Does having siblings really protect against childhood atopic diseases? A total population and within-family analysis.

The association between having older siblings and decreased risk for atopic symptoms is well-established. This has been interpreted as evidence for the microbiota hypothesis, i.e. that increased early-childhood microbial exposure caused by siblings protects from immune hypersensitivities. However, possible confounders of the association have received little attention. We used register data on Finnish cohorts born in 1995-2004 (N = 559,077) to assess medication purchases for atopic diseases: antihistamines, eczema medication, asthma medication and Epinephrine. We modelled the probability of atopic medication purchases at ages 0-15 by birth order controlling for important observed confounders and all unobserved genetic and environmental characteristics shared by siblings in a within-family fixed effects model. We further studied medication purchases among first-borns according to the age difference with younger siblings to assess whether having younger siblings in early childhood is beneficial. Having older siblings was associated with a lower probability of atopic medication purchases. Compared to first-borns, the probability was 10-20% lower among second-borns, 20-40% lower among third-borns, and 30-70% lower among subsequent children, depending on medication type. Confounding accounted for up to 75% of these differences, particularly for asthma and eczema medication, but significant differences by birth order remained across all medication types. Among first-borns, a smaller age difference with younger siblings was related to a lower likelihood of atopic medication use. Our results, based on designs that account for unobserved confounding, show that exposure to siblings in early childhood, protects from atopic diseases, and thus strongly support the microbiota hypothesis.

Grandparental support and maternal depression: Do grandparents' characteristics matter more for separating mothers?

Grandparental support may protect mothers from depression, particularly mothers who separate and enter single parenthood. Using longitudinal Finnish register data on 116,917 separating and 371,703 non-separating mothers with young children, we examined differences in mothers' antidepressant purchases by grandparental characteristics related to provision of support. Grandparents' younger age (<70 years), employment, and lack of severe health problems predicted a lower probability of maternal depression. Depression was also less common if grandparents lived close to the mother and if the maternal grandparents' union was intact. Differences in maternal depression by grandparental characteristics were larger among separating than among non-separating mothers, particularly during the years before separation. Overall, maternal grandmothers' characteristics appeared to matter most, while the role of paternal grandparents was smaller. The findings suggest that grandparental characteristics associated with increased potential for providing support and decreased need of receiving support predict a lower likelihood of maternal depression, particularly among separating mothers.

Fatherhood timing and men's midlife earnings: A within-family study of Finnish cohorts born in 1938-50.

Fathers tend to achieve higher earnings than childless men, but there is limited evidence on the associations between fatherhood timing and men's later earnings. Using a longitudinal census-based sample of Finnish men, including a subsample of brothers, we investigated fatherhood timing and men's midlife earnings using both between- and within-family models. Earnings around age 50 were lower among adolescent and young fathers than for men who became fathers at ages 25-29 or later, but these associations became negligible after accounting for measured confounders and unobserved familial confounding. Overall, our findings highlight the important roles of selection into early childbearing and into childlessness. At the population level, early fatherhood was associated with clear negative distributional shifts in fathers' midlife earnings. However, among all men, any influence of fatherhood timing on men's midlife earnings distribution paled in comparison with that of childlessness.

Medically assisted reproduction and mental health: a 24-year longitudinal analysis using Finnish register data.

