The impact of tightened prescribing restrictions for PBS-subsidised opioid medicines and the introduction of half-pack sizes, Australia, 2020-21: an interrupted time series analysis.

OBJECTIVES: To evaluate the impact of the tightened Pharmaceutical Benefits Scheme (PBS) prescribing rules for immediate release (IR) and controlled release (CR) opioid medicines (1 June 2020), which also eliminated repeat dispensing without authorisation for codeine/paracetamol and tramadol IR and introduced half-pack size item codes for IR formulations. DESIGN, SETTING: Population-based interrupted time series analysis of PBS dispensing data claims for a 10% sample of PBS-eligible residents and IQVIA national opioid medicine sales data (PBS-subsidised and private prescriptions), 28 May 2018 - 6 June 2021. MAIN OUTCOME MEASURES: Mean amount of PBS-subsidised opioid medicines dispensed per day and mean overall amount sold per day - each expressed as oral morphine equivalent milligrams (OME) - overall, by formulation type (IR, CR), and by specific formulation. RESULTS: During the twelve months following the PBS changes, daily PBS-subsidised opioid medicine dispensing was 81 565 OME lower (95% CI, -106 146 to -56 984 OME) than the mean daily level for 2018-20, a decline of 3.8% after adjusting for the pre-intervention trend; the relative reduction was greater for IR (8.4%) than CR formulations (2.6%). Total daily sales of all, IR formulation, and CR formulation opioid medicines did not change significantly after the PBS changes. Repeat dispensing of prescriptions comprised 7.4% of PBS-subsidised opioid dispensing before 1 June 2020, and 1.3% after the changes. Half-pack sizes comprised 8.4% of PBS-subsidised IR opioid medicine dispensing and 2.8% of all opioid medicines sold in the twelve months after the PBS changes. CONCLUSIONS: The introduction of new PBS rules for subsidised opioid medicines was followed by a decline in PBS-subsidised dispensing. Some people may have bypassed the new restrictions by switching to private prescriptions, but our findings suggest that opioid medicine use in Australia declined as a result of the new restrictions.

Age, crash type and the changing patterns of cycling fatalities in Australia between 1991 and 2022.

BACKGROUND: Australia has made significant efforts in recent years to promote cycling. METHODS: Trends in cyclist fatalities in Australia between 1991 and 2022, particularly in those aged 60 years and over, were examined using Poisson regression modelling. RESULTS: Overall, cyclist fatalities decreased by 1.1% annually. However, while there was an annual decline of 2.5% in those aged <60 years, fatalities in the 60+ age group increased by 3.3% annually. Mortality rates also showed an annual decrease of 3.5% for cyclists aged <60 years but remained almost stable in the 60+ age group over the study period. Single vehicle fatalities increased markedly, particularly among the 60+ age group (4.4% annually). DISCUSSION: The observed increase in 60+ fatalities is due to the ageing of the population rather than a rise in cycling popularity as previously thought. The rise in single vehicle fatalities is likely to be related to the increase in the availability and use of dedicated cycling infrastructure.

Updated population-level estimates of child restraint practices among children aged 0-12 years in Australia, 10 years after introduction of age-appropriate restraint use legislation.

OBJECTIVE: Optimal child passenger protection requires use of a restraint designed for the age/size of the child (appropriate use) that is used in the way the manufacturer intended (correct use).This study aimed to determine child restraint practices approximately 10 years after introduction of legislation requiring correct use of age-appropriate restraints for all children aged up to 7 years. METHODS: A stratified cluster sample was constructed to collect observational data from children aged 0-12 years across the Greater Sydney region of New South Wales (NSW). Methods replicated those used in a similar 2008 study. Population weighted estimates for restraint practices were generated, and logistic regression used to examine associations between restraint type, and child age with correct use accounting for the complex sample. RESULTS: Almost all children were appropriately restrained (99.3%, 95% CI 98.4% to 100%). However, less than half were correctly restrained (no error=27.3%, 95% CI 10.8% to 43.8%, no serious error=43.8%, 95% CI 35.0% to 52.7%). For any error, the odds of error decreased by 39% per year of age (OR 0.61, 95% CI 0.46 to 0.81) and for serious error by 25% per year (OR 0.75, 95% CI 0.60 to 0.93). CONCLUSION: The findings demonstrate high levels of appropriate restraint use among children across metropolitan Sydney approximately 10 years after introduction of legislation requiring age-appropriate restraint use until age 7, however, errors in the way restraints remain common. IMPLICATIONS FOR PUBLIC HEALTH: Given the negative impact incorrect use has on crash protection, continuing high rates of incorrect use may reduce effectiveness of legislative change on injury reduction.

