Comparison of logistic-regression based methods for simple mediation analysis with a dichotomous outcome variable

Sex-based differences in TB treatment compliance: A mediating factor for sputum conversion among newly diagnosed pulmonary TB patients in Chennai, South India

Background

Tuberculosis (TB) remains a global health concern, particularly in India, which carries a significant portion of the global burden. The role of sex as a determinant of health is increasingly recognized, impacting various aspects of TB, including treatment compliance and outcomes. This study aimed to determine the mediating role of treatment compliance in the relationship between sex and sputum conversion in newly diagnosed pulmonary TB patients in Chennai, South India.

Methods

We conducted a retrospective cohort study among patients newly diagnosed for TB at ESIC Medical College & PGIMSR between April 2020 and April 2022. A causal mediation analysis was performed to identify the direct and indirect effects of sex on sputum conversion via the mediator, treatment compliance. We employed logistic regression models and the "paramed" package for the analysis, with bootstrapping technique for examining the significance of indirect and direct effects.

Results

The Marginal Total Effect (MTE) suggested that females were more likely to have sputum positivity compared to males (OR: 6.77; p = 0.003). Direct effect of being female increased the odds of sputum positivity at the end of the intensive phase (OR: 3.42; p = 0.03). The indirect effect of being female via treatment compliance significantly increased the odds of sputum positivity at the end of the intensive phase (OR: 1.98; p = 0.03).

Conclusion

The study provides evidence that treatment compliance significantly mediates the relationship between sex and sputum conversion in TB patients, highlighting the necessity to consider gendered dimensions of health in TB control strategies.

Borderline personality traits mediate the relationship between negative life events and nonsuicidal self-injury in a clinical sample with youth depression

BACKGROUND

Borderline personality traits play a significant role in nonsuicidal self-injury (NSSI), particularly in depressed youths. NSSI is also highly correlated with negative life events. This research aimed to explore the connections between negative life events, borderline personality traits, and NSSI.

METHODS

The study included 338 depressed youth aged 13 to 25 years. Self-reported measures and clinical interviews were utilized to evaluate the depressive symptoms, borderline personality traits, negative life events, and NSSI behaviours of these participants. Identifying variables linked to NSSI was the aim of our analysis, and we also conducted a mediation analysis to look into the influence of borderline traits on the connection between negative life events and NSSI.

RESULTS

Of the 338 depressed youth, approximately 59.47% (201/338) displayed NSSI, which was associated with greater clinical severity. Borderline traits had an independent influence on NSSI and it partially explained the connection between negative life events and NSSI, even when accounting for depression symptoms. Depressed youth who were more vulnerable to NSSI behaviours often experienced negative life events such as interpersonal relationships, academic pressure, being punished, and loss.

CONCLUSIONS

Our research suggests that depressed youth who experience more negative life events are more likely to experience NSSI, and negative life events indirectly influence nonsuicidal self-injury through borderline personality traits. Implementing interventions focused on mitigating borderline symptoms could be a promising therapeutic approach for addressing NSSI in young people.

Building consensus on priority areas for Sub-Saharan Africa's ageing population research: An e-Delphi study protocol

BACKGROUND

Improvement in medico-social services has increased life expectancy and population ageing in Sub-Saharan Africa (SSA). It was estimated that about 163 million people aged 65 and older will be resident in SSA by 2050. There is inadequate ageing research capacity in SSA which necessitates this study to (a) identify a decade-long ageing research opportunities, challenges, and solutions, and (b) prioritize critical ageing research areas and methodologies relevant to the SSA.

METHODS

We designed an e-Delphi protocol following the Reporting Guideline for Priority Setting of Health Research with Stakeholder. The stakeholders will be researchers, practitioners, older adults, and caregivers purposively selected through snowballing quota sampling to complete three rounds of e-Delphi surveys. Round 1 will involve open-ended questions derived from the study objectives. Responses from round 1 will be prepared as a checklist for stakeholders to rate during rounds 2 & 3, using a 9-point scale: low priority (1-3), moderate priority (4-6), and high priority (7-9). The criterion for reaching a consensus will be ≥ 70% of stakeholders rating an item "high priority" and ≤ 15% as "low priority." Quantitative data will be analysed using descriptive statistics, Wilcoxon matched-pairs signed-rank test will be used to assess the stability of stakeholders' responses, and qualitative comments will be analysed using content analysis.

DISCUSSION AND IMPLICATIONS

Setting aging research/practice priorities will help maximize the benefits of research investment and provide valuable direction for allocating public and private research funds to areas of strategic importance.

Association between breakfast skipping and psychosomatic symptoms among Canadian adolescents

This cross-sectional study aimed to examine the mediating roles of gender and substance use in the influence of breakfast skipping on psychosomatic symptoms. The study used data among a nationally-representative sample of 2855 Canadian adolescents who participated in the 2018 Health Behavior in School-aged Children (HBSC) survey. Sequential logistic regressions were used to estimate the associations between breakfast skipping and psychosomatic symptoms. Path analysis using a non-parametric bootstrapping technique tested the hypothesized mediating roles. Results showed that adolescents who skipped breakfast were 2.55 times more likely to report higher psychosomatic symptoms compared to non-breakfast skippers (AOR = 2.55; 95% CI = 1.75-3.82). The bootstrapping mediation models showed that breakfast skipping indirectly influenced psychosomatic symptoms through substance use and gender, accounting for 18.47% ( β = 0.0052, Boots 95% CI = 0.0025, 0.00730) and 10.70% ( β = 0.0091, Boots 95% CI = 0.0052, 0.0125), respectively, of the total effect. Our findings have important implications for targeted public and mental health interventions to address both breakfast skipping and psychosomatic symptoms among adolescents.  Conclusion: The study compellingly underscores the significance of incorporating gender-specific factors and substance use in understanding the correlation between breakfast skipping and psychosomatic symptoms. These insights hold importance for tailoring public health interventions to alleviate the prevalence of psychosomatic symptoms among adolescents by actively addressing breakfast skipping. What is Known: • Breakfast is considered the most important meal of the day due to its role in providing the brain with the energy necessary to enhance cognitive functions. • Adolescents commonly exhibit a prevalent lifestyle behaviour of skipping breakfast. What is New: • This study provides robust evidence supporting the association between breakfast skipping and elevated psychosomatic symptoms in adolescents. • Gender and substance use mediate this association, offering novel insights into the complex interplay that contributes to psychosomatic symptoms among this demographic group. • Longitudinal research is needed to unravel causal relationships and illuminate the underlying mechanisms of this intricate connection.

Association of chronic pain with suicide attempt and death by suicide: a two-sample Mendelian randomization

Prior studies have suggested an association between chronic pain and suicidal behavior. However, evidence supporting the causal nature of this association, and the role played by depression, remain difficult to establish due to confounding. We investigated associations of chronic pain with suicide attempt and death by suicide as well as the mediating role of depression in this association using a genetically informed method strengthening causal inference. We conducted a two-sample Mendelian randomization. Independent SNPs (N = 97) from the multisite chronic pain GWAS (NGWAS = 387,649) were used as instrumental variables to test associations of chronic pain with suicide attempt (measured from hospital records; NGWAS = 50,264) and death by suicide (measured from official death causes; NGWAS = 18,085). Indirect associations of chronic pain with suicide attempt and death by suicide via major depressive disorder (NGWAS = 173,005) were estimated. Primary analyses were supported by a range of sensitivity and outlier analyses. We found evidence supporting the contribution of chronic pain to increasing the risk of suicide attempt (OR = 1.67, CI = 1.21-2.35) and death by suicide (OR = 2.00, CI = 1.10-3.62). Associations were consistent across sensitivity analysis methods, and no evidence for outliers driving these associations was found. Through mediation analyses, we found that major depressive disorder explained a substantial proportion of the association between chronic pain and suicide attempt (proportion mediated = 39%; ORindirect association = 1.32, CI = 1.09-1.61) and death by suicide (proportion mediated = 34%; ORindirect association = 1.40, CI = 1.13-1.73). Our findings suggest that both pain management interventions and prevention of depression are likely to be effective strategies to reduce suicide risk in individuals with chronic pain.

Associations of plasma NfL, GFAP, and t-tau with cerebral small vessel disease and incident dementia: longitudinal data of the AGES-Reykjavik Study

We investigated the associations of plasma neurofilament light (NfL), glial fibrillary acidic protein (GFAP), and total tau (t-tau) with markers of cerebral small vessel disease (SVD) and with incident dementia. We also investigated whether associations of NfL, GFAP, and t-tau with incident dementia were explained by SVD. Data are from a random subsample (n = 1069) of the population-based AGES-Reykjavik Study who underwent brain MRI and in whom plasma NfL, GFAP, and t-tau were measured at baseline (76.1 ± 5.4 years/55.9% women/baseline 2002-2006/follow-up until 2015). A composite SVD burden score was calculated using white matter hyperintensity volume (WMHV), subcortical infarcts, cerebral microbleeds, and large perivascular spaces. Dementia was assessed in a 3-step process and adjudicated by specialists. Higher NfL was associated with a higher SVD burden score. Dementia occurred in 225 (21.0%) individuals. The SVD burden score significantly explained part of the association between NfL and incident dementia. WMHV mostly strongly contributed to the explained effect. GFAP was not associated with the SVD burden score, but was associated with WMHV, and WMHV significantly explained part of the association between GFAP and incident dementia. T-tau was associated with WMHV, but not with incident dementia. In conclusion, the marker most strongly related to SVD is plasma NfL, for which the association with WMHV appeared to explain part of its association with incident dementia. This study suggests that plasma NfL may reflect the contribution of co-morbid vascular disease to dementia. However, the magnitude of the explained effect was relatively small, and further research is required to investigate the clinical implications of this finding.

