first, and whether there are modifiable risk factors that forecast the development of the disorder. This study investigated potential early-warning-sign symptoms for the development of AUD. METHODS: Data were from the RADAR study, a prospective cohort study of contemporary emerging adults across Australia (n = 565, mean age = 18.9, range = 18-21 at baseline, 48% female). Participants were interviewed five times across a 2.5-year period. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) AUD criteria and diagnoses were assessed by clinical psychologists using the Structured Clinical Interview for DSM-IV (SCID-IV), modified to cover DSM-5 criteria. Hazard analyses modeled the time from first alcoholic drink to the emergence of any AUD criteria and determined which first-emergent AUD criteria were associated with a faster transition to disorder. RESULTS: By the final time point, 54.8% of the sample had experienced at least one DSM-5 AUD criterion and 26.1% met criteria for DSM-5 AUD. The median time from first AUD criterion to a diagnosis of AUD was 4 years. Social problems from drinking (hazard ratio [HR] = 3.24, CI95 = 2.14, 4.92, p < 0.001), major role (HR = 2.53, CI95 = 1.58, 4.06, p < 0.001), and drinking larger amounts/for longer than intended (HR = 2.04, CI95 = 1.20, 3.46, p = 0.008) were first-onset criteria associated with a faster transition to AUD. CONCLUSION: In the context of a prospective general population cohort study of the temporal development of AUD, alcohol-related social problems, major role problems, and using more or for longer than intended are key risk factors that may be targeted for early intervention.

Generational shifts in attitudes and beliefs about alcohol: An age-period-cohort approach.

INTRODUCTION AND AIMS: Population level alcohol consumption has declined markedly in Australia in the past two decades, with distinct generational patterns. The underlying reason for this shift remains unclear and there has been little work assessing how attitudes and beliefs about alcohol have shifted in population sub-groups. DESIGN AND METHODS: Using seven waves of survey data spanning 19 years (2001-2019, n = 166,093 respondents aged 14 +), we assess age, time-period and birth cohort effects on trends in four measures of alcohol attitudes (disapproval of regular alcohol use, perceptions of safe drinking levels for men and women and perception that alcohol causes the most deaths of any drug in Australia). RESULTS: There were steady increases in period effects for perceived safe drinking levels (especially for men) and belief that alcohol causes the most deaths. Disapproval of regular use has been stable at the population level, but there are marked cohort differences, with early and recent cohorts more likely than others to disapprove of regular alcohol use. DISCUSSIONS AND CONCLUSIONS: These findings point to a broad lowering of perceived safe levels of drinking across the population alongside a sharp increase in disapproval of drinking for recent cohorts, potentially contributing to the reductions in drinking that have been reported in these cohorts.

Trends in alcohol-related liver disease mortality in Australia: An age-period-cohort perspective.

BACKGROUND AND AIMS: There have been few systematic attempts to examine how alcohol-related mortality has changed in Australia, and no studies that have explored cohort effects in alcohol-related mortality. This study uses more than 50 years of data to measure age, period and cohort trends in alcohol-related liver disease (ALD) mortality. DESIGN, SETTING AND CASES: This was a retrospective age-period-cohort analysis of total Australian ALD mortality data from 1968 to 2020 in Australia. There was a total of 35 822 deaths-27 208 men (76%) and 8614 women (24%). MEASUREMENTS: Deaths from ALD were grouped into 5-year age groups and periods (e.g. deaths for 20-24-year-olds between 1968 and 1972 were combined). FINDINGS: ALD mortality peaked in the late 1970s and early 1980s for both men and women. In age-period-cohort models, mortality was highest for cohorts born 1915-30. For example, men born between 1923 and 1927 had a relative risk of 1.58 [95% confidence interval (CI) = 1.52, 1.64] compared with men born between 1948 and 1952. For women, there was an increase in risk for cohorts born in the 1960s [e.g. the 1963-67 cohort had a relative risk (RR) of 1.16 (95% CI = 1.07, 1.25) compared with women born in 1948-52]. For men, there was a broad decline in mortality over time [e.g. in 2020, the RR was 0.87 (95% CI = 0.82, 0.92) compared with the reference year of 2000]. For women, mortality declined until 2000 and has been stable since. CONCLUSIONS: Alcohol-related liver disease mortality has declined across the Australian population since the 1970s and 1980s partly due to cohort-specific shifts as the highest-risk birth cohorts age. For women, this decline had stalled by the year 2000, and cohorts of women born during the 1960s were at higher risk than earlier cohorts, suggesting the need for thoughtful interventions as this population enters its highest-risk years for ALD mortality.

