Using emulated clinical trials to investigate the risk of being diagnosed with psychiatric ill health following the cancer diagnosis of a sibling.

BACKGROUND: The sibling bond is often the longest relationship in an individual's life, spanning both good and bad times. Focusing on the latter, we investigated whether a cancer diagnosis in one adult sibling is predictive of psychiatric illness in the other, and if any such effect differs according the 'sociodemographic closeness' between the siblings in terms of sex, age, education, marital status and residence. METHODS: We used hospital records to identify psychiatric diagnoses (2005-2019) in a Swedish total-population cohort born in 1953, and cancer diagnoses (2005-2017) in their full siblings. By means of emulated clinical trials, the cohort member's risk of a diagnosis within two years following a first exposure (or non-exposure) to a sibling's cancer was analyzed through Cox regression. RESULTS: Exposed cohort members had a higher risk of psychiatric diagnosis than unexposed (HR = 1.15; CI: 1.08-1.23), with men displaying a higher risk (1.19; CI: 1.09-1.31) than women (HR = 1.11; CI: 1.01-1.22). Sub-analyses of the exposed group showed that women with a cancer-stricken sister had a higher risk of adverse psychiatric outcomes (HR = 1.31; CI: 1.07-1.61) than women with a cancer-stricken brother. Furthermore, unmarried cohort members ran a higher risk, both when the cancer-stricken sibling was married (HR = 2.03; CI: 1.67-2.46) and unmarried (HR = 2.61; CI: 2.16-3.15), than in cases where both siblings were married. No corresponding difference were detected for 'closeness' in age, education and residence. CONCLUSIONS: In line with theories of linked lives, our findings suggest that negative events in one sibling's life tend to 'spill over' on the other sibling's wellbeing, at least during the 15-year-long period leading up to retirement age.

Parental and family determinants of the Flynn effect.

Research about the Flynn effect, the secular rise in IQ, is heavily based on conscript data from successive male birth cohorts. This inevitably means that two distinct phenomena are mixed: fertility differences by IQ group ('compositional Flynn effect'), and any difference between parents and children ('within-family Flynn effect'). Both will influence trends in cognitive ability. We focused on the latter phenomenon, exploring changes in cognitive abilities during adolescence within one generation, and between two successive generations within the same family. We identified determinants and outcomes in three linked generations in the Stockholm Multigenerational Study. School and conscript data covered logical/numerical and verbal scores for mothers at age 13, fathers at 13 and 18, and their sons at 18. Raw scores, and change in raw scores, were used as outcomes in linear regressions. Both parents' abilities at 13 were equally important for sons' abilities at 18. Boys from disadvantaged backgrounds caught up with other boys during adolescence. Comparing fathers with sons, there appeared to be a positive Flynn effect in logical/numeric and verbal abilities. This was larger if the father had a working-class background or many siblings. A Flynn effect was only visible in families where the father had low general cognitive ability at 18. We conclude that there is a general improvement in logical/numeric and verbal skills from one generation to the next, primarily based on improvement in disadvantaged families. The Flynn effect in Sweden during the later 20th century appears to represent a narrowing between social categories.

The Work Environment during Coronavirus Epidemics and Pandemics: A Systematic Review of Studies Using Quantitative, Qualitative, and Mixed-Methods Designs.

We aimed to provide an overview of how work environment and occupational health are affected, and describe interventions designed to improve the work environment during epidemics and pandemics. The guidelines on Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) were followed. The databases Cinahl, Medline, PsycInfo, and Web of Science were searched for population: working population; exposure: coronavirus epidemic or pandemic; and outcome: work environment, in articles published until October 2020. Quality assessment was based on a modified version of the Mixed Methods Appraisal Tool (MMAT). After deduplication 3711 articles remained, of which 530 were selected for full-text screening and 119 for quality assessment. After the exclusion of studies that were low quality, 95 remained, of which 85 focused on healthcare personnel and 10 on employees in other industries; 73 used quantitative methods and 22 used qualitative or mixed methods; the majority were based on cross-sectional data. Healthcare staff experienced increased job demands, poor leadership, and lack of resources (personal protective equipment, personnel, and competence). High demands and work with infected patients were associated with negative mental health outcomes. There was a lack of studies assessing interventions, studies from industries other than healthcare, and studies of high quality.

Psychosocial School Conditions and Mental Wellbeing Among Mid-adolescents: Findings From the 2017/18 Swedish HBSC Study.

