Sickness absence due to otoaudiological diagnoses and risk of disability pension: a nationwide Swedish prospective cohort study

Background

Hearing difficulties are a large public health problem. Knowledge is scarce regarding risk of disability pension among people who have been sickness absent due to these difficulties.

Methods

A cohort including all 4,687,756 individuals living in Sweden in 2005, aged 20–64, and not on disability or old-age pension, was followed through 2009. Incidence rate ratios (RR) of disability pension with 95% confidence intervals (CI) were estimated using Cox proportional hazard models.

Results

In multivariable models, individuals who had a sick-leave spell due to otoaudiological diagnoses in 2005 had a 1.52-fold (95% CI: 1.43–1.62) increased risk of being granted a disability pension compared to individuals on sick leave due to other diagnoses. Hearing and tinnitus sick-leave diagnoses were associated with risk of disability pension: RR 3.38, 95% CI: 3.04–3.75, and 3.30, 95% CI: 2.95–3.68, respectively. No association was observed between sick leave due to vertigo diagnoses and disability pension whereas otological diagnoses and no sick leave were inversely associated with risk of disability pension compared to non-otoaudiological sick-leave diagnoses. Sick leave due to otoaudiological diagnoses was positively associated with risk of disability pension due to otoaudiological diagnoses and sick leave due to a tinnitus diagnosis was also associated with risk of disability pension due to mental diagnoses. The risk of disability pension among individuals with hearing or tinnitus sick-leave diagnoses was highest in the age group 35–44. Moreover, men had a slightly higher risk.

Conclusion

This large cohort study suggests an increased risk of disability pension among those with sickness absence due to otoaudiological diagnoses, particularly hearing and tinnitus diagnoses, compared to those with sickness absence due to non-otoaudiological diagnoses.     

Psychiatric Diagnoses and Risk of Suicidal Behaviour in Young Disability Pensioners: Prospective Cohort Studies of All 19-23 Year Olds in Sweden in 1995, 2000, and 2005, Respectively

Objective

Increasing rates of disability pension (DP) have been observed among young adults. We studied specific psychiatric DP diagnoses and subsequent risk of suicidal behaviour in a series of three cohorts of young adult in Sweden.

Method

In a nationwide register study, we included all young adults who in 1995, 2000, and 2005, respectively, were 19–23 years old and lived in Sweden (n≈500,000 per cohort). Rates of DP and specific psychiatric DP diagnoses were recorded in each cohort. Hazard ratios (HRs) and 95% confidence intervals (CIs) for suicidal behaviour during the following five years, with the corresponding age group as reference, were calculated by Cox proportional hazard regression, adjusted for demographic variables and previous own and parental suicidal behaviour.

Results

The overall proportion with DP in this age group increased from 0.92% in 1995 to 2.29% in 2005, with particularly large increases in psychiatric diagnoses such as hyperkinetic disorders, pervasive developmental disorders, and depression/anxiety. The overall proportion of young disability pensioners attempting suicide during the five-year follow-up increased from 2.21% in the 1995 cohort to 3.81% in the 2005 cohort. Within most psychiatric DP diagnoses, the risk of attempted suicide did not change significantly over time, whereas suicide attempts increased in the reference group. Accordingly, the HRs for suicide attempt decreased in some psychiatric DP diagnoses. The highest adjusted HRs were observed for depression/anxiety (16.41; CI: 9.06 to 29.74) and schizophrenia (9.37; 6.13 to 14.31) in the 1995 cohort. The rate of suicide among young disability pensioners during follow-up ranged from 0.19% in 1995 to 0.37% in 2005, mainly occurring in individuals with psychiatric diagnoses.

Conclusion

Suicidal behaviour has become more prevalent among young disability pensioners, which co-occurred with an increased tendency to grant DP in psychiatric diagnoses with a known high risk of suicidal behaviour. Preventive measures are warranted.     

Psychiatric Disorders after Epilepsy Diagnosis: A Population-Based Retrospective Cohort Study

Background

Psychiatric manifestations after occurrence of epilepsy have often been noted. However, the association between newly diagnosed epilepsy and psychiatric disorders afterward is not completely understood. We conducted two longitudinal cohorts for patients with and without epilepsy to investigate the risk factors and hazard ratios of developing psychiatric disorders after patients were newly diagnosed with epilepsy.