Comparing police use of drug detection dogs amongst injecting and non-injecting groups of people who regularly use drugs in Australia.

INTRODUCTION: Drug detection dogs are utilised across multiple settings, however existing literature focuses predominantly on festival-based encounters. We compare drug dog encounters in non-festival settings among two samples of people who regularly use drugs, and investigate factors associated with witness only versus stop and/or search encounters. METHODS: Australians who regularly (i.e., ≥monthly) use ecstasy and/or other illegal stimulants (n = 777; Ecstasy and Related Drugs Reporting System (EDRS)) or inject illegal drugs (n = 862; Illicit Drugs Reporting System (IDRS)) were surveyed between April-June, 2019. Univariable regression analyses were used to test for differences in drug dog encounters between samples, and to identify factors associated with a more intensive drug dog encounter (namely those that involved a stop and/or search). RESULTS: People who inject drugs were less likely to witness drug dogs than those who regularly use ecstasy and/or other illegal stimulants (odds ratio (OR) 0.46; 95 % CI 0.30-0.69). They were significantly more likely than EDRS participants to report being stopped and searched (3.29; 1.68-6.44) however. Among those carrying drugs at their last stop and/or search encounter, the majority of both samples reported that their drugs were not detected by police. IDRS participants aged 35-49 were more likely to report a stop and/or search encounter than those aged 17-34; no significant associations were found among the EDRS sample. CONCLUSIONS: Despite participants who use ecstasy and/other stimulants being more likely than those who regularly inject drugs to report encountering drug dogs in non-festival settings, participants who inject drugs were more likely to report an intensive or invasive drug dog encounter and/or receiving a formal criminal justice consequence. This study reinforces questions about the efficacy and appropriateness of drug dog operations.

Age, period and cohort effects on alcohol-related risky behaviours in Australia from 2001 to 2016.

AIMS: The aim of this study is to examine age, period and birth cohort trends in the prevalence of any alcohol-related risky behaviour and to compare these trends between men and women. DESIGN AND SETTING: We used an age-period-cohort analysis of repeated cross-sectional survey data from the Australian National Drug Strategy Household Survey from 2001 to 2016. PARTICIPANTS: Participants were 121 281 people aged 14-80 years who reported consuming alcohol in the past 12 months. MEASUREMENTS: Any risky behaviour undertaken while under the influence of alcohol in the past 12 months (e.g. operating a motor vehicle) was measured: male or female. FINDINGS: Controlling for age and cohort, cubic spline models showed that any alcohol-related risky behaviour declined with time among participants who consumed alcohol [2016 versus 2007 rate ratio (RR) = 0.80, 95% confidence interval (CI) = 0.76-0.84]. Risky behaviour peaked in the 1954 birth cohort (1954 versus 1971 RR = 1.42, 95% CI = 1.30-1.55) and then steadily declined with more recent birth cohorts (2002 versus 1971 RR = 0.32, 95% CI = 0.27-0.39). Risky behaviour peaked at age 21 years, followed by steady decline and stabilization at approximately age 70 years. Males were overall twice as likely as females to report alcohol-related risky behaviour (RR = 2.10, 95% CI = 1.84-2.39), but this effect was smaller in cohorts born after 1980 [1980 prevalence rate ratios (PRR) = 2.09, 95% CI = 1.81-2.43; 2002 PRR = 1.31, 95% CI = 1.03-1.68]. CONCLUSIONS: Alcohol-related risky behaviour in Australia has declined generally since 2001, with rates for recent cohorts having the sharpest decline. Risky behaviour remains most prevalent in young adults, and the male-female gap in risky behaviour is closing for more recent birth cohorts. These trends are consistent with alcohol consumption trends observed in Australia and world-wide.

All-cause and cause-specific mortality in individuals with an alcohol-related emergency or hospital inpatient presentation: A retrospective data linkage cohort study.

