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Previous studies indicate that the use of disability benefits is associated with reduced chances of having children. The current study aimed to identify the bidirectional nature of this association which has been overlooked in previous research. The longitudinal data used in this study were obtained from the Swedish national registers. It consists of 440,200 individuals born from 1968 to 1970 with a follow-up period extending up to 2010. Descriptive analysis, heat map visualization, and multinomial logistic regression were performed. The results show a complex and dynamic association between disability and parenthood. Starting on disability benefits at the age of 20–25 years was associated with a reduced chance of having children during the follow-up duration (≤42 years). Interestingly, another pattern was also revealed, and individuals who had their first child as teenagers (aged 13–19 years) were at higher odds of starting to receive disability benefits during their 30s and 40s compared to the rest of the study population. This is the first study to show evidence of a bidirectional nature of the association between age at starting to use disability benefits and the age of having a first child. Our findings demonstrate the potential of using heatmaps and multinomial regression on time-to-event data to examine bidirectional relationships between various factors investigated across several disciplines.

Background: Inbreeding, arising from consanguinity between related parents, has been observed to impact the health of individuals, typically attributed to biological factors. Nevertheless, these effects may be influenced by the social and environmental conditions. The prevalence of consanguineous marriages increased in certain parts of Sweden after it became legal in 1844, which offers a unique opportunity to study and understand the effects of inbreeding on health.

Aim: The objective of this study is to explore the potential impact of inbreeding on the longevity, fertility, and impairments of individuals born in the Skellefteå region, Sweden, between 1890 and 1905, with a follow-up period extending until 1950.

Subjects and methods: The level of inbreeding is calculated using micro-level parish register data and related to longevity, fertility, and impairments using regression analysis.

Results: Inbreeding is shown to be associated with longevity, fertility, and impairments. It seems to affect the risk of stillbirth and impairments and male longevity and fertility.

Conclusion: Inbreeding seems to have had a detrimental effect on some health outcomes in this historical population under study.

Analysis of colonization processes that occurred before the availability of written records has traditionally relied on methods from fields such as archaeology and linguistics. However, the rapid development of DNA testing has introduced a novel approach to investigating these historical processes. In this study, we utilize genetictesting to examine the colonization of Västerbotten, a region in northern Sweden. Although detailed written records exist from the 18th century onward through parishregisters, the region’s earlier history remains only partially understood.

This study employs genetic analysis to explore the demographic and migratory patterns of Västerbotten’s early inhabitants. The primary objective was to tracethe progression of colonization, including the demographics, migration routes, andancestry of early settlers. By analyzing haplogroup patterns, we uncovered insightsinto the paternal lines that have shaped the region’s genetic landscape over the past two millennia, providing valuable implications for understanding the colonizationprocess.

Furthermore, this study underscores the significant potential of genetic genealogyas a tool for reconstructing complex historical demographic processes. Our findings demonstrate how analyzing paternal lineages that contribute to the genetic makeup of the Västerbotten population can reveal clues about regional colonization dynam-ics. This work illustrates the broader applicability of genetic analysis in deepeningour understanding of historical events, not only in this region but also in similar contexts worldwide.

Background: Over the past decades the number of young people using disability pensions (DP) has gradually increased in Europe but the reasons for this change are poorly understood. We hypothesize that teenage parenthood could be associated with an increased risk of receiving early DP. The aim of this study was to examine the association between having a first child at age 13-19 and receiving DP at age 20-42 (here called early DP).

Methods: A longitudinal cohort study was undertaken based on national register data obtained from 410,172 individuals born in Sweden in 1968, 1969, and 1970. Teenage mothers and fathers were followed until age 42 and compared to non-teenage parent counterparts to examine their early receipt of DP. Descriptive analysis, Kaplan-Meier curves, and Cox regression analyses were performed.

Results: The proportion of teenage parents was more than twice higher in the group that received early DP (16%) compared to the group that did not receive early DP (6%) during the study duration. A higher proportion of teenage mothers and fathers started to receive DP at 20-42 years old compared to non-teenage parents, and the difference between the two groups increased during the observation period. A strong association was observed between being a teenage parent and receiving early DP, significant both independently and after adjusting for the year of birth and the father's level of education. From the age of 30 to 42 years, teenage mothers used early DP more often than teenage fathers or non-teenage parents, and this difference also increased during the follow-up period.