BACKGROUND: Medically assisted reproduction can negatively affect women's mental health, particularly when the treatments do not result in a live birth. Although the number of women relying on medically assisted reproduction to conceive has grown rapidly, our knowledge about the mental health effects before, during, and after treatment is limited. OBJECTIVE: This study aimed to understand the long-term association between medically assisted reproduction and mental health outcomes for women before, during, and after their treatments, and according to whether the treatment resulted in a live birth. STUDY DESIGN: Using Finnish register data for the period from 1995 to 2018, we estimated the probability of psychotropic purchases (antidepressants, anxiolytics, hypnotics, and sedatives) for 3 groups of women who: (1) gave birth after natural conception, (2) gave birth after medically assisted reproduction treatments, or (3) underwent medically assisted reproduction but remained childless. We followed up women for up to 12 years before and 12 years after the reference date, which corresponded to the conception date for women who had a first live birth either after a natural or a medically assisted conception, or the date of the last medically assisted reproduction treatment for women with no live birth by the end of 2017. We estimated linear probability models before and after adjustment for sociodemographic characteristics. RESULTS: The results show that women who did not have a live birth after undergoing medically assisted reproduction treatments purchased more psychotropics than women who gave birth after conceiving naturally or through medically assisted reproduction, and that these differences did not attenuate over time. Twelve years after the reference date, 17.73% (95% confidence interval, 16.82-18.63) of women who underwent medically assisted reproduction but remained childless purchased psychotropics vs 11.11% of women who gave birth after natural conception (95% confidence interval, 10.98-11.26) and 12.17% (95% confidence interval, 11.65-12.69) of women who gave birth after medically assisted reproduction treatments. In addition, women who conceived naturally and through medically assisted reproduction had very similar psychotropic use patterns from 3 years before conception to 4 years after, and over the long term. Adjustment for women's sociodemographic characteristics did not change the results. CONCLUSION: The similarities in psychotropic purchases of women who had a live birth, whether naturally or through medically assisted reproduction, suggest that the higher psychotropic use among women who remained childless after undergoing medically assisted reproduction were likely driven more by involuntary childlessness than by treatment-related stress. The results highlight the importance of counseling for women undergoing medically assisted reproduction treatments, especially if their attempts to conceive are unsuccessful.

Labor epidural analgesia and subsequent risk of offspring autism spectrum disorder and attention-deficit/hyperactivity disorder: a cross-national cohort study of 4.5 million individuals and their siblings.

BACKGROUND: A recent study has suggested that labor epidural analgesia may be associated with increased rates of offspring autism spectrum disorder. Subsequent replication attempts have lacked sufficient power to confidently exclude the possibility of a small effect, and the causal nature of this association remains unknown. OBJECTIVE: This study aimed to investigate the extent to which exposure to labor epidural analgesia is associated with offspring autism spectrum disorder and attention-deficit/hyperactivity disorder following adjustments for unmeasured familial confounding. STUDY DESIGN: We identified 4,498,462 singletons and their parents using the Medical Birth Registers in Finland (cohorts born from 1987-2005), Norway (1999-2015), and Sweden (1987-2011) linked with population and patient registries. These cohorts were followed from birth until they either had the outcomes of interest, emigrated, died, or reached the end of the follow-up (at mean ages 13.6-16.8 years), whichever occurred first. Cox regression models were used to estimate country-specific associations between labor epidural analgesia recorded at birth and outcomes (eg, at least 1 secondary care diagnosis of autism spectrum disorder and attention-deficit/hyperactivity disorder or at least 1 dispensed prescription of medication used for the treatment of attention-deficit/hyperactivity disorder). The models were adjusted for sex, birth year, birth order, and unmeasured familial confounders via sibling comparisons. Pooled estimates across all the 3 countries were estimated using inverse variance weighted fixed-effects meta-analysis models. RESULTS: A total of 4,498,462 individuals (48.7% female) were included, 1,091,846 (24.3%) of which were exposed to labor epidural analgesia. Of these, 1.2% were diagnosed with autism spectrum disorder and 4.0% with attention-deficit/hyperactivity disorder. On the population level, pooled estimates showed that labor epidural analgesia was associated with increased risk of offspring autism spectrum disorder (adjusted hazard ratio, 1.12; 95% confidence interval, 1.10-1.14, absolute risks, 1.20% vs 1.07%) and attention-deficit/hyperactivity disorder (adjusted hazard ratio, 1.20; 95% confidence interval, 1.19-1.21; absolute risks, 3.95% vs 3.32%). However, when comparing full siblings who were differentially exposed to labor epidural analgesia, the associations were fully attenuated for both conditions with narrow confidence intervals (adjusted hazard ratio [autism spectrum disorder], 0.98; 95% confidence interval, 0.93-1.03; adjusted hazard ratio attention-deficit/hyperactivity disorder, 0.99; 95% confidence interval, 0.96-1.02). CONCLUSION: In this large cross-national study, we found no support for the hypothesis that exposure to labor epidural analgesia causes either offspring autism spectrum disorder or attention-deficit/hyperactivity disorder.

Socioeconomic differences in children's victimization to maternal and paternal violence: a register-based study.