Longitudinal associations between anxiety sensitivity and substance use in adolescents: Mediation by depressive affect

Though anxiety sensitivity (AS)-fear of anxiety-related experiences-is primarily tied to anxiety vulnerability, AS has also been prospectively associated with general negative affect and depression. Furthermore, depression has been longitudinally associated with different forms of substance use, and some AS subfactors (e.g., cognitive concerns) have been associated more consistently with depression and substance use than others. However, no previous study has investigated if longitudinal associations of AS with substance use may be mediated by depression or whether aspects of AS may be prospectively associated with substance use among adolescents. Hence, the present study tested depressive affect (the negative affective aspect of depression) as a prospective mediator of AS associations with substance use and examined longitudinal AS subfactor associations with substance use and problems. High school 9th graders (N = 2,877; Mage = 14.1 years; 55.3% female) completed self-report measures at baseline and at 6 months and 1 year later. Depressive affect mediated AS associations with subsequent alcohol, cigarette, electronic cigarette, cannabis, benzodiazepine, and opioid use. Also, AS cognitive and social concerns (vs. physical concerns) were more consistently associated with later depressive affect and substance use and problems. Current findings suggest that adolescents high in anxiety sensitivity tend to prospectively experience greater depressive affect, which in turn is related to a higher likelihood of engaging in several different forms of substance use. Thus, it is possible that interventions which target AS (particularly AS cognitive concerns) may help to treat or prevent depression and substance use among adolescents. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Determinants of perceived health in university employees

Objective: Employee health plays an important role in overall campus health and wellbeing. Therefore, this research explored the physical, mental, and environmental determinants of perceived health in employees of higher education. Participants: 422 full-time employees from one university took the American College Health Association National Faculty and Staff Health Assessment (NFSHA) online in April 2021. Methods: A cross-sectional correlational design was used to explore which physical, mental, and environmental health factors influenced perceived health of employees. Results: Sleep, body mass index (BMI), flourishing, and the extent to which employees felt the university cared about their health and wellbeing were the four significant factors that increased the odds of employees reporting higher levels of perceived health. Conclusions: Using Bandura's reciprocal determinism as a theoretical lens, these results reinforce that behaviors, personal attributes, and the environment are interdependent and influence perceived health in this sample of university employees.

Can psychological distress account for the associations between COVID-19 vaccination acceptance and socio-economic vulnerability?

Socially disadvantaged individuals and communities consistently showed lower COVID-19 vaccination acceptance. We aimed to examine the psychological mechanisms that could explain such vaccination disparities. This study used data from serial population-based surveys conducted since the COVID-19 vaccination programme being launched in Hong Kong (N = 28,734). We first assessed the correlations of community-level and individual-level social vulnerability with COVID-19 vaccination acceptance. Structural equation modelling (SEM) was then conducted to test whether psychological distress measured by PHQ-4 can account for the associations between participants' socio-economic vulnerability and COVID-19 vaccination acceptance. The third part analysis examined whether perceived negativity of vaccine-related news and affect towards COVID-19 vaccines accounted for the association between psychological distress and COVID-19 vaccination. Communities with higher social vulnerability scores and participants who had more vulnerable socio-economic status showed lower COVID-19 vaccination acceptance. Individuals with more vulnerable socio-economic status reported higher psychological distress, which lowered COVID-19 vaccination acceptance. Furthermore, higher psychological distress was associated with lower vaccination acceptance through its psychological mechanisms of processing vaccine-related information. We proposed a renewed focus on tackling psychological distress rather than merely increasing vaccine accessibility in more socio-economic-disadvantaged groups for promoting COVID-19 vaccination acceptance.

Testing indirect effect with a complete or incomplete dichotomous mediator

Past methodological research on mediation analysis mainly focused on situations where all variables were complete and continuous. When issues of categorical data occur combined with missing data, more methodological considerations are involved. Specifically, appropriate decisions need to be made on estimation methods of the indirect effects and on confidence intervals for testing the indirect effects with accommodations of missing data. We compare strategies that address these issues based on a model with a dichotomous mediator, aiming to provide guidelines for researchers facing such challenges in practice.

A query theory account of the attraction effect

We provide novel support for Query Theory, a reason-based decision framework, extending it to multialternative choices and applying it to the classic phenomenon known as the attraction effect. In Experiment 1 (N = 261), we generalised the two key metrics used in Query Theory from binary to multialternative choices and found that reasons supporting the target option were generated earlier and in greater quantity than those supporting the competitor, as predicted by the theory. In Experiment 2 (N = 703), we investigated the causal relationships between reasoning and choices by exogenously manipulating the order in which participants generated their reasons. As predicted, the size of the attraction effect was a function of this query order manipulation. We also introduced a bidirectional reason coding protocol to measure the valence of reasons, which confirmed support for Query Theory. We suggest the Query Theory framework can be useful for studying the high-level deliberation processes behind multialternative choices.

Father trait anger: Associations with father–infant bonding and subsequent parenting stress

Introduction

Parent anger presents a risk to family safety and child development. Father trait anger may also compromise the early relational context of fathers and offspring, yet evidence is lacking. The aim of this study is to examine effects of father trait anger on parenting stress in the toddler years, and the mediational role of father–infant bonding.

Method

Data were from 177 Australian fathers of 205 children. Trait anger (total, angry temperament, and angry reaction), father–infant bonding subscales (patience and tolerance, affection and pride, and pleasure in interaction), and subsequent parenting stress (parental distress, difficult child, and parent–child dysfunctional interaction) were assessed. At each of the subscale levels, mediational path models examined whether father–infant bonding explained the relationship between trait anger and parenting stress. Models were presented where there was at least a small association between the mediator and both the predictor and outcome.

Results

Patience and tolerance was the only domain of father–infant bonding correlated with both trait anger and all parenting stress outcomes. Patience and tolerance partially mediated the effect of total trait anger on parental distress and fully mediated effects on difficult child and parent–child dysfunctional interaction. Patience and tolerance fully mediated relationships between angry temperament and all domains of parenting stress. Angry reactions only had a direct effect on parental distress.

Discussion

Father trait anger both directly and indirectly (through patience and tolerance in the father–infant bond) impacts their experiences of parenting stress in the toddler years. Early interventions to manage father trait anger and improve father–infant bonding may benefit fathers and children.

Effectiveness and cost-effectiveness of behavioural support for prolonged abstinence for smokers wishing to reduce but not quit: Randomised controlled trial of physical activity assisted reduction of smoking (TARS)

AIMS

For smokers unmotivated to quit, we assessed the effectiveness and cost-effectiveness of behavioural support to reduce smoking and increase physical activity on prolonged abstinence and related outcomes.

DESIGN

A multi-centred pragmatic two-arm parallel randomised controlled trial.

SETTING

Primary care and the community across four United Kingdom sites.

PARTICIPANTS

Nine hundred and fifteen adult smokers (55% female, 85% White), recruited via primary and secondary care and the community, who wished to reduce their smoking but not quit.

INTERVENTIONS

Participants were randomised to support as usual (SAU) (n = 458) versus multi-component community-based behavioural support (n = 457), involving up to eight weekly person-centred face-to-face or phone sessions with additional 6-week support for those wishing to quit.

MEASUREMENTS

Ideally, cessation follows smoking reduction so the primary pre-defined outcome was biochemically verified 6-month prolonged abstinence (from 3-9 months, with a secondary endpoint also considering abstinence between 9 and 15 months). Secondary outcomes included biochemically verified 12-month prolonged abstinence and point prevalent biochemically verified and self-reported abstinence, quit attempts, number of cigarettes smoked, pharmacological aids used, SF12, EQ-5D and moderate-to-vigorous physical activity (MVPA) at 3 and 9 months. Intervention costs were assessed for a cost-effectiveness analysis.

FINDINGS

Assuming missing data at follow-up implied continued smoking, nine (2.0%) intervention participants and four (0.9%) SAU participants achieved the primary outcome (adjusted odds ratio, 2.30; 95% confidence interval [CI] = 0.70-7.56, P = 0.169). At 3 and 9 months, the proportions self-reporting reducing cigarettes smoked from baseline by ≥50%, for intervention versus SAU, were 18.9% versus 10.5% (P = 0.009) and 14.4% versus 10% (P = 0.044), respectively. Mean difference in weekly MVPA at 3 months was 81.6 minutes in favour of the intervention group (95% CI = 28.75, 134.47: P = 0.003), but there was no significant difference at 9 months (23.70, 95% CI = -33.07, 80.47: P = 0.143). Changes in MVPA did not mediate changes in smoking outcomes. The intervention cost was £239.18 per person, with no evidence of cost-effectiveness.

CONCLUSIONS

For United Kingdom smokers wanting to reduce but not quit smoking, behavioural support to reduce smoking and increase physical activity improved some short-term smoking cessation and reduction outcomes and moderate-to-vigorous physical activity, but had no long-term effects on smoking cessation or physical activity.

Motivational support intervention to reduce smoking and increase physical activity in smokers not ready to quit: the TARS RCT

Background

Physical activity can support smoking cessation for smokers wanting to quit, but there have been no studies on supporting smokers wanting only to reduce. More broadly, the effect of motivational support for such smokers is unclear.

Objectives

The objectives were to determine if motivational support to increase physical activity and reduce smoking for smokers not wanting to immediately quit helps reduce smoking and increase abstinence and physical activity, and to determine if this intervention is cost-effective.

Design

This was a multicentred, two-arm, parallel-group, randomised (1 : 1) controlled superiority trial with accompanying trial-based and model-based economic evaluations, and a process evaluation.

Setting and participants

Participants from health and other community settings in four English cities received either the intervention (n = 457) or usual support (n = 458).

Intervention

The intervention consisted of up to eight face-to-face or telephone behavioural support sessions to reduce smoking and increase physical activity.

