Sickness absence transitions among Swedish twins with back, neck or shoulder pain and common mental disorders applying a multi-state approach.

We aimed to investigate transitions to and from sickness absence, or disability pension among individuals with back, neck, or shoulder pain and/or with common mental disorders (CMDs), and the role of familial (genetics and shared environment) influences on the transitions. Swedish twins born 1935-1985 who responded to pain and CMDs survey items (N = 41,516) were followed on average 8.7 years for sickness absence states in national registers. Multi-state Cox regression models were applied for three exposure groups: pain, CMDs, and presence of both, compared to unexposed. Exposure discordant twin pairs, stratified by zygosity, were analysed to assess the role of familial factors. Hazard Ratios (HR) with 95% confidence intervals and transition intensities were calculated. HRs were similar for transitions between states among those with pain or CMDs. The highest HRs were for transitions from entry to sickness absence and sickness absence to disability pension among those with both pain and CMDs (HRs: 1.61 and 1.43, respectively). Higher HRs for dizygotic compared to monozygotic twins for the first transition to sickness absence and for altering back to not being sickness absent indicate familial confounding. Back, neck, or shoulder pain and/or CMDs indicate a higher risk to become sickness absent and for repeated sickness absence episodes over time compared to unaffected.

Tobacco use and risk of COVID-19 infection in the Finnish general population.

Empirical evidence, primarily based on hospital-based or voluntary samples, suggests that current smokers have a lower risk of COVID-19 infection than never smokers. In this study, we used nationally representative data to examine the association between tobacco use and the risk of having a confirmed COVID-19 case. We explored several forms of tobacco use, contributing to separate the role of nicotine from smoking. We used data from 44,199 participants from three pooled national health surveys in Finland (FinSote 2018-2020). The primary outcome was a confirmed COVID-19 case. We examined current smoking, moist smokeless tobacco (snus), e-cigarettes with and without nicotine and nicotine replacement therapy products. Current daily smokers had a relative risk of 1.12 of a confirmed COVID-19 case (95% CI 0.65; 1.94) in fully adjusted models compared with never smokers. Current snus use was associated with a 68% higher risk of a confirmed COVID-19 case (RR 1.68, 95% CI 1.02; 2.75) than never users. We did not find conclusive evidence of associations between e-cigarettes with and without nicotine and nicotine replacement therapy products and the risk of confirmed COVID-19 cases. Our findings suggest that nicotine might not have a protective role in the risk of COVID-19 as previously hypothesized.

Role of social benefits for future long-term sickness absence, disability pension and unemployment among individuals on sickness absence due to mental diagnoses: a competing risk approach.

PURPOSE: To investigate associations between social benefits and disability pension (DP), long-term sickness absence (LTSA, ≥ 90 days), or unemployment among Swedish twins with sickness absence (SA) due to mental diagnoses. METHODS: This population-based prospective twin study included register data on first incident SA spell (< 90 days) due to mental diagnoses (ICD 10 codes F00-F99) during the follow-up 2005-2016. SA < 90 days due to other diagnoses than mental diagnoses or any other social insurance benefit was identified for the preceding year of the first incident SA spell due to mental diagnoses (coded yes/no). Comparing those with any previous social benefits vs without, cumulative incidence curve to compare time to an event, and Cox proportional hazards models for cause-specific hazard ratios (HR, 95% confidence intervals, CI) treating first incident DP, LTSA and unemployment as competing risks were modeled. RESULTS: During follow-up, 21 DP, 1619 LTSA, and 808 unemployment events took place. Compared to those without, those with at least one benefit had a higher risk for DP (HR 5.03; 95%CI 1.80, 14.01), LTSA (1.67; 1.50, 1.84) and unemployment (1.24; 1.03, 1.50). The cumulative incidence for DP was very low, < 1%, for LTSA 80% with any previous social benefits vs. 60% without, and for unemployment ≤ 5%. CONCLUSION: Social benefits received during the preceding year of SA due to mental diagnoses (< 90 days) predict DP, LTSA, and unemployment. Hence, previous social benefits may provide means for early identification of persons at risk for exit from labor market.

The role of sickness absence diagnosis for the risk of future inpatient- or specialized outpatient care in a Swedish population-based twin sample.