BACKGROUND AND AIMS: Alcohol consumption is a leading risk factor for premature mortality globally, but there are limited studies of broader cohorts of people presenting with alcohol-related problems outside of alcohol treatment services. We used linked health administrative data to estimate all-cause and cause-specific mortality among individuals who had an alcohol-related hospital inpatient or emergency department presentation. DESIGN: Observational study using data from the Data linkage Alcohol Cohort Study (DACS), a state-wide retrospective cohort of individuals with an alcohol-related hospital inpatient or emergency department presentation. SETTING: Hospital inpatient or emergency department presentation in New South Wales, Australia, between 2005 and 2014. PARTICIPANTS: Participants comprised 188 770 individuals aged 12 and above, 66% males, median age 39 years at index presentation. MEASUREMENTS: All-cause mortality was estimated up to 2015 and cause-specific mortality (by those attributable to alcohol and by specific cause of death groups) up to 2013 due to data availability. Age-specific and age-sex-specific crude mortality rates (CMRs) were estimated, and standardized mortality ratios (SMRs) were calculated using sex and age-specific deaths rates from the NSW population. FINDINGS: There were 188 770 individuals in the cohort (1 079 249 person-years of observation); 27 855 deaths were recorded (14.8% of the cohort), with a CMR of 25.8 [95% confidence interval (CI) = 25.5, 26.1] per 1000 person-years and SMR of 6.2 (95% CI = 5.4, 7.2). Mortality in the cohort was consistently higher than the general population in all adult age groups and in both sexes. The greatest excess mortality was from mental and behavioural disorders due to alcohol use (SMR = 46.7, 95% CI = 41.4, 52.7), liver cirrhosis (SMR = 39.0, 95% CI = 35.5, 42.9), viral hepatitis (SMR = 29.4, 95% CI = 24.6, 35.2), pancreatic diseases (SMR = 23.8, 95% CI = 17.9, 31.5) and liver cancer (SMR = 18.3, 95% CI = 14.8, 22.5). There were distinct differences between the sexes in causes of excess mortality (all causes fully attributable to alcohol female versus male risk ratio = 2.5 (95% CI = 2.0, 3.1). CONCLUSIONS: In New South Wales, Australia, people who came in contact with an emergency department or hospital for an alcohol-related presentation between 2005 and 2014 were at higher risk of mortality than the general New South Wales population during the same period.

Tracking the decline in Australian adolescent drinking into adulthood.

BACKGROUND AND AIMS: Adolescent drinking in Australia (and many other countries) has declined substantially since the early 2000s. This study aimed to test whether these declines have been maintained into adulthood and whether they are consistent across sub-groups defined by sex and socio-economic status. DESIGN: Quasi-cohorts were constructed from seven repeated waves of cross-sectional household survey data (2001-2019). SETTING: Australia. PARTICIPANTS: A total of 20 733 respondents age between 14 and 24 (male: 9492; female: 11 241). MEASUREMENTS: Participants were grouped into five cohorts based on their birth year (from 1979-1983 to 1999-2003). Three measures of drinking were assessed: any past-year consumption (yes/no), past-year regular risky drinking (12 or more drinking episodes of >40 g of pure alcohol, yes/no) and total volume of alcohol consumed in the past year (in Australian standard drinks, 10 g of alcohol). Socio-economic status was measured based on neighbourhood of residence. FINDINGS: Drinking declines were consistent across socio-economic groups on all measures and trends were broadly similar for women and men. More recent birth cohorts had significantly lower levels of drinking across all three measures (odds ratios between 0.31 and 0.70 for drinking and risky drinking, coefficients between -0.28 and -0.80 for drinking volume). There were significant interactions between birth cohort and age for past-year drinking and past-year regular risky drinking, with cohort differences diminishing as age increased. CONCLUSIONS: Lighter drinking adolescent cohorts appear to partly 'catch up' to previous cohorts by early adulthood, but maintain lower levels of drinking and risky drinking up to the age of 24. These ongoing reductions in drinking are spread evenly across socio-economic groups.

An age-period-cohort analysis of trends in psychedelic and ecstasy use in the Australian population.