Main outcome measures

The main outcome measures were carbon monoxide-verified 6- and 12-month floating prolonged abstinence (primary outcome), self-reported number of cigarettes smoked per day, number of quit attempts and carbon monoxide-verified abstinence at 3 and 9 months. Furthermore, self-reported (3 and 9 months) and accelerometer-recorded (3 months) physical activity data were gathered. Process items, intervention costs and cost-effectiveness were also assessed.

Results

The average age of the sample was 49.8 years, and participants were predominantly from areas with socioeconomic deprivation and were moderately heavy smokers. The intervention was delivered with good fidelity. Few participants achieved carbon monoxide-verified 6-month prolonged abstinence [nine (2.0%) in the intervention group and four (0.9%) in the control group; adjusted odds ratio 2.30 (95% confidence interval 0.70 to 7.56)] or 12-month prolonged abstinence [six (1.3%) in the intervention group and one (0.2%) in the control group; adjusted odds ratio 6.33 (95% confidence interval 0.76 to 53.10)]. At 3 months, the intervention participants smoked fewer cigarettes than the control participants (21.1 vs. 26.8 per day). Intervention participants were more likely to reduce cigarettes by ≥ 50% by 3 months [18.9% vs. 10.5%; adjusted odds ratio 1.98 (95% confidence interval 1.35 to 2.90] and 9 months [14.4% vs. 10.0%; adjusted odds ratio 1.52 (95% confidence interval 1.01 to 2.29)], and reported more moderate-to-vigorous physical activity at 3 months [adjusted weekly mean difference of 81.61 minutes (95% confidence interval 28.75 to 134.47 minutes)], but not at 9 months. Increased physical activity did not mediate intervention effects on smoking. The intervention positively influenced most smoking and physical activity beliefs, with some intervention effects mediating changes in smoking and physical activity outcomes. The average intervention cost was estimated to be £239.18 per person, with an overall additional cost of £173.50 (95% confidence interval -£353.82 to £513.77) when considering intervention and health-care costs. The 1.1% absolute between-group difference in carbon monoxide-verified 6-month prolonged abstinence provided a small gain in lifetime quality-adjusted life-years (0.006), and a minimal saving in lifetime health-care costs (net saving £236).

Conclusions

There was no evidence that behavioural support for smoking reduction and increased physical activity led to meaningful increases in prolonged abstinence among smokers with no immediate plans to quit smoking. The intervention is not cost-effective.

Limitations

Prolonged abstinence rates were much lower than expected, meaning that the trial was underpowered to provide confidence that the intervention doubled prolonged abstinence.

Future work

Further research should explore the effects of the present intervention to support smokers who want to reduce prior to quitting, and/or extend the support available for prolonged reduction and abstinence.

Trial registration

This trial is registered as ISRCTN47776579.

Funding

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 27, No. 4. See the NIHR Journals Library website for further project information.

Youth organizations, social mobility and health in middle age: evidence from a Scottish 1950s prospective cohort study

BACKGROUND

Informal educational programmes focused on youth development appear to improve health and well-being at time of involvement. Less is known about long-term effects. We investigate their impact on self-reported general health in mid-life using the Aberdeen Children of the 1950s (ACONF) cohort.

METHODS

We use a subset (n = 1333) of the ACONF cohort, born 1950-56, in Aberdeen Scotland, who took part in Family and Reading Surveys in 1964 and a follow-up questionnaire in 2001. We explore exposure to youth development focused clubs in childhood on self-reported general health around age 50 mediated by adult socioeconomic position. Logistic regression and mediation analysis were used to report odds ratios and natural direct and indirect effects, respectively, on multiply imputed data.

RESULTS

Being a member of the Scouts/Guides (G&S) was associated with a 53% (95% confidence interval 1.03-2.27) higher odds of 'excellent' general health in adulthood compared to children attending 'other clubs'. Indirect effects of G&S and Boys'/Girls' Brigade (B&GB) on general health acting via higher socioeconomic position show positive associations; 12% and 6% higher odds of 'excellent' general health in adulthood compared to children attending 'other clubs', respectively. Comparison of indirect with direct effects suggests 27% of this association is mediated through a higher adult socioeconomic position in adulthood.

CONCLUSIONS

These results suggest a beneficial association between attending G&S and B&GB clubs in childhood and adult general health. As these organizations are volunteer-led, this may represent a cost-effective method for improving population health.

Mental health risk factors for shift work disorder in paramedics: A longitudinal study

OBJECTIVES

Depression and anxiety are prominent in paramedics, as is the prevalence of shift work disorder (SWD), a circadian sleep condition comorbid with mental health disorders. However, the role of mental health risk factors for SWD is largely unknown. This study investigated whether mental health levels in recruit paramedics before shift work predicted greater risk of SWD at 6-months into their career and explored whether shift and sleep factors mediated this relationship.

DESIGN

A longitudinal study.

SETTING

Victoria, Australia.

PARTICIPANTS

Recruit paramedics were assessed at baseline (n = 101; ie, pre-shift work) and after 6-months (n = 93) of shift and emergency work.

MEASUREMENTS

At both time points, participants completed self-reported measures of depression (Patient Health Questionnaire-9), anxiety (Generalized Anxiety Disorder Questionnaire-7), and SWD (SWD-Screening Questionnaire). Participants also filled a sleep and work diary for 14-days at each timepoint.

RESULTS

After 6-months of emergency work 21.5% of paramedics had a high SWD risk. Logistic regression models showed baseline depression predicted 1.24-times greater odds for SWD at 6-months. Through Lavaan path analysis we found shift and sleep variables did not mediate the relationship between baseline mental health and SWD risk. Baseline depression was associated with increased sleepiness levels following paramedics' major sleep periods at 6-months. Pre-existing depression levels also predicted greater perceived nightshift workload.

CONCLUSIONS

Our results highlight depression symptoms before emergency work are a risk factor for SWD within 6-months of work. Depression represents a modifiable risk factor amenable to early interventions to reduce paramedics' risk of SWD.

Differences in the Mediating Role of HL in Socioeconomic Inequalities in Health Across Age Groups: Results from the Dutch Doetinchem Cohort Study

BACKGROUND

Although it is known that health literacy (HL) plays an explanatory role in educational inequalities in health, it is unknown whether this role varies across age groups.

OBJECTIVE

The purpose of this study was to investigate whether the mediating role of HL in educational inequalities in four health outcomes varies across age groups: age 46 to 58 years, age 59 to 71 years, and age 72 to 84 years.

METHODS

We used data from the Dutch Doetinchem Cohort Study, which included 3,448 participants. We included years of education as predictor, chronic illness prevalence and incidence, mental and self-perceived health as outcomes, and HL, based on self-report, as mediator. We used multiple-group mediation models to compare indirect effects across age groups.

KEY RESULTS

In the complete sample without age stratification, HL partly mediated the effect of education on all health outcomes except for incidence of chronic diseases. These indirect effect estimates were larger for subjective (self-perceived health, proportion mediated [PM] = 37%, and mental health, PM = 37%) than for objective health outcomes (prevalence of chronic disease, PM = 17%). For the prevalence of chronic disease, the indirect effect estimate was significantly larger among individuals age 46 to 58 years compared to individuals age 59 to 71 years and for incidence of chronic disease also compared to individuals age 72 to 84 years. All other indirect effect estimates did not differ significantly between age groups. Using an alternative cut-off point for HL or adjusting for cognitive functioning did not meaningfully change the results.

CONCLUSIONS

Overall, we found that the explanatory role of HL in educational inequalities in mental and subjective health was stable but that it varied across age groups for chronic diseases, where it was largest among individuals age 46 to 58 years. Future studies may investigate the benefits of starting to intervene on HL from a younger age but means to improve HL may also benefit the subjective health of older adults with lower education. [HLRP: HL Research and Practice. 2023;7(1):e26-e38.] Plain Language Summary: This study examined age-group differences in the mediating role of HL in the relationship between education and health. Overall, we found that the explanatory role of HL in educational inequalities in mental and subjective health was stable but that it varied across age groups for chronic diseases, where it was largest among individuals age 46 to 58 years compared to individuals age 59 to 71 years and individuals age 72 to 84 years.

Sexual minority status, school-based violence, and current tobacco use among youth

INTRODUCTION

Sexual minority individuals experience elevated risk for smoking and violence due to a combination of general and unique identity-based risk factors. This study examined associations among sexual minority status, school-based violence, and tobacco use, among youth.

METHODS

Data for this secondary data analysis consisted of Chicago-specific data from the 2019 Youth Risk Behavior Surveillance System (n=1562). Current use (≥1 day during the previous 30 days) of any tobacco product (cigarettes, e-cigarettes, smokeless tobacco, and cigars) and school-based violence (avoided school because they felt unsafe, were threatened/injured with a weapon, were in a physical fight, and were bullied) were estimated by sexual orientation (heterosexual vs gay, lesbian, bisexual, and unsure). A chi-squared test was used to investigate associations among the variables. Path analysis was employed to examine possible mediation effects of school-based violence.

RESULTS

Thirty percent of sexual minority youth and 11.5% of heterosexual youth reported current tobacco use (χ²=55.91; p<0.001). Nearly one-third (31.8%) of youth reported school-based violence, with a higher rate (41.2%) reported by sexual minority youth compared to heterosexual youth (28.1%; χ²=19.48; p<0.001). Path analysis confirmed these associations, controlling for sex, age, and race/ethnicity. The model showed that sexual minority status increased odds of current tobacco use by a factor of 1.8 (95% CI: 1.3-2.6) via its relationship with school-based violence, explaining 33.8% of the total association between sexual minority status and tobacco use.

CONCLUSIONS

Tobacco use was higher among sexual minority youth. School-based violence partially mediated the association between sexual minority status and tobacco use. Findings highlight the need for tobacco prevention and treatment efforts for sexual minority youth and school-based interventions to reduce exposure to violence.