Improving population-level refractive error monitoring via mixture distributions.

INTRODUCTION: Sampling and describing the distribution of refractive error in populations is critical to understanding eye care needs, refractive differences between groups and factors affecting refractive development. We investigated the ability of mixture models to describe refractive error distributions. METHODS: We used key informants to identify raw refractive error datasets and a systematic search strategy to identify published binned datasets of community-representative refractive error. Mixture models combine various component distributions via weighting to describe an observed distribution. We modelled raw refractive error data with a single-Gaussian (normal) distribution, mixtures of two to six Gaussian distributions and an additive model of an exponential and Gaussian (ex-Gaussian) distribution. We tested the relative fitting accuracy of each method via Bayesian Information Criterion (BIC) and then compared the ability of selected models to predict the observed prevalence of refractive error across a range of cut-points for both the raw and binned refractive data. RESULTS: We obtained large raw refractive error datasets from the United States and Korea. The ability of our models to fit the data improved significantly from a single-Gaussian to a two-Gaussian-component additive model and then remained stable with ≥3-Gaussian-component mixture models. Means and standard deviations for BIC relative to 1 for the single-Gaussian model, where lower is better, were 0.89 ± 0.05, 0.88 ± 0.06, 0.89 ± 0.06, 0.89 ± 0.06 and 0.90 ± 0.06 for two-, three-, four-, five- and six-Gaussian-component models, respectively, tested across US and Korean raw data grouped by age decade. Means and standard deviations for the difference between observed and model-based estimates of refractive error prevalence across a range of cut-points for the raw data were -3.0% ± 6.3, 0.5% ± 1.9, 0.6% ± 1.5 and -1.8% ± 4.0 for one-, two- and three-Gaussian-component and ex-Gaussian models, respectively. CONCLUSIONS: Mixture models appear able to describe the population distribution of refractive error accurately, offering significant advantages over commonly quoted simple summary statistics such as mean, standard deviation and prevalence.

Estimated stroke risk, yield, and number needed to screen for atrial fibrillation detected through single time screening: a multicountry patient-level meta-analysis of 141,220 screened individuals.