AIM: To test the age, cohort, and period effect on past-year use trends in psychedelic drugs and ecstasy. METHOD: Data were from a repeated cross-sectional nationally representative household survey in Australia conducted every three years between 2001 and 2019. An age-period-cohort model was used to test the effect of age, birth cohort, and period on past year psychedelic and ecstasy use. Participants were between 18 and 80 years old at the time of the survey. The total sample size was 149,296 (Mean age = 45.8; 56% female). Past-year use of psychedelics and ecstasy were the key outcome variables. There were six birth cohorts that were derived in each survey: 1936-50, 1951-60, 1961-70, 1971-80, 1981-90, and 1991-2001. There were seven periods that coincided with survey years: 2001, 2004, 2007, 2010, 2013, 2016 and 2019. Age was treated as continuous. RESULTS: Past-year use of both psychedelics and ecstasy decreased with age, b = -0.87, 95% CI [-1.14, -0.61] and b = -0.84, 95% CI [-1.08, -0.60]. For ecstasy, while there was significant variation across periods (p < .001), there was no obvious trend. There was a significant birth cohort effect (p < .001), with prevalence increasing from the 1936-50 cohort, peaking in the 1971-80 cohort and then decreasing in the 1991-2001 cohort. For psychedelics, there was significant variation across periods (p < .001) with an upward trend. There was a significant birth cohort effect (p < .001), with prevalence increasing from the 1936-50 cohort to similarly high prevalence for the three most recent cohorts (1971-80, 1981-90, 1991-2001). CONCLUSION: There were strong cohort and period effects in trends in the use of psychedelic and ecstasy.

Definition matters: assessment of tolerance to the effects of alcohol in a prospective cohort study of emerging adults.

BACKGROUND AND AIMS: Tolerance to the effects of alcohol is an important element in the diagnosis of alcohol use disorders (AUD); however, there is ongoing debate about its utility in the diagnosis AUD in adolescents and young adults. This study aimed to refine the assessment of tolerance in young adults by testing different definitions of tolerance and their associations with longitudinal AUD outcomes. DESIGN: Prospective cohort study. SETTINGS: Australia. PARTICIPANTS: A contemporary cohort of emerging adults across Australia (n = 565, mean age = 18.9, range = 18-21 at baseline). MEASUREMENTS: Clinician-administered Structured Clinical Interview for DSM-IV Research Version (SCID-IV-RV) assessed for AUD criteria across five interviews, at 6-month intervals over 2.5 years. Tolerance definitions were operationalized using survey-type response (yes/no), clinician judgement (SCID-IV-RV), different initial drinking quantity and percentage increase thresholds and average heavy consumption metrics. AUD persistence was operationalized by the number of times AUD was present across the 2.5-year study period (n = 491), and new-onset AUD was operationalized as any new incidence of AUD during the follow-up period (n = 461). FINDINGS: The (i) SCID-IV-RV clinician judgement [odds ratio (OR) = 2.50, P = 0.005], (ii) an initial drinking quantity threshold of four to five drinks and 50% minimum increase (OR = 2.48, P = 0.007) and (iii) 50% increase only (OR = 2.40, P = 0.005) were the tolerance definitions more strongly associated with any new onset of AUD throughout the four follow-up time-points than other definitions. However, these definitions were not associated with persistent AUD (Ps > 0.05). Average heavy consumption definitions of tolerance were most strongly associated with persistent AUD (OR = 6.66, P = 0.001; OR = 4.65, P = 0.004) but not associated with new-onset AUD (Ps > 0.05). CONCLUSIONS: Initial drink and percentage change thresholds appear to improve the efficacy of change-based tolerance as an indicator for new-onset alcohol use disorder diagnosis in self-report surveys of young adults. When predicting persistent alcohol use disorder, average heavy consumption-based indicators appear to be a better way to measure tolerance than self-reported change-based definitions.

Trajectories of parental and peer supply of alcohol in adolescence and associations with later alcohol consumption and harms: A prospective cohort study.

BACKGROUND: Supply of alcohol to adolescents is associated with increased alcohol consumption and harms including alcohol use disorder (AUD). We aimed to identify: (1) trajectories of alcohol supply to adolescents; (2) sociodemographic characteristics associated with supply trajectory; (3) patterns of alcohol consumption by supply trajectory; and (4) supply trajectory associations with adverse alcohol outcomes. METHODS: We used Australian longitudinal survey data (N = 1813) to model latent trajectories of parent and peer alcohol supply over five annual follow-ups (Waves 2-6; Mage 13.9-17.8 years). Regression models assessed associations between supply trajectories and Wave 1 (Mage=12.9 years) sociodemographic factors and associations between supply trajectories and Wave 7 (Mage=18.8 years) alcohol outcomes. RESULTS: We identified five alcohol supply classes: (1) minimal supply (n = 739, 40.8%); (2) early parent sips, late peer/parent whole drinks (n = 254, 14.0%); (3) late peer/parent whole drinks (n = 419, 23.1%); (4) early parent sips, mid peer/parent whole drinks (n = 293, 16.2%); (5) early peer/parent whole drinks (n = 108, 6.0%). Compared to minimal supply, the other classes were 2.7-12.9 times as likely to binge drink, 1.6-3.0 times as likely to experience alcohol-related harms, and 2.1-8.6 times as likely to report AUD symptoms at age 19. CONCLUSION: Earlier supply of whole drinks, particularly from peers, was associated with increased risk of early adulthood adverse alcohol outcomes. While minimal supply represented the lowest risk, supplying sips only in early-mid adolescence and delaying supply of whole drinks until late adolescence is likely to be less risky than earlier supply of whole drinks.