AIMS: To explore the potential of administrative data in assessment of the association between parental socioeconomic position (SEP) and children's violent victimization by biological parents. METHODS: A longitudinal register-linkage study based on child-mother and child-father data, including all children born in Finland between 1991 and 2017. The data included 1,535,428 children, 796,335 biological mothers, and 775,966 fathers. We used logistic regression with person-years as observations and cluster-robust standard errors to predict children's violent victimization in 2009-2018 and assessed effect modification by child's age and gender. RESULTS: For the SEP indicators, lower maternal education (adjusted odds ratio (OR) 2.90, secondary education OR 1.99) and lower paternal education (OR 2.24, secondary education OR 1.59) were risk factors for violent victimization. Parental social assistance receipt (OR 2.4) and non-employment (OR 1.8-1.9) increased the risk of victimization to maternal and paternal violence. Income was associated with victimization in a gradient-like manner, with ORs ranging from 1.14 to 1.98 among mothers and from 1.29 to 2.56 among fathers. Children with low parental SEP were at the highest risk of parental violence, particularly paternal violence, at ages 3-8 years. CONCLUSIONS: All indicators of low SEP increased the risk of children experiencing both maternal and paternal physical violence, especially at ages 3-8 years. Longitudinal register data-because of large samples, no nonresponse or self-report bias, and the possibility to analyze violence committed by mother and father and age-groups separately-have great potential for comprehensive research on the risk factors of parental violence that are difficult to reliably assess with other types of data.

Income differences in partial life expectancy between ages 35 and 64 from 1988 to 2017: the contribution of living arrangements.

BACKGROUND: Socioeconomic differences in mortality among the working-age population have increased in several high-income countries. The aim of this study was to assess whether changes in the living arrangement composition of income groups have contributed to changing income differences in life expectancy during the past 30 years. METHODS: We used Finnish register data covering the total population to calculate partial life expectancies between ages 35 and 64 by income quartile in 1988-2017. The contribution of living arrangements to these differences was assessed by direct standardization. Decomposition methods were used to determine the extent of life expectancy differences due to external (accidental, violent and alcohol-related) causes of death. RESULTS: The life expectancy gap between the highest and lowest income quartile increased until 2003-07, but decreased thereafter. The contribution of living arrangements to these differences remained mostly stable: 36-39% among men and 15-23% among women. Those living without children consistently showed the greatest life expectancy differences by income. External causes of death significantly contributed to income differences in life expectancy. CONCLUSIONS: The living arrangement composition of income groups explained part of the differences in life expectancy, but not their changes. Our results on the contribution of external causes of death imply that both the persistent income gradient in mortality as well as the mortality disparities by living arrangements are at least partially related to similar selection or causal mechanisms.

Partnership trajectories preceding medically assisted reproduction.

The number of people who undergo medically assisted reproduction (MAR) to conceive has increased considerably in recent decades. However, existing research into the demographics and the partnership histories of this growing subgroup is limited. Using unique data from Finnish population registers on nulliparous women born in Finland in 1971-77 (n = 21,129; ∼10 per cent of all women) who had undergone MAR treatment, we created longitudinal partnership histories from age 16 until first MAR treatment. We identified six typical partnership trajectories and used relative frequency sequence plots to investigate heterogeneity in partnership transitions within and between these groups. The majority of women (60.7 per cent) underwent MAR with their first partner, followed by women who underwent MAR in a second (21.5 per cent) or higher-order partnership (7.1 per cent), while 10.7 per cent underwent MAR without a partner. On average, women undergoing MAR were relatively young (with around half starting treatment before age 30) and were highly educated with high incomes.

Income differences in COVID-19 incidence and severity in Finland among people with foreign and native background: A population-based cohort study of individuals nested within households.

