Associations between fruit and vegetable consumption and depressive symptoms: evidence from a national Canadian longitudinal survey

BACKGROUND: Several cross-sectional studies have demonstrated associations between diet quality, including fruit and vegetable consumption, and mental health. However, research examining these associations longitudinally, while accounting for related lifestyle factors (eg, smoking, physical activity) is scarce. METHODS: This study used data from the National Population Health Survey (NPHS), a large, national longitudinal survey of Canadians. The sample included 8353 participants aged 18 and older. Every 2 years from 2002/2003 to 2010/2011, participants completed self-reports of daily fruit and vegetable consumption, physical activity, smoking and symptoms of depression and psychological distress. Using generalised estimating equations, we modelled the associations between fruit and vegetable consumption at each timepoint and depression at the next timepoint, adjusting for relevant covariates. RESULTS: Fruit and vegetable consumption at each cycle was inversely associated with next-cycle depression (β=-0.03, 95% CI -0.05 to -0.01, p<0.01) and psychological distress (β=-0.03, 95% CI -0.05 to -0.02, p<0.0001). However, once models were adjusted for other health-related factors, these associations were attenuated (β=-0.01, 95% CI -0.04 to 0.02, p=0.55; β=-0.00, 95% CI -0.03 to 0.02, p=0.78 for models predicting depression and distress, respectively). CONCLUSIONS: These findings suggest that relations between fruit and vegetable intake, other health-related behaviours and depression are complex. Behaviours such as smoking and physical activity may have a more important impact on depression than fruit and vegetable intake. Randomised control trials of diet are necessary to disentangle the effects of multiple health behaviours on mental health.

Body size at birth, physical development and cognitive outcomes in early childhood: evidence from the Longitudinal Survey of Australian Children

Using a rich sample created from the Longitudinal Survey of Australian Children, we investigate the extent to which the relationship between body size at birth and early childhood cognitive skills is mediated by physical development indicators. Consistent with existing evidence from other countries, we find a significant relationship between body size at birth and future development among Australian children as well, in terms of both weight and length. Accounting for progressive measures of physical developments and other confounding factors, however, indicates that only a small proportion of this association works through these pathways, while most of it remains persistent.

Depressed mood during early to middle adolescence: a bi-national longitudinal study of the unique impact of family conflict

Adolescent depressed mood is related to the development of subsequent mental health problems, and family problems have been linked to adolescent depression. Longitudinal research on adolescent depressed mood is needed to establish the unique impact of family problems independent of other potential drivers. This study tested the extent to which family conflict exacerbates depressed mood during adolescence, independent of changes in depressed mood over time, academic performance, bullying victimization, negative cognitive style, and gender. Students (13 years old) participated in a three-wave bi-national study (n = 961 from the State of Washington, United States, n = 981 from Victoria, Australia; 98 % retention, 51 % female in each sample). The model was cross-lagged and controlled for the autocorrelation of depressed mood, negative cognitive style, academic failure, and bullying victimization. Family conflict partially predicted changes in depressed mood independent of changes in depressed mood over time and the other controls. There was also evidence that family conflict and adolescent depressed mood are reciprocally related over time. The findings were closely replicated across the two samples. The study identifies potential points of intervention to interrupt the progression of depressed mood in early to middle adolescence.

Longitudinal surveys of Australian youth : active citizenship and the secondary school experience : community participation rates of Australian youth

LSAY is a research program that follows young Australians as they move through secondary school, into further education or training, and into the labour market and adult life. This website provides access to the electronic full text versions of LSAY research reports, from 1996 to present.

Modifiable determinants of youth violence in Australia and the United States : a longitudinal study

Youth violence is a global problem. Few studies have examined whrther the prevalence or predictors of youth violence are similar in comparable Western countries like Australia and the United States (US). In the current article, analyses are conducted using two waves of data collected as part of a longitudinal study of adolescent development in approximately 4,000 students aged 12 to 16 years in Victoria, Australia and Washington State, US. Students completed a self-report survey of problem behaviours including violent behaviour, as well as risk and protective factors across five domains (individual, family, peer, school, community). Compared to Washington State, rates of attacking or beating another over the past 12 months were lower in Victoria for females in the first survey and higher for Victorian males in the follow-up survey. Preliminary analyses did not show state-specific predictors of violent behaviour. In the final multivariate analyses of the combined Washington State and Victorian samples, protective factors were being female and student emotion control. Risk factors were prior violent behaviour, family conflict, association with violent peers, community disorganisation, community norms favourable to drug use, school suspensions and arrests. Given the similarity of influential factors in North America and Australia, application of US early intervention and prevention programs may be warranted, with some tailoring to the Australian context.