Trajectories of alcohol-induced blackouts in adolescence: early risk factors and alcohol use disorder outcomes in early adulthood.

BACKGROUND AND AIMS: Experience of alcohol-induced memory blackouts in adolescence may be an important risk factor for later harms. This longitudinal study (i) modelled trajectories of alcohol-related blackouts throughout adolescence, (ii) explored early-adolescent predictors of blackout trajectories and (iii) examined the association between blackout trajectories and alcohol use disorder (AUD) symptoms. DESIGN: Longitudinal study in which data from six annual surveys of a longitudinal cohort of Australian adolescents were used to model latent class growth trajectories of blackouts, adjusting for alcohol consumption frequency and typical quantity. Regression models were used to determine whether parent, child and peer factors at baseline (mean age = 12.9) predicted profiles of blackout trajectory membership and whether blackout trajectories predicted meeting criteria for AUD in early adulthood (mean age = 19.8). SETTING AND PARTICIPANTS: Australian adolescents (n = 1821; mean age = 13.9-18.8 years). MEASUREMENTS: Alcohol-related blackouts, alcohol consumption frequency, typical consumption quantity and DSM-5 AUD in early adulthood were all self-reported. FINDINGS: We identified a three-class solution: delayed alcohol initiation, rare blackouts (n = 701; 38.5%); early initiation, rare blackouts (n = 869; 47.7%); and early initiation, increasing blackouts (n = 251; 13.8%). Female sex was associated with increased risk of early initiation, increasing blackouts relative to delayed initiation, rare blackouts [relative risk ratio (RRR) = 3.90; 99.5% confidence interval (CI) = 1.96, 7.76] and relative to early initiation, rare blackouts (RRR = 2.89; 99.5% CI = 1.42, 5.87). Early initiation, rare blackouts [odds ratio (OR) = 1.96; 99.5% CI = 1.17, 3.29] and early initiation, increasing blackouts (OR = 4.93; 99.5% CI = 2.32, 10.48) were each associated with increased odds of meeting criteria for AUD in early adulthood relative to delayed initiation, rare blackouts. Early initiation, increasing blackouts was associated with increased odds of meeting criteria for AUD in early adulthood relative to early initiation, rare blackouts (OR = 2.51; 99.5% CI = 1.18, 5.38). CONCLUSIONS: Females in Australia appear to be at higher risk of adolescent alcohol-related blackouts independent of alcohol consumption levels and age of initiation. Alcohol-related blackouts may be associated with later alcohol use disorder.

Alcohol use among young Australian adults in May-June 2020 during the COVID-19 pandemic: a prospective cohort study.

AIMS: To estimate change in young people's alcohol consumption during COVID-19 restrictions in Australia in early-mid 2020, and test whether those changes were consistent by gender and level of consumption prior to the pandemic. DESIGN: Prospective longitudinal cohort. SETTING: Secondary schools in New South Wales, Tasmania and Western Australia. PARTICIPANTS: Subsample of a cohort (n = 443) recruited in the first year of secondary school in 2010-11. Analysis data included three waves collected in September 2017-July 2018, September 2018-May 2019 and August 2019-January 2020), and in May-June 2020. MEASUREMENTS: The primary predictors were time, gender and level of consumption prior to the pandemic. Outcome variables, analysed by mixed-effects models, included frequency and typical quantity of alcohol consumption, binge drinking, peak consumption, alcohol-related harm and drinking contexts. FINDINGS: Overall consumption (frequency × quantity) during the restrictions declined by 17% [incidence rate ratio (IRR) = 0.83; 95% confidence interval (CI) = 0.73, 0.95] compared to February 2020, and there was a 35% decline in the rate of alcohol-related harms in the same period (IRR = 0.66; 95% CI = 0.54, 0.79). Changes in alcohol consumption were largely consistent by gender. CONCLUSIONS: From a survey of secondary school students in Australia, there is evidence for a reduction in overall consumption and related harms during the COVID-19 restrictions.