BACKGROUND: Although intrahousehold transmission is a key source of Coronavirus Disease 2019 (COVID-19) infections, studies to date have not analysed socioeconomic risk factors on the household level or household clustering of severe COVID-19. We quantify household income differences and household clustering of COVID-19 incidence and severity. METHODS AND FINDINGS: We used register-based cohort data with individual-level linkage across various administrative registers for the total Finnish population living in working-age private households (N = 4,315,342). Incident COVID-19 cases (N = 38,467) were identified from the National Infectious Diseases Register from 1 July 2020 to 22 February 2021. Severe cases (N = 625) were defined as having at least 3 consecutive days of inpatient care with a COVID-19 diagnosis and identified from the Care Register for Health Care between 1 July 2020 and 31 December 2020. We used 2-level logistic regression with individuals nested within households to estimate COVID-19 incidence and case severity among those infected. Adjusted for age, sex, and regional characteristics, the incidence of COVID-19 was higher (odds ratio [OR] 1.67, 95% CI 1.58 to 1.77, p < 0.001, 28.4% of infections) among individuals in the lowest household income quintile than among those in the highest quintile (18.9%). The difference attenuated (OR 1.23, 1.16 to 1.30, p < 0.001) when controlling for foreign background but not when controlling for other household-level risk factors. In fact, we found a clear income gradient in incidence only among people with foreign background but none among those with native background. The odds of severe illness among those infected were also higher in the lowest income quintile (OR 1.97, 1.52 to 2.56, p < 0.001, 28.0% versus 21.6% in the highest quintile), but this difference was fully attenuated (OR 1.08, 0.77 to 1.52, p = 0.64) when controlling for other individual-level risk factors-comorbidities, occupational status, and foreign background. Both incidence and severity were strongly clustered within households: Around 77% of the variation in incidence and 20% in severity were attributable to differences between households. The main limitation of our study was that the test uptake for COVID-19 may have differed between population subgroups. CONCLUSIONS: Low household income appears to be a strong risk factor for both COVID-19 incidence and case severity, but the income differences are largely driven by having foreign background. The strong household clustering of incidence and severity highlights the importance of household context in the prevention and mitigation of COVID-19 outcomes.

Socioeconomic differences in psychiatric treatment before and after self-harm: an observational study of 4,280 adolescents and young adults.

BACKGROUND: Individuals in higher socioeconomic positions tend to utilise more mental health care, especially specialist services, than those in lower positions. Whether these disparities in treatment exist among adolescents and young adults who self-harm is currently unknown. METHODS: The study is based on Finnish administrative register data on all individuals born 1986-1994. Adolescents and young adults with an episode of self-harm treated in specialised healthcare at ages 16-21 in 2002-2015 (n=4280, 64% female) were identified and followed 2 years before and after the episode. Probabilities of specialised psychiatric inpatient admissions and outpatient visits and purchases of psychotropic medication at different time points relative to self-harm were estimated using generalised estimation equations, multinomial models and cumulative averages. Socioeconomic differences were assessed based on parental education, controlling for income. RESULTS: An educational gradient in specialised treatment and prescription medication was observed, with the highest probabilities of treatment among the adolescents and young adults with the highest educated parents and lowest probabilities among those whose parents had basic education. These differences emerged mostly after self-harm. The probability to not receive any treatment, either in specialised healthcare or psychotropic medication, was highest among youth whose parents had a basic level of education (before self-harm 0.39, 95% CI 0.34-0.43, and after 0.29, 95% CI 0.25-0.33 after) and lowest among youth with higher tertiary educated parents (before self-harm: 0.22, 95% CI 0.18-0.26, and after 0.18, 95% CI 0.14-0.22). The largest differences were observed in inpatient care. CONCLUSIONS: The results suggest that specialised psychiatric care and psychotropic medication use are common among youth who self-harm, but a considerable proportion have no prior or subsequent specialised treatment. The children of parents with lower levels of education are likely to benefit from additional support in initiating and adhering to treatment after an episode of self-harm. Further research on the mechanisms underlying the educational gradient in psychiatric treatment is needed.

Medically assisted reproduction and birth outcomes: a within-family analysis using Finnish population registers.