Allostatic Load and Adverse Pregnancy Outcomes

OBJECTIVE

To assess the association between allostatic load, as an estimate of chronic stress, and adverse pregnancy outcomes.

METHODS

This was a secondary analysis of nuMoM2b (Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be), a prospective observational cohort study. Our primary exposure was dichotomous high allostatic load in the first trimester, defined as 4 or more of 12 biomarkers in the "worst" quartile. The primary outcome was a composite adverse pregnancy outcome: hypertensive disorders of pregnancy (HDP), preterm birth, small for gestational age (SGA), and stillbirth. Secondary outcomes included components of the composite. Multivariable logistic regression was used to test the association between high allostatic load and adverse pregnancy outcomes, adjusted for potential confounders. Mediation and moderation analyses were conducted to assess the role of allostatic load along the causal pathway between racial disparities and adverse pregnancy outcomes.

RESULTS

Among 4,266 individuals, 34.7% had a high allostatic load. Composite adverse pregnancy outcome occurred in 1,171 (27.5%): 14.0% HDP, 8.6% preterm birth (48.0% spontaneous and 52.2% indicated), 11.0% SGA, and 0.3% stillbirth. After adjustment for maternal age, gravidity, smoking, bleeding in the first trimester, and health insurance, high allostatic load was significantly associated with a composite adverse pregnancy outcome (adjusted odds ratio [aOR] 1.5, 95% CI 1.3, 1.7) and HDP (aOR 2.5, 95% CI 2.0-2.9), but not preterm birth or SGA. High allostatic load partially mediated the association between self-reported race and adverse pregnancy outcomes. The association between allostatic load and HDP differed by self-reported race, but not for a composite adverse pregnancy outcome, preterm birth, or SGA.

CONCLUSION

High allostatic load in the first trimester is associated with adverse pregnancy outcomes, particularly HDP. Allostatic load was a partial mediator between race and adverse pregnancy outcomes. The association between allostatic load and HDP differed by self-reported race.

Serum extracellular vesicle microRNA dysregulation and childhood trauma in adolescents with major depressive disorder

Major depressive disorder (MDD) seriously endangers adolescent mental and physical health. Extracellular vesicles (EVs) are mediators of cellular communication and are involved in many physiological brain processes. Although EV miRNAshave been implicated in adults with major psychiatric disorders, investigation into their effects in adolescent MDDremains scarce. In discovery set, we conducted a genome-wide miRNA sequencing of serum EVs from 9 untreated adolescents with MDD and 8 matched healthy controls (HCs), identifying 32 differentially expressed miRNAs (18 upregulated and 14 downregulated). In the validation set, 8 differentially expressed and highly enriched miRNAs were verified in independent samples using RT-PCR, with 4 (miR-450a-2-3p, miR-3691-5p, miR-556-3p, and miR-2115-3p) of the 8 miRNAs found to be significantly elevated in 34 untreated adolescents with MDD compared with 38 HCs and consistent with the sequencing results. After the Bonferroni correction, we found that three miRNAs (miR-450a-2-3p, miR-556-3p, and miR-2115-3p) were still significantly different. Among them, miR-450a-2-3p showed the most markeddifferential expression and was able to diagnose disease with 67.6% sensitivity and 84.2% specificity. Furthermore, miR-450a-2-3p partially mediated the associations between total childhood trauma, emotional abuse, and physical neglect and adolescent MDD. We also found that the combination of miR-450a-2-3p and emotional abuse could effectively diagnose MDD in adolescents with 82.4% sensitivity and 81.6% specificity. Our data demonstrate the association of serum EV miRNA dysregulation with MDD pathophysiology and, furthermore, show that miRNAs may mediate the relationship between early stress and MDD susceptibility. We also provide a valid integrated model for the diagnosis of adolescent MDD.

Time-Varying Mediation of Pharmacological Smoking Cessation Treatments on Smoking Lapse via Craving, Cessation Fatigue, and Negative Mood

INTRODUCTION

The addictive nature of nicotine makes smoking cessation an extremely challenging process. With prolonged exposure, tobacco smoking transforms from being a positive reinforcer to a negative one, as smoking is used to mitigate aversive withdrawal symptoms. Studying the variations in withdrawal symptoms, especially during their peak in the first week of a quit attempt, could help improve cessation treatment for the future. The time-varying mediation model effectively studies whether altering withdrawal symptoms act as mediators in the pathway between treatment and cessation.

AIMS AND METHODS

This secondary data analysis of a randomized clinical smoking cessation trial of three pharmacotherapy regimens (nicotine patch, varenicline, and nicotine patch + mini-lozenge) analyzes ecological momentary assessment (EMA) data from the first 4 weeks post-target quit day (TQD). We assess whether withdrawal symptoms (eg, negative mood, cessation fatigue, and craving) mediate the pathway between pharmacotherapy and daily smoking status and whether this effect varies over time.

RESULTS

We found a statistically significant time-varying mediation effect of varenicline on smoking status through craving, which shows decreasing risk of lapse via reduction in craving. We did not find significant time-varying mediation effects through negative mood and cessation fatigue.

CONCLUSIONS

This study supports the importance of craving suppression in the smoking cessation process. It also helped identify specific timepoints when withdrawal symptoms increased that would likely benefit from targeted cessation intervention strategies.

IMPLICATIONS

This study aimed to understand the underlying dynamic mechanisms of the smoking cessation process using a new analytical approach that capitalizes on the intensive longitudinal data collected via EMAs. The findings from this study further elucidate the smoking cessation process and provide insight into behavioral intervention targets and the timing of such interventions through the estimation of time-varying mediation effects.

Where does residents' choice of primary medical treatment come from?-A logical analysis based on the perspective of service accessibility and residents' cognition

The uneven distribution of medical and health resources leads to changes in the choice of patients for medical treatment, which is the key to restrict the reform of medical services in China currently. Taking service accessibility and residents' cognition as the starting point, this study utilized the data from the questionnaire and applied logistic regression and mediation test. By taking service accessibility as an explanatory variable and residents' cognition as an intermediary variable, the study examined the differences between residents' choice of medical treatment at the primary and non-primary levels. Thus, the influencing factors of residents' choice of medical treatment at the primary level were explored. The research statistics came from questionnaires of 1,589 residents in Nanjing, Jiangsu Province, China. The results showed that service accessibility and residents' cognition were significantly correlated with the residents' choice of primary medical treatment. Household registration, age, the signing situation with family doctors, hospital service fees, and distance to the hospital were positively related to residents' choice of primary medical treatment; while the reputation, scale, residents' income, and the reimbursement ratio of residents' medical insurance were negatively correlated with the choice. In addition, residents' cognition played an intermediary effect between service accessibility and the residents' choice of primary medical treatment. The signing situation with family doctors indirectly affected the choice of primary medical treatment through residents' cognition, and residents' cognition masked some negative influence of the reimbursement ratio of residents' medical insurance on the choice of primary medical treatment.

Molecular mediators of the association between child obesity and mental health

Biological mechanisms underlying the association between obesity and depression remain unclear. We investigated the role of metabolites and DNA methylation as mediators of the relationship between childhood obesity and subsequent poor mental health in the English Avon Longitudinal Study of Parents and Children. Obesity was defined according to United Kingdom Growth charts at age 7 years and mental health through the Short Mood and Feelings Questionnaire (SMFQ) completed at age 11 years. Metabolites and DNA methylation were measured by nuclear magnetic resonance spectroscopy and Illumina array in blood at the age of 7 years. The associations between obesity and SMFQ score, as continuous count data or using cut-offs to define depressive symptoms (SMFQ >7) or depression (SMFQ >11), were tested using adjusted Poisson and logistic regression. Candidate metabolite mediators were identified through metabolome-wide association scans for obesity and SMFQ score, correcting for false-discovery rate. Candidate DNA methylation mediators were identified through testing the association of putative BMI-associated CpG sites with SMFQ scores, correcting for look-up false-discovery rate. Mediation by candidate molecular markers was tested. Two-sample Mendelian randomization (MR) analyses were additionally applied to test causal associations of metabolites with depression in independent adult samples. 4,018 and 768 children were included for metabolomics and epigenetics analyses, respectively. Obesity at 7 years was associated with a 14% increase in SMFQ score (95% CI: 1.04, 1.25) and greater odds of depression (OR: 1.46 (95% CI: 0.78, 2.38) at 11 years. Natural indirect effects (mediating pathways) between obesity and depression for tyrosine, leucine and conjugated linoleic acid were 1.06 (95% CI: 1.00, 1.13, proportion mediated (PM): 15%), 1.04 (95% CI: 0.99, 1.10, PM: 9.6%) and 1.06 (95% CI: 1.00, 1.12, PM: 13.9%) respectively. In MR analysis, one unit increase in tyrosine was associated with 0.13 higher log odds of depression (p = 0.1). Methylation at cg17128312, located in the FBXW9 gene, had a natural indirect effect of 1.05 (95% CI: 1.01,1.13, PM: 27%) as a mediator of obesity and SMFQ score. Potential biologically plausible mechanisms involving these identified molecular features include neurotransmitter regulation, inflammation, and gut microbiome modulation. These results require replication in further observational and mechanistic studies.

The Association Between Adverse Childhood Experiences and Positive Dementia Screen in American Older Adults

BACKGROUND

Adverse childhood experiences (ACEs) are linked to higher risk of common conditions driving mortality in adulthood, but little evidence exists on whether ACEs are associated with risk of dementia, a leading cause of death in the USA.

OBJECTIVE

To estimate the relationship between US adults' reported ACE scores and a positive screen for dementia.

DESIGN

Cross-sectional analysis of a longitudinal, national population-based survey of US older adults.

PARTICIPANTS

Survey respondents aged ≥ 65 years with dementia screening data from the 2017 wave of the Panel Study of Income Dynamics (PSID) and ACE scores from the 2014 PSID Childhood Retrospective Circumstances Survey supplement (1,488 eligible participants unweighted).