Objectives: To investigate mid-adolescent boys' and girls' experiences of school demands, teacher support, and classmate support, and explore the associations of these factors with mental wellbeing. Methods: Data were derived from the Swedish Health Behaviour in School-aged Children (HBSC) study of 2017/18, with information collected among 1,418 students in grade 9 (∼15-16 years). School demands, teacher support, and classmate support were measured by indices based on three items each. Mental wellbeing was measured by the Short Warwick-Edinburgh Mental Wellbeing Scale (SWEMWBS). Linear regression analyses were performed. Results: Higher demands were associated with lower mental wellbeing. Conversely, mental wellbeing increased with greater teacher support and classmate support. Interactions between demands and the support variables showed that at the lowest levels of teacher and of classmate support, mental wellbeing was low and not associated with school demands. With increasing levels of teacher and classmate support, the overall level of mental wellbeing increased and revealed an inverse association between school demands and mental wellbeing. Conclusion: The study contributes with knowledge about how psychosocial conditions in school may hinder or enhance wellbeing among students.

Workplace violence and health in human service industries: a systematic review of prospective and longitudinal studies.

OBJECTIVES: To provide systematically evaluated evidence of prospective associations between exposure to physical, psychological and gender-based violence and health among healthcare, social care and education workers. METHODS: The guidelines on Preferred Reporting Items for Systematic Reviews and Meta-Analyses were followed. Medline, Cinahl, Web of Science and PsycInfo were searched for population: human service workers; exposure: workplace violence; and study type: prospective or longitudinal in articles published 1990-August 2019. Quality assessment was performed based on a modified version of the Cochrane's 'Tool to Assess Risk of Bias in Cohort Studies'. RESULTS: After deduplication, 3566 studies remained, of which 132 articles were selected for full-text screening and 28 were included in the systematic review. A majority of the studies focused on healthcare personnel, were from the Nordic countries and were assessed to have medium quality. Nine of 11 associations between physical violence and poor mental health were statistically significant, and 3 of 4 associations between physical violence and sickness absence. Ten of 13 associations between psychological violence and poor mental health were statistically significant and 6 of 6 associations between psychological violence and sickness absence. The only study on gender-based violence and health reported a statistically non-significant association. CONCLUSION: There is consistent evidence mainly in medium quality studies of prospective associations between psychological violence and poor mental health and sickness absence, and between physical violence and poor mental health in human service workers. More research using objective outcomes, improved exposure assessment and that focus on gender-based violence is needed.

Stress resilience in young men mediates the effect of childhood trauma on their offspring's birth weight - An analysis of 250,000 families.

Experiencing the death of a parent during childhood is a severe trauma that seems to affect the next generation's birth weight. We studied the consequences of parental loss during childhood for men's psychological and physiological characteristics at age 18, and whether these were important for their first-born offspring's birth outcomes. We used a structured life-course approach and four-way decomposition analysis to analyse data for 250,427 three-generation families retrieved from nationwide Swedish registers and found that psychological resilience was impaired and body mass index was higher in men who had experienced parental death. Both characteristics were linked to offspring birth weight. This was lower by 18.0 g (95% confidence interval: 5.7, 30.3) for men who lost a parent at ages 8-17 compared to other ages. Resilience mediated 40% of this influence. Mediation by body mass index, systolic and diastolic blood pressure was negligible, as was the effect of parental loss on length of gestation. There was no mediation by the education of the men's future spouse. Previous literature has indicated that the period before puberty, the "slow growth period", is sensitive. Our evidence suggests that this may be too narrow a restriction: boys aged 8-17 appear to be particularly likely to respond to parental loss in a way which affects their future offspring's birth weight. We conclude that the observed transgenerational influence on birth weight is mediated by the father's psychological resilience but not by his body mass index or blood pressure.

Does social and professional establishment at age 30 mediate the association between school connectedness and family climate at age 16 and mental health symptoms at age 43?

