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APOE is among the most extensively studied genetic loci in research on aging, morbidity, and mortality. Despite its well-established biological roles, empirical findings on the association between APOE and mortality remain inconsistent across studies. This heterogeneity is often attributed to biological complexity. In this Perspective, we argue that much of the apparent inconsistency instead reflects differences in modeling choices, variable definitions, and reporting practices, resulting in limited reproducibility and comparability. We highlight how pleiotropy, age-dependent effects, and selective survival make APOE particularly sensitive to analytical decisions. We focus on three underappreciated sources of irreproducibility: selective exclusion of rare APOE genotypes, lack of standardized baseline models, and routine adjustment for variables that are not confounders under Mendelian inheritance. We argue that all observed APOE genotypes should be included in primary analyses, that parsimonious baseline models adjusted only for variables independent of genotype should always be reported, and that overadjustment can obscure rather than clarify genetic effects. We propose a set of conceptual principles to improve reproducibility in studies of APOE, morbidity, and mortality, with implications for genetic epidemiology more broadly.

This study examines changes in disability prevalence during Sweden's demographic transition, focusing on the relative contributions of population aging and changing disability rates. Using unique longitudinal data from parish registers covering 194,500 individuals in Västerbotten county 1900–1950, we analyze trends in four disability categories: sensory, physical, mental and intellectual disabilities. Through demographic decomposition methods, we separate the effects of changes in population age structure from changes in age-specific disability rates. Our findings reveal that the substantial increase in disability prevalence was primarily driven by changes in disability rates during the period studied rather than population aging. Mental disabilities showed the most pronounced increase, rising from 0.8% to 2.5%, while other disability types remained stable or declined. The impact was particularly strong among middle-aged adults (25–54 years), challenging assumptions about the predominant role of population aging in historical disability trends. Our results suggest that social and environmental factors played a more significant role than demographic change in shaping disability prevalence during times of demographic transition.

Under finska kriget (1808–1809) spelade sjukhusen i Umeå en central roll i vården av sårade och sjuka soldater. När försvaret av Finland kollapsade evakuerades skadade soldater i stort antal till hastigt upprättade vårdinrättningar i Umeå. Läkarna gjorde inte bara avgörande insatser för att rädda liv utan också för att dokumentera situationen genom sina journaler.

During the Finnish War (1808–1809), the hospitals in Umeå played a central role in caring for wounded and sick soldiers. When the defense of Finland collapsed, large numbers of injured soldiers were evacuated to hastily established medical facilities in Umeå. The doctors not only made crucial efforts to save lives but also documented the situation through their medical records.

Suomen sodan (1808–1809) aikana Uumajan sairaaloilla oli keskeinen rooli haavoittuneiden ja sairaiden sotilaiden hoidossa. Kun Suomen puolustus romahti, suuri määrä haavoittuneita sotilaita evakuoitiin kiireesti perustettuihin hoitolaitoksiin Uumajaan. Lääkärit eivät ainoastaan tehneet ratkaisevia ponnistuksia hengen pelastamiseksi, vaan myös dokumentoivat tilanteen sairaskertomustensa kautta.

Во время Финской войны (1808–1809) больницы в Умео сыграли центральную роль в оказании помощи раненым и больным солдатам. Когда оборона Финляндии рухнула, большое количество раненых солдат было эвакуировано в спешно организованные медицинские учреждения в Умео. Врачи не только прилагали решающие усилия для спасения жизней, но и документировали ситуацию в своих медицинских журналах.

Finska kriget 1808–1809 utkämpades mellan Sverige och Ryssland som en del av Napoleonkrigen. I skuggan av de storpolitiska händelserna utspelade sig en mortalitetskatastrof som drabbade inte bara soldaterna, utan även i hög grad den civila befolkningen. Genom bevarat källmaterial kan vi i dag få en unik inblick i hur både befolkningen och soldaterna i Umeå med omnejd påverkades.

The Finnish War of 1808–1809 was fought between Sweden and Russia as part of the Napoleonic Wars. In the shadow of these geopolitical events, a mortality catastrophe unfolded, affecting not only the soldiers but also, to a great extent, the civilian population. Through preserved source material, we can today gain a unique insight into how both the population and the soldiers in Umeå and its surroundings were affected.

Suomen sota vuosina 1808–1809 käytiin Ruotsin ja Venäjän välillä osana Napoleonin sotia. Näiden geopoliittisten tapahtumien varjossa kehkeytyi kuolleisuuskatastrofi, joka vaikutti paitsi sotilaisiin myös suuressa määrin siviiliväestöön. Säilyneen lähdeaineiston ansiosta voimme tänä päivänä saada ainutlaatuisen käsityksen siitä, miten sekä väestö että sotilaat Uumajassa ja sen ympäristössä kärsivät tilanteesta.

Финская война 1808–1809 годов велась между Швецией и Россией как часть Наполеоновских войн. В тени этих геополитических событий разразилась катастрофа смертности, затронувшая не только солдат, но и в значительной степени гражданское население. Благодаря сохранившимся источникам мы сегодня можем получить уникальное представление о том, как эти события повлияли как на население, так и на солдат в Умео и его окрестностях.

Background: Intimate partner violence (IPV) is a global issue, with women, especially those with disabilities, facing a higher lifetime risk than those without disabilities. Given the elevated risk factors and challenges related to having a disability, it is crucial to provide effective IPV support. The competence and expertise of service providers regarding IPV significantly influence their ability to provide adequate IPV support. Understanding service providers' self-perceived competence is essential for improving the quality of IPV support for women with disabilities.

Objective: This study assesses the self-perceived competence of service providers in supporting women with disabilities subjected to IPV in Sweden.

Methods: A cross-sectional survey was distributed to professionals in healthcare, social services, and the police, and 1,151 people participated. Descriptive statistics and linear regression analyses were performed to assess the factors influencing service providers' self-perceived competence.

Results: The findings indicate that healthcare, police, and social services professionals often encounter women with disabilities, but they rarely ask them directly about IPV. Many don't routinely inquire about IPV exposure. While institutional routines for addressing IPV exist, service providers don't consistently implement or use them. Key factors influencing self-perceived competence include receiving IPV and disability-specific training and sufficient employer support for addressing IPV among women with disabilities.

Conclusions: The findings underscore the need for a more consistent application of routines and enhanced training to strengthen the capacity of service providers to support women with disabilities subjected to IPV.

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.