MAIN MEASURES

Dementia screening data was collected in the 2017 wave of the PSID using the 8-item informant interview to differentiate normal cognition and dementia (AD8). Mean change in AD8 score and probability of a positive dementia screen by ACE score were calculated using adjusted regression models with post-estimation. Analyses were stratified by age group. Measures were analyzed in 2020.

RESULTS

Complete data were available for 1,223 (82%) participants, with a mean age of 73.4 years (SD 7.1, range 65 to 96 years). Adjusted estimated probability of a positive dementia screen increased with each additional adverse childhood experience reported. Older adults with ≥ 4 ACEs had higher rates of a positive dementia screen (AD8 score ≥ 2 points) compared to those with no ACEs (adjusted rate 26.6% versus 16.3%, p = 0.034). Compared to those with no ACE history, respondents with ≥ 4 ACEs had higher odds of a 1-point increase in AD8 score across all intervals of the AD8 scale (aOR 1.79, 95% CI 1.05-3.04). The ACE-positive dementia screen associations were strongest among those aged 65-75.

CONCLUSIONS

Greater exposure to ACEs is independently associated with higher probability of a positive dementia screen in older adulthood.

Effect of treatment adherence on the association between sex and unfavourable treatment outcomes among tuberculosis patients in Puducherry, India: a mediation analysis

BACKGROUND

A better understanding of the complex interplay between risk factors of tuberculosis (TB) is essential. This study was part of the Regional Prospective Observational Research for Tuberculosis (RePORT) India consortium and includes newly diagnosed TB patients in Puducherry between 2014 and 2018. We employed mediation analysis to identify the effect of treatment adherence on association between sex and unfavourable TB treatment outcomes.

METHODS

Required demographic and treatment-related variables were extracted from the RePORT India consortium database and causal mediation analysis using parametric regression models was done.

RESULTS

Of the 712 TB patients, ~87 (12.2%) had unfavourable TB treatment outcomes. Total effect of male sex was significantly associated with the unfavourable TB treatment outcomes [adjusted odds ratio (aOR) = 2.48; 95% confidence interval (CI): 1.11-5.55]. However, the overall association between male sex and TB treatment outcomes was dominated by the indirect pathway, as the direct pathway does not show significant association (aOR = 1.67; 95% CI: 0.75-3.75), while the indirect pathway shows significantly higher odds of TB treatment outcomes (aOR = 1.48; 95% CI:1.27-1.73), indicating complete mediation by the treatment adherence.

CONCLUSIONS

The study has shown a complete mediation of sexes through TB treatment adherence for unfavourable treatment outcomes. Developing of treatment strategies require better understanding between the biological and social factors related to TB.

The impact of social unrest and pandemic on mental health of young people in Hong Kong: The transdiagnostic role of event-based rumination

OBJECTIVE

Co-occurring population-level events, such as social unrest and coronavirus disease 2019, are observed in many societies today. Few studies have explored their combined mental health effects on young people. While self-focused rumination has been suggested to be a key mechanism underlying depression, the role of event-based rumination in mediating the impact of population stressors has yet to be elucidated.

METHODS

Data were collected from 6988 young people in a large-scale community online survey in Hong Kong. The survey assessed symptoms of post-traumatic stress disorder and depression, direct exposure to social unrest-related traumatic events, coronavirus disease 2019 pandemic-related events, personal stressful life events, event-based rumination and other individual risk factors.

RESULTS

High levels of comorbid post-traumatic stress disorder and depressive symptoms were observed. Logistic regression analysis revealed that probable post-traumatic stress disorder was associated with traumatic events (odds ratio = 1.73, 95% confidence interval = [1.64, 1.82]), pandemic-related events (odds ratio = 1.08, confidence interval = [1.01, 1.16]), stressful life events (odds ratio = 1.20, confidence interval = [1.21, 1.37]), high event-based rumination (odds ratio = 3.00, confidence interval = [2.58, 3.48]), lower resilience (odds ratio = 1.18, confidence interval = [1.15, 1.21]), higher smartphone reliance (odds ratio = 1.09, confidence interval = [1.05, 1.13]) and financial concerns (odds ratio = 1.25, confidence interval = [1.18, 1.33]). The odds for probable post-traumatic stress disorder was also significantly higher when two or more traumatic events were experienced (odds ratio = 4.03, confidence interval = [3.52, 4.62]). Factors associated with moderate-to-severe level depressive symptoms were similar. Event-based rumination significantly mediated between different types of external events (traumatic events, pandemic-related events, stressful life events) and both post-traumatic stress disorder and depressive symptoms.

CONCLUSION

These findings suggest that diverse types of stressful events during population-level crises could add to personal stressors to affect mental health outcomes in young people. Among other protective and risk factors, event-based rumination presented as a prominent transdiagnostic mediator for different symptom dimensions which may be a potentially important target for early risk detection and intervention.

Borderline personality traits mediate the relationship between low perceived social support and non-suicidal self-injury in a clinical sample of adolescents

BACKGROUND

Non-suicidal self-injury (NSSI) is a serious public health concern among adolescents, especially in clinical settings. Social support plays a critical role in the onset and maintenance of NSSI in adolescence. NSSI is closely associated with borderline personality disorder (BPD), yet no previous work has analyzed the mediating role of borderline traits in the relationship between perceived social support (PSS) and NSSI. This study aimed to address this gap.

METHODS

Participants were 228 adolescent patients (12 to 18 years old), who completed a clinical interview and self-report measures of BPD-traits, current psychological distress, emotion dysregulation and PSS. They were grouped based on the presence (vs. absence) of NSSI. Univariate and multivariate logistic regression analyses were used to identify risk factors of NSSI, and a mediation analysis was conducted to examine the intermediary role of borderline traits in the relationship between PSS and NSSI.

RESULTS

NSSI was highly prevalent in our sample (58%) and was associated with higher clinical severity. Low PSS predicted NSSI in univariate, but not multivariate regression. Mediation analyses showed that borderline traits fully accounted for the relationship between low PSS and NSSI, even when controlling for current psychological distress and gender.

LIMITATIONS

Cross-sectional design through self-report assessment.

CONCLUSIONS

Findings suggest that adolescents with low PSS are especially vulnerable for developing NSSI due to elevated BPD traits. In clinical settings, interventions aimed to reduce borderline symptoms may be a promising treatment option for adolescents with NSSI and low PSS.

Association of Asthma Exacerbation Risk and Physician Time Expenditure With Provision of Asthma Action Plans and Education for Pediatric Patients

OBJECTIVE

To provide information about factors underlying provision of asthma action plans (AAPs) to a minority of pediatric patients with asthma, assess whether risk of exacerbation acts on provision of AAP and asthma education directly, suggesting targeting to highest-risk patients, or indirectly by influencing physician-patient interaction time.

METHODS

This study was a retrospective cross-sectional analysis of a nationally representative sample of physician office visits that consisted of patients aged 2 to 18 years with asthma. Exacerbation risk comprised proxy indicators of control and severity. Direct and time-mediated effects of exacerbation risk on provision of AAP and education were calculated from logistic regression models.

RESULTS

Asthma action plans were provided in 14.3% of visits, education in 23.9%. Total direct effects of exacerbation risk (ORs = 3.88-4.69) far exceeded indirect, time-mediated effects (both ORs = 1.03) on AAPs. Direct effects on education were similar but smaller. After adjusting for risk, physician time expenditure of ≥30 minutes was associated with nearly doubled odds of providing AAP or education (ORs = 1.90-1.99). Visits that included allied health professionals alongside physician care were significantly associated with all 4 outcomes in multivariate analyses (ORs = 3.06-5.28).

CONCLUSIONS

Exacerbation risk has a strong, direct association with AAP provision in pediatric asthma, even controlling for physician time expenditure. Provision of AAP and education to pediatric patients with asthma may be facilitated by increasing available time for office visits and involving allied health professionals.

Comparative study of two birth cohorts: did the explanatory role of behavioural, social and psychological factors in educational inequalities in mortality change over time?

OBJECTIVES

To investigate the contribution of behavioural, social and psychological factors to inequalities in mortality by educational level between birth cohorts.

DESIGN

Cohort-sequential design.

SETTING

Two population-based studies in the Netherlands: the Longitudinal Aging Study Amsterdam (LASA) and the Doetinchem Cohort Study (DCS).

PARTICIPANTS

Data from the LASA included 1990 individuals with birth years 1928-1937 (cohort 1) and 1938-1947 (cohort 2) and, for replication, data from the DCS included 2732 individuals with birth years 1929-1941 (cohort 1) and 1939-1951 (cohort 2).

METHODS

Years of education, 15-year mortality, lifestyle factors, social factors and psychological factors were modelled using multiple-group accelerated failure time models based on structural equation modelling to compare indirect effects between cohorts.

RESULTS

Both studies showed similar educational inequalities, with higher mortality among those with lower education. The indirect effects of education via smoking (LASA: difference in survival time ratio (TR)=1.0018, 95% CI 1.0000 to 1.0155, DCS: TR=1.0051, 95% CI 1.0000 to 1.0183), physical activity (LASA: TR=1.0056, 95% CI 1.00009 to 1.0132) and alcohol use (LASA: TR=1.0275, 95% CI 1.0033 to 1.0194) on mortality were stronger in cohort 2 than in cohort 1. In contrast to the other effects, alcohol use was the only factor that was associated positively with education and survival time, which effect increased in the most recent cohort. Emotional support, network size and cognitive functioning showed no difference between cohorts.

CONCLUSIONS

Smoking, physical activity and alcohol use contributed more to educational inequalities in mortality in recent cohorts. Hence, in addition to tackling fundamental social causes of inequality, policies focusing on intermediary mechanisms such as lifestyle need to adapt their targets to those that prove to be most important within a given time frame.