BACKGROUND: The aim was to use a theoretical framework developed by Bronfenbrenner in order to investigate if the association between school connectedness and family climate at age 16 and mental health symptoms at age 43 is mediated by social and professional establishment at age 30. METHODS: Data were drawn from The Northern Swedish Cohort, a prospective population-based cohort. The present study included 506 women and 577 men who responded to questionnaires at age 16 (in year 1981), age 30 (in 1995) and age 43 (in 2008). Mediation was tested by fitting structural equation models (SEM) and estimating direct effects between proximal processes (school connectedness and family climate) and symptoms of depression and anxiety respectively, and indirect effects via social and professional establishment (professional activity, educational level, and civil status). RESULTS: The standardised estimate for the direct path from school connectedness to depression was -0.147 (p = .000) and the indirect effect mediated by professional activity -0.017 (p = .011) and by civil status -0.020 (p = .002). The standardised direct effect between school connectedness and anxiety was -0.147 (p = .000) and the indirect effect mediated by civil status -0.018 (p = .005). Family climate was not significantly associated with the outcomes or mediators. LIMITATIONS: Self-reported data; mental health measures not diagnostic; closed cohort; intelligence, personality and home situation before age 16 not accounted for. CONCLUSIONS: Professional and social establishment in early adulthood appear to partially mediate the association between adolescent school connectedness and mental health symptoms in middle-age.

Prevailing over Adversity: Factors Counteracting the Long-Term Negative Health Influences of Social and Material Disadvantages in Youth.

Disadvantaged circumstances in youth tend to translate into poor health development. However, the fact that this is not always the case has been seen as indicative of differential resilience. The current study highlights factors outside the context of the family with the potential to counteract the long-term negative influences of social and material adversity in adolescence on general health status. This study was based on two waves of questionnaire data from the Northern Swedish Cohort. From the wave in 1981 (age 16), indicators of social and material conditions as well as factors related to school, peers, and spare time were derived. From the wave in 2008 (age 43), information about self-rated health was used. Ordinal logistic regression models (n = 908) showed that adversity in youth was associated with poorer self-rated health in midlife among men and women alike, net of health status at baseline. However, having an advantaged situation with regard to school, peers, or spare time appeared to protect against the detrimental influences of disadvantaged circumstances in the family context on subsequent health. This suggests that health-promoting interventions may benefit from focusing on contexts outside the family in their effort to strengthen processes of resilience among disadvantaged youths.

Job demands, control and social support as predictors of trajectories of depressive symptoms.

BACKGROUND: Job demands, job control and social support have been associated with depressive symptoms. However, it is unknown how these work characteristics are associated with different trajectories of depressive symptoms, which this study aimed to examine. METHODS: We included 6679 subjects in the Swedish Longitudinal Occupational Survey of Health (SLOSH), who completed biennial questionnaires in 2006-2016. Group-based trajectory models identified groups with similar development of depressive symptoms. Multinomial logistic regression estimated associations between baseline demands, control, social support and trajectories of depressive symptoms. RESULTS: We identified six depression trajectories with varying severity and stability across four measurements. High job demands and low social support, but not low control, were associated with higher probability of belonging to subsequent trajectories with higher symptom level compared to very low symptom level. Adjusted risk ratios ranged from 1.26, 95% CI = 1.06-1.51 (low symptom trajectory) to 2.51, 95% CI = 1.43-4.41 (persistent severe symptom trajectory). Results also indicated that onset of high demands, low control and low social support increases depressive symptoms over time. LIMITATIONS: The results were based on self-reported data and all individuals did not have complete data in all waves. CONCLUSIONS: The results indicated that especially perceptions of high job demands and low social support are associated with higher or increasing levels of depressive symptoms over time. This support the supposition that high job demands, and low social support may have long-term consequences for depressive symptoms and that interventions targeting job demands and social support may contribute to a more favourable course of depression.

A randomized controlled intervention of workplace-based group cognitive behavioral therapy for insomnia.

PURPOSE: Sleep disturbance is common in the working population, often associated with work stress, health complaints and impaired work performance. This study evaluated a group intervention at work, based on cognitive behavioral therapy (CBT) for insomnia, and the moderating effects of burnout scores at baseline. METHODS: This is a randomized controlled intervention with a waiting list control group. Participants were employees working at least 75% of full time, reporting self-perceived regular sleep problems. Data were collected at baseline, post-intervention and at a 3-month follow-up through diaries, wrist-actigraphy and questionnaires including the Insomnia Severity Index (ISI) and the Shirom-Melamed Burnout Questionnaire (SMBQ). Fifty-one participants (63% women) completed data collections. RESULTS: A multilevel mixed model showed no significant differences between groups for sleep over time, while there was a significant effect on insomnia symptoms when excluding participants working shifts (N = 11) from the analysis (p = 0.044). Moreover, a moderating effect of baseline-levels of burnout scores was observed on insomnia symptoms (p = 0.009). A post-hoc analysis showed that individuals in the intervention group with low burnout scores at baseline (SMBQ < 3.75) displayed significantly reduced ISI scores at follow-up, compared to individuals with high burnout scores at baseline (p = 0.005). CONCLUSIONS: Group CBT for insomnia given at the workplace did not reduce sleep problems looking at the group as a whole, while it was indicated that the intervention reduced insomnia in employees with regular daytime work. The results also suggest that workplace-based group CBT may improve sleep in employees with primary insomnia if not concomitant with high burnout scores.