Profile and correlates of injecting-related injuries and diseases among people who inject drugs in Australia.

INTRODUCTION: People who inject drugs (PWID) commonly experience harms related to their injecting, many of which are consequences of modifiable drug use practices. There is currently a gap in our understanding of how certain injecting-related injuries and diseases (IRID) cluster together, and socio-demographic and drug use characteristics associated with more complex clinical profiles. METHOD: Surveys were conducted with 902 Australian PWID in 2019. Participants provided information regarding their drug use, and past month experience of the following IRID: artery injection, nerve damage, skin and soft tissue infection, thrombophlebitis, deep vein thrombosis, endocarditis, septic arthritis, osteomyelitis, and septicaemia. We performed a latent class analysis, grouping participants based on reported IRID and ran a class-weighted regression analysis to determine variables associated with class-membership. RESULTS: One-third (34 %) of the sample reported any IRID. A 3-class model identified: 1) no IRID (73 %), moderate IRID (21 %), and 3) high IRID (6%) clusters. Re-using one`s own needles was associated with belonging to the high IRID versus moderate IRID class (ARRR = 2.38; 95 % CI = 1.04-5.48). Other factors, including daily injecting and past 6-month mental health problems were associated with belonging to moderate and high IRID classes versus no IRID class. CONCLUSION: A meaningful proportion of PWID reported highly complex IRID presentations distinguished by the presence of thrombophlebitis and associated with greater re-use of needles. Increasing needle and syringe coverage remains critical in addressing the harms associated with injecting drug use and expanding the capacity of low-threshold services to address less severe presentations might aid in reducing IRID amongst PWID.

The association between parental supply of alcohol and supply from other sources to young people: a prospective cohort.

AIMS: Despite legal age limits set for alcohol consumption, parents are one of the main suppliers of alcohol to underage minors. Although supply from non-parental sources has been found to be associated with greater risk of harm compared with parental supply, the association between parental supply and supply from other sources is unclear. This study investigated the associations between parental supply of sips and whole serves of alcohol on subsequent other supply, conditional on current supply from non-parental sources. METHODS: Data from the Australian Parental Supply of Alcohol Longitudinal Study cohort of adolescents was used. A cohort of 1927 Australian children recruited in grade 7 (mean age 12.9 years) was surveyed annually from 2010 to 2016 (94%, n = 1821 included for analyses). The primary outcome was alcohol exposure from other sources ('other supply'), including alcohol supply from other adults, friends, siblings, or self-supply, compared with adolescents reporting no supply from these sources. Analyses were conducted using random intercept logistic regression (to account for within-respondent correlation). RESULTS: Parental supply of alcohol alone was associated with increased odds of receiving alcohol from other non-parental sources in subsequent years (OR: 1.99; 95% CI: 1.65-2.39) after adjusting for confounders. Increased odds of subsequent other supply were associated with current parental supply of sips (OR: 1.92; 95% CI: 1.56-2.36) and whole drinks (OR: 2.76; 95% CI: 1.85-4.11). CONCLUSIONS: Parental supply of alcohol appears to increase the risk of subsequent supply of alcohol from other sources in certain contexts.

Adolescent Alcohol Use Trajectories: Risk Factors and Adult Outcomes.

OBJECTIVES: Adolescents often display heterogenous trajectories of alcohol use. Initiation and escalation of drinking may be important predictors of later harms, including alcohol use disorder (AUD). Previous conceptualizations of these trajectories lacked adjustment for known confounders of adolescent drinking, which we aimed to address by modeling dynamic changes in drinking throughout adolescence while adjusting for covariates. METHODS: Survey data from a longitudinal cohort of Australian adolescents (n = 1813) were used to model latent class alcohol use trajectories over 5 annual follow-ups (mean age = 13.9 until 17.8 years). Regression models were used to determine whether child, parent, and peer factors at baseline (mean age = 12.9 years) predicted trajectory membership and whether trajectories predicted self-reported symptoms of AUD at the final follow-up (mean age = 18.8 years). RESULTS: We identified 4 classes: abstaining (n = 352); late-onset moderate drinking (n = 503); early-onset moderate drinking (n = 663); and early-onset heavy drinking (n = 295). Having more alcohol-specific household rules reduced risk of early-onset heavy drinking compared with late-onset moderate drinking (relative risk ratio: 0.31; 99.5% confidence interval [CI]: 0.11-0.83), whereas having more substance-using peers increased this risk (relative risk ratio: 3.43; 99.5% CI: 2.10-5.62). Early-onset heavy drinking increased odds of meeting criteria for AUD in early adulthood (odds ratio: 7.68; 99.5% CI: 2.41-24.47). CONCLUSIONS: Our study provides evidence that parenting factors and peer influences in early adolescence should be considered to reduce risk of later alcohol-related harm. Early initiation and heavy alcohol use throughout adolescence are associated with increased risk of alcohol-related harm compared with recommended maximum levels of consumption (late-onset, moderate drinking).