Factors that mediate the relationships between household socio-economic status and childhood Attention Deficit Hyperactivity Disorder (ADHD) in children and adolescents: A systematic review

BACKGROUND

ADHD is one of the most prevalent mental health disorders among children and adolescents. Household socio-economic status (SES) in early childhood is inversely related to ADHD later in childhood or adolescence. We conducted a systematic review to examine psychological, social and behavioural factors that mediate these relationships (PROSPERO Registration number: CRD42020182832).

METHODS AND FINDINGS

We searched Medline, EMBASE, PsychINFo, and Web of Science from inception until May 2020. Both authors independently reviewed abstracts and identified papers for inclusion. We sought primary observational studies (cohort, cross-sectional and case control studies) of general population-based samples of children and adolescents aged 18 and under that investigated potential mediators of the relationships between SES and ADHD. Studies based upon non-general population-based samples, twins or biochemical/physiological changes were excluded. Direct and indirect effects derived from standard validated mediation analysis were extracted for potential mediators. We assessed risk of bias using a modified NIH tool and synthesised quantitative data without meta-analysis according to the (SWiM) protocol because of heterogeneity between included studies. Family adversity, paternal and maternal ADHD symptoms, Home Learning Environment, breastfeeding duration and a combined fine motor and language score at age 2 may lie on the SES-ADHD pathway. Evidence concerning the influence of maternal depression/anxiety and adverse parenting was inconsistent across studies. There was no evidence that mother's health-related behaviour, family characteristics, child's consumption of fizzy drinks or other developmental characteristics at birth/during infancy lie on the SES-ADHD pathway. Publication bias may have been introduced by our decision not to search grey literature, not to approach study authors and limit the search to the English language.

CONCLUSIONS

Evidence for mediation of the SES-ADHD pathway in childhood/adolescence is under-researched. Maternal mental health, family adversity, parenting and health-related behaviours warrant further research based on longitudinal data and employing the most advanced mediation analysis methods.

Association among the exposure to giving knowledge, attitude and practice for handwashing in people residing in Seoul, South Korea: a retrospective cross-sectional study

OBJECTIVES

Handwashing is known as the most preventive method for various infectious diseases. Health authorities have conducted various campaigns and public relations targeting the general population but few evaluations of these long-term interventions. This study aimed to investigate the association between experience of educational events or public relations (EXEP), attitude towards the effectiveness of handwashing (AEHW) and handwashing practice (HWP).

SETTING

Using a population-based cross-sectional study with a complex sample design, we explored the response outcomes of handwashing. Those outcomes were collected biennially using Community Health Survey among the years 2013, 2015, 2017 and 2019. We applied multivariate logistic regression for the association among sociodemographic factors, health conditions, EXEP, AEHW and HWP.

PARTICIPANTS

Total participants residing in Seoul were 23 139 (men 44.2%), 23 004 (men 44.4%), 22 955 (men 44.8%) and 22 930 (men 43.9%), in 2013, 2015, 2017 and 2019, respectively.

RESULTS

Overall, participants with EXEP are more likely to be women, aged between the 30s and 60s, and with a higher educational level. Particularly, participants with EXEP had an increased association with HWP (OR 1.21, 95% CI 1.19 to 1.33) and AEHW (OR 1.50, 95% CI 1.38 to 1.63). In addition, AEHW also had an increased association with HWP (OR 1.67, 95% CI 1.53 to 1.81). The mediated effect of AEHW to HWP is not determined evidently.

CONCLUSION

The results showed that EXEP is positively associated with HWP and AEHW among community-dwelling people. Our results confirm that educational activity can lead to more pronounced behavioural changes only when it forms a positive attitude.

An Empirical Study of How Both Environmental Awareness and Interest in Artwork Can Be Incorporated into the Interior Design of Urban Hotels

Prior studies on urban hotel service settings show that the positive response to the lobby artwork and interior design in a hotel is a performance determinant since it directly impacts the orientation of green customers’ preferences who form a significant part of the primary and secondary consumers outcome of emotional satisfaction. In addition, it elaborates on the importance of marketing strategy based on hotel interior design for urban hotels intending to increase customer loyalty. For this reason, the present study collected a total of 330 South Korean participants to identify the mediating role of hotel lobby interior design and artworks between green customers’ preferences and hotel loyalty. The survey instrument designed for the current study included 15 questions to test the hypotheses and a path analysis using AMOS 24.0 was conducted as the main tool to determine the relationship key factors. According to our statistical findings, it is acceptable to relate the customers’ environmental awareness with interest in artwork in the hotel lobby due to the first impression created. The artwork gives a general perception of the value and quality that the consumer is likely to gain by interacting with the available products and services. It is also valid to indicate that the customers’ environmental awareness closely relates to their preference for interior design to develop customer loyalty. Therefore, we conclude that the environmental awareness and hotel loyalty factors impact the marketing strategy and segmentation process used for the urban hotels that deal with green customers with unique and exclusive needs.

Explaining the association between frailty and mortality in older adults: The mediating role of lifestyle, social, psychological, cognitive, and physical factors

•

Frailty in older adults is associated with adverse outcomes such as mortality.

•

Not much is known about underlying pathways of the frailty-mortality association.

•

We assessed the mediating role of a wide range of factors.

•

In both men and women, only polypharmacy was identified as explanatory factor.

•

Targeting polypharmacy in frail older adults could reduce their risk of mortality.

Frailty is associated with a higher risk of mortality, but not much is known about underlying pathways of the frailty-mortality association. In this study, we explore a wide range of possible mediators of the relation between frailty and mortality. Data were used from the Longitudinal Aging Study Amsterdam (LASA). We included 1477 older adults aged 65 years and over who participated in the study in 2008–2009 and linked their data to register data on mortality up to 2015. We examined a range of lifestyle, social, psychological, cognitive, and physical factors as potential mediators. All analyses were stratified by sex. We used causal mediation analyses to estimate the indirect effects in single-mediator analyses. Statistically significant mediators were then included in multiple-mediator analyses to examine their combined effect. The results showed that older men (OR = 2.79, 95% CI = 1.23;6.34) and women (OR = 2.31, 95% CI = 1.24;4.30) with frailty had higher odds of being deceased 6 years later compared to those without frailty. In men, polypharmacy (indirect effect OR = 1.21, 95% CI = 1.03;1.50) was a statistically significant mediator in this association. In women, polypharmacy, self-rated health, and multimorbidity were statistically significant mediators in the single-mediator models, but only the indirect effect of polypharmacy remained in the multiple-mediator model (OR = 1.16, 95% CI = 1.03;1.38). In conclusion, of many factors that were considered, we identified polypharmacy as explanatory factor of the association between frailty and mortality in older men and women. This finding has important clinical implications, as it suggests that targeting polypharmacy in frail older adults could reduce their risk of mortality.

Estimating the natural indirect effect and the mediation proportion via the product method

Background

The natural indirect effect (NIE) and mediation proportion (MP) are two measures of primary interest in mediation analysis. The standard approach for mediation analysis is through the product method, which involves a model for the outcome conditional on the mediator and exposure and another model describing the exposure–mediator relationship. The purpose of this article is to comprehensively develop and investigate the finite-sample performance of NIE and MP estimators via the product method.

Methods

With four common data types with a continuous/binary outcome and a continuous/binary mediator, we propose closed-form interval estimators for NIE and MP via the theory of multivariate delta method, and evaluate its empirical performance relative to the bootstrap approach. In addition, we have observed that the rare outcome assumption is frequently invoked to approximate the NIE and MP with a binary outcome, although this approximation may lead to non-negligible bias when the outcome is common. We therefore introduce the exact expressions for NIE and MP with a binary outcome without the rare outcome assumption and compare its performance with the approximate estimators.

Results

Simulation studies suggest that the proposed interval estimator provides satisfactory coverage when the sample size ≥500 for the scenarios with a continuous outcome and sample size ≥20,000 and number of cases ≥500 for the scenarios with a binary outcome. In the binary outcome scenarios, the approximate estimators based on the rare outcome assumption worked well when outcome prevalence less than 5% but could lead to substantial bias when the outcome is common; in contrast, the exact estimators always perform well under all outcome prevalences considered.

Conclusions

Under samples sizes commonly encountered in epidemiology and public health research, the proposed interval estimator is valid for constructing confidence interval. For a binary outcome, the exact estimator without the rare outcome assumption is more robust and stable to estimate NIE and MP. An R package mediateP is developed to implement the methods for point and variance estimation discussed in this paper.

Supplementary Information

The online version contains supplementary material available at (10.1186/s12874-021-01425-4).

Mediation of the Relationship of Acculturation With Glycemic Control in Asian Americans With Diabetes

PURPOSE

To assess the role of physical activity and healthcare access in mediating the association of acculturation with cardiometabolic health in Asian American adults with diabetes.

DESIGN

Cross-sectional study.

SETTING

National Health and Nutrition Examination Survey (NHANES) 2011-2018.

SUBJECTS

Non-pregnant Asian American adults with doctor diagnosed diabetes.

MEASURES

Participants were classified into low, moderate, and high acculturation status. Self-reported leisure-time, work, and transportation-based physical activity were summed for overall physical activity. Health insurance, frequency of healthcare receipt, and glycohemoglobin (HbA1c) check in the past year indicated healthcare access. Cardiometabolic health indicators included HbA1c, total and high density lipoprotein-cholesterol, and systolic and diastolic blood pressure.

ANALYSIS

Linear and logistic regression estimates, standardized using y-standardization, and assessed mediation of acculturation with cardiometabolic health.

RESULTS

Low acculturation was significantly related to greater leisure-time inactivity odds [OR (95% CI) = 2.25 (1.05, 4.82)], overall insufficient activity [OR (95% CI) = 2.30 (1.12, 4.74)], and uninsured status [OR (95% CI) = 5.62 (1.55, 20.41)]. Asian Americans with low acculturation had significantly higher log HbA1c than those with high acculturation (β ± SE = .078 ± .038); however, this association was not significant after adjusting for leisure-time activity. Leisure-time activity mediated 48.9% of acculturation and HbA1c association, and the indirect effect was statistically significant [estimate (95% CI) = .021 (.002, 0.047)].

