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

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

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

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

Inadequate sun protection practices lead to sunburn among New Zealanders.

Nil.

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

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

Adult Externalizing and Suicidal Behavior in Children Who Set Fires: Analysis of a 40 Year Birth Cohort Study.

OBJECTIVE: Firesetting in children is thought to be an indicator of severe conduct problems in young people. However, no research has examined whether childhood firesetting is also associated with increased risk of externalizing and suicidal behaviors in adulthood. METHOD: Data were obtained from a longitudinal study (n = 1265). Childhood firesetting/conduct problems (7-10 years) were derived from an assessment of antisocial behavior. Externalizing/suicidal behavior was derived from the Composite International Diagnostic Interview and the Self-Report Delinquency Inventory. Generalized estimating equation (GEE) models estimated associations between childhood firesetting and adult substance use disorders, criminal offending, and suicidal ideation, adjusting for childhood conduct problems and other confounding factors. Associations between childhood and adult firesetting (age 18-40 years) were examined using cross-tabulation (χ2). RESULTS: Five percent of children reported firesetting (7-10 years). Childhood firesetting appeared to increase the risk of adult firesetting; however, in most cases adult firesetting was not associated with childhood firesetting (χ2 (1) = 4.15, p = .0417). Childhood firesetting was a risk marker for adult externalizing/suicidal behavior; however, the effect was relatively weak (IRR = 1.51; 95% CI: 1.11-2.05). Children with conduct problems who also engaged in firesetting were found to be at substantially higher risk of later externalizing/suicidal behavior (IRR = 2.84; 95% CI: 1.24-6.49). CONCLUSION: This study found that childhood firesetting is a risk marker for adult externalizing/suicidal behavior, not an independent risk factor. It may be more useful for clinicians to focus on child conduct problems generally, rather than focussing on firesetting behavior.

Biomarkers of ageing in New Zealand VLBW young adults and controls.

BACKGROUND: There is individual variation in physiological ageing. Former very low birthweight (VLBW; birthweight < 1500 g) young adults may have less satisfactory measurements on some physiological parameters than term controls. We hypothesized that a summation score of physiological biomarkers that change with age would show VLBW adults to have a more advanced physiologic age than controls. METHODS: VLBW adults (229; 71% survivors of a national VLBW cohort) and term-born controls (100) were clinically assessed at 26-30 years. Ten measured physiological biomarkers were selected and measurements converted to z-scores using normative reference data. Between-group comparisons were tested for statistical significance for individual biomarker z-scores and a summation score. RESULTS: Nine of 10 biomarkers showed a mean z-score suggestive of older physiological age in the VLBW group versus controls. The observed mean difference in the summation score was highly significant (p < 0.001), representing a mean shift of 0.47 SD in the distribution of test scores for VLBW relative to controls. CONCLUSIONS: Utilizing a 10-biomarker score, VLBW young adults have a score indicative of poorer physiological functioning than term-born controls. Repeating these measures after an interval could provide insights into the comparative pace of ageing between VLBW and term-born adults. IMPACT: A summation score of 10 physiological biomarkers that are known to change with age shows that former very low birthweight adults have significantly poorer physiological functioning by the end of their third decade than term-born controls. This result adds to existing literature showing very preterm and very low birthweight young adults often have physiological and metabolic test results that are less satisfactory than those from term controls, despite mostly being in the normal range for age; for instance, higher systolic blood pressure. Although the pace of ageing in later years is yet to be established, the implications of this study are that preventative measures and lifestyle choices that impact on physiological ageing might have even greater importance for very preterm and very low birthweight graduates.

Attitudes towards cannabis and cannabis law change in a New Zealand birth cohort.

AIMS: Personal cannabis use is common across New Zealand, and an upcoming referendum will enable the public to vote on whether this should be legalised. The present research aimed to examine the attitudes of midlife New Zealand adults on cannabis use and legalisation, and to identify potential predictors of those attitudes. METHODS: At age 40, 899 participants drawn from the Christchurch Health and Development Study were interviewed about the perceived harmfulness of cannabis use, opinions on legalisation for recreational use and supply, and the use of cannabis for medicinal purposes. In addition, a range of potential predictors of legislative attitudes were examined. RESULTS: We identified a wide range of attitudes across the cohort, however the majority tended to hold a neutral view. More than 80% of the cohort expressed support for medicinal cannabis, while 47.8% supported decriminalisation, and 26.8% expressed support for legalisation for recreational use. The strongest predictors of support for legalisation were prior use of cannabis and other drugs, while additional positive predictors included a history of depression, Maori ancestry, parental drug use, novelty seeking and higher educational attainment. Predictors of more negative attitudes were also identified, and included female gender and having dependent children. CONCLUSIONS: These findings provide insight into cannabis-related views within the New Zealand context, and may help to predict voting behaviour during the 2020 Cannabis Referendum.

Life-course trajectories of cannabis use: a latent class analysis of a New Zealand birth cohort.

BACKGROUND AND AIMS: Little is known about how cannabis use over the life-course relates to harms in adulthood. The present study aimed to identify trajectories of cannabis use from adolescence to adulthood and examine both the predictors of these trajectories and adverse adult outcomes associated with those trajectories. DESIGN: A latent trajectory analysis of a longitudinal birth cohort (from birth to age 35 years). SETTING AND PARTICIPANTS: General community sample (n = 1065) from New Zealand. MEASUREMENT: Annual frequency of cannabis use (ages 15-35 years); childhood family and individual characteristics (birth to age 16 years); measures of adult outcomes (substance use disorders, ages 30-35 years; mental health disorders, ages 30-35 years; socio-economic outcomes at age 35 years; social/family outcomes at age 35 years). FINDINGS: A six-class solution was the best fit to the data. Individuals assigned to trajectories with higher levels of cannabis use were more likely to have experienced adverse childhood family and individual circumstances. Membership of trajectories with higher levels of use was associated with increased risk of adverse outcomes at ages 30-35 years. Adjustment of these associations for the childhood family and individual predictors largely did not reduce the magnitude of the associations. CONCLUSIONS: In New Zealand, long-term frequent cannabis use, or transition to such use, appears to be robustly associated with diverse harms in adulthood.

Effects of global changes on ecosystems services of multiple natural resources in mountain agricultural landscapes.

Ongoing global changes can make unprecedented alterations in the state of some natural resources and their ecosystems services (ESs), especially in mountain agricultural landscapes. Considering the risk suggested by the Millennium Ecosystems Assessment, this study collected descriptive (qualitative) data in Nepalese mountain farming communities through field observation, group discussion, and personal interview, and investigated changing conditions of ESs of various natural resources in agricultural landscapes and their repercussions on mountain communities. The results showed that global changes induced new resources and institutions for mountain farming practices and altered important socioecological processes determining ESs. They have contributed to reductions in natural hazards and climate change and improvements in recreational and waste management services in mountain farming landscapes. Biodiversity status changes of the external factors in the agricultural landscapes are mixed: reasonably enriched plant species diversity and wildlife habitat, and seriously degraded or extinct indigenous species and genetic diversity. One of the serious negative changes is they have contributed to extinction of locally adaptable natural capitals and community heritages that had been developed through century-long socioecological processes and passed through extreme climatic variabilities and other environmental stresses at numerous times. The study determined that some recently emerging local biotic conditions result mainly from changes in the condition of water resources, not from changes in climatic conditions. The external factors also hampered human input into soil formation in degraded lands, soil quality, soil-water conservation and local knowledge systems. Overall, the effects of the changes found mixed on human and environment health. This multiple natural resources-based study has contested some arguments and conclusions of popular literatures.