BACKGROUND: Children born after medically assisted reproduction are at higher risk of adverse birth outcomes than are children conceived naturally. We aimed to establish the extent to which this excess risk should be attributed to harmful effects of treatment or to pre-existing parental characteristics that confound the association. METHODS: We used data from Finnish administrative registers covering a 20% random sample of households with at least one child aged 0-14 years at the end of 2000 (n=65 723). We analysed birthweight, gestational age, risk of low birthweight, and risk of preterm birth among children conceived both by medically assisted reproduction and naturally. First, we estimated differences in birth outcomes by mode of conception in the general population, using standard multivariate methods that controlled for observed factors (eg, multiple birth, birth order, and parental sociodemographic characteristics). Second, we used a sibling-comparison approach that has not been used before in medically assisted reproduction research. We compared children conceived by medically assisted reproduction with siblings conceived naturally and, thus, controlled for all observed and unobserved factors shared by siblings. FINDINGS: Between 1995 and 2000, 2776 (4%) children in our sample were conceived by medically assisted reproduction; 1245 children were included in the sibling comparison. Children conceived by medically assisted reproduction had worse outcomes than did those conceived naturally, for all outcomes, even after adjustments for observed child and parental characteristics-eg, difference in birthweight of -60 g (95% CI -86 to -34) and 2·15 percentage point (95% CI 1·07 to 3·24) increased risk of preterm delivery. In the sibling comparison, the gap in birth outcomes was attenuated, such that the relation between medically assisted reproduction and adverse birth outcomes was statistically and substantively weak for all outcomes-eg, difference in birthweight of -31 g (95% CI -85 to 22) and 1·56 percentage point (95% CI -1·26 to 4·38) increased risk of preterm delivery. INTERPRETATION: Children conceived by medically assisted reproduction face an elevated risk of adverse birth outcomes. However, our results indicate that this increased risk is largely attributable to factors other than the medically assisted reproduction treatment itself. FUNDING: European Research Council, the Academy of Finland, and the Signe and Ane Gyllenberg Foundation.

Maternal age and risk of low birth weight and premature birth in children conceived through medically assisted reproduction. Evidence from Finnish population registers.

STUDY QUESTION: Does the risk of low birth weight and premature birth increase with age among mothers who conceive through medically assisted reproduction (MAR)? SUMMARY ANSWER: Among MAR mothers, the risk of poorer birth outcomes does not increase with maternal age at birth except at very advanced maternal ages (40+). WHAT IS KNOWN ALREADY: The use of MAR treatments has been increasing over the last few decades and is especially diffused among women who conceive at older ages. Although advanced maternal age is a well-known risk factor for adverse birth outcomes in natural pregnancies, only a few studies have directly analysed the maternal age gradient in birth outcomes for MAR mothers. STUDY DESIGN, SIZE, DURATION: The base dataset was a 20% random sample of households with at least one child aged 0-14 at the end of 2000, drawn from the Finnish population register and other administrative registers. This study included children who were born in 1995-2000, because the information on whether a child was conceived through MAR or naturally was available only from 1995 onwards. PARTICIPANTS/MATERIALS, SETTING, METHODS: The outcome measures were whether the child had low birth weight (LBW, <2500 g at birth) and whether the child was delivered preterm (<37 weeks of gestation). Conceptions through MAR were identified by examining data on purchases of prescription medication from the National Prescription Register. Linear probability models were used to analyse and compare the maternal age gradients in birth outcomes of mothers who conceived through MAR or naturally before and after adjustment for maternal characteristics (i.e. whether the mother suffered from acute/chronic conditions before the pregnancy, household income and whether the mother smoked during pregnancy). MAIN RESULTS AND THE ROLE OF CHANCE: A total of 56 026 children, 2624 of whom were conceived through MAR treatments, were included in the study. Among the mothers who used MAR to conceive, maternal age was not associated with an increased risk of LBW (the overall prevalence was 12.6%) at ages 25-39. For example, compared to the risk of LBW at ages 30-34, the risk was 0.22 percentage points lower (95% CI: -3.2, 2.8) at ages 25-29 and was 1.34 percentage points lower (95% CI: -4.5, 1.0) at ages 35-39. The risk of LBW was increased only at maternal ages ≥40 (six percentage points, 95% CI: 0.2, 12). Adjustment for maternal characteristics only marginally attenuated these associations. In contrast, among the mothers who conceived naturally, the results showed a clear age gradient. For example, compared to the risk of LBW (the overall prevalence was 3.3%) at maternal ages 30-34, the risk was 1.1 percentage points higher (95% CI: 0.6, 1.6) at ages 35-39 and was 1.5 percentage points higher (95% CI: 0.5, 2.6) at ages ≥40. The results were similar for preterm births. LIMITATIONS, REASON FOR CAUTION: A limited number of confounders were included in the study because of the administrative nature of the data used. Our ability to reliably distinguish mothers based on MAR treatment type was also limited. WIDER IMPLICATIONS OF THE FINDINGS: This is the first study to analyse the maternal age gradient in the risk of adverse birth outcomes among children conceived through MAR using data from a nationally representative sample and controlling for important maternal health and socio-economic characteristics. This topic is of considerable importance in light of the widespread and increasing use of MAR treatments. STUDY FUNDING/COMPETING INTEREST(S): Funding for this project was provided by the European Research Council (grant no. 803959 MARTE to Alice Goisis and grant no. 336475 COSTPOST to Mikko Myrskylä). E.S. reports personal fees from Theramex, personal fees from Merck Serono, personal fees from Health Reimbursement Arrangement, non-financial support from Merck Serono and grants from Ferring, grants from Theramex, outside the submitted work. The remaining authors have no competing interests. TRIAL REGISTRTION NUMBER: N/A.