Conclusion: A strong association was found between teenage parenthood and the use of DP between 20 and 42 years of age. Teenage mothers used DP more than teenage fathers and non-teenage parents.

OBJECTIVE: To quantify the risk of deep vein thrombosis, pulmonary embolism, and bleeding after covid-19.

DESIGN: Self-controlled case series and matched cohort study.

SETTING: National registries in Sweden.

PARTICIPANTS: 1 057 174 people who tested positive for SARS-CoV-2 between 1 February 2020 and 25 May 2021 in Sweden, matched on age, sex, and county of residence to 4 076 342 control participants.

MAIN OUTCOMES MEASURES: Self-controlled case series and conditional Poisson regression were used to determine the incidence rate ratio and risk ratio with corresponding 95% confidence intervals for a first deep vein thrombosis, pulmonary embolism, or bleeding event. In the self-controlled case series, the incidence rate ratios for first time outcomes after covid-19 were determined using set time intervals and the spline model. The risk ratios for first time and all events were determined during days 1-30 after covid-19 or index date using the matched cohort study, and adjusting for potential confounders (comorbidities, cancer, surgery, long term anticoagulation treatment, previous venous thromboembolism, or previous bleeding event).

RESULTS: Compared with the control period, incidence rate ratios were significantly increased 70 days after covid-19 for deep vein thrombosis, 110 days for pulmonary embolism, and 60 days for bleeding. In particular, incidence rate ratios for a first pulmonary embolism were 36.17 (95% confidence interval 31.55 to 41.47) during the first week after covid-19 and 46.40 (40.61 to 53.02) during the second week. Incidence rate ratios during days 1-30 after covid-19 were 5.90 (5.12 to 6.80) for deep vein thrombosis, 31.59 (27.99 to 35.63) for pulmonary embolism, and 2.48 (2.30 to 2.68) for bleeding. Similarly, the risk ratios during days 1-30 after covid-19 were 4.98 (4.96 to 5.01) for deep vein thrombosis, 33.05 (32.8 to 33.3) for pulmonary embolism, and 1.88 (1.71 to 2.07) for bleeding, after adjusting for the effect of potential confounders. The rate ratios were highest in patients with critical covid-19 and highest during the first pandemic wave in Sweden compared with the second and third waves. In the same period, the absolute risk among patients with covid-19 was 0.039% (401 events) for deep vein thrombosis, 0.17% (1761 events) for pulmonary embolism, and 0.101% (1002 events) for bleeding.

CONCLUSIONS: The findings of this study suggest that covid-19 is a risk factor for deep vein thrombosis, pulmonary embolism, and bleeding. These results could impact recommendations on diagnostic and prophylactic strategies against venous thromboembolism after covid-19.

Den natur- och kulturmiljö som vi lever i är under ständig förändring. I dag är debatten livlig om hur vi genom vårt agerande har påverkat vårt klimat och vår livsmiljö. Det gäller exempelvis hur vi utnyttjar våra naturresurser: skogen, jordbruksmarken, vattenkraften, vindkraften och infrastrukturen generellt. Det gäller inte minst utnyttjandet av våra sjöar och vattendrag som påverkats mycket av mänsklig aktivitet.

Sjöarnas, älvarnas och bäckarnas närområden med sina naturliga ängsmarker har bidragit till att skapa förutsättningar för boskapsskötsel, som varit en viktig näring i Västerbotten under lång tid. Med tiden blev de naturliga ängsmarkerna utarmade på näringsämnen vilket resulterade i att avkastningen minskade. Det var därför viktigt att finna metoder för att öka avkastningen på de naturliga ängsmarkerna och naturligtvis också skapa nya ängs- och åkermarker. En av de metoder som kom till användning var att sänka eller helt dränera sjöar. Sjöns utlopp försågs med en dammbyggnad som gjorde det möjligt att reglera vattennivån i sjön. Sjösänkningarna/regleringarna hade till syfte att skapa förutsättningar för en utvidgning av åker- och ängsmarken och förbättra skörden på existerande ängsmark.

Här studeras hur sjösänkningar 1830 till 1870 format landskapet i Västerbotten.

BACKGROUND: Studies from across the world show that disability limits people’s health and social wellbeing in present-day populations. This disadvantage can lead to premature death, but there is dearth knowledge about the relationship between disability and mortality and changes over time.   

OBJECTIVES: Unique access to longitudinal micro data on comprehensive Swedish populations enabled us to examine how disability affects premature death in men and women from the 1800s until 2010. 