Social norms in the development of adolescent substance use: a longitudinal analysis of the International Youth Development Study.

Identifying specific aspects of peer social norms that influence adolescent substance use may assist international prevention efforts. This study examines two aggregated measures of social norms in the school setting and their predictive association with substance (alcohol, tobacco and marijuana) use 2 years later in a large cross-national population-based cohort of adolescents. The primary hypothesis is that in Grade 7 both "injunctive" school norms (where students associate substance use with "coolness") and "descriptive" norms (where student substance use is common) will predict Grade 9 substance use. Data come from the International Youth Development Study, including 2,248 students (51.2% female) in the US and Australia attending 121 schools in Grade 7. Independent variables included injunctive norms (aggregating measures of school-wide coolness ratings of each substance use) and descriptive norms (aggregating the prevalence of school substance use) in Grade 7. Dependent variables included binge drinking and current use of alcohol, tobacco and marijuana in Grade 9. Associations between each type of school-wide social norm and substance use behaviors in Grade 9 were tested using multilevel logistic regression, adjusting for covariates. In unadjusted models, both injunctive and descriptive norms each significantly predicted subsequent substance use. In fully adjusted models, injunctive norms were no longer significantly associated with Grade 9 use, but descriptive norms remained significantly associated with tobacco and marijuana use in the expected direction. The findings identify descriptive social norms in the school context as a particularly important area to address in adolescent substance use prevention efforts.

Reassessing the Effects of Early Adolescent Alcohol Use on Later Antisocial Behavior : A Longitudinal Study of Students in Victoria, Australia and Washington State, United States

The effect of early adolescent alcohol use on antisocial behavior was examined at one- and two-year follow-up in Washington, United States and Victoria, Australia. Each state used the same methods to survey statewide representative samples of students (N = 1,858, 52% female) in 2002 (Grade 7 [G7]), 2003 (Grade 8 [G8]), and 2004 (Grade 9 [G9]). Rates of lifetime, current, frequent, and heavy episodic alcohol use were higher in Victoria than Washington State, whereas rates of five antisocial behaviors were generally comparable across states. After controlling for established risk factors, few associations between alcohol use and antisocial behavior remained, except that G7 current use predicted G8 police arrests and stealing and G9 carrying a weapon and stealing; G7 heavy episodic use predicted G8 and G9 police arrests; and G7 lifetime use predicted G9 carrying a weapon. Hence, risk factors other than alcohol were stronger predictors of antisocial behaviors.

Attaching unit costs to Australia`s national survey of mental health and wellbeing

Background: In mental health, policy-makers and planners are increasingly being asked to set priorities. This means that health economists, health services researchers and clinical investigators are being called upon to work together to define and measure costs. Typically, these researchers take available service utilisation data and convert them to costs, using a range of assumptions. There are inefficiencies, as individual groups of researchers frequently repeat essentially similar exercises in achieving this end. There are clearly areas where shared or common investment in the development of statistical software syntax, analytical frameworks and other resources could maximise the use of data.

Aims of the Study: This paper reports on an Australian project in which we calculated unit costs for mental health admissions and community encounters. In reporting on these calculations, our purpose is to make the data and the resources associated with them publicly available to researchers interested in conducting economic analyses, and allow them to copy, distribute and modify them, providing that all copies and modifications are available under the same terms and conditions (i.e., in accordance with the `Copyleft' principle). Within this context, the objectives of the paper are to: (i) introduce the `Copyleft' principle; (ii) provide an overview of the methodology we employed to derive the unit costs; (iii) present the unit costs themselves; and (iv) examine the total and mean costs for a range of single and comorbid conditions, as an example of the kind of question that the unit cost data can be used to address.