Total workload and recovery in relation to worktime reduction: a randomised controlled intervention study with time-use data.

OBJECTIVES: A 25% reduction of weekly work hours for full-time employees has been shown to improve sleep and alertness and reduce stress during both workdays and days off. The aim of the present study was to investigate how employees use their time during such an intervention: does total workload (paid and non-paid work) decrease, and recovery time increase, when work hours are reduced? METHODS: Full-time employees within the public sector (n=636; 75% women) were randomised into intervention group and control group. The intervention group (n=370) reduced worktime to 75% with preserved salary during 18 months. Data were collected at baseline, after 9 months and 18 months. Time-use was reported every half-hour daily between 06:00 and 01:00 during 1 week at each data collection. Data were analysed with multilevel mixed modelling. RESULTS: Compared with the control group, the intervention group increased the time spent on domestic work and relaxing hobby activities during workdays when worktime was reduced (P≤0.001). On days off, more time was spent in free-time activities (P=0.003). Total workload decreased (-65 min) and time spent in recovery activities increased on workdays (+53 min). The pattern of findings was similar in subgroups defined by gender, family status and job situation. CONCLUSIONS: A worktime reduction of 25% for full-time workers resulted in decreased total workload and an increase of time spent in recovery activities, which is in line with the suggestion that worktime reduction may be beneficial for long-term health and stress.

Trajectories of musculoskeletal pain from adolescence to middle age: the role of early depressive symptoms, a 27-year follow-up of the Northern Swedish Cohort.

Depression and musculoskeletal pain are associated, but long-term follow-up studies are rare. We aimed to examine the relationship of early depressive symptoms with developmental patterns of musculoskeletal pain from adolescence to middle age. Adolescents ending compulsory school (age 16) in Luleå, Northern Sweden, in 1981 (n = 1083) were studied and followed up in 1986, 1995, and 2008 (age 43) for musculoskeletal pain. Attrition was very low. Indicators for any and severe pain were based on pain in the neck-shoulders, low back, and the extremities. Latent class growth analyses were performed on 563 men and 503 women. Associations of a depressive symptoms score (DSS, range 0.0-2.0) at age 16 with pain trajectory membership were assessed by logistic and multinomial regression, adjusting for parental socioeconomic status, social adversities, smoking, exercise, body mass index, and alcohol consumption at age 16. For any pain, 3 trajectories emerged: high-stable (women 71%, men 61%), moderate (11%, 17%), and low-increasing (18%, 22%). With the low-increasing trajectory as reference, for each 0.1-point increase in the DSS, the odds ratio of belonging to the high-stable trajectory was 1.25 (95% confidence interval 1.11-1.41) in women and 1.23 (1.10-1.37) in men. For severe pain, 2 trajectories were found: moderate-increasing (women 19%, men 9%) and low-stable. For each 0.1-point increase in the DSS, the odds ratio of membership in the moderate-increasing trajectory was 1.14 (1.04-1.25) in women and 1.17 (1.04-1.31) in men in the fully adjusted model. Thus, depressive symptoms at baseline are strongly associated with pain trajectory membership.

The longitudinal relationship between control over working hours and depressive symptoms: Results from SLOSH, a population-based cohort study.

