Aims: Social inequalities in mortality persist or even increase in high-income countries. Most evidence is based on a period approach to measuring mortality – that is, data from individuals born decades apart. A cohort approach, however, provides complementary insights using data from individuals who grow up and age under similar social and institutional arrangements. This study compares income inequalities in cohort life expectancy in two Swedish cohorts, one born before and one born after the expansion of the welfare state. Methods: Data on individuals born in Sweden in 1922–1926 and 1951–1955 were obtained from total population registries. These data were linked to individual disposable income from 1970 and 1999 and mortality between 50 and 61 years of age in 1972–1987 and 2001–2016, respectively. We calculated cohort temporary life expectancies in the two cohorts by income and gender. Results: Life expectancy, income, and income inequalities in life expectancy increased between the two cohorts, for both men and women. Women born in 1922–1926 had modest income differences in life expectancy, but pronounced differences emerged in the cohort born in 1951–1955. Men with low incomes born in 1951–1955 had roughly similar life expectancy as those with low incomes born in 1922–1926. Conclusions: Compared with a period approach to life expectancy trends, the cohort approach highlights the stagnation of mortality at the lowest income groups for men and the rapid emergence of a mortality gradient for women. Future research on health inequalities in welfare states should consider underlying factors both from a cohort and period perspective.

Aims: Married individuals have a lower coronary heart disease (CHD) risk than non-married, but the mechanisms behind this are not fully understood. We analyzed whether genetic liability to CHD may affect these associations. Methods: Marital status, a polygenic score of CHD (PGS-CHD), and other risk factors for CHD were measured from 35,444 participants (53% female) in Finnish population-based surveys conducted between 1992 and 2012. During the register-based follow-up until 2020, there were 2439 fatal and non-fatal incident CHD cases. The data were analyzed using linear and Cox regression models. Results: Divorced and cohabiting men and women had a higher genetic risk of CHD than married individuals, but the difference was very small (0.023–0.058 standard deviation of PGS-CHD, p-values 0.011–0.429). Both marital status and PGS-CHD were associated with CHD incidence, but the associations were largely independent. Adjusting for behavioral and metabolic risk factors for CHD explained part of these associations (11–20%). No interaction was found between marital status and PGS-CHD for CHD incidence. Conclusions: We showed minor differences between the marital status categories in PGS-CHD and demonstrated that marital status and genetic liability predicted CHD incidence largely independently. This emphasizes the need to measure multiple risk factors when predicting CHD risk.

The study of the mortality differences between groups has traditionally focused on metrics that describe average levels of mortality, for example life expectancy and standardized mortality rates. Additional insights can be gained by using statistical distance metrics to examine differences in lifespan distributions between groups. Here, we use a distance metric, the non-overlap index, to capture the sociological concept of stratification, which emphasizes the emergence of unique, hierarchically layered social strata. We show an application using Finnish registration data that cover the entire population over the period from 1996 to 2017. The results indicate that lifespan stratification and life-expectancy differences between income groups both increased substantially from 1996 to 2008; subsequently, life-expectancy differences declined, whereas stratification stagnated for men and increased for women. We conclude that the non-overlap index uncovers a unique domain of inequalities in mortality and helps to capture important between-group differences that conventional approaches miss.

The effects of marriage on criminal behavior have been studied extensively. As marriages today are typically preceded by cohabiting relationships, there is a growing need to clarify how different relationship types are associated with criminality, and how these effects may be modified by relationship duration, partner's criminality, and crime type. We used Finnish longitudinal register data and between- and within-individual analyses to examine how cohabitation and marriage were associated with suspected crime. The data included 638,118 residents of Finland aged 0-14 in 2000 and followed for 17 years for a suspected crime: having been suspected of violent, drug, or any crime. Between-individual analyses suggested that those who were cohabiting or married had a 40-65% lower risk of being suspected of a crime compared to those who were single, depending on the type of crime. The within-individual analysis showed a 25-50% lower risk for suspected crime when people were cohabiting or married compared to time periods when they were single. Those in a relationship with a criminal partner had 11 times higher risk for suspected crime than those in a relationship with a non-criminal partner. Forming a cohabiting relationship with a non-criminal partner was associated with reduced criminality. The risk reduction was not fully explained by selection effects due to between-individual differences. Marriage did not introduce further reduction to criminality. Our findings demonstrate that selection effects partly explain the association between relationship status and criminality but are also compatible with a causal effect of cohabitation on reduced risk of being suspected of a crime.