BACKGROUND: The precise age distribution and calculated stroke risk of screen-detected atrial fibrillation (AF) is not known. Therefore, it is not possible to determine the number needed to screen (NNS) to identify one treatable new AF case (NNS-Rx) (i.e., Class-1 oral anticoagulation [OAC] treatment recommendation) in each age stratum. If the NNS-Rx is known for each age stratum, precise cost-effectiveness and sensitivity simulations can be performed based on the age distribution of the population/region to be screened. Such calculations are required by national authorities and organisations responsible for health system budgets to determine the best age cutoffs for screening programs and decide whether programs of screening should be funded. Therefore, we aimed to determine the exact yield and calculated stroke-risk profile of screen-detected AF and NNS-Rx in 5-year age strata. METHODS AND FINDINGS: A systematic review of Medline, Pubmed, and Embase was performed (January 2007 to February 2018), and AF-SCREEN international collaboration members were contacted to identify additional studies. Twenty-four eligible studies were identified that performed a single time point screen for AF in a general ambulant population, including people ≥65 years. Authors from eligible studies were invited to collaborate and share patient-level data. Statistical analysis was performed using random effects logistic regression for AF detection rate, and Poisson regression modelling for CHA2DS2-VASc scores. Nineteen studies (14 countries from a mix of low- to middle- and high-income countries) collaborated, with 141,220 participants screened and 1,539 new AF cases. Pooled yield of screening was greater in males across all age strata. The age/sex-adjusted detection rate for screen-detected AF in ≥65-year-olds was 1.44% (95% CI, 1.13%-1.82%) and 0.41% (95% CI, 0.31%-0.53%) for <65-year-olds. New AF detection rate increased progressively with age from 0.34% (<60 years) to 2.73% (≥85 years). Neither the choice of screening methodology or device, the geographical region, nor the screening setting influenced the detection rate of AF. Mean CHA2DS2-VASc scores (n = 1,369) increased with age from 1.1 (<60 years) to 3.9 (≥85 years); 72% of ≥65 years had ≥1 additional stroke risk factor other than age/sex. All new AF ≥75 years and 66% between 65 and 74 years had a Class-1 OAC recommendation. The NNS-Rx is 83 for ≥65 years, 926 for 60-64 years; and 1,089 for <60 years. The main limitation of this study is there are insufficient data on sociodemographic variables of the populations and possible ascertainment biases to explain the variance in the samples. CONCLUSIONS: People with screen-detected AF are at elevated calculated stroke risk: above age 65, the majority have a Class-1 OAC recommendation for stroke prevention, and >70% have ≥1 additional stroke risk factor other than age/sex. Our data, based on the largest number of screen-detected AF collected to date, show the precise relationship between yield and estimated stroke risk profile with age, and strong dependence for NNS-RX on the age distribution of the population to be screened: essential information for precise cost-effectiveness calculations.

Regression to the mean for the bivariate binomial distribution.

Regression to the mean (RTM) occurs when subjects having relatively high or low measurements are remeasured and found closer to the population mean. This phenomenon can potentially lead to an inaccurate conclusion in a pre-post study design. Expressions are available for quantifying RTM when the distribution of pre and post observations are bivariate normal and bivariate Poisson. However, situations exist where the response variables are the number of successes in a fixed number of trials and follow the bivariate binomial distribution. In this article, expressions for quantifying RTM effects are derived when the underlying distribution is the bivariate binomial. Unlike the normal and Poisson distributions, the correlation between pre and post observations can be either negative or positive under the bivariate binomial distribution and the severity of RTM is greater in the former case. The percentage relative difference is used to highlight the differences in quantifying RTM under the bivariate binomial distribution and normal and Poisson approximations to the bivariate binomial distribution. Expressions for estimating RTM using the method of maximum likelihood along with its asymptotic distribution are derived. A simulation study is conducted to empirically assess the statistical properties of the RTM estimator and its asymptotic distribution. Data examples using the number of obese individuals and the number of nonconforming cardboard cans are discussed.

Crash characteristics of on-road single-bicycle crashes: an under-recognised problem.

Compared with crashes with motor vehicles, single-bicycle crashes are an under-recognised contributor to cycling injury and the aetiology is poorly understood. Using an in-depth crash investigation technique, this study describes the crash characteristics and patient outcomes of a sample of cyclists admitted to hospital following on-road bicycle crashes. Enrolled cyclists completed a structured interview, and injury details and patient outcomes were extracted from trauma registries. Single-bicycle crashes (n=62) accounted for 48% of on-road crashes and commonly involved experienced cyclists. Common single-bicycle crash types included loss-of-control events, interactions with tram tracks, striking potholes or objects or resulting from mechanical issues with the bicycle. To address single-bicycle crashes, targeted countermeasures are required for each of these specific crash types.

The interaction between cytosine methylation and processes of DNA replication and repair shape the mutational landscape of cancer genomes.

