Background  Immigrants in Sweden, particularly those from low- and middle-income countries, had higher risks of COVID-19 mortality and morbidity compared to the Swedish-born. However, prior studies have not quantified the contribution of the differential distribution of health and social determinants to the increased risks.

Methods  We used total population registers from Sweden to investigate disparities in COVID-19 hospitalization between five groups of immigrants and Swedish-born, using a cohort 577911 working-age adults (18–65 years) living in Stockholm during the first two waves of the COVID-19 pandemic. Applying a decomposition analysis, we quantified the relative contribution of age, sex, income, education, occupation type, residential area, and pre-existing medical conditions to these disparities.

Results  Our study shows that immigrants have higher risks of hospitalization compared to Swedish-born, and that the investigated factors accounted for these disparities to varying degrees across immigrant groups. For the most affected immigrant groups (from Africa and Middle East), the examined factors together account for only a minor part of the disparities (21% and 18% for Wave 1; 16% and 11% for Wave 2), with occupation type and residential area contributing substantially.

Conclusions  Common observable social determinants of health account for a moderate share of the overall disparities in COVID-19 hospitalizations between Swedish-born individuals and immigrant from the most affected regions of origin.

Background

The processes that underlie aging may advance at different rates in different individuals and an advanced biological age, relative to the chronological age, is associated with increased risk of disease and death. Here we set out to quantify the extent to which heterogeneous aging shapes health outcomes in midlife by following a Swedish birth-cohort and using parental age at death as a proxy for biological age in the offspring.

Methods

We followed a nationwide Swedish birth cohort (N = 89,688) between the ages of 39 and 66 years with respect to hospitalizations and death. Cox regressions were used to quantify the association, in the offspring, between parental age at death and all-cause mortality, as well as hospitalization for conditions belonging to the 10 most common ICD-10 chapters.

Results

Longer parental lifespan was consistently associated with reduced risks of hospitalization and all-cause mortality. Differences in risk were mostly evident from before the age of 50 and persisted throughout the follow-up. Each additional decade of parental survival decreased the risk of offspring all-cause mortality by 22% and risks of hospitalizations by 9 to 20% across the 10 diseases categories considered. The number of deaths and hospitalizations attributable to having parents not living until old age were 1500 (22%) and 11,000 (11%) respectively.

Conclusions

Our findings highlight that increased parental lifespan is consistently associated with health benefits in the offspring across multiple outcomes and suggests that heterogeneous aging processes have clinical implications already in midlife.

Purpose: People age at different rates and the available evidence suggests that the rate of aging is partly inherited from previous generations. This heterogeneity in aging is evident already in midlife, but to what extent aging is associated with the timing of events earlier in life is not fully known. Here we aim to shed light on this topic by investigating the trade-off between reproduction and aging postulated by evolutionary theories of aging.

Methods: Drawing on the inheritance of aging we use parental age at death as a proxy for aging-rates in the offspring, and study how age at first birth depends on this variable. We use data from an almost complete Swedish birth cohort comprising 92,359 individuals. Accelerated failure time models are used to estimate the association between parental age at death and age at first birth while adjusting for parental occupational class, educational attainment, and income.

Results: Longer parental lifespans were consistently associated with older age at first births, both in men and women.

Conclusion: Our findings suggest that aging-related processes may be interrelated with the processes underlying the timing of reproduction and are in general agreement with evolutionary theories of aging.

We read with interest the recent paper by Sariaslan et al.1 investigating the associations between childhood family income and three outcomes observed later in life: psychiatric disorders, substance misuse and violent crime arrests. The paper contains a careful analysis of a large and relevant dataset of more than 650 000 individuals born in Finland in 1986–96, who were followed from age 15, when income was assessed, until 2017 or 2018. The authors use two types of analysis in the paper: one in which differences in the outcomes are accounted for by variability in income between families (henceforth between-family analysis) and one, the so-called sibling comparison, in which outcome differences are accounted for only by income variability within families (henceforth within-family analysis). In the between-family analysis, the authors find consistent associations between a number of related estimates of childhood family income and the three outcomes (e.g. Figure 2 in the paper). However, and this is the main finding of the paper, these associations between income and the three outcomes completely disappear in the within-family analysis. From this, the authors conclude that ‘[a]ssociations between childhood family income and subsequent risks … were not consistent with a causal interpretation’.

