Survival of Critically Ill COVID-19 Patients in Sweden During the First Two and a Half Years of the Pandemic.

OBJECTIVES: Some studies have examined survival trends among critically ill COVID-19 patients, but most were case reports, small cohorts, and had relatively short follow-up periods. We aimed to examine the survival trend among critically ill COVID-19 patients during the first two and a half years of the pandemic and investigate potential predictors across different variants of concern periods. DESIGN: Prospective cohort study. SETTING: Swedish ICUs, between March 6, 2020, and December 31, 2022. PATIENTS: Adult COVID-19 ICU patients of 18 years old or older from the Swedish Intensive Care Register (SIR) that were linked to multiple other national registers. MEASUREMENT AND MAIN RESULTS: Survival probability and predictors of COVID-19 death were estimated using Kaplan-Meier and Cox regression analysis. Of 8975 patients, 2927 (32.6%) died. The survival rate among COVID-19 critically ill patients appears to have changed over time, with a worse survival in the Omicron period overall. The adjusted hazard ratios (aHRs) comparing older and younger ages were consistently strong but slightly attenuated in the Omicron period. After adjustment, the aHR of death was significantly higher for men, older age (40+ yr), low income, and with comorbid chronic heart disease, chronic lung disease, impaired immune disease, chronic renal disease, stroke, and cancer, and for those requiring invasive or noninvasive respiratory supports, who developed septic shock or had organ failures ( p < 0.05). In contrast, foreign-born patients, those with booster vaccine, and those who had taken steroids had better survival (aHR = 0.87; 95% CI, 0.80-0.95; 0.74, 0.65-0.84, and 0.91, 0.84-0.98, respectively). Observed associations were similar across different variant periods. CONCLUSIONS: In this nationwide Swedish cohort covering over two and a half years of the pandemic, ICU survival rates changed over time. Older age was a strong predictor across all periods. Furthermore, most other mortality predictors remained consistent across different variant periods.

A Capture-Recapture-based Ascertainment Probability Weighting Method for Effect Estimation With Under-ascertained Outcomes.

Outcome under-ascertainment, characterized by the incomplete identification or reporting of cases, poses a substantial challenge in epidemiologic research. While capture-recapture methods can estimate unknown case numbers, their role in estimating exposure effects in observational studies is not well established. This paper presents an ascertainment probability weighting framework that integrates capture-recapture and propensity score weighting. We propose a nonparametric estimator of effects on binary outcomes that combines exposure propensity scores with data from two conditionally independent outcome measurements to simultaneously adjust for confounding and under-ascertainment. Demonstrating its practical application, we apply the method to estimate the relationship between health care work and coronavirus disease 2019 testing in a Swedish region. We find that ascertainment probability weighting greatly influences the estimated association compared to conventional inverse probability weighting, underscoring the importance of accounting for under-ascertainment in studies with limited outcome data coverage. We conclude with practical guidelines for the method's implementation, discussing its strengths, limitations, and suitable scenarios for application.

The sociodemographic patterning of sick leave and determinants of longer sick leave after mild and severe COVID-19: a nationwide register-based study in Sweden.

BACKGROUND: Studies on sociodemographic differences in sick leave after coronavirus disease 2019 (COVID-19) are limited and research on COVID-19 long-term health consequences has mainly addressed hospitalized individuals. The aim of this study was to investigate the social patterning of sick leave and determinants of longer sick leave after COVID-19 among mild and severe cases. METHODS: The study population, from the Swedish multi-register observational study SCIFI-PEARL, included individuals aged 18-64 years in the Swedish population, gainfully employed, with a first positive polymerase chain reaction (PCR) test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from 1 January 2020 until 31 August 2021 (n = 661 780). Using logistic regression models, analyses were adjusted for sociodemographic factors, vaccination, prior sick leave, comorbidities and stratified by hospitalization. RESULTS: In total, 37 420 (5.7%) individuals were on sick leave due to COVID-19 in connection with their first positive COVID-19 test. Individuals on sick leave were more often women, older, had lower income and/or were born outside Sweden. These differences were similar across COVID-19 pandemic phases. The highest proportion of sick leave was seen in the oldest age group (10.3%) with an odds ratio of 4.32 (95% confidence interval 4.18-4.47) compared with the youngest individuals. Among individuals hospitalized due to COVID-19, the sociodemographic pattern was less pronounced, and in some models, even reversed. The intersectional analysis revealed considerable variability in sick leave between sociodemographic groups (range: 1.5-17.0%). CONCLUSION: In the entire Swedish population of gainfully employed individuals, our findings demonstrated evident sociodemographic differences in sick leave due to COVID-19. In the hospitalized group, the social patterning was different and less pronounced.