Methylated cytosines (5mCs) are frequently mutated in the genome. However, no studies have yet comprehensively analysed mutation-methylation associations across cancer types. Here we analyse 916 cancer genomes, together with tissue type-specific methylation and replication timing data. We describe a strong mutation-methylation association across colorectal cancer subtypes, most interestingly in samples with microsatellite instability (MSI) or Polymerase epsilon (POLE) exonuclease domain mutations. By analysing genomic regions with differential mismatch repair (MMR) efficiency, we suggest a possible role for MMR in the correction of 5mC deamination events, potentially accounting for the high rate of 5mC mutation accumulation in MSI tumours. Additionally, we propose that mutant POLE asserts a mutator phenotype specifically at 5mCs, and we find coding mutation hotspots in POLE-mutant cancers at highly-methylated CpGs in the tumour-suppressor genes APC and TP53. Finally, using multivariable regression models, we demonstrate that different cancers exhibit distinct mutation-methylation associations, with DNA repair influencing such associations in certain cancer genomes. Taken together, we find differential associations with methylation that are vital for accurately predicting expected mutation loads across cancer types. Our findings reveal links between methylation and common mutation and repair processes, with these mechanisms defining a key part of the mutational landscape of cancer genomes.

Quantifying the regression to the mean effect in Poisson processes.

Regression to the mean (RTM) can occur whenever an extreme observation is selected from a population and a later observation is closer to the population mean. A consequence of this phenomenon is that natural variability can be mistaken as real change. Simple expressions are available to quantify RTM when the underlying distribution is bivariate normal. However, there are many real-world situations, which are better approximated as a Poisson process. Examples include the number of hard disk failures during a year, the number of cargo ships damaged by waves, daily homicide counts in California, and the number of deaths per quarter attributable to acquired immune deficiency syndrome in Australia. In this paper, we derive expressions for quantifying RTM effects for the bivariate Poisson distribution for both the homogeneous and inhomogeneous cases. Statistical properties of our derivations have been evaluated through a simulation study. The asymptotic distributions of RTM estimators have been derived. The RTM effect for the number of people killed in road accidents in different regions of New South Wales (Australia) is estimated using maximum likelihood.

Recent trends in cyclist fatalities in Australia.

The study examines trends in bicycling fatalities reported to the Australian police between 1991 and 2013. Trends were estimated using Poisson regression modelling. Overall, cycling fatalities decreased by 1.9% annually between 1991 and 2013. However, while deaths following multivehicle crashes decreased at a rate of 2.9% per annum (95% CI -4.0% to -1.8%), deaths from single vehicle crashes increased by 5.8% per annum (95% CI 4.1% to 7.5%). Over the study period, the average age of cyclists who died in single vehicle crashes (45.3 years, 95% CI 41.5 to 49.1) was significantly higher than cyclists who died in multivehicle crashes (36.2 years, 95% CI 34.7 to 37.7). The average age of deceased cyclists increased significantly for both types of crashes. The observed increase in single vehicle crashes need to be closely monitored in Australia and internationally. In-depth studies are needed to investigate the circumstances of fatal single bicycle crashes in order to develop appropriate countermeasures.

Pregaming and Emotion Regulation's Relationship to Alcohol Problems in College Students: A Cross-Sectional Study.

BACKGROUND: Pregaming is a high-risk drinking behavior associated with increased alcohol consumption and alcohol-related problems. Quantity of alcohol consumed does not fully explain the level of problems associated with pregaming; yet, limited research has examined factors that may interact with pregaming behavior to contribute to the experience of alcohol-related problems. OBJECTIVES: The current study examined whether use of two emotion regulation strategies influence pregaming's contribution to alcohol-related problems. METHODS: Undergraduates (N = 1857) aged 18-25 years attending 19 different colleges completed an online survey in 2008-2009. Linear mixed models were used to test whether emotion regulation strategies moderate the association between pregaming status (pregamers vs. non/infrequent pregamers) and alcohol-related problems, when controlling for alcohol consumption, demographic covariates, and site as a random effect. RESULTS: Greater use of cognitive reappraisal was associated with decreased alcohol problems. Expressive suppression interacted with pregaming status. There was no relationship between pregaming status and alcohol problems for students who rarely used expression suppression; however, the relationship between pregaming status and alcohol problems was statistically significant for students who occasionally to frequently used expression suppression. CONCLUSIONS/IMPORTANCE: Findings suggest that the relationship between pregaming and alcohol-related problems is complex. Accordingly, future studies should utilize event-level methodology to understand how emotion regulation strategies influence alcohol-related problems. Further, clinicians should tailor alcohol treatments to help students increase their use of cognitive reappraisal and decrease their use of suppression.