Methods

We identified 938 patients with a new diagnosis of epilepsy and 518,748 participants without epilepsy from the National Health Insurance Research Database in 2000–2002 and tracked them until 2008. We compared the incidence of developing psychiatric disorders between the two cohorts, evaluated risk factors and measured the associated hazard ratios (HRs) and 95% confidence intervals (CIs) of developing psychiatric disorders.

Findings

The incidences of psychiatric disorders for people with and without epilepsy were 94.1 and 22.6 per 1000 person-years, respectively. After adjusting the covariates, the epilepsy cohort showed the highest risks in mental retardation (HR 31.5, 95% CI 18.9 to 52.4), bipolar disorder (HR 23.5, 95% CI 11.4 to 48.3) and alcohol or drug psychosis (HR 18.8, 95% CI 11.1 to 31.8) among psychiatric complications developed after newly diagnosed epilepsy. The risk increased with epileptic general seizure and frequency of outpatient visits for epilepsy, as well as with emergency room visits and hospitalizations for epilepsy, and with older age. Chronologically, the highest risk occurred in the first year after epilepsy diagnosis (HR 11.4, 95% CI 9.88 to 13.2).

Conclusion

Various psychiatric disorders were demonstrated after newly diagnosed epilepsy and closely related to general seizure and use of medical services for epilepsy. This shows a need for integrated psychiatric care for patients newly diagnosed with epilepsy, especially in the first year.     

Risk of Psychiatric Disorders following Polycystic Ovary Syndrome: A Nationwide Population-Based Cohort Study

Background

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders among women of reproductive age. A higher prevalence of psychiatric comorbidities, including depressive disorder, anxiety disorder, and bipolar disorder has been proved in patients with PCOS. However, a clear temporal causal relationship between PCOS and psychiatric disorders has not been well established.

Objective

We explored the relationship between PCOS and the subsequent development of psychiatric disorders including schizophrenia, bipolar disorder, depressive disorder, anxiety disorder, and sleep disorder.

Methods

We identified patients who were diagnosed with PCOS by an obstetrician-gynecologist in the Taiwan National Health Insurance Research Database. A comparison cohort was constructed of patients without PCOS who were matched according to age and sex. The occurrence of subsequent new-onset psychiatric disorders was evaluated in both cohorts based on diagnoses made by psychiatrists.

Results

The PCOS cohort consisted of 5431 patients, and the comparison cohort consisted of 21,724 matched control patients without PCOS. The incidence of depressive disorder (hazard ratio [HR] 1.296, 95% confidence interval [CI] 1.084–.550), anxiety disorder (HR 1.392, 95% CI 1.121–1.729), and sleep disorder (HR 1.495, 95% CI 1.176–1.899) were higher among the PCOS patients than among the patients in the comparison cohort. In addition, a higher incidence of newly diagnosed depressive disorder, anxiety disorder, and sleep disorder remained significantly increased in all of the stratified follow-up durations (0–1, 1–5, ≥5 y).

Conclusions

PCOS might increase the risk of subsequent newly diagnosed depressive disorder, anxiety disorder, and sleep disorder. The risk of newly diagnosed bipolar disorder, which has often been reported in the literature to be comorbid with PCOS, was not significantly elevated.     

Is There an Association between Long-Term Sick Leave and Disability Pension and Unemployment beyond the Effect of Health Status? – A Cohort Study

Background

Studies have shown that long-term sick leave is a strong predictor of disability pension. However, few have aimed to disentangle the effect of sick leave and of health status.The objective of this study was to investigate whether there is an association between long-term sick leave and disability pension and unemployment, when taking health status into account.

Methods/Principal Findings

The study was based on the Stockholm Public Health Cohort, restricted to 13,027 employed individuals (45.9% men) aged 18–59 in 2002 and followed until 2007.Hazard ratios (HR) with 95% Confidence Interval (CI) were estimated by Cox regression models adjusting for socio-demographic factors and five measures of health status.Having been on long-term sick leave increased the risk of disability pension (HR 4.01; 95% CI 3.19–5.05) and long-term unemployment (HR 1.45; 95% CI 1.05–2.00), after adjustment for health status. The analyses of long-term sick leave due to specific illness showed that the increased risk for long-term unemployment was confined to the group on sick leave due to musculoskeletal (HR 1.70 95% CI 1.00–2.89) and mental illness (HR 1.80 95% CI 1.13–2.88) and further that there was an increased risk for short-term unemployment in the group on sick leave due to mental illness (HR1.57 95%CI 1.09–2.26).