Evaluating the Role of Parental Education and Adolescent Health Problems in Educational Attainment.

This article reconsiders the role of social origin in health selection by examining whether parental education moderates the association between early health and educational attainment and whether health problems mediate the intergenerational transmission of education. We used longitudinal register data on Finns born in 1986-1991 (n = 352,899). We measured the completion of secondary and tertiary education until age 27 and used data on hospital care and medication reimbursements to assess chronic somatic conditions, frequent infections, and mental disorders at ages 10-16. We employed linear probability models to estimate the associations between different types of health problems and educational outcomes and to examine moderation by parental education, both overall in the population and comparing siblings with and without health problems. Finally, we performed a mediation analysis with g-computation to simulate whether a hypothetical eradication of health problems would weaken the association between parental and offspring education. All types of health problems reduced the likelihood of secondary education, but mental disorders were associated with the largest reductions. Among those with secondary education, there was further evidence of selection to tertiary education. High parental education buffered against the negative impact of mental disorders on completing secondary education but exacerbated it in the case of tertiary education. The simulated eradication of health problems slightly reduced disparities by parental education in secondary education (up to 10%) but increased disparities in tertiary education (up to 2%). Adolescent health problems and parental education are strong but chiefly independent predictors of educational attainment.

The Population Impact of Childhood Health Conditions on Dropout from Upper-Secondary Education.

OBJECTIVES: To quantify how large a part of educational dropout is due to adverse childhood health conditions and to estimate the risk of dropout across various physical and mental health conditions. STUDY DESIGN: A registry-based cohort study was conducted on a 20% random sample of Finns born in 1988-1995 (n = 101 284) followed for school dropout at ages 17 and 21. Four broad groups of health conditions (any, somatic, mental, and injury) and 25 specific health conditions were assessed from inpatient and outpatient care records at ages 10-16 years. We estimated the immediate and more persistent risks of dropout due to health conditions and calculated population-attributable fractions to quantify the population impact of childhood health on educational dropout, while accounting for a wide array of sociodemographic confounders and comorbidity. RESULTS: Children with any health condition requiring inpatient or outpatient care at ages 10-16 years were more likely to be dropouts at ages 17 years (risk ratio 1.71, 95% CI 1.61-1.81) and 21 years (1.46, 1.37-1.54) following adjustment for individual and family sociodemographic factors. A total of 30% of school dropout was attributable to health conditions at age 17 years and 21% at age 21 years. Mental disorders alone had an attributable fraction of 11% at age 21 years, compared with 5% for both somatic conditions and injuries. Adjusting for the presence of mental disorders reduced the effects of somatic conditions. CONCLUSIONS: More than one fifth of educational dropout is attributable to childhood health conditions. Early-onset mental disorders emerge as key targets in reducing dropout.

Advanced Maternal Age and the Risk of Low Birth Weight and Preterm Delivery: a Within-Family Analysis Using Finnish Population Registers.