CONCLUSIONS

Results suggest that promoting sufficient leisure-time activity could improve glycemic control in least acculturated Asian Americans with diabetes.

Statistical Mediation Analysis for Models with a Binary Mediator and a Binary Outcome: the Differences Between Causal and Traditional Mediation Analysis

Mediation analysis is an important statistical method in prevention research, as it can be used to determine effective intervention components. Traditional mediation analysis defines direct and indirect effects in terms of linear regression coefficients. It is unclear how these traditional effects are estimated in settings with binary variables. An important recent methodological advancement in the mediation analysis literature is the development of the causal mediation analysis framework. Causal mediation analysis defines causal effects as the difference between two potential outcomes. These definitions can be applied to any mediation model to estimate natural direct and indirect effects, including models with binary variables and an exposure-mediator interaction. This paper aims to clarify the similarities and differences between the causal and traditional effect estimates for mediation models with a binary mediator and a binary outcome. Causal and traditional mediation analyses were applied to an empirical example to demonstrate these similarities and differences. Causal and traditional mediation analysis provided similar controlled direct effect estimates, but different estimates of the natural direct effects, natural indirect effects, and total effect. Traditional mediation analysis methods do not generalize well to mediation models with binary variables, while the natural effect definitions can be applied to any mediation model. Causal mediation analysis is therefore the preferred method for the analysis of mediation models with binary variables.

Mediation analysis methods used in observational research: a scoping review and recommendations

Background

Mediation analysis methodology underwent many advancements throughout the years, with the most recent and important advancement being the development of causal mediation analysis based on the counterfactual framework. However, a previous review showed that for experimental studies the uptake of causal mediation analysis remains low. The aim of this paper is to review the methodological characteristics of mediation analyses performed in observational epidemiologic studies published between 2015 and 2019 and to provide recommendations for the application of mediation analysis in future studies.

Methods

We searched the MEDLINE and EMBASE databases for observational epidemiologic studies published between 2015 and 2019 in which mediation analysis was applied as one of the primary analysis methods. Information was extracted on the characteristics of the mediation model and the applied mediation analysis method.

Results

We included 174 studies, most of which applied traditional mediation analysis methods (n = 123, 70.7%). Causal mediation analysis was not often used to analyze more complicated mediation models, such as multiple mediator models. Most studies adjusted their analyses for measured confounders, but did not perform sensitivity analyses for unmeasured confounders and did not assess the presence of an exposure-mediator interaction.

Conclusions

To ensure a causal interpretation of the effect estimates in the mediation model, we recommend that researchers use causal mediation analysis and assess the plausibility of the causal assumptions. The uptake of causal mediation analysis can be enhanced through tutorial papers that demonstrate the application of causal mediation analysis, and through the development of software packages that facilitate the causal mediation analysis of relatively complicated mediation models.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-021-01426-3.

Adverse employment histories, work stress and self-reported depression in the French CONSTANCES study

BACKGROUND

Job instability and disadvantaged work were shown to be associated with poor mental health, but few studies analyzed these conditions in a life course perspective. In this study, adverse employment histories are retrospectively assessed and linked to self-reported depression. Furthermore, indirect effects of later stressful psychosocial work in terms of effort-reward imbalance are investigated.

METHODS

With data from the French CONSTANCES cohort study of 13 716 male and 12 767 female employees aged 45 and older, we identify adverse employment histories between age 25 and 45, focussing on job discontinuity, job instability and cumulative disadvantage. Direct effects of these conditions on self-reported depression over a period of up to 5 years are analyzed, using discrete-time logistic regression. Indirect effects of stressful work at baseline are examined.

RESULTS

Moderately elevated odds ratios of self-reported depression are observed among participants with discontinued employment histories (number of unemployment periods; years out of work for men). Effort-reward imbalance at work is consistently related to elevated risk of self-reported depression and explains parts of the association between discontinuous employment and depression.

CONCLUSIONS

Applying a life course perspective to occupational health research extends current knowledge. Specifically, adverse employment histories in terms of recurrent job discontinuity are related to the risk of self-reported depression. This association is partly explained by exposure to a stressful psychosocial work environment. These results can instruct labour market policies and the development of targeted worksite interventions that address disadvantage throughout entire employment trajectories.

Suicidal ideation and suicide attempts: associations with sleep duration, insomnia, and inflammation

BACKGROUND

Sleep disturbance has been consistently identified as an independent contributor to suicide risk. Inflammation has emerged as a potential mechanism linked to both sleep disturbance and suicide risk. This study tested associations between sleep duration, insomnia, and inflammation on suicidal ideation (SI) and history of a suicide attempt (SA).

METHODS

Participants included 2329 adults with current or remitted depression and/or anxiety enrolled in the Netherlands Study of Depression and Anxiety. Sleep duration, insomnia, past week SI, and SA were assessed with self-report measures. Plasma levels of C-reactive protein, interleukin-6, and tumor necrosis factor-α were obtained.

RESULTS

Short sleep duration (⩽6 h) compared to normal sleep duration (7-9 h) was associated with reporting a prior SA, adjusting for covariates [adjusted odds ratio (AOR) 1.68, 95% CI 1.13-2.51]. A higher likelihood of SI during the past week was observed for participants with long sleep duration (⩾10 h) compared to normal sleep duration (AOR 2.22, 95% CI 1.02-4.82), more insomnia symptoms (AOR 1.44, 95% CI 1.14-1.83), and higher IL-6 (AOR 1.31, 95% CI 1.02-1.68). Mediation analyses indicated that the association between long sleep duration and SI was partially explained by IL-6 (AOR 1.02, 95% CI 1.00-1.05).

CONCLUSIONS

These findings from a large sample of adults with depression and/or anxiety provide evidence that both short and long sleep duration, insomnia symptoms, and IL-6 are associated with the indicators of suicide risk. Furthermore, the association between long sleep duration and SI may operate through IL-6.

Parametric-Regression-Based Causal Mediation Analysis of Binary Outcomes and Binary Mediators: Moving Beyond the Rareness or Commonness of the Outcome

In the causal mediation framework, several parametric-regression–based approaches have been introduced in the last decade for estimating natural direct and indirect effects. For a binary outcome, a number of proposed estimators use a logistic model and rely on specific assumptions or approximations that may be delicate or not easy to verify in practice. To circumvent the challenges prompted by the rare outcome assumption in this context, an exact closed-form natural-effects estimator on the odds ratio scale was recently introduced for a binary mediator. In this work, we further push this exact approach and extend it for the estimation of natural effects on the risk ratio and risk difference scales. Explicit formulas for the delta method standard errors are provided. The performance of our proposed exact estimators is demonstrated in simulation scenarios featuring various levels of outcome rareness/commonness. The total effect decomposition property on the multiplicative scales is also examined. Using a SAS macro (SAS Institute, Inc., Cary, North Carolina) we developed, our approach is illustrated to assess the separate effects of exposure to inhaled corticosteroids and placental abruption on low birth weight mediated by prematurity. Our exact natural-effects estimators are found to work properly in both simulations and the real data example.

Perceived built environment and type 2 diabetes incidence: Exploring potential mediating pathways through physical and mental health, and behavioural factors in a longitudinal study

AIMS

The evidence on the pathways through which the built environment may influence type 2 diabetes (T2D) risk is limited. This study explored whether behavioural, physical and mental health factors mediate the associations between perceived built environment and T2D.

METHODS

Longitudinal data on 36,224 participants aged ≥45 years (The Sax Institute's 45 and Up Study) was analysed. Causal mediation analysis that uses the counterfactual approach to decompose the total effect into direct and indirect effects was performed.

RESULTS

The results showed that physical activity, recreational walking, and BMI mediated around 6%, 11%, and 30%, respectively, of the association between perceived lack of access to local amenities and T2D incidence. Physical activity (4.8% for day-time crime), recreational walking (2.3% for day-time crime), psychological distress (5.2% for day-time, 3.7% for night-time crime), and BMI (29.6% for day-time crime, 17.4% for night-time crime) also partially mediated the effect of perceived crime. Mediated effects appeared larger at wave 3 than the same wave 2 mediators.

CONCLUSIONS

The findings demonstrate that physical activity, psychological distress, and BMI mediate the pathways between the built environment and T2D. Policies aimed to bring amenities closer to homes, prevent crime, and address mental health may help reduce T2D risk.

Childhood trauma and bullying-victimization as an explanation for differences in mental disorders by sexual orientation

Sexual minority individuals are more likely to have mental disorders, including mood, anxiety, and substance use disorders, compared to heterosexual individuals. Whether experiencing trauma or bullying-victimization during childhood explains these differences is currently unclear. We used a psychiatric epidemiological general population-based study to assess whether childhood trauma severity and bullying-victimization before age 16 explains the difference by sexual attraction in mental disorders. Data from the Netherlands Mental Health Survey and Incidence Study-2 (NEMESIS-2; N = 6392) were used to examine (1) whether same/both-sex attraction and predominantly other-sex attraction is linked to self-reports of childhood trauma (types and severity) and bullying-victimization, and (2) whether these experiences explain differences between these groups in lifetime and 12-month prevalence of DSM-IV disorders assessed by the Composite International Diagnostic Interview 3.0. Same/both-sex attracted individuals reported a higher childhood trauma severity score compared to exclusively other-sex attracted individuals (B = 0.93, SE = 0.20, p < .001), and were more likely to report bullying-victimization (OR = 2.51 95%CI[1.68, 3.74]). DSM-IV disorders were more prevalent among same/both-sex attracted individuals than among exclusively other-sex attracted individuals (ORs ranged from 1.57 to 4.68). There were no differences in DSM-IV disorders for predominantly other-sex attracted individuals. Childhood trauma severity explained between 9.0% and 57.0% of significant indirect associations between same/both-sex attraction and DSM-IV disorders. Sexual minority individuals experience more types of, and more severe childhood trauma, and are more likely to experience bullying-victimization. These negative experiences partly explained disparities in mental disorders.