Background Previous Mendelian randomization (MR) studies using population samples (population MR) have provided evidence for beneficial effects of educational attainment on health outcomes in adulthood. However, estimates from these studies may have been susceptible to bias from population stratification, assortative mating and indirect genetic effects due to unadjusted parental genotypes. MR using genetic association estimates derived from within-sibship models (within-sibship MR) can avoid these potential biases because genetic differences between siblings are due to random segregation at meiosis. Methods Applying both population and within-sibship MR, we estimated the effects of genetic liability to educational attainment on body mass index (BMI), cigarette smoking, systolic blood pressure (SBP) and all-cause mortality. MR analyses used individual-level data on 72 932 siblings from UK Biobank and the Norwegian HUNT study, and summary-level data from a within-sibship Genome-wide Association Study including >140 000 individuals. Results Both population and within-sibship MR estimates provided evidence that educational attainment decreased BMI, cigarette smoking and SBP. Genetic variant-outcome associations attenuated in the within-sibship model, but genetic variant-educational attainment associations also attenuated to a similar extent. Thus, within-sibship and population MR estimates were largely consistent. The within-sibship MR estimate of education on mortality was imprecise but consistent with a putative effect. Conclusions These results provide evidence of beneficial individual-level effects of education (or liability to education) on adulthood health, independently of potential demographic and family-level confounders.

Background The associations between height, socioeconomic position (SEP) and coronary heart disease (CHD) incidence are well established, but the contribution of genetic factors to these associations is still poorly understood. We used a polygenic score (PGS) for height to shed light on these associations.

Methods Finnish population-based health surveys in 1992–2011 (response rates 65–93%) were linked to population registers providing information on SEP and CHD incidence up to 2019. The participants (N=29 996; 54% women) were aged 25–75 at baseline, and there were 1767 CHD incident cases (32% in women) during 472 973 person years of follow-up. PGS-height was calculated based on 33 938 single-nucleotide polymorphisms, and residual height was defined as the residual of height after adjusting for PGS-height in a linear regression model. HRs of CHD incidence were calculated using Cox regression.

Results PGS-height and residual height showed clear gradients for education, social class and income, with a larger association for residual height. Residual height also showed larger associations with CHD incidence (HRs per 1 SD 0.94 in men and 0.87 in women) than PGS-height (HRs per 1 SD 0.99 and 0.97, respectively). Only a small proportion of the associations between SEP and CHD incidence was statistically explained by the height indicators (6% or less).

Conclusions Residual height associations with SEP and CHD incidence were larger than for PGS-height. This supports the role of material and social living conditions in childhood as contributing factors to the association of height with both SEP and CHD risk.

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.

Background Minimum legal drinking age (MLDA) is an effective policy tool in preventing youth drinking and shortterm alcohol-attributable harm, but studies concerning long-term associations are scarce. Methods In this register-based, national cohort study, we assessed alcohol-attributable morbidity and mortality of cohorts born in 1944-54 in Finland. Data were from the 1970 census, the Care Register for Healthcare (maintained by the Finnish Institute of Health and Welfare), and the Cause-of-Death Register (maintained by Statistics Finland). As MLDA was lowered from 21 years to 18 years in 1969, these cohorts were effectively allowed to buy alcohol from different ages (18-21 years). We used survival analysis to compare their alcohol-attributable mortality and hospitalisations with a 36-year follow-up. Findings Compared with the first cohort (1951) allowed to buy alcohol from age 18, the hazard ratios (HRs) for alcohol-attributable morbidity and mortality were lower in cohorts who could not buy alcohol until age 20 or 21 years. For alcohol-attributable morbidity in those aged 21 years when the reform took place, HR was 0 center dot 89 (95% CI 0 center dot 86-0 center dot 93) for men and 0 center dot 87 (0 center dot 81-0 center dot 94) for women versus those aged 17 years. For alcohol-attributable mortality, HR was 0 center dot 86 (0 center dot 79-0 center dot 93) for men and 0 center dot 78 (0 center dot 66-0 center dot 92) for women aged 21 years when the reform took place. The outcomes of the later-born 1952-54 cohorts did not differ from the 1951 cohort. Interpretation Earlier cohorts had consistently lower alcohol-attributable mortality and morbidity; however, other simultaneous increases in alcohol availability probably contributed to increased alcohol-related harm among the younger cohorts. Overall, differences between cohorts born only a few years apart highlight late adolescence as a crucial period for the establishment of lifelong patterns of alcohol use and suggest that higher MLDA could be protective for health beyond young adulthood. 

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.

Single motherhood is known to be distressing, and to be associated with poor mental health. However, less is known about the pathways into and out of single motherhood, or about the mental health trajectories of single mothers. We used total population registry data on Finnish women who experienced the life events of separation (616,762), widowhood (43,355), or child birth (515,756) during the 1995–2018 period while between the ages of 15–64. Single mothers were compared with women who experienced the same life event, but without becoming a single mother. The results for women who separated showed that among single mothers, there was a substantial increase in antidepressant use at the time of separation, and only a moderate decline after separation. Among women who experienced widowhood, those who had underage children initially had lower antidepressant use than women without children, but this gap narrowed in the post-widowhood period. In addition, single women experienced more unfavorable mental health trajectories than partnered women around the time they gave birth. Re-partnering was associated with more favorable mental health among all groups of single mothers. Given the growing prevalence of single-parent households, our results underscore the need for context-specific interventions to support single mothers’ mental health.