Advanced maternal age at birth is considered a major risk factor for birth outcomes. It is unclear to what extent this association is confounded by maternal characteristics. To test whether advanced maternal age at birth independently increases the risk of low birth weight (<2,500 g) and preterm birth (<37 weeks' gestation), we compared between-family models (children born to different mothers at different ages) with within-family models (children born to the same mother at different ages). The latter procedure reduces confounding by unobserved parental characteristics that are shared by siblings. We used Finnish population registers, including 124,098 children born during 1987-2000. When compared with maternal ages 25-29 years in between-family models, maternal ages of 35-39 years and ≥40 years were associated with percentage increases of 1.1 points (95% confidence intervals: 0.8, 1.4) and 2.2 points (95% confidence intervals: 1.4, 2.9), respectively, in the probability of low birth weight. The associations are similar for the risk of preterm delivery. In within-family models, the relationship between advanced maternal age and low birth weight or preterm birth is statistically and substantively negligible. In Finland, advanced maternal age is not independently associated with the risk of low birth weight or preterm delivery among mothers who have had at least 2 live births.

Education as a social pathway from parental socioeconomic position to depression in late adolescence and early adulthood: a Finnish population-based register study.

PURPOSE: There is inconsistent evidence for social differentials in the risk of depression in youth, and little is known about how education at this age influences the risk. We assess how parental socioeconomic position (SEP) and education predict depression from late adolescence to early adulthood, a time of major educational transitions. METHODS: We followed a nationally representative 20 % sample of Finnish adolescents born in 1986-1990 (n = 60,829) over two educational transitory stages at the age of 17-19 and 20-23 covering the years 2003-2011. We identified incident depression using health care register data. We estimated the risk of depression by parental SEP and personal education using Cox regression, adjusting for family structure, parental depression and the individual's own psychiatric history. RESULTS: Lower parental income was associated with up to a twofold risk of depression. This effect was almost fully attributable to other parental characteristics or mediated by the individual's own education. Educational differences in risk were attenuated following adjustment for prior psychiatric history. Adjusted for all covariates, not being in education increased the risk up to 2.5-fold compared to being enrolled in general upper secondary school at the age of 17-19 and in tertiary education at the age of 20-23. Vocationally oriented women experienced a 20 % higher risk than their academically oriented counterparts in both age groups. CONCLUSIONS: Education constitutes a social pathway from parental SEP to the risk of depression in youth, whereby educational differences previously shown in adults are observed already before the establishment of adulthood SEP.

Young adult's own and parental social characteristics predict injury morbidity: a register-based follow-up of 135,000 men and women.

BACKGROUND: Sociodemographic differences in injury mortality are well-established, but population-level studies on social patterns of injury morbidity remain few in numbers, particularly among young adults. Yet injuries are the leading cause of mortality, morbidity and disability among young people. Studies among children have shown steep social gradients in severe injuries, but less is known on the social patterning of injuries in late adolescence and early adulthood, when young people are in the process of becoming independent adults. This study examines how young adults' current living arrangements, education, main economic activity, and parental social background are associated with hospital-treated injuries in late adolescence and early adulthood. METHODS: The study uses prospective, individual-level data gathered from several administrative sources. From a representative 11% sample of the total Finnish population, we included young people between ages 17-29 years during the follow-up (N = 134,938). We used incidence rates and Cox proportional hazards models to study hospital-treated injuries and poisonings in 1998-2008. RESULTS: Higher rates of injury were found among young adults living alone, single mothers, the lower educated and the non-employed, as well as those with lower parental social background, experience of childhood family changes or living with a single parent, and those who had left the parental home at a young age. Injury risks were consistently higher among young adults with lower education, but current living arrangements and main economic activity showed some age-related nuances in the associations: both earlier and later than average transitions in education, employment, and family formation associated with increased injury risks. The social differentials were strongest in poisonings, intentional self-harm, and assaults, but social patterns were also found in falls, traffic-related injuries and other unintentional injuries, underlining the existence of multiple distinct mechanisms and pathways behind the differentials. CONCLUSIONS: The transition to adulthood is a life period of heightened risk of injury, during which both parental social background and the young people's own social position are important determinants of serious injuries that require inpatient care.

Contribution of causes of death to changing inequalities in life expectancy by income in Finland, 1997-2020.