Occupational role and COVID-19 among foreign-born healthcare workers in Sweden: a registry-based study.

BACKGROUND: Many studies report that foreign-born healthcare workers (HCWs) in high-income countries have an elevated risk of COVID-19. However, research has not yet specifically evaluated the distribution of COVID-19 among foreign-born workers in different healthcare work groups. We examined the risk of COVID-19 infection and hospitalization among foreign-born HCWs in different occupational roles in Sweden. METHODS: We linked occupational data (2019) of 783 950 employed foreign-born workers (20-65 years) to COVID-19 data registered between 1 January 2020 and 30 September 2021. We used Cox proportional hazards regression to estimate the hazard ratio (HR) with 95% confidence intervals (95% CIs) of COVID-19 infection and hospitalization in eight healthcare occupational groups vs. non-HCWs and assessed whether region of birth modified the association between healthcare occupations and COVID-19. RESULTS: All HCWs had a higher risk of COVID-19 outcomes than non-HCWs, but the risk differed by occupational role. Hospital-based assistant nurses had the highest risk (infection: HR 1.78; 95% CI 1.72-1.85; hospitalization: HR 1.79; 95% CI 1.52-2.11); allied HCWs had the lowest risk (infection: HR 1.22; 95% CI 1.10-1.35; hospitalization: HR 0.98; 95% CI 0.59-1.63). The relative hazard of the outcomes varied across foreign-born workers from different regions. For example, the relative risk of COVID-19 infection associated with being a physician compared to a non-HCW was 31% higher for African-born than European-born workers. CONCLUSIONS: The risk of COVID-19 among foreign-born HCWs differed by occupational role and immigrant background. Public health efforts that target occupational exposures as well as incorporate culturally responsive measures may help reduce COVID-19 risk among foreign-born HCWs.

Determinants of non-response in a longitudinal study of participants in the Women and Alcohol in Gothenburg project.

Longitudinal assessment is useful for tracking patterns of alcohol use over time. Non-response is a common feature of longitudinal design and can bias estimates of alcohol use if there exist systematic differences between respondents and non-respondents. We investigated whether alcohol use, health status, and sociodemographic characteristics were determinants of non-response in a longitudinal cohort of women in the general population. We used data from a stratified, random sample of 479 women born in 1925, 1935, 1945, 1955, 1965, and 829 women born in 1970 and 1975, who were initially selected as participants in the Women and Alcohol in Gothenburg project. Results from multivariable logistic regression revealed that problematic alcohol use, depression, poor self-rated physical health, and basic education were associated with increased odds of non-response among women born in 1925, 1935, 1945, 1955, and 1965. Among women born between 1970 and 1975, older age and being unmarried increased the odds of non-response at follow-up. Surprisingly, problematic alcohol use and poor health were not associated with non-response in these younger birth cohorts. This study finding suggests that approaches to improve future survey response rates need to consider factors of greatest relevance to birth year and age.

Musculoskeletal pain and re-employment among unemployed job seekers: a three-year follow-up study.

BACKGROUND: Poor health is a potential risk factor for not finding employment among unemployed individuals. We investigated the associations between localized and multiple-site musculoskeletal pain and re-employment in a three-year follow-up of unemployed job seekers. METHODS: Unemployed people (n = 539) from six localities in southern Finland who participated in various active labour market policy measures at baseline in 2002/2003 were recruited into a three-year health service intervention trial. A questionnaire was used to collect data on musculoskeletal health and background characteristics at baseline and on employment status at the end of the follow-up. We conducted a complete case (n = 284) and multiple imputation analyses using logistic regression to investigate the association between baseline musculoskeletal pain and re-employment after three years. RESULTS: Participants with severe pain in the lower back were less likely to become re-employed. This was independent of potential confounding variables. Pain in the hands/upper extremities, neck/shoulders, lower extremities, as well as multiple site were not determinants of re-employment. CONCLUSIONS: Our findings lend some support to the hypothesis that poor health can potentially cause health selection into employment. There is the need to disentangle health problems in order to clearly appreciate their putative impact on employment. This will allow for more targeted interventions for the unemployed.

Occupation and COVID-19 diagnosis, hospitalisation and ICU admission among foreign-born and Swedish-born employees: a register-based study.