Activity of a heptad of transcription factors is associated with stem cell programs and clinical outcome in acute myeloid leukemia.

Aberrant transcriptional programs in combination with abnormal proliferative signaling drive leukemic transformation. These programs operate in normal hematopoiesis where they are involved in hematopoietic stem cell (HSC) proliferation and maintenance. Ets Related Gene (ERG) is a component of normal and leukemic stem cell signatures and high ERG expression is a risk factor for poor prognosis in acute myeloid leukemia (AML). However, mechanisms that underlie ERG expression in AML and how its expression relates to leukemic stemness are unknown. We report that ERG expression in AML is associated with activity of the ERG promoters and +85 stem cell enhancer and a heptad of transcription factors that combinatorially regulate genes in HSCs. Gene expression signatures derived from ERG promoter-stem cell enhancer and heptad activity are associated with clinical outcome when ERG expression alone fails. We also show that the heptad signature is associated with AMLs that lack somatic mutations in NPM1 and confers an adverse prognosis when associated with FLT3 mutations. Taken together, these results suggest that transcriptional regulators cooperate to establish or maintain primitive stem cell-like signatures in leukemic cells and that the underlying pattern of somatic mutations contributes to the development of these signatures and modulate their influence on clinical outcome.

Cannabis use among treatment-seeking smokers: motives and the moderating effects of anxiety sensitivity.

BACKGROUND AND OBJECTIVES: Concurrent use of cannabis and tobacco is associated with poor tobacco cessation outcomes. As little research has examined why treatment-seeking tobacco users engage in cannabis use, the objective of this study was to discover if emotional vulnerability and cannabis use motives are associated with concurrent users' cannabis use. METHODS: One hundred thirty-eight (n = 138) daily cigarette smokers seeking smoking cessation treatment completed measures of anxiety sensitivity, cannabis use motives, and cannabis use. RESULTS: Stronger coping, enhancement, social, and expansion motives were associated with using greater amounts of cannabis per use occasion. In a model accounting for all these motives, anxiety sensitivity moderated the relationship between enhancement motives and cannabis use. DISCUSSION AND CONCLUSIONS: Clinical interventions for concurrent tobacco-cannabis users may be advanced by targeting low anxiety sensitive individuals' use of cannabis to increase excitement and fun. Such an approach may consist of having clients identify and engage in healthier pleasurable activities and by teaching clients to accept the trade-off between perceived less pleasurable, but healthier activities and cannabis use.

Scientific rigour in psycho-oncology trials: why and how to avoid common statistical errors.

OBJECTIVE: It is well documented that statistical and methodological flaws are common in much of the health research literature, including psycho-oncology. These can have far-reaching effects, including the publishing of misleading results; the wasting of time, effort, and financial resources; exposure of patients to the potential harms of research and decreased confidence in science and researchers by the public. METHODS: Several of the most common statistical errors and methodological pitfalls that occur in the field of psycho-oncology are discussed, including those that occur at the design, analysis, reporting and conclusion stages. RESULTS: Fourteen topics are briefly discussed, explaining why there is a problem and how to avoid it. These include proper approaches to power, clustering, missing data, categorization of continuous variables, subgroup analyses, multiple comparisons, statistical interactions, confidence intervals and correct interpretation of p-values. Extensive referencing points the reader to more in-depth explanations. CONCLUSIONS: To increase the scientific rigour in psycho-oncology, researchers should involve a biostatistician from the beginning of the study and should commit to continuing education on best practices in the fields of statistics and reporting.