Background: In Sweden, approximately 1000 persons per year are committed to compulsory care for substance abuse for a maximum duration of six months. People admitted to compulsory care are known to suffer high mortality risks, but whether the risk of dying is further heightened immediately after discharge is not known.

Methods: Individual data from Swedish national registers were used to follow all persons discharged from a six months compulsory care episode in the period 2000–2017 (N = 7, 929). Based on a competing risks framework including re-admissions to compulsory care or imprisonment, hazard rates were estimated in five non-overlapping time windows covering the first year after discharge.

Results: In total, 494 persons died during follow-up, corresponding to an overall mortality rate of 7.1 per 100 person years (95% confidence interval: 6.5, 7.8). The risk was higher for men than for women and increased with age. The risk of dying during the first two weeks after discharge was higher than during the remaining follow-up period – hazard rate ratios comparing the first two weeks with subsequent time windows were between 2.6 (1.3, 5.0) and 3.7 (2.4, 5.9). This heightened risk in close proximity to discharge was only observed for deaths due to external causes, and only for people below the median age of 36 years.

Conclusions: The risk of dying immediately after discharge from compulsory care is very high, especially for younger clients, and more efforts should be made to prevent these deaths.

Influenza viruses have caused disease outbreaks in human societies for a long time. Influenza often has rapid onset and relatively short duration, both in the individual and in the population. The case fatality rate varies for different strains of the virus, as do the effects on total mortality. Outbreaks related to coronavirus infections have recently become a global concern but much less is known about the dynamics of these outbreaks and their effects on mortality. In this work, disease outbreaks in Sweden, in the time period of 1860-2020, are characterized and compared to the currently ongoing COVID-19 outbreak. The focus is on outbreaks with a sharp increase in all-cause mortality. Outbreak onset is defined as the time point when death counts start to increase consistently for a period of at least 10 days. The duration of the outbreak is defined as the time period in which mortality rates are elevated. Excess mortality is estimated by standard methods. In total there were 15 outbreaks detected in the time period, the first 14 were likely caused by influenza virus infections, the last by SARS-CoV-2. The mortality dynamics of the SARS-CoV-2 outbreak is shown to be similar to outbreaks due to influenza virus, and in terms of the number of excess deaths, it is the worst outbreak in Sweden since the Spanish flu of 1918-1919.

Background: Mortality rates are known to depend on the seasons and, in temperate climates, rates are highest during winter. The magnitude of these seasonal fluctuations in mortality has decreased substantially in many countries during the 20th century, but the extent to which this decrease has contributed to the concurrent increase in life expectancy is not known. Here, I describe how the seasonality of all-cause mortality among people ages 60 years or more has changed in Sweden between 1860 and 1995, and investigate how this change has contributed to the increase in life expectancy observed during the same time period.

Methods: Yearly sex-specific birth cohorts consisting of all people born in Sweden between 1800 and 1901 who reached at least 59 years of age were obtained from a genealogical database. The mortality rates for each cohort were modeled by an exponential function of age modulated by a sinusoidal function of time of year. The potential impact of seasonal fluctuations on life expectancy was investigated by a novel decomposition of the total mortality rate into a seasonal part and a part independent of the seasons. Cohort life expectancy at age 60 was used to quantify changes in lifespan during the time period.

Results: The magnitude of seasonal fluctuations in mortality rates decreased substantially between 1860 and 1995. For cohorts born in 1800, the risk of dying during the winter season was almost twice that of dying during summer. For cohorts born in 1900, the relative increase in winter mortality was 10%. Cohort life expectancy at age 60 increased by 4.3 years for men and 6.8 years for women, and the decrease in seasonal mortality fluctuations accounted for approximately 40% of this increase in average lifespan.

Conclusion: By following a large number of extinct cohorts, it was possible to show how the decrease in seasonal fluctuations in mortality has contributed to an increase in life expectancy. The decomposition of total mortality introduced here might be useful to better understand the processes and mechanisms underlying the marked improvements in life expectancy seen over the last 150 years.