BACKGROUND: Research on occupation and risk of COVID-19 among foreign-born workers is lacking. We investigated whether working in essential occupations was associated with COVID-19 diagnosis, hospitalisation and intensive care unit (ICU) admission and whether foreign-born workers in similar occupations as Swedish-born individuals had a higher risk of the studied outcomes. METHODS: Occupational data (2018-2019) of 326 052 employees (20-65 years) who were resident in Sweden as of 1 January 2020 were linked to COVID-19 data registered from 1 January 2020 to 28 February 2021. We analysed the risk of COVID-19 outcomes in different occupational groups and in four immigrant/occupation intersectional groups using Cox proportional hazards regression with adjustments for sociodemographic and socioeconomic characteristics and pre-existing comorbidities. RESULTS: We identified 29797, 1069 and 152 cases of COVID-19 diagnosis, hospitalisations and ICU admissions, respectively, in our cohort. Workers in essential occupations had an elevated risk of COVID-19 diagnosis, hospitalisation, and ICU admissions. Healthcare workers had a higher risk of all the outcomes compared with other essential workers. Relative to Swedish-born workers in non-essential occupations, foreign-born workers in essential occupations had 1.85 (95% CI 1.78 to 1.93), 3.80 (95% CI 3.17 to 4.55) and 3.79 (95% CI 2.33 to 6.14) times higher risk of COVID-19 diagnosis, hospitalisation and ICU admission, respectively. The corresponding risks among Swedish-born workers in essential occupations were 1.44 (95% CI 1.40 to 1.49), 1.30 (95% CI 1.08 to 1.56) and 1.46 (95% CI 0.90 to 2.38). CONCLUSION: Occupation was associated with COVID-19 outcomes and contributed to the burden of COVID-19 among foreign-born individuals in this study.

The social patterning of Covid-19 vaccine uptake in older adults: A register-based cross-sectional study in Sweden.

BACKGROUND: A broad vaccination coverage is crucial for preventing the spread of Covid-19 and reduce serious illness or death. The aim of this study was to examine social inequalities in Covid-19 vaccination uptake as of 17th May 2021 among Swedish adults aged ≥ 60 years. METHODS: The study population comprised a general population cohort aged 60 years or older (n = 350,805), representative of the Swedish population. Data were collected through the nationwide linked multi-register observational study SCIFI-PEARL, and associations between sociodemographic determinants and Covid-19 vaccination uptake were analysed using logistic regression. Intersectional analyses of sociodemographic heterogeneity were performed by taking several overlapping social dimensions into account. Data availability extended to 17 May 2021. FINDINGS: The overall vaccination coverage was 87·2% by 17th May 2021. Younger age, male sex, lower income, living alone, and being born outside Sweden, were all associated with a lower uptake of vaccination. The lowest Covid-19 vaccination uptake was seen in individuals born in low-or middle-income countries, of which only 60% had received vaccination, with an odds ratio (OR) of not being vaccinated of 6·05 (95% CI: 5·85-6·26) compared to individuals born in Sweden. These associations persisted after adjustments for possible confounding factors. The intersectional analyses showed even larger variations in vaccination in cross-classified sociodemographic subgroups (ranging from 44% to 97%) with marked differences in uptake of vaccination within sociodemographic groups. INTERPRETATION: The uptake of Covid-19 vaccine during the spring of 2021 in Sweden varied substantially both between and within sociodemographic groups. The use of an intersectional approach, taking several overlapping social dimensions into account at the same time rather than only using one-dimensional measures, contributes to a better understanding of the complexity in the uptake of vaccination. FUNDING: SciLifeLab / Knut & Alice Wallenberg Foundation, Swedish Research Council, Swedish government ALF-agreement, FORMAS.

Occupational prestige and sickness absence inequality in employed women and men in Sweden: a registry-based study.

OBJECTIVES: Socioeconomic position has been linked to sickness absence (SA). However, less is known about the role of occupational prestige, a measure of social status afforded by one's occupation, in SA. We investigated the association between occupational prestige and SA and the distribution of the association in women and men. We also examined the effect of intersections of gender and occupational prestige on SA. DESIGN: Longitudinal. SETTING: A nationwide representative sample of Swedish working population. PARTICIPANTS: 97 397 employed individuals aged 25-59 years selected from the 2004, 2007 and 2010 waves of the Swedish Labour Force Survey and prospectively linked to the Swedish Longitudinal Integration Database for Health Insurance and Labour Market Studies. OUTCOME MEASURES: The number of SA days in any particular year during a 3-year follow-up and long-term (>120 days) SA based on those with at least one sick leave spell during the follow-up. RESULTS: Occupational prestige was weakly associated with SA in the total sample after adjusting for potential confounders. In the gender-stratified analysis, women in lower prestige occupations had higher absenteeism rates than women in high prestige occupations; men in lower prestige occupations had higher odds for long-term SA than men in high prestige occupations. In the intersectional analysis, women regardless of prestige level and men in lower prestige occupations had higher probability of SA compared with men in high prestige occupations. Women in high prestige occupations had the highest absenteeism rates (incidence rate ratio (IRR), 2.25, 95% CI, 2.20 to 2.31), while men in medium prestige occupations had the lowest rates (IRR, 1.17, 95% CI, 1.13 to 1.20). Compared with the rest of the groups, men in low and medium prestige occupations had higher odds for long-term absence. CONCLUSION: There is need to pay close attention to occupational prestige as a factor that may influence health and labour market participation.