A population-based cross-sectional study examining homicides among community-dwelling older adults in Victoria, Australia: A study protocol.

BACKGROUND: There is a need for both descriptive and analytical evidence on the factors associated with older adult homicide. The current landscape is insufficient because most published research is confined to the United States, and contains insufficient data about the homicide context. This study protocol describes the proposed method for examining the characteristics and factors associated with older adult homicide in the Australian state of Victoria, using data generated for the criminal and coronial investigation into these deaths stored in the Victorian Homicide Register (VHR). Outcomes will support practitioners, policy makers and other key stakeholders to strengthen prevention strategies to reduce the risk of future homicides among older Victorians. METHODS: This study will comprise a single-jurisdiction population-based cross-sectional design to analyse consecutive cases of homicide among community-dwelling older adults in Victoria, Australia for the period 2001 to 2015. All homicides of adults aged 18 years and older, and where the Coroner's investigation is completed at data extraction will be included. Variables will be selected in accordance with elements of the social-ecological model (i.e., individual, interpersonal, incident, and community). This will include: socio-demographic characteristics; presence of mental or physical illness; deceased-offender relationship; nature of any abuse between the deceased and offender; incident location and weapon used; the presence of alcohol or drugs; and criminal justice outcomes. Homicide rates per 100,000 population will be calculated for older adults (aged 65 years and older) and younger adults (aged 18-64 years), and compared as rate ratios using Poisson regression. Descriptive statistics and cross-tabulation will be generated for factors associated with homicide for older compared to younger adults. Homicide typologies based on deceased-offender relationship and motive will be explored within group and family homicides will be compared between older and younger adults.

Epidemiology of Homicide in Community-Dwelling Older Adults: A Systematic Review and Meta-Analysis.

BACKGROUND: Empirical research investigating older adult homicide is sparse and rarely accumulated for greater insights. This systematic review and meta-analysis quantifies the prevalence and characteristics of homicide victimization among older adults (65 years and older) compared with younger adults (18-64 years). METHOD: We searched Cumulative Index to Nursing and Allied Health Literature, Cochrane, Criminal Justice Abstracts, EMBASE, MEDLINE, ProQuest, PsycINFO, Scopus, and Web of Science for studies published before December 31, 2018 (International Prospective Register of Systematic Reviews registration: CRD42017054536). Included were English-language, original, peer-reviewed studies describing the homicide of older adults. Excluded were studies not meeting age criteria, residence as an institution, or with insufficient outcome variables. The review included 39 studies; 17 were included in the meta-analysis. Data were extracted via open access or from study authors. Heterogeneity was assessed through study-level random effects estimates. RESULTS: Pooled homicide rates per 100,000 population were 2.02 (95% CI [1.23, 3.33]) for older adults (n = 35,325) and 3.98 (95% CI [2.42, 6.53]) for younger adults (n = 607,224; rate ratio = .51, 95% CI [0.37, 0.70], p < .001). Proportion estimates for older adults: victim female 46.3%, location home 71.4%, offender familiar 25.2%, compared to stranger, 24.2%, motive argument 36.1%, compared to felony 30.8%, and weapon firearm 24.5%. Older adults were significantly different to younger adult victims (p = <.001) for female (OR = 2.5, 95% CI [2.02, 3.10]), home (3.87, 95% CI [3.45, 4.35]), stranger (1.81, 95% CI [1.66, 1.98]), argument (0.33, 95% CI [0.28, 0.39]), felony (2.78, 95% CI [2.58, 2.99]), and firearm (0.38, 95% CI [0.36, 0.40]). CONCLUSIONS: Homicide against older adults differs from younger adults and warrants specific research and tailored prevention strategies.

Attention, response inhibition, and hoarding: A neuropsychological examination.