Patient and family views of team functioning in primary healthcare teams with nurse practitioners: a survey of patient-reported experience and outcomes

BACKGROUND

Nurse practitioners (NPs) have been added to primary healthcare teams to improve access to care. Team processes, including communication and decision-making, explicate how patients and families view team functioning. Yet, important gaps exist in our understanding of patient-reported experience and outcomes at the level of the healthcare team. We aimed to examine the influence of individual, team, and organizational characteristics, and role clarity on outcomes of care mediated by team processes in primary healthcare teams that include NPs.

METHODS

A cross-sectional survey across six sites representing practices with NPs in Québec, Canada, was conducted between March 2018 and April 2019 as part of a multiple-case study. Patients and families (n = 485; response rate: 53%) completed a validated questionnaire, which included a patient-reported experience measure (PREM) and a patient-reported outcome measure (PROM) of team functioning (Cronbach alpha: 0.771 (PROM) to 0.877 (PREM)). We performed logistic regression and mediation analyses to examine relationships between the individual, team, and organizational characteristics, role clarity, and outcomes of care mediated by team processes.

RESULTS

Patients and families expressed positive perceptions of team functioning (mean 4.97/6 [SD 0.68]) and outcomes of care (5.08/6 [0.74]). Also, high team processes (adjusted odds ratio [AOR] 14.92 [95% CI 8.11 to 27.44]) was a significant predictor of high outcomes of care. Role clarity (indirect effect coefficient ab = 6.48 [95% CI 3.79 to 9.56]), living in an urban area (-1.32 [-2.59 to -0.13]), patient as respondent (-1.43 [-2.80 to -0.14]), and income (1.73 [0.14 to 3.45]) were significant predictors of outcomes of care mediated by team processes.

CONCLUSIONS

This study provides key insights on how primary healthcare teams with NPs contribute to team functioning, using a validated instrument consistent with a conceptual framework. Results highlight that high role clarity, living in a non urban area, family as respondent, and adequate income were significant predictors of high outcomes of care mediated by high team processes. Additional research is needed to compare teams with and without NPs in different settings, to further explicate the relationships identified in our study.

Do low-priced ski pass owners perceive a higher quality of life? A case study of the Leisure Card Tirol

OBJECTIVES

The study investigated a potential correlation between owning a superregional low-cost ski and leisure card, namely the Leisure Card Tirol (LCT), and perceived quality of life (QOL).

DESIGN

A cross-sectional, quantitative approach (online questionnaire) was chosen.

METHODS

In total, 1588 LCT users as well as 684 non-users (residents living in the Alpine region of Tyrol, Austria) were reached throughout the study period.

RESULTS

Compared to non-users, LCT users reported significantly higher scores in all domains of QOL. However, the correlation was neither mediated nor moderated by the level of general physical activity (in contrast to alpine skiing in particular).

CONCLUSIONS

As superregional low-cost leisure cards were suggested as a way of facilitating access to skiing-at least according to its buyers-owning the LCT was associated with higher perceived QOL. Subsequent research should elaborate the extent to which this correlation is causal. If there is a causal link, such cards should be actively promoted to improve/maintain residents' QOL.

Patients With Higher Treatment Outcome Expectations Are More Satisfied With the Results of Nonoperative Treatment for Thumb Base Osteoarthritis: A Cohort Study

OBJECTIVE

To investigate how satisfaction with treatment outcome is associated with patient mindset and Michigan Hand Outcome Questionnaire (MHQ) scores at baseline and 3 months in patients receiving nonoperative treatment for first carpometacarpal joint (CMC-1) osteoarthritis (OA).

DESIGN

Cohort study SETTING: A total of 20 outpatient locations of a clinic for hand surgery and hand therapy in the Netherlands.

PARTICIPANTS

Patients (N=308) receiving nonoperative treatment for CMC-1 OA, including exercise therapy, an orthosis, or both, between September 2017 and February 2019.

INTERVENTIONS

Nonoperative treatment (ie, exercise therapy, an orthosis, or both) MAIN OUTCOME MEASURES: Satisfaction with treatment outcomes was measured after 3 months of treatment. We measured total MHQ score at baseline and at 3 months. As baseline mindset factors, patients completed questionnaires on treatment outcome expectations, illness perceptions, pain catastrophizing, and psychological distress. We used multivariable logistic regression analysis and mediation analysis to identify factors associated with satisfaction with treatment outcomes.

RESULTS

More positive pretreatment outcome expectations were associated with a higher probability of being satisfied with treatment outcomes at 3 months (odds ratio, 1.15; 95% confidence interval, 1.07-1.25). Only a relatively small part (33%) of this association was because of a higher total MHQ score at 3 months. None of the other mindset and hand function variables at baseline were associated with satisfaction with treatment outcomes.

CONCLUSIONS

This study demonstrates that patients with higher pretreatment outcome expectations are more likely to be satisfied with treatment outcomes after 3 months of nonoperative treatment for CMC-1 OA. This association could only partially be explained by a better functional outcome at 3 months for patients who were satisfied. Health care providers treating patients nonoperatively for CMC-1 OA should be aware of the importance of expectations and may take this into account in pretreatment counseling.

Mediational Occupational Risk Factors Pertaining to Work Ability According to Age, Gender and Professional Job Type

The predictive value of work ability for several health and occupational outcomes is well known. Maintaining the ability to work of all employees has become an important topic in research although some evidence suggests that some groups of workers need greater attention than others. Healthcare workers (x¯ = 54.46 ± 5.64 years) attending routine occupational health checkups completed their work ability, occupational risk and sociodemographic measures. An analysis examined whether work ability differed according to gender, age and professional category. Mediation of these relationships by occupational risk variables, such as work–family conflict, was examined. Females and older adults had worse work ability than their counterparts. Professional group was not independently associated. Gender-related differences were mediated by current and historic ergonomic risk, psychosocial risk and work–family conflict. Age-related differences were mediated by violence/discrimination at work. All job risk variables, apart from current ergonomic risk, mediated associations between professional category and work ability. The present study identified the importance of risk variables for the work ability of health workers according to gender, age and professional job type. Perceptions of work–family conflict and violence–discrimination seem particularly important and should be considered when targeting improvements in work ability.

Cocaine and Marijuana Polysubstance Use and Cocaine Use Disorder: Investigating Mediated Effects through Patterns of Cocaine Use

Cocaine use is on the rise and it is comorbid with marijuana use. We examined the association between lifetime cocaine + marijuana polysubstance use (CM PSU) versus cocaine only and lifetime cocaine use disorder (CocUD) and examined the potential mediation by cocaine use patterns. Methods: A total of 2,968 lifetime cocaine users were identified from the National Epidemiologic Survey on Alcohol and Related Conditions-III. Mediation analysis was utilized to examine cocaine use quantity, frequency, and duration as potential mediators in the association between CM PSU and CocUD. A parallel multiple mediator model and a structural equation model were used, respectively, to examine: (1) the individual contribution of cocaine use quantity, frequency, and duration, and (2) combined contribution as a set specified by a latent variable. Results: Cocaine users were divided into 2,782 (93.7%) CM polysubstance users and 186 (6.3%) cocaine only users. CM PSU was associated with decreased risk of CocUD, but after including the mediators, the association was no longer significant. Examined separately, only quantity was found to be a significant mediator over and above frequency and duration, while the latent variable with three cocaine use pattern indicators explained 56.6% of the total association between CM PSU and CocUD. Conclusions: Compared to cocaine only users, CM polysubstance users were less likely to use cocaine heavily; this lower intensity of cocaine use was in turn associated with decreased risk of CocUD. Future research is warranted to determine the nature of the association between CM PSU and reduced CocUD.

Birth Weight and Diabetic Retinopathy: Results From the Population-Based Gutenberg Health Study (GHS)

PURPOSE

This study investigates the relationship between diabetic retinopathy (DR) and birth weight (BW) in diabetic subjects sampled from the general population.

METHODS

The Gutenberg Health Study (GHS) is a population-based, observational cohort study in participants aged from 35 to 74 years. Criteria for diabetes diagnosis were HbA1c ≥6.5% at study entry, a doctor-diagnosis of diabetes, or diabetes medication. The presence of DR was determined by evaluating fundus photographs. BW was assessed by self-reports. GHS participants were divided into three different BW groups (low: <2500 g; normal: 2500-4000 g; high:>4000 g). Logistic regression analysis was conducted as uni- and multivariable analysis with adjustment for age and sex. Effect mediators were separately investigated.

RESULTS

A total of 1,124 GHS participants (7.5% of the cohort) had diabetes at study entry. Of these, 402 subjects (35.8%) had gradable fundus photographs, reported BW data and were included into this study. Overall, 91/402 subjects (23%) had DR. With regard to BW groups, DR was descriptively more frequent in subjects with low (28.1% [95%-CI: 14.4-47.0%; n = 32]) and high BW (30.8% [95%-CI: 19.1-45.3%; n = 52]) compared to normal BW (20.8% [95%-CI: 16.5-25.7%; n = 318]). Both high and low BW were associated with DR in multivariable analysis (high: OR = 1.68, p = .037; low: OR = 1.81, p = .05). The BW effect was mediated by duration of diabetes in both BW groups and by arterial hypertension in the low BW group.

CONCLUSION

Low and high BW in persons with diabetes is related to higher risk of diabetic retinopathy. Longer duration of diabetes and higher prevalence of arterial hypertension are factors in these subjects explaining the elevated risk.