Method: We took relevant data from the Australian National Survey of Mental Health and Wellbeing (NSMHWB), and developed a set of unit costs for inpatient and community encounters. We then examined total and mean costs for a range of single and comorbid conditions.

Results: We present the unit costs for mental health admissions and mental health community contacts. Our example, which explored the association between comorbidity and total and mean costs, suggested that comorbidly occurring conditions cost more than conditions which occur on their own.

Discussion: Our unit costs, and the materials associated with them, have been published in a freely available form governed by a provision termed `Copyleft'. They provide a valuable resource for researchers wanting to explore economic questions in mental health.

Implications for Health Policies: Our unit costs provide an important resource to inform economic debate in mental health in Australia, particularly in the area of priority-setting. In the past, such debate has largely been based on opinion. Our unit costs provide the underpinning to strengthen the evidence-base of this debate.

Implications for Further Research: We would encourage other Australian researchers to make use of our unit costs in order to foster comparability across studies. We would also encourage Australian and international researchers to adopt the `Copyleft' principle in equivalent circumstances. Furthermore, we suggest that the provision of `Copyleft'-contingent funding to support the development of enabling resources for researchers should be considered in the planning of future large-scale collaborative survey work, both in Australia and overseas.

ACCCN national nursing workforce survey of intensive care units

A descriptive study was designed and implemented by the Australian College of Critical Care Nurses (ACCCN) Workforce Planning Advisory Committee to capture data pertaining to workforce issues of intensive care nurses. All intensive care units (ICUs) within Australia were mailed a self reporting survey. Despite a low response rate (52 per cent) and difficulty reported by respondents in gaining the appropriate data requested, the results revealed an interesting snapshot of the intensive care nursing workforce.
Types of services offered by units varied considerably; paid overtime hours were low (<2 per cent of total hours worked) and use of both part-time and agency staff was also low (10 per cent of total hours worked). Private hospitals utilised a greater proportion of part-time and agency nursing staff than public hospitals (20:10 per cent). The turnover rate for registered nursing staff was estimated at 18 per cent, with education, skill acquisition and improved communication reported as the major incentives used by managers to attract and retain staff. This study demonstrated that valuable data are currently uncaptured and recommends a more refined process of a national database to record and manage this important information for future workforce planning.

The measurement of socio-economic status: investigation of gender-and age-specific indicators in Australia: national health survey 1995

Objective: To investigate thecorrelations between age- and gender-specificmeasures of socio-economic status versus healthstatus as measured by the SF-36.

Design: Population based study.

Participants: 38187 people aged between18 to 79 years who participated in the NationalHealth Survey in 1995.

Results: Factor analysis producedconsistent results that were interpreted interms of five conceptually meaningful domains(employment, housing, migration, family unitand education). The relative rank of thefactors differs between groups and in somecases factor composition requires items to beadded or deleted from the conceptual domains.

Conclusions: Age- and gender-specific SESscores based on these factors had strongerassociations with the physical and mentalcomponents of SF-36 than either an area basedindex or scores derived from males aged 40–44years. Overall the results supported thehypothesis that SES measures composed of socialand demographic items exhibit important age-and gender-specific differences which arerelevant for health.

Dietary patterns of Australian adults and their association with socio-economic status: results from the 1995 national nutrition survey

Objective: To describe dietary patterns among men and women in the Australian population, and to explore how these varied according to socioeconomic status (SES).

Design: A cross-sectional self-report population survey, the 1995 Australian National Nutrition Survey (NNS), was used.

Setting: Private dwelling sample, covering urban and rural areas across Australia.

Subjects: Data provided by 6680 adults aged 18-64 who participated in the NNS were used in the analyses.

Methods: Factor analyses were used to analyse data from a Food Frequency Questionnaire (FFQ) completed by participants. Associations between SES and dietary pattens were assessed using ANOVA.

Results: Separate factor analyses of the FFQ data for men and women revealed 15 factors, accounting for approximately 50% of the variance in both men's and women's dietary patterns. Several gender and SES differences in food patterns were observed. Lower SES males more frequently consumed 'tropical fruits', 'protein foods', and 'offal and canned fish', while high SES males more often ate 'breakfast cereals' and 'wholemeal bread'. Lower SES females more often ate 'traditional vegetables', 'meat dishes' and 'pasta, rice and other mixed foods', while high SES females more frequently ate 'ethnic vegetables' and 'breakfast cereal/muesli'.