Sickness absence in a re-employment program as a predictor of labor market attachment among long-term unemployed individuals: A 6-year cohort study in Finland.

Objectives We examined whether sickness absence during participation in a state subsidized re-employment program among long-term unemployed people was associated with subsequent labor market attachment. Methods We linked 18 944 long-term unemployed participants (aged 18-60 years) of a six-month subsidized re-employment program in Finland to their records of sickness absence during the program and labor market status after the program. We used the latent class growth model to identify labor market attachment trajectories over a six-year follow-up period and multinomial logistic regression to investigate the association between sickness absence and labor market attachment trajectories. Results We identified four labor market attachment trajectories: "strengthening", (77%), "delayed" (6%), "leavers" (10%), and "non-attached" (7%). Sickness absence was associated with an increased risk of belonging to the leavers and non-attached trajectories. Having >30 days of sickness absence during the six-month re-employment program increased the risk for belonging to the future non-attached trajectory in all age groups, but in particular for those aged 30-44 [odds ratio (OR) 7.35, 95% confidence interval (CI) 4.85-11.14] and 18-29 years (OR 5.38, 95%CI 3.76-7.69). At these ages, having fewer than 30 days sickness absences was also associated with an elevated risk of belonging to the non-attached trajectory, while this risk was lower for those aged 45-60. Conclusions Sickness absence during participation in a subsidized re-employment program increased the risk for poor labor market attachment during the subsequent six years. The risk was particularly high among younger participants with >30 days of sickness absence.

Chronic diseases as predictors of labour market attachment after participation in subsidised re-employment programme: a 6-year follow-up study.

BACKGROUND: Little is known about the work patterns of re-employed people. We investigated the labour market attachment trajectories of re-employed people and assessed the influence of chronic diseases on these trajectories. METHODS: The study was based on register data of 18 944 people (aged 18-60 years) who participated in a subsidised re-employment programme in Finland. Latent class growth analysis with zero-inflated Poisson was used to model the labour market attachment trajectories over a 6-year follow-up time. Multinomial logistic regression was used to examine the associations between chronic diseases and labour market attachment trajectories, adjusting for age, gender, educational level, size of town and calendar year in subsidised re-employment programme. RESULTS: We identified four distinct labour market attachment trajectories, namely: strengthening (a relatively stable attachment throughout the follow-up time; 77%), delayed (initial weak attachment increasing later; 6%), leavers (attachment declined with time; 10%) and none-attached (weak attachment throughout the study period; 7%). We found that severe mental problems strongly increased the likelihood of belonging in the leavers (OR 3.61; 95% CI 2.23 to 5.37) and none-attached (OR 3.41; 95% CI 1.91 to 6.10) trajectories, while chronic hypertension was associated with none-attached (OR 1.37; 95% CI 1.06 to 1.77) trajectory. The associations between other chronic diseases (diabetes, heart disease, asthma and arthritics) and labour market attachment trajectories were less evident. CONCLUSIONS: Re-employed people appear to follow distinct labour market attachment trajectories over time. Having chronic diseases, especially mental disorders appear to increase the risk for relatively poor labour market attachment.

Muscular fitness and re-employment among unemployed job seekers in Finland: a three-year follow-up study.

BACKGROUND: Research suggests that health is an important determinant of re-employment. However, the association between specific physical health components, such as muscular fitness, and re-employment has not been well studied. OBJECTIVE: In a three-year follow-up of unemployed people, we investigated whether muscular fitness is associated with re-employment. METHODS: In 2002-2005, unemployed people (n=130) who were participants in active labour market policy measures were recruited to participate in a Career Health Care (CHC) project. Data on background characteristics and muscular fitness were collected in 2002/2003 using a questionnaire and laboratory measurements. Clientship in the CHC lasted for three years, and at its end, participants' employment status was assessed by a questionnaire. Logistic regression was used to investigate the association between baseline muscular fitness (repetitive lift, sit-ups, and squats) and re-employment after three years. RESULTS: The probability of re-employment within three years significantly increased with improved performances on muscular fitness tests (lifting, sit-up, and squatting) after adjustment for age and gender. CONCLUSIONS: Unemployed people with good muscular fitness had increased probability for re-employment as compared to those with poor muscular fitness.