Parental supply of sips and whole drinks of alcohol to adolescents and associations with binge drinking and alcohol-related harms: A prospective cohort study.

BACKGROUND: Parents frequently supply alcohol to their children, often only sips. We investigated whether supply of sips and whole drinks, from parents and other sources, are differentially associated with subsequent drinking outcomes. METHODS: A cohort of 1910 adolescents (mean age 12.9yrs) were surveyed annually over seven years from 2010-11. We examined prospective, adjusted associations between the quantity of supply from parental and non-parental sources in the preceding 12 months and five outcomes in the subsequent year, over several consecutive years: binge drinking; alcohol-related harms; symptoms of alcohol abuse, dependence and alcohol use disorder (AUD). RESULTS: In early waves, most parental supply comprised sips, while supply of whole drinks increased in later waves. Among those not receiving alcohol from other sources, parental supply of sips was associated with increased odds of binge drinking (OR: 1.85; 99.5 % CI: 1.17-2.91) and alcohol-related harms (OR: 1.70; 99.5 % CI: 1.20-2.42), but not with reporting symptoms of alcohol abuse, dependence or AUD, compared with no supply. Relative to no supply, supply of sips from other sources was associated with increased odds of binge drinking (OR: 2.04; 99.5 % CI: 1.14-3.67) only. Compared with supply of sips, supply of whole drinks by parents or others had higher odds of binge drinking, alcohol-related harms, symptoms of dependence and of AUD. Secondary analysis demonstrated that supply of larger quantities was associated with an increased risk of all outcomes. CONCLUSION: Parental provision of sips is associated with increased risks and the supply of greater quantities was associated with an increasing risk of adverse outcomes. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov (NCT02280551).

The overall effect of parental supply of alcohol across adolescence on alcohol-related harms in early adulthood-a prospective cohort study.

BACKGROUND AND AIMS: Recent research suggests that parental supply of alcohol is associated with more risky drinking and alcohol-related harm among adolescents. However, the overall effect of parental supply throughout adolescence remains unclear, because parental supply of alcohol varies during adolescence. Due to the complexity of longitudinal data, standard analytical methods can be biased. This study examined the effect of parental supply of alcohol on alcohol-related outcomes in early adulthood using robust methods to minimize risk of bias. DESIGN: Prospective longitudinal cohort study. SETTING: Australia PARTICIPANTS: A cohort of school students (n = 1906) recruited in the first year of secondary school (average age 12.9 years) from Australian schools in 2010-11, interviewed annually for 7 years. MEASUREMENTS: The exposure variable was self-reported parental supply of alcohol (including sips/whole drinks) during 5 years of adolescence (waves 1-5). Outcome variables were self-reported binge drinking, alcohol-related harm and symptoms of alcohol use disorder, measured in the two waves after the exposure period (waves 6-7). To reduce risk of bias, we used targeted maximum likelihood estimation to assess the (counterfactual) effect of parental supply of alcohol in all five waves versus no supply on alcohol-related outcomes. FINDINGS: Parental supply of alcohol throughout adolescence saw greater risk of binge drinking [risk ratios (RR) = 1.53; 95% confidence interval (CI) = 1.27-1.84] and alcohol-related harms (RR = 1.44; 95% CI = 1.22-1.69) in the year following the exposure period compared with no supply in adolescence. Earlier initiation of parental supply also increased risk of binge drinking (RR = 1.10; 95% CI = 1.05-1.14), and any alcohol-related harm (RR = 1.09; 95% CI = 1.05-1.13) for each year earlier parental supply began compared with later (or no) initiation. CONCLUSIONS: Adolescents whose parents supply them with alcohol appear to have an increased risk of alcohol-related harm compared with adolescents whose parents do not supply them with alcohol. The risk appears to increase with earlier initiation of supply.