BACKGROUND: Psychosocial work factors can affect depressive moods, but research is inconclusive if flexibility to self-determine working hours (work-time control, WTC) is associated with depressive symptoms over time. We investigated if either sub-dimension of WTC, control over daily hours and control over time off, was related to depressive symptoms over time and examined causal, reversed-causal, and reciprocal pathways. METHODS: The study was based on four waves of the Swedish Longitudinal Occupational Survey of Health which is a follow-up of representative samples of the Swedish working population. WTC was measured using a 5-item index. Depressive symptoms were assessed with a brief subscale of the Symptom Checklist. Latent growth curve models and cross-lagged panel models were tested. RESULTS: Best fit was found for a model with correlated intercepts (control over daily hours) and both correlated intercepts and slopes (control over time off) between WTC and depressive symptoms, with stronger associations for control over time off. Causal models estimating impacts from WTC to subsequent depressive symptoms were best fitting, with a standardised coefficient between -0.023 and -0.048. LIMITATIONS: Results were mainly based on self-report data and mean age in the study sample was relatively high. CONCLUSION: Higher WTC was related to fewer depressive symptoms over time albeit small effects. Giving workers control over working hours - especially over taking breaks and vacation - may improve working conditions and buffer against developing depression, potentially by enabling workers to recover more easily and promoting work-life balance.

The impact of reduced worktime on sleep and perceived stress - a group randomized intervention study using diary data.

Objective Insufficient time for recovery between workdays may cause fatigue and disturbed sleep. This study evaluated the impact of an intervention that reduced weekly working hours by 25% on sleep, sleepiness and perceived stress for employees within the public sector. Method Participating workplaces (N=33) were randomized into intervention and control groups. Participants (N=580, 76% women) worked full-time at baseline. The intervention group (N=354) reduced worktime to 75% with preserved salary during 18 months. Data were collected at baseline and after 9 and 18 months follow-up. Sleep quality, sleep duration, sleepiness, perceived stress,and worries and stress at bedtime were measured with diary during one week per data collection. Result A multilevel mixed model showed that compared with the control group, at the 18-month follow-up, the intervention group had improved sleep quality and sleep duration (+23 minutes) and displayed reduced levels of sleepiness, perceived stress, and worries and stress at bedtime on workdays (P<0.002). The same effects were shown for days off (P<0.006), except for sleep length. Effect sizes were small (Cohen's f2<0.08). Adding gender, age, having children living at home, and baseline values of sleep quality and worries and stress at bedtime as additional between-group factors did not influence the results. Conclusion A 25% reduction of weekly work hours with retained salary resulted in beneficial effects on sleep, sleepiness and perceived stress both on workdays and days off. These effects were maintained over an 18-month period. This randomized intervention thus indicates that reduced worktime may improve recovery and perceived stress.

Does childhood trauma influence offspring's birth characteristics?

Background: : A recent epigenetic hypothesis postulates that 'a sex-specific male-line transgenerational effect exists in humans', which can be triggered by childhood trauma during 'the slow growth period' just before puberty. The evidence is based on a few rather small epidemiological studies. We examine what response childhood trauma predicts, if any, in the birth size and prematurity risk of almost 800 000 offspring. Methods: Children of parity 1, 2 or 3, born 1976-2002 in Sweden, for whom we could trace both parents and all four grandparents, constituted generation 3 (G3, n = 764 569). Around 5% of their parents, G2, suffered parental (G1) death during their own childhood. The association of such trauma in G2 with G3 prematurity and birthweight was analysed, while controlling for confounders in G1 and G2. We examined whether the slow growth period was extra sensitive to parental loss. Results: Parental (G1) death during (G2) childhood predicts premature birth and lower birthweight in the offspring generation (G3). This response is dependent on G2 gender, G2 age at exposure and G3 parity, but not G3 gender. Conclusions: The results are compatible with the Pembrey-Bygren hypothesis that trauma exposure during boys' slow growth period may trigger a transgenerational response; age at trauma exposure among girls seems less important, suggesting a different set of pathways for any transgenerational response. Finally, parental death during childhood was not important for the reproduction of social inequalities in birthweight and premature birth.

Social adversities in adolescence predict unfavourable trajectories of internalized mental health symptoms until middle age: results from the Northern Swedish Cohort.

BACKGROUND: Experiencing adversities during upbringing has short-term and long-term effects on mental health. This study aims to explore how social adversities in adolescence predict trajectories of internalized mental health symptoms (IMHS), from adolescence and onward until middle age. METHODS: Based on 1040 individuals from the Northern Swedish Cohort Study, a community-based cohort with 27 years of follow-up. We applied latent class growth analysis to extract trajectories of IMHS between ages 16 and 43. Multinomial logistic regression was used to study the association of social adversities (residential mobility, residential crowding, parental loss, unemployment of a parent, physical illness of a parent, mental illness or alcohol problems of a parent) in adolescence with IMHS trajectories. RESULTS: Five trajectory classes were identified: 'very low stable' (26% of the sample), 'low stable' (58%), 'moderate stable' (5%), 'increasing' (8%) and 'high decreasing' (3%). Both in men and women, reporting social adversities at the age of 16 increased the risk of belonging to the classes with less favourable development of IMHS. Reporting adversities was positively associated with the initial level of the IMHS trajectories. Thus it seems that the influence of adversities is more pronounced during the early years of follow-up and is attenuated over time. CONCLUSION: Experiencing social adversities in adolescence increases the risk of entering unfavourable developmental trajectories of mental health until middle age.