Conclusions/Significance

Long-term sick leave increases the risks of both disability pension and unemployment even when taking health status into account. The results support the hypothesis that long-term sick leave may start a process of marginalization from the labor market.     

Parental Socioeconomic Status,Childhood Asthma and Medication Use – A Population-Based Study

Background

Little is known about how parental socioeconomic status affects offspring asthma risk in the general population, or its relation to healthcare and medication use among diagnosed children.

Methods

This register-based cohort study included 211,520 children born between April 2006 and December 2008 followed until December 2010. Asthma diagnoses were retrieved from the National Patient Register, and dispensed asthma medications from the Prescribed Drug Register. Parental socioeconomic status (income and education) were retrieved from Statistics Sweden. The associations between parental socioeconomic status and outcomes were estimated by Cox proportional hazard regression.

Results

Compared to the highest parental income level, children exposed to all other levels had increased risk of asthma during their first year of life (e.g. hazard ratio, HR 1.19, 95% confidence interval, CI 1.09–1.31 for diagnosis and HR 1.17, 95% CI 1.08–1.26 for medications for the lowest quintile) and the risk was decreased after the first year, especially among children from the lowest parental income quintile (HR 0.84, 95% CI 0.77–0.92 for diagnosis, and HR 0.80, 95% CI 0.74–0.86 for medications). Further, compared to children with college-educated parents, those whose parents had lower education had increased risk of childhood asthma regardless of age. Children with the lowest parental education had increased risk of an inpatient (HR 2.07, 95% CI 1.61–2.65) and outpatient (HR 1.32, 95% CI 1.18–1.47) asthma diagnosis. Among diagnosed children, those from families with lower education used fewer controller medications than those whose parents were college graduates.

Conclusions

Our findings indicate an age-varying association between parental income and childhood asthma and consistent inverse association regardless of age between parental education and asthma incidence, dispensed controller medications and inpatient care which should be further investigated and remedied.     

All-Cause and Cause-Specific Mortality after Long-Term Sickness Absence for Psychiatric Disorders: A Prospective Cohort Study

Objective

The aim was to examine if long-term psychiatric sickness absence was associated with all-cause and diagnosis-specific (cardiovascular disease (CVD), cancer and suicide) mortality for the period 1990–2007. An additional aim was to examine these associations for psychiatric sickness absence in 1990 and 2000, with follow-up on mortality during 1991–1997 and 2001–2007, separately.

Methods

Employees within municipalities and county councils, 244,990 individuals in 1990 and 764,137 individuals in 2000, were followed up to 2007 through register linkages. Analyses were conducted with flexible parametric survival models comparing sickness absentees due to psychiatric diagnoses (>90 days) with those not receiving sick leave benefit.

Results

Long-term sickness absence for psychiatric disorders was associated with an increased risk of mortality due to all causes; CVD; cancer (smoking and non-smoking related); and suicide during the period 1990–2007. After full adjustment for socio-demographic covariates and previous inpatient care due to somatic and psychiatric diagnoses, these associations remained significant for all-cause mortality (Hazard ratios (HR) and 95% confidence interval (CI)): HR 1.56, 95% CI 1.3–1.8; CVD: HR 1.35, 95% CI 1.0–1.9, and suicide: HR 3.84, 95% CI 2.4–6.1. For both cohorts 1990 and 2000 estimates point in the same direction. For the time-period 2000–2007, we found increased risks of mortality in the fully adjusted model due to all causes: HR 1.47, 95% CI 1.2–1.7; CVD: HR 1.83, 95% CI 1.2–2.7; overall cancer: HR 1.33, 95% CI 1.0–1.7; and suicide: HR 2.15, 95% CI 1.3–3.7.

Conclusion

Long-term sickness absence for psychiatric disorders predicted premature mortality from all-causes, cardiovascular disease, cancer, and suicide.     