METHODS: Cox proportional regressions were used to estimate mortality hazards by disability status, gender and socio-economic indicators in three study populations from the 1800s, 1900s and 2000s. We followed all adults having disability from age 25 to compare their premature death risks (< age 43) relative to non-disabled groups.

RESULTS: Irrespective of gender and century studied, the adjusted hazard ratios show that adults with disabilities had a significantly higher premature death risk relative to adults without disabilities, and it increased over time. In the 1800s, disability about doubled this risk (HR: 2.31, CI: 1.65–3.22) and it tripled from 1900–1959 (HR 3.01, CI 2.60– 3.48). At the turn of the 21th century, the mortality risk was almost ten-folded (HR 9.90, CI 8.03–10.5). 

CONCLUSIONS: This study provides the first comprehensive estimates on how disability increased mortality in Swedish populations from the 1800s until the 2000s. Across three centuries, disability was associated with a profoundly higher relative death risk in adults aged 25–42. This risk grew when the general survival in Sweden improved and it was the highest in the 1990–2010 period. Fundamental societal changes and extensive welfare provisions promoting equality in gender, health and social wellbeing of all citizens have not come to include younger generations with disabilities. 

Background: Climate vulnerability of the unborn can contribute to adverse birth outcomes, in particular, but it is still not well under-stood. We investigated the association between ambient temperature and stillbirth risk among a historical population in northern Sweden (1880–1950).

Methods: We used digitized parish records and daily temperature data from the study region covering coastal and inland communi-ties some 600 km north of Stockholm, Sweden. The data included 141,880 births, and 3,217 stillbirths, corresponding to a stillbirth rate of 22.7 (1880–1950). The association between lagged temperature (0–7 days before birth) and stillbirths was estimated using a time-stratified case-crossover design. Incidence risk ratios (IRR) with 95% confidence intervals were computed, and stratified by season and sex.

Results: We observed that the stillbirth risk increased both at low and high temperatures during the extended summer season (April to September), at −10°C, and the IRR was 2.3 (CI 1.28, 4.00) compared to the minimum mortality temperature of +15°C. No clear effect of temperature during the extended winter season (October to March) was found. Climate vulnerability was greater among the male fetus compared to the female counterparts.

Conclusion: In this subarctic setting before and during industrialization, both heat and cold during the warmer season increased the stillbirth risk. Urbanization and socio-economic development might have contributed to an uneven decline in climate vulnerability of the unborn.

Background: In resource-poor societies, neonatal mortality (death in the first 28 days of life) is usually very high.Young infants are particularly vulnerable to environmental health risks, which are modified by socioeconomicfactors that change over time. We investigated the association between ambient temperature and neonatalmortality in northern Sweden during the demographic transition.

Methods: Parish register data and temperature data in coastal Vasterbotten, ¨ Sweden, between 1880 and 1950were used. Total and sex-specific neonatal mortality was modelled as a function of mean temperature, adjustingfor age, seasonality and calendar time, using discrete-time survival analysis. A linear threshold function wasapplied with a cut point at 14.5 ◦C (the minimum mortality temperature). Odds ratios (ORs) with 95% confidence intervals (CIs) were computed. Further analyses were stratified by study period (1800–1899, 1900–1929,and 1930–1950).

Results: Neonatal mortality was 32.1 deaths/1000 live births, higher in boys than in girls, and decreased between1880 and 1950, with high inter-annual variability. Mean daily temperature was +2.5 ◦C, ranging from − 40.9 ◦Cto +28.8 ◦C. At − 20 ◦C, the OR of neonatal death was 1.56 (CI 1.30–1.87) compared to the reference at +14.5 ◦C.Among girls, the OR of mortality at − 20 ◦C was 1.17 (0.88–1.54), and among boys, it was 1.94 (1.53–2.45). Atemperature increase from +14.5 to +20 ◦C was associated with a 25% increase of neonatal mortality (OR 1.25,CI 1.04–1.50). Heat- and cold-related risks were lowest between 1900 and 1929.

Conclusions: In this remote sub-Arctic region undergoing socio-economic changes, we found an increased mortality risk in neonates related to low but also to high temperature. Climate vulnerability varied across time andwas particularly high among boys. This demonstrates that environmental impacts on human health are complexand highly dependent on the specific local context, with many, often unknown, contributing determinants ofvulnerability.