Parental academic involvement in adolescence as predictor of mental health trajectories over the life course: a prospective population-based cohort study.

BACKGROUND: Mental health problems are rising, especially among younger people, indicating a need to identify determinants of the development of mental health over the life course. Parental involvement in their children's studies, particularly in terms of academic socialisation, has been shown to predict better mental health in adulthood, as well as other more favourable health outcomes, but no study published so far has examined its impact on trajectories of mental health. We therefore sought to elucidate the role of parental involvement at age 16 on the life course development of internalised mental health symptoms. METHODS: In a population-based cohort (452 women and 488 men, 87% of the eligible participants), we examined the association between parental involvement in their offspring's studies, measured by teacher and pupil ratings at age 16, and an index of internalised mental health symptoms at the ages of 16, 18, 21, 30, and 43. Using latent class trajectory analysis, 5 different trajectories were derived from these indices: Very low stable (least symptoms), Low stable, Increasing, Moderate stable, and High decreasing (most symptoms). Multinomial logistic regression was used to regress trajectory membership on the parental involvement variables. RESULTS: Teacher-rated parental interest in their offspring's studies during the last year of compulsory school was associated with a lower risk of entering the Moderate stable (OR = 0.54; 95% CI 0.30 to 0.98) and High decreasing (OR = 0.41; 0.18 to 0.91) trajectories, compared with the Low stable, also after adjustment for sex, parental social class and mental health, family unemployment and own school grades. Both these associations were present only in children with grades above the national average. Student-rated availability of assistance with homework was associated with a higher chance of entering the Very low stable trajectory in the whole sample (OR = 1.24; 1.07 to 1.43), in men (OR = 1.25; 1.05 to 1.48) and in those with above average grades (OR = 1.39; 1.13 to 1.72), and with a lower risk of entering the Moderate stable in women (OR = 0.74; 0.55 to 0.99), also after the same adjustments. CONCLUSIONS: Parental involvement in their offspring's studies may buffer against poor mental health in adolescence which may track into adulthood.

Impact of maternal obesity on inhaled corticosteroid use in childhood: a registry based analysis of first born children and a sibling pair analysis.

BACKGROUND: It has been proposed that maternal obesity during pregnancy may increase the risk that the child develops allergic disease and asthma, although the mechanisms underpinning this relationship are currently unclear. We sought to assess if this association may be due to confounding by genetic or environmental risk factors that are common to maternal obesity and childhood asthma, using a sibling pair analysis. METHODS: The study population comprised a Swedish national cohort of term children born between 1992 and 2008 to native Swedish parents. Maternal body mass index (BMI) was measured at 8-10 weeks gestation. Unconditional logistic regression models were used to determine if maternal obesity was associated with increased risk of inhaled corticosteroid (ICS) in 431,718 first-born children, while adjusting for potential confounders. An age-matched discordant sib-pair analysis was performed, taking into account shared genetic and environmental risk factors. RESULTS: Maternal over-weight and obesity were associated with increased risk that the child would require ICS (for BMI≥35 kg/m(2), aOR = 1.30, 95%CI = 1.10-1.52 compared with normal weight mothers) in children aged 6-12 years. Similar effects were seen in younger children, but in children aged 13-16 years, maternal obesity (BMI≥30) was related to increased risk of ICS use in girls (aOR = 1.28, 95%CI = 1.07-1.53) but not boys (OR = 1.05, 95%CI = 0.87-1.26). The sib-pair analysis, which included 2,034 sib-pairs older than six years who were discordant for both ICS use and maternal BMI category, failed to find any evidence that increasing maternal weight was related to increased risk of ICS use. CONCLUSION: Maternal obesity is associated with increased risk of childhood ICS use up to approximately 12 years of age, but only in girls after this age. These effects could not be confirmed in a sib pair analysis, suggesting either limited statistical power, or the effects of maternal BMI may be due to shared genetic or environmental risk factors.