Causes of Death among Commercially Insured Multiple Sclerosis Patients in the United States

Background

Information on causes of death (CODs) for patients with multiple sclerosis (MS) in the United States is sparse and limited by standard categorizations of underlying and immediate CODs on death certificates. Prior research indicated that excess mortality among MS patients was largely due to greater mortality from infectious, cardiovascular, or pulmonary causes.

Objective

To analyze disease categories in order to gain insight to pathways, which lead directly to death in MS patients.

Methods

Commercially insured MS patients enrolled in the OptumInsight Research database between 1996 and 2009 were matched to non-MS comparators on age/residence at index year and sex. The cause most-directly leading to death from the death certificate, referred to as the “principal” COD, was determined using an algorithm to minimize the selection of either MS or cardiac/pulmonary arrest as the COD. Principal CODs were categorized into MS, cancer, cardiovascular, infectious, suicide, accidental, pulmonary, other, or unknown. Infectious, cardiovascular, and pulmonary CODs were further subcategorized.

Results

30,402 MS patients were matched to 89,818 controls, with mortality rates of 899 and 446 deaths/100,000 person-years, respectively. Excluding MS, differences in mortality rate between MS patients and non-MS comparators were largely attributable to infections, cardiovascular causes, and pulmonary problems. Of the 95 excessive deaths (per 100,000 person-years) related to infectious causes, 41 (43.2%) were due to pulmonary infections and 45 (47.4%) were attributed to sepsis. Of the 46 excessive deaths (per 100,000 person-years) related to pulmonary causes, 27 (58.7%) were due to aspiration. No single diagnostic entity predominated for the 60 excessive deaths (per 100,000 person-years) attributable to cardiac CODs.

Conclusions

The principal COD algorithm improved on other methods of determining COD in MS patients from death certificates. A greater awareness of the common CODs in MS patients will allow physicians to anticipate potential problems and, thereby, improve the care that they provide.     

Psychiatric Comorbidity and Its Impact on Mortality in Patients Who Attempted Suicide by Paraquat Poisoning during 2000–2010

Background

Paraquat poisoning is a lethal method of suicide used around the world. Although restricting its accessibility had been widely discussed, the underlying psychopathological mechanism of paraquat self-poisoning and its association with mortality have not yet been explicitly evaluated.

Methods

We included all patients admitted to a tertiary general hospital in Taiwan between 2000 and 2010 following a suicide attempt by paraquat self-administration. Diagnoses were made upon psychiatric consultation based on the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria. The risk of mortality was calculated by logistic regression with various psychiatric or medical covariates.

Results

The consultation-liaison psychiatry team assessed 157 patients who attempted suicide by paraquat poisoning. Mood disorders (54.0%), including dysthymic (26.7%) and major depressive disorders (24.7%), were the most common psychiatric diagnoses among the self-poisoning patients. Among those who attempted suicide, 87 patients (58.0%) died and dysthymic disorder (OR = 5.58, 95% CI: 1.13–27.69; p<0.05) significantly increased the mortality risk after adjustment for relevant medical variables, including age, gender, severity index of paraquat poisoning (SIPP), and risk for respiratory failure.

Conclusions

Awareness of comorbid psychiatric illnesses, especially dysthymic disorder, is vital in the prevention and treatment of suicide by paraquat poisoning.     

Sickness Absence Due to Specific Mental Diagnoses and All-Cause and Cause-Specific Mortality: A Cohort Study of 4.9 Million Inhabitants of Sweden

Background

Despite the magnitude and increase of sickness absence due to mental diagnoses, little is known regarding long-term health outcomes. The aim of this nationwide population-based, prospective cohort study was to investigate the association between sickness absence due to specific mental diagnoses and the risk of all-cause and cause-specific mortality.

Methods

A cohort of all 4 857 943 individuals living in Sweden on 31.12.2004 (aged 16–64 years, not sickness absent, or on retirement or disability pension), was followed from 01.01.2005 through 31.12.2008 for all-cause and cause-specific mortality (suicide, cancer, circulatory disease) through linkage of individual register data. Individuals with at least one new sick-leave spell with a mental diagnosis in 2005 were compared to individuals with no sickness absence. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated by Cox regression, adjusting for age, sex, education, country of birth, family situation, area of residence, and pre-existing morbidity (diagnosis-specific hospital inpatient (2000–2005) and outpatient (2001–2005) care).