Background and aims: The prominent cognitive-behavioral model of hoarding posits that information processing deficits contribute to hoarding disorder. Although individuals with hoarding symptoms consistently self-report attentional and impulsivity difficulties, neuropsychological tests have inconsistently identified impairments. These mixed findings may be the result of using different neuropsychological tests, tests with poor psychometric properties, and/or testing individuals in a context that drastically differs from their own homes. Methods: One hundred twenty-three participants (hoarding = 63; control = 60) completed neuropsychological tests of sustained attention, focused attention, and response inhibition in cluttered and tidy environments in a counterbalanced order. Results: Hoarding participants demonstrated poorer sustained attention and response inhibition than the control group (CPT-3 Omission and VST scores) and poorer response inhibition in the cluttered environment than when in the tidy environment (VST scores). CPT-3 Detectability and Commission scores also indicated that hoarding participants had greater difficulty sustaining attention and inhibiting responses than the control group; however, these effect sizes were just below the lowest practically meaningful magnitude. Posthoc exploratory analyses demonstrated that fewer than one-third of hoarding participants demonstrated sustained attention and response inhibition difficulties and that these participants reported greater hoarding severity and greater distress in the cluttered room. Discussion and conclusions: Given these findings and other studies showing that attentional difficulties may be a transdiagnostic factor for psychopathology, future studies will want to explore whether greater sustained attention and response inhibition difficulties in real life contexts contribute to comorbidity and functional impairment in hoarding disorder.

Differences in participant characteristics and observed child restraint use between population-based and restraint fitting service samples.

OBJECTIVE: To compare characteristics and restraint use between a population-based and fitting service sample of child restraint users. METHOD: Characteristics of the two samples were compared using chi-squared tests. Differences in errors in restraint use observed in the two samples were modeled using logistic regression. RESULTS: There were significant differences in child age (p < 0.001), and restraint types (p < 0.001) between the two samples, with more younger children in the fitting service sample. Controlling for differences in restraint type, the odds that adult participants were female were 61% less in the fitting service sample than in the population-based sample (OR 0.39, 95%CI 0.21-0.71). The odds that adult participants perceived a large risk associated with restraint misuse (OR 3.62, 95%CI 1.33-9.84), had a household income in the highest bracket (OR 3.89, 95%CI 1.20-12.62) and were living in areas of highest socioeconomic advantage (OR 2.72, 95%CI 1.22-6.06) were approximately three times higher in the fitting service sample. Overall, more participants had errors in restraint use in the population-based sample (p = 0.021). However, after controlling for restraint type, securing errors were three times more likely (OR 3.34, 95%CI 1.12-10.2), and serious installation errors were almost twice as likely (OR 1.91, 95% CI 1.09-3.39) in the fitting service sample. CONCLUSIONS: While less resource intensive, convenience and/or fitting service samples may be less representative than population-based samples. Given the need for efficiency, methods that combine randomized population-based invitations to participate in restraint fitting check day events across geographically representative areas may be useful for ongoing surveillance of child restraint use.

Descriptive characteristics and cluster analysis of male veteran hazardous drinkers in an alcohol moderation intervention.

Current efforts underway to develop the fifth edition of the Diagnostic and Statistical Manual (DSM-5) have reignited discussions for classifying the substance use disorders. This study's aim was to contribute to the understanding of abusive alcohol use and its validity as a diagnosis. Cluster analysis was used to identify relatively homogeneous groups of hazardous, nondependent drinkers by using data collected from the Prevention and Treatment of Hypertension Study (PATHS), a multisite trial that examined the ability of a cognitive-behavioral-based alcohol reduction intervention, compared to a control condition, to reduce alcohol use. Participants for this study (N = 511) were male military veterans. Variables theoretically associated with alcohol use (eg, demographic, tobacco use, and mental health) were used to create the clusters and a priori, empirically based external criteria were used to assess discriminant validity. Bivariate correlations among cluster variables were generally consistent with previous findings in the literature. Analyses of internal and discriminant validity of the identified clusters were largely nonsignificant, suggesting meaningful differences between clusters could not be identified. Although the typology literature has contributed supportive validity for the alcohol dependence diagnosis, this study's results do not lend supportive validity for the construct of alcohol abuse.