BACKGROUND: Socioeconomic inequalities in mortality originate from different causes of death. Alcohol-related and smoking-related deaths are major drivers of mortality inequalities across Europe. In Finland, the turn from widening to narrowing mortality disparities by income in the early 2010s was largely attributable to these causes of death. However, little is known about recent inequalities in life expectancy (LE) and lifespan variation. METHODS: We used individual-level total population register-based data with annual information on disposable household income and cause-specific mortality for ages 30-95+, and assessed the contribution of smoking on mortality using the Preston-Glei-Wilmoth method. We calculated trends in LE at age 30 and SD in lifespan by income quintile in 1997-2020 and conducted age and cause-of-death decompositions of changes in LE. RESULTS: Disparity in LE and lifespan variation by income increased in 2015-2020, largely attributable to the stagnation of both measures in the lowest income quintile. The LE gap between the extreme quintiles in 2018-2020 was 11.2 (men) and 5.9 (women) years, of which roughly 40% was attributable to alcohol and smoking. However, the recent widening of the gap and the stagnation in LE in the lowest quintile over time were not driven by any specific cause-of-death group. CONCLUSIONS: After a decade of narrowing inequalities in LE and lifespan variation in Finland, the gaps between income groups are growing again. Increasing LE disparity and stagnating mortality on the lowest income levels are no longer attributable to smoking and alcohol-related deaths but are more comprehensive, originating from most cause-of-death groups.

Excess winter mortality in Finland, 1971-2019: a register-based study on long-term trends and effect modification by sociodemographic characteristics and pre-existing health conditions.

OBJECTIVES: Excess winter mortality is a well-established phenomenon across the developed world. However, whether individual-level factors increase vulnerability to the effects of winter remains inadequately examined. Our aim was to assess long-term trends in excess winter mortality in Finland and estimate the modifying effect of sociodemographic and health characteristics on the risk of winter death. DESIGN: Nationwide register study. SETTING: Finland. PARTICIPANTS: Population aged 60 years and over, resident in Finland, 1971-2019. OUTCOME MEASURES: Age-adjusted winter and non-winter death rates, and winter-to-non-winter rate ratios and relative risks (multiplicative interaction effects between winter and modifying characteristics). RESULTS: We found a decreasing trend in the relative winter excess mortality over five decades and a drop in the series around 2000. During 2000-2019, winter mortality rates for men and women were 11% and 14% higher than expected based on non-winter rates. The relative risk of winter death increased with age but did not vary by income. Compared with those living with at least one other person, individuals in institutions had a higher relative risk (1.07, 95% CI 1.05 to 1.08). Most pre-existing health conditions did not predict winter death, but persons with dementia emerged at greater relative risk (1.06, 95% CI 1.04 to 1.07). CONCLUSIONS: Although winter mortality seems to affect frail people more strongly-those of advanced age, living in institutions and with dementia-there is an increased risk even beyond the more vulnerable groups. Protection of high-risk groups should be complemented with population-level preventive measures.

Moderating role of sociodemographic factors in parental psychiatric treatment before and after offspring severe self-harm.

BACKGROUND: Parental psychiatric disorders are known risk factors for adolescent self-harm. Although this association is likely to have a bidirectional element, evidence on changes in parental psychiatric treatment following offspring self-harm is scarce. METHODS: Finnish children born in 1987-1996 with a hospital-treated episode of self-harm between the ages 13 and 19 years (N = 3636) were identified using administrative register data, and their biological mothers (N = 3432) and fathers (N = 3167) were followed two years before and after the episode. Data on purchases of psychotropic medication, specialized psychiatric treatment and psychiatric sickness allowances were used to examine psychiatric treatment among parents. Differences by parental education, employment and living arrangements were assessed, and offspring self-harm was compared with offspring accidental poisonings and traffic accidents. RESULTS: Psychiatric treatment peaked among mothers during the three-month period after offspring self-harm, after which the treatment prevalence decreased but remained slightly elevated relative to the time preceding offspring self-harm. Higher levels of education and being employed increased the likelihood of treatment right after the episode. Among fathers, changes in treatment were negligible. Treatment trajectories around the comparison events of accidents were similar in shape but more muted than among the parents whose children had self-harmed. LIMITATIONS: General practitioner visits or other data from primary health care were not available. CONCLUSION: Mothers receive increased psychiatric treatment after stressful offspring events. Our results indicate that prevention of self-harm and accidents would be beneficial not only for those directly concerned but also for their family members.