Results

In the multivariate analyses, mental sickness absence in 2005 was associated with an increased risk for all-cause mortality: HR: 1.65, 95% CI: 1.47–1.86 in women and in men: 1.73, 1.57–1.91; for suicide, cancer (both smoking and non-smoking related) as well as mortality due to circulatory disease only in men. Estimates for cause-specific mortality ranged from 1.48 to 3.37. Associations with all-cause mortality were found for all mental sickness absence diagnostic groups studied.

Conclusions

Knowledge about the prognosis of patients sickness absent with specific mental diagnoses is of crucial clinical importance in health care. Sickness absence due to specific mental diagnoses may here be used as a risk indictor for subsequent mortality.     

Multiple Sclerosis and CCSVI: A Population-Based Case Control Study

Background

Chronic cerebrospinal venous insufficiency (CCSVI) has been associated to multiple sclerosis (MS).

Objective

To evaluate the possible association between CCSVI and MS, using a population-based control design.

Methods

A random cohort of 148 incident MS patients were enrolled in the study. We have also studied 20 patients with clinically isolated syndrome (CIS), 40 patients with other neurological diseases (OND), and 172 healthy controls. Transcranial (TCC) and Echo Color Doppler (ECD) were carried out in 380 subjects. A subject was considered CCSVI positive if ≥2 venous hemodynamic criteria were fulfilled.

Results

CCSVI was present in 28 (18.9%) of the MS patients, in 2 (10%) of CIS patients, in 11 (6.4%) of the controls, and in 2 (5%) of the OND patients. A significant association between MS and CCSVI was found with an odds ratio of 3.41 (95% confidence interval 1.63–7.13; p = 0.001). CCSVI was significantly more frequent among MS subjects with a disease duration longer than 144 months (26.1% versus 12.6% of patients with duration shorter than 144 months; p = 0.03) and among patients with secondary progressive (SP) and primary progressive (PP) forms (30.2% and 29.4, respectively) than in patients with relapsing remitting (RR) MS (14.3%). A stronger association was found considering SP and PP forms (age adjusted OR = 4.7; 95% CI 1.83–12.0, p = 0.001); the association was weaker with the RR patients (age adjusted OR = 2.58; 95%CI 1.12–5.92; p = 0.02) or not significant in CIS group (age adjusted OR = 2.04; 95%CI 0.40–10.3; p = 0.4).

Conclusions

A higher frequency of CCSVI has been found in MS patients; it was more evident in patients with advanced MS, suggesting that CCSVI could be related to MS disability.     

The Risk of Cancer in Patients with Generalized Anxiety Disorder: A Nationwide Population-Based Study

Objective

To evaluate the risk of cancer among patients with generalized anxiety disorder (GAD) in a nationwide population-based dataset.

Methods

We recruited newly-diagnosed GAD patients aged 20 years or older without antecedent cancer from the Taiwan National Health Insurance Research database between 2000–2010. Standardized incidence ratios (SIRs) of cancers were calculated in GAD patients, and the subgroup of GAD patients diagnosed by psychiatric specialists.

Results

A total of 559 cancers developed among 19,793 GAD patients with a follow-up of 89,485 person-years (median follow-up of 4.34 years), leading to a significantly increased SIR of 1.14 [95% confidence interval (CI) 1.05–1.24]. Male GAD patients had a significantly increased SIR overall (1.30, 95% CI 1.15–1.46) and for lung and prostate cancer (1.77, 95% CI 1.33–2.30 and 2.17, 95% CI 1.56–2.93, respectively). Patients over 80 years of age also had a significantly increased SIR (1.56, 95% CI 1.25–1.92), especially in males. However, psychiatrist-diagnosed GAD patients did not show increased cancer risk relative to the general population, perhaps due to having fewer physical comorbidities than non-psychiatrist-diagnosed GAD patients.

Conclusion

This study found that overall cancer risk is elevated among patients with GAD. The risk of lung and prostate cancer also increased in male patients with GAD. This increased cancer risk may be due to physical comorbidities and surveillance bias. Further prospective study is necessary to confirm these findings.     