BACKGROUND: Studies of consequences of sickness absence such as health and well-being have been rare whereas risk factors for sickness absence have been studied extensively. This study assumed the consequences of sickness absence would differ by diagnostic group or by patient care type. The aim was to investigate sickness absence due to various diagnosis groups as a predictor for subsequent inpatient- and specialized outpatient care while controlling for familial confounding. METHODS: We utilized the register data of 69,552 twin individuals between 16 and 80 years of age (48% women). The first incident sickness absence spell, from baseline year 2005, including diagnosis of sickness absence was our primary exposure of interest and we followed them until the first incident inpatient- and specialized outpatient care episode with main diagnosis code or until 31.12.2013. RESULTS: A total of 7464 incident sickness absence spells took place (11%), 42% had inpatient care and 83% specialized outpatient care (mean follow-up time 3.2 years, SD 3.1 years). All the main sickness absence diagnosis groups were associated with increased risk of future care in comparison to no sickness absence. Controlling for confounders attenuated the associations in magnitude but with retaining direction, and we could not confirm an effect of familial factors. CONCLUSIONS: Sickness absence predicts both inpatient- and specialized outpatient care and the association is universal across diagnosis groups. The lower survival time and incidence rates of inpatient than specialized outpatient care point towards severity of diseases assumption. This finding was also universal across sickness absence diagnosis groups.

The predictive role of sickness absence spell durations in associations with inpatient- and specialized outpatient care among a population-based Swedish twin sample.

BACKGROUND: The associations between a sickness absence spell duration and patient care have been rarely studied. An assumption is that associations would differ by spell duration and by the patient care type, inpatient- or specialized outpatient, due to severity of diseases and/or conditions. We aimed to investigate sickness absence spells in various spell durations as a predictor for subsequent inpatient- and specialized outpatient care separately, and to study if familial confounding plays a role in these associations. METHODS: We followed a population-based sample of Swedish twins born 1925-90 with national registers from 2001 for first incident sickness absence spell (days to calculate spell duration categorized into ≤30 days, 31-90 days, 91-180 days and ≥ 181 days), or no sickness absence, and for inpatient- and specialized outpatient care until 2013 (n = 24,975). Cox proportional hazards models were applied for hazard ratios (HR) with 95% confidence intervals (CI) while accounting for covariates and familial confounding. RESULTS: First incident sickness absence spell across all duration categories was associated with an increased risk of inpatient- (age- and sex adjusted HR 1.28 to 6.05) or specialized outpatient care (HR 1.17-2.50), both in comparison to those without any sickness absence or the shortest sickness absence spell category (1-30 days). The associations remained statistically significant while controlling for covariates or familial confounding. CONCLUSIONS: First incident sickness absence spell increases the risk of inpatient care or specialized outpatient care regardless of the duration of the sickness absence spell. Hence, incident sickness absence spells should be noted and targeted to actions at workplaces as well as in primary and occupational health care.

Sick leave due to back pain, common mental disorders and disability pension: Common genetic liability.

BACKGROUND: Back pain and common mental disorders are often comorbid and known risk factors for future disability pension. However, the reason for the covariation is not known. The aim was to investigate the common genetic and environmental influences on the covariation between sick leave due to back pain, sick leave due to common mental disorders and disability pension. METHODS: Register data from the Swedish Social Insurance Agency on sick leave due to back pain, common mental disorders and disability pension between 2005 and 2018, in a population-based sample of 56,686 working age twins was used to construct biometric twin models to calculate if the covariation between the traits were due to Additive (A) or Dominant (D) genetic factors, Common environmental factors (C) or unique Environmental factors (E), for women and men. RESULTS: The phenotypic correlations ranged between 0.17 and 0.25. A common factor common pathway AE model fitted best for both women and men. The latent underlying common factor, that explained the covariation was mostly explained by genetic factors (87% for women and 90% for men). Each trait was also influenced by its own unique genetic and unique environment factors. A higher heritability was found for disability pension than for sick leave. CONCLUSIONS: The covariation between sick leave due to back pain and common mental disorders, and disability pension were mostly explained by common genetic factors, while the unique variation in each trait was influenced by both genetic and environmental factors not shared within the twin pairs. SIGNIFICANCE: A common genetic liability seems to be of importance in the comorbidity of sick leave due to back pain and common mental disorders and the transition to disability pension, both among women and men. However, the proportion in each trait that was explained by genetic factors was somewhat higher for men than for women in all traits. This may be of importance to consider in intervention or prevention efforts.