The risk of dying increases exponentially with age, in humans as well as in many other species. This increase is often attributed to the accumulation of damage known to occur in many biological structures and systems. The aim of this paper is to describe a generic model of damage accumulation and death in which mortality increases exponentially with age. The damage-accumulation process is modeled by a stochastic process know as a queue, and risk of dying is a function of the accumulated damage, i.e., length of the queue. The model has four parameters and the main characteristics of the model are: (i) damage occurs at random times with a constant high rate; (ii) the damage is repaired at a limited rate, and consequently damage can accumulate; (iii) the efficiency of the repair mechanism decays linearly with age; (iv) the risk of dying is a function of the accumulated damage. Using standard results from the mathematical theory of queues it is shown that there is an exponential dependence between risk of dying and age in these models, and that this dependency holds irrespective of how the damage-accumulation process is modeled. Furthermore, the ways in which this exponential dependence is shaped by the model parameters are also independent of the details of the damage accumulation process. These generic features suggest that the model could be useful when interpreting changes in the relation between age and mortality in real data. To exemplify, historical mortality data from Sweden are interpreted in the light of the model. The decrease in mortality seen between cohorts born in 1905, compared to those born in 1885, can be accounted for by higher threshold to damage. This fits well with the many advances made in public health during the 20th century.

Background: Methadone maintenance treatment (MMT) of opiate addiction was introduced in Sweden 50years ago. The first Swedish programs were modeled after the original Dole and Nyswander program, with strict criteria for admittance into treatment, and have been shown to have positive effects on social andhealth variables, including mortality. During the last 11 years, there have been a number of changes in the regulations controlling MMT-programs in Sweden, and the criteria for admittance are now much less strict compared to previous ones. This study aims to characterize the current MMT-programs with respect to mortality and to compare the results to those obtained in earlier periods.

Methods: Persons entering into treatment in Stockholm county, between 2006 and 2011, were followed until September 2013 or until death occurred. Death rates for periods in treatment and out of treatment were determined and compared to rates for the general population. Proportional hazards models with treatment status as time-varying covariate were fitted to the data. A competing risk analysis was made to investigate the effects of MMT on drug-related mortality as compared to mortality from other causes. Mortality data for earlier periods were retrieved from the literature.

Results: A total of 441 persons entered MMT during the time period. Of these 67 died during follow-up, the death rate being almost twenty times higher than in the general population. Not being in treatment was associated with a significantly increased hazard of dying (hazard ratio: 2.1, 95% confidence interval: 1.3–3.4). The hazard ratio was mainly increased for drug-related deaths (hazard ratio: 4.4 (2.1–9.2).

Conclusions: Mortality rates among persons who entered MMT-programs in Stockholm during 2006–2011 were not increased compared to persons in treatment twenty years ago. The mortality was significantly increased during periods off treatment. Changes in regulations that minimizes the time off treatment are therefore likely to reduce the mortality rates among clients of MMT-programs.

Background

In recent years the recreational use of new psychoactive substances (NPS) has increased. NPS are considered a threat to public health and the main response to this threat is to make the selling and buying of these substances illegal. In Sweden, during the last 5 years, 62 new substances have been classified as narcotics but little is known of the effects of making a particular substance illegal. The aim of this work is to study how legal status influences the interest in NPS in Sweden.

Methods

Forty-five thousand posts made in a Swedish Internet discussion forum (Flashback Forum) related to eight NPS (MDPV, Methylone, 4-MEC, 4-HO-MET, MXE, 6-APB, AH-7921, and 3-MMC) were used to derive time-dependent measures of interest in these substances. Intervention analyses were used to investigate the effects of legal status on the forum interest.

Results

For all eight substances the activity on the forum (measured as number of posts per day) showed a drastic decrease around the time of classification. The statistical analysis showed that in seven of eight cases, the drop in activity could be accounted for by the legal status of the substances.

Conclusions

The legal status of the substances was shown to have a substantial effect on the interest in the substances. The novel measure used to trace the interest in particular NPS could be a useful tool to follow trends in substance use in almost real-time.