Respective Contribution of Chronic Conditions to Disability in France: Results from the National Disability-Health Survey

Background

Representative national data on disability are becoming increasingly important in helping policymakers decide on public health strategies. We assessed the respective contribution of chronic health conditions to disability for three age groups (18–40, 40–65, and >65 years old) using data from the 2008–2009 Disability-Health Survey in France.

Methods

Data on 12 chronic conditions and on disability for 24,682 adults living in households were extracted from the Disability-Health Survey results. A weighting factor was applied to obtain representative estimates for the French population. Disability was defined as at least one restriction in activities of daily living (ADL), severe disability as the inability to perform at least one ADL alone, and self-reported disability as a general feeling of being disabled. To account for co-morbidities, we assessed the contribution of each chronic disorder to disability by using the average attributable fraction (AAF).

Findings

We estimated that 38.8 million people in France (81.7% [95% CI 80.9;82.6]) had a chronic condition: 14.3% (14.0;14.6) considered themselves disabled, 4.6% (4.4;4.9) were restricted in ADL and 1.7% (1.5;1.8) were severely disabled. Musculoskeletal and sensorial impairments contributed the most to self-reported disability (AAF 15.4% and 12.3%). Neurological and musculoskeletal diseases had the largest impact on disability (AAF 17.4% and 16.4%, respectively). Neurological disorders contributed the most to severe disability (AAF 31.0%). Psychiatric diseases contributed the most to disability categories for patients 18–40 years old (AAFs 23.8%–40.3%). Cardiovascular conditions were also among the top four contributors to disability categories (AAFs 8.5%–11.1%).

Conclusions

Neurological, musculoskeletal, and cardiovascular chronic disorders mainly contribute to disability in France. Psychiatric impairments have a heavy burden for people 18–40 years old. These findings should help policymakers define priorities for health-service delivery in France and perhaps other developed countries.     

Does Social Isolation and Low Societal Participation Predict Disability Pension? A Population Based Study

Purpose

The aim was to examine the potential influence of social isolation and low societal participation on the future risk of receiving disability pension among individuals in Sweden. A specific aim was to describe differences depending on disability pension diagnoses, and how the results were modified by sex and age.

Method

The study comprised representative samples of Swedish women and men, who had been interviewed in any of the annual Swedish Surveys of Living Conditions between 1990 and 2007. Information on disability pension and diagnoses was added from the Swedish Social Insurance Agency’s database (1991-2011). The mean number of years of follow-up for the 53920 women and men was twelve years (SD 5.5), and the study base was restricted to the ages 20 to 64 years of age. The predictors were related to disability pension by Cox’s proportional hazards regression.

Results

Social isolation and low societal participation were associated with future disability pension also after control for age, year of interview, socio demographic conditions and self reported longstanding illness. Lone individuals were at increased risk of disability pension, and the effect of living without children was modified by sex and age. An increase in risk was particularly noticeable among younger women who reported that they had sparse contacts with others, and no close friend. Both women and men who reported that they did not participate in political discussions and who could not appeal on a decision by a public authority were also at increased risk. The effects of social isolation were mainly attributed to disability pension with mental diagnoses, and to younger individuals.

Conclusions

The study suggests that social isolation and low societal participation are predictors of future disability pension. Social isolation and low societal participation increased particularly the risk of future disability pension in mental diagnoses among younger individuals.     

The genetic liability to disability retirement: a 30-year follow-up study of 24,000 Finnish twins

Background

No previous studies on the effect of genetic factors on the liability to disability retirement have been carried out. The main aim of this study was to investigate the contribution of genetic factors on disability retirement due to the most common medical causes, including depressive disorders.

Methods

The study sample consisted of 24 043 participants (49.7% women) consisting of 11 186 complete same-sex twin pairs including 3519 monozygotic (MZ) and 7667dizygotic (DZ) pairs. Information on retirement events during 1.1.1975–31.12.2004, including disability pensions (DPs) with diagnoses, was obtained from the Finnish nationwide official pension registers. Correlations in liability for MZ and DZ twins and discrete time correlated frailty model were used to investigate the genetic liability to age at disability retirement.