Life events as predictors for disability pension due to musculoskeletal diagnoses: a cohort study of Finnish twins.

PURPOSE: Musculoskeletal diagnoses (MSD) are one of the largest diagnostic groups for disability pensions (DP). This study investigated the associations between life events and DP due to MSD, considering sociodemographic, health, and familial factors. METHODS: The study sample included 18,530 Finnish twins, 24-64 years old at baseline, who responded to a questionnaire in 1981 including a 21-item life event inventory. Information on DP with diagnosis codes (ICD codes: M00-M99) were obtained from the official national pension registers. Life events were divided into family- and work-related events. "Positive change in life" was analyzed separately. Cox proportional hazards models were used to calculate hazard ratios (HR) with 95% confidence intervals (CI). RESULTS: During the follow-up of 23 years, 1273 (7%) individuals were granted DP due to MSD. In discordant pair analysis, family-related events (≥ 4 events) increased (HR 1.63, 95% CI 1.31, 2.03) and the absence of such events decreased (HR 0.68, 95% CI 0.48, 0.95) the risk of DP due to MSD. For work-related events (≥ 3 events), the risk estimates were non-significant when controlling for familial factors. Having had a positive change in life decreased the risk of DP due to MSD (HR 0.79, 95% CI 0.65, 0.96) while controlling for familial confounding, but were non-significant in the full model controlling for various covariates (HR 0.91, 95% CI 0.75, 1.12). CONCLUSIONS: The associations between life events and the risk of DP due to MSD are complex and potentially affected by familial and other confounding factors including sociodemographics and health.

Night work as a risk factor of future disability pension due to musculoskeletal diagnoses: a prospective cohort study of Swedish twins.

Background: This study investigated the associations between night work, sleep and disability pension (DP) due to musculoskeletal disorders (MSD), while controlling for several confounding factors including both genetic factors and shared family background. Methods: The study sample consisted of 27 165 Swedish twin individuals born in 1935-58 with comprehensive survey data on sociodemographic, health and lifestyle factors. Night work was assessed as years of working hours at night at least every now and then, and categorized into 'not at all, 1-10 years and over 10 years'. Data on DP with MSD (ICD-diagnoses M00-M99) were obtained from the National Social Insurance Agency. Follow-up was from the time of the interview in 1998-2003 until 2013. Information on the length and quality of sleep was available for a sub-sample of twins (n = 1684). Cox proportional hazards models were used to calculate hazard ratios (HR) with 95% confidence intervals (CI). Results: During the follow-up, 1338 (5%) participants were granted DP due to MSD. Both 1-10 years (HR 1.33, 95% CI 1.17-1.53) and over 10 years of night work (HR 1.39 95% CI 1.18-1.64) increased the risk of future DP. The associations were not affected by health, lifestyle or sleep factors. In the discordant twin pair analysis, the associations between night work and DP due to MSD attenuated. Conclusions: Night work was associated with increased risk of DP due to MSD independently from health and lifestyle factors. Familial confounding could not be ruled out.

Disability pension due to musculoskeletal diagnoses: importance of work-related factors in a prospective cohort study of Finnish twins.

OBJECTIVES: The aim of this study was to investigate the impact of work-related risk factors for future disability pension (DP) due to musculoskeletal diagnoses and for a subgroup of these, namely, DP due to osteoarthritis. METHODS: For this prospective study of 16,028 Finnish twins born in 1911-1957 and employed at baseline, a postal questionnaire collected information in 1975 on work-related factors; follow-up data on DP was gathered through register linkages up to 2004. A series of proportional hazards (Cox) regression models were used to analyze the associations between work-related factors and the incidence of DP. RESULTS: During the 30-year follow-up, 1297 participants (8%) were granted DP due to musculoskeletal diagnoses, 376 of which were due to osteoarthritis. High stress of daily activities, monotonous work, physical workload (namely work including lifting and carrying or physically heavy work), several workplace changes, and unemployment displayed a strong association with DP due to musculoskeletal diagnoses that was not affected by familial factors, including genetics and shared environment. Additionally, standing work increased the risk for DP due to osteoarthritis. CONCLUSIONS: Uninfluenced by family background or other confounding factors, several work-related factors were identified as being strong and direct risk factors for DP due to musculoskeletal diagnoses.