Conclusions: These findings contribute to a better understanding of the dietary patterns that underscore gender-specific SES differences in nutrient intakes. Analyses of the type employed in this study will facilitate the development of interventions aimed at modifying overall eating patterns, rather than specific components of the diet.

Under-reporting of energy intake in the 1997 national nutrition survey

Aims To estimate the level of under-reporting of energy intake by gender, age, ethnicity and body size (normal, overweight, obese) in the 1997 National Nutrition Survey (NNS97) in New Zealand.
Methods Data were from 4,258 participants (1,808 men and 2,450 women aged 15 years and over) who completed the 24-hour diet recall; the primary methodology used in the NNS97. Under-reporting was assessed using the ratio of reported energy intake to estimated resting metabolic rate (EI: RMRest). Cut-off limits were used to identify percentages of under-reporters in the various subgroups.
Results Mean EI: RMRest was 1.40 for all participants (1.51 for men, 1.30 for women, p<0.001) with older age being associated with lower EI: RMRest (p<0.001). There were no significant differences in mean EI: RMRest between ethnic groups for men.
Mean EI: RMRest for women were: Maori 1.46, European 1.29, and Pacific 1.37 (p<0.01). A larger body size was associated with a significantly lower EI: RMRest especially for women.
Percentages of ‘definite’ under-reporters (individual EI: RMRest <0.9) were as follows: men 12%, women 21%; Europeans 16%, Maori 23% and Pacific 26%; normal weight (11%), overweight (19%) and obese (27%) participants; and from 10% in the youngest to 23% in the oldest age group (p<0.001 for all results).
Conclusion In this study, in agreement with the literature, women, older people and obese people under-reported more than men, younger people and non-obese people. Possible ethnic differences in under-reporting rates need further study. Care is needed in interpreting the energy intake data from the NNS97.

The effect of school suspensions and arrests on subsequent adolescent antisocial behavior in Australia and the United States

Purpose: To examine the effect of school suspensions and arrests (i.e., being taken into police custody) on subsequent adolescent antisocial behavior such as violence and crime, after controlling for established risk and protective factors in Victoria, Australia and Washington State, United States (U.S.). Methods: This article reports on analyses of two points of data collected 1 year apart within a cross-national longitudinal study of the development of antisocial behavior, substance use, and related behaviors in approximately 4000 students aged 12 to 16 years in Victoria, Australia and Washington State, U.S. Students completed a modified version of the Communities That Care self-report survey of behavior, as well as risk and protective factors across five domains (individual, family, peer, school, and community). Multivariate logistic regression analyses investigate the effect of school suspensions and arrests on subsequent antisocial behavior, holding constant individual, family, peer, school, and community level influences such as being female, student belief in the moral order, emotional control, and attachment to mother. Results: At the first assessment, school suspensions and arrests were more commonly reported in Washington, and school suspensions significantly increased the likelihood of antisocial behavior 12 months later, after holding constant established risk and protective factors (adjusted odds ratio [OR] 1.5, 95% confidence interval [CI] 1.1–2.1, _p < .05). Predictors of antisocial behavior spanned risk and protective factors across five individual and ecological areas of risk. Risk factors in this study were pre-existing antisocial behavior (OR 3.6, CI 2.7–4.7, _p < .001), association with antisocial peers (OR 1.8, CI 1.4–2.4, _p < .001), academic failure (OR 1.3, CI 1.1–1.5, _p < .01), and perceived availability of drugs in the community (OR 1.3, CI 1.1–1.5, _p < .001). Protective factors included being female (OR 0.7, CI 0.5–0.9, _p < .01), student belief in the moral order (OR 0.8, CI 0.6–1.0, p < .05), student emotional control (OR 0.7, CI 0.6–0.8, _p < .001), and attachment to mother (OR 0.8, CI 0.7–1.0, _p < .05). Conclusions:  School suspensions may increase the likelihood of future antisocial behavior. Further research is required to both replicate this finding and establish the mechanisms by which school suspensions exert their effects.