Results

The 30 year cumulative incidence of disability retirement was 20%. Under the best fitting genetic models, the heritability estimate for DPs due to any medical cause was 0.36 (95% CI 0.32–0.40), due to musculoskeletal disorders 0.37 (0.30–0.43), cardiovascular diseases 0.48 (0.39–0.57), mental disorders 0.42 (0.35–0.49) and all other reasons 0.24 (0.17–0.31). The effect of genetic factors decreased with increasing age of retirement. For DP due to depressive disorders, 28% of the variance was explained by environmental factors shared by family members (95% CI 21–36) and 58% of the variance by the age interval specific environmental factors (95% CI 44–71).

Conclusions

A moderate genetic contribution to the variation of disability retirement due to any medical cause was found. The genetic effects appeared to be stronger at younger ages of disability retirement suggesting the increasing influence of environmental factors not shared with family members with increasing age. Familial aggregation in DPs due to depressive disorders was best explained by the common environmental factors and genetic factors were not needed to account for the pattern of familial aggregation.     

Prevalence of All-Cause and Diagnosis-Specific Disability Pension at the Time of First Coronary Revascularisation: A Population-Based Swedish Cross-Sectional Study

Background

Although coronary revascularisation by coronary artery bypass graft surgery (CABG) and percutaneous coronary intervention (PCI) is well documented, scientific knowledge on disability pension (DP) at the time of revascularisation is lacking. The aim was to investigate the prevalence of all-cause and diagnosis-specific DP at the time of a first coronary revascularisation, accounting for socio-demographic and medical factors.

Materials and Methods

A population-based cross-sectional study using Swedish registers was conducted including all 65,676 patients (80% men) who when aged 30–63 years, within 1994–2006, had a first CABG (n = 22,959) or PCI (n = 42,717) and did not have old-age pension. Associations between socio-demographic and medical factors and the probability of DP were estimated by odds ratios (OR) with 95% confidence intervals (CI) using logistic regression analyses.

Findings

The prevalence of DP at time of revascularisation was 24%, mainly due to musculoskeletal diagnoses. Sixty-two percent had had DP for at least four years before the revascularisation. In the multivariable analyses, DP was more common in women (OR: 2.40; 95% CI: 2.29–2.50), older patients (50–63 years); especially men aged 60–63 years with CABG (OR: 4.91; 95% CI: 4.27–5.66), lower educational level; especially men with PCI (OR: 2.96; 95% CI: 2.69–3.26), patients born outside Sweden; especially men with PCI (OR: 2.11; 95% CI: 1.96–2.27), and in women with an indication of other diagnoses than acute coronary syndrome (ACS) or stable angina pectoris for PCI (OR: 1.72; 95% CI: 1.31–2.24).

Conclusion

About a quarter had DP at the time of revascularisation, often due to musculoskeletal diagnoses. More than half had had DP for at least four years before the intervention. DP was associated with female gender, older age, lower educational level, and being born outside Sweden.     

Switching multiple sclerosis patients with breakthrough disease to second-line therapy

Background

Multiple sclerosis (MS) patients with breakthrough disease on immunomodulatory drugs are frequently offered to switch to natalizumab or immunosuppressants. The effect of natalizumab monotherapy in patients with breakthrough disease is unknown.

Methods

This is an open-label retrospective cohort study of 993 patients seen at least four times at the University of California San Francisco MS Center, 95 had breakthrough disease on first-line therapy (60 patients switched to natalizumab, 22 to immunosuppressants and 13 declined the switch [non-switchers]). We used Poisson regression adjusted for potential confounders to compare the relapse rate within and across groups before and after the switch.

Results

In the within-group analyses, the relapse rate decreased by 70% (95% CI 50,82%; p<0.001) in switchers to natalizumab and by 77% (95% CI 59,87%; p<0.001) in switchers to immunosuppressants; relapse rate in non-switchers did not decrease (6%, p = 0.87). Relative to the reduction among non-switchers, the relapse rate was reduced by 68% among natalizumab switchers (95% CI 19,87%; p = 0.017) and by 76% among the immunosuppressant switchers (95% CI 36,91%; p = 0.004).

Conclusions

Switching to natalizumab or immunosuppressants in patients with breakthrough disease is effective in reducing clinical activity of relapsing MS. The magnitude of the effect and the risk-benefit ratio should be evaluated in randomized clinical trials and prospective cohort studies.