Register-based Matched Cohort Study Research Articles

Future sick leave, disability pension, and unemployment among patients with cancer after returning to work: Swedish register-based matched prospective cohort study.

Despite increasing numbers of working-age cancer survivors, evidence on their future work-related circumstances is limited. This study examined their future sick leave, disability pension, and unemployment benefits compared to matched cancer-free individuals. A matched cohort study was conducted using nationwide Swedish registers. In total, 94,411 individuals aged 25 to 59 years when diagnosed with incident cancer in 2001-2012 and who returned to work after cancer were compared with their matched cancer-free individuals (N = 354,814). Follow-up started from the year before cancer diagnosis and continued up to 14 years. Generalized estimating equations were used to calculate incidence rate ratios (IRR) and odds ratios for the difference between cancer survivors and matched cancer-free individuals. Compared with cancer-free individuals, cancer survivors had six times higher sick-leave days per year after cancer (IRR 6.25 [95% CI, 5.97-6.54] for men; IRR, 5.51 [5.39-5.64] for women). This higher number of sick-leave days declined over time but a two-fold difference persisted. An approximate 1.5 times higher risk of receiving disability pension remained during follow-up. The unemployment days tended to be lower for cancer survivors (IRR, 0.84 [0.75-0.94] for men; IRR, 0.91 [0.86-0.96] for women). Risk of sick leave and disability pension was higher among those with leukemia, colorectal, and breast cancer than skin and genitourinary cancers. Cancer survivors who returned to work experienced a high and persisting sick leave and disability pension for over a decade. Prolonged receipt of a high amount of benefits may have long-term adverse impacts on financial circumstances; more knowledge to promote the environment that encourages returning to and remaining in work is needed.

Association of continuous subcutaneous insulin therapy and diabetic retinopathy in type 1 diabetes: A national cohort study

AimThis study aimed to investigate the short-and long-term effect on diabetic retinopathy (DR) in individuals with type 1 diabetes treated with continuous subcutaneous insulin injections (CSII) compared to those using multiple daily injections (MDI). MethodsWe conducted a register-based matched cohort study utilizing data from the Danish Registry of Diabetic Retinopathy as well as several other national Danish health registers. Our cohort consisted of all individuals with type 1 diabetes who attended the Danish screening program for DR from 2013 to 2022. We included individuals registered with CSII treatment, and compared them to individuals using MDI, matched by age, sex, and DR level. Cox regression analysis was performed to evaluate the outcomes. ResultsThe study included 674 individuals treated with CSII and 2006 matched MDI users. In our cohort 53.4 % were female and median age was 36 (IQR 27–47). Average follow-up risk-time was 4.8 years. There was no difference in the risk of DR worsening between the CSII group and MDI group (HR 1.05 [95%CI 0.91; 1.22], p = 0.49). However, an increased risk of focal photocoagulation was observed in the CSII group (HR 2.40 [95%CI 1.11; 5.19], p = 0.03). ConclusionsOur findings indicate that CSII treatment does not confer a significant difference in the overall short- and long-term risk of DR worsening or ocular intervention compared to MDI treatment. These results provide insights into the DR outcomes of CSII treatment in individuals with type 1 diabetes.

Major cardiovascular events and death in parents of children with type 1 diabetes: a register-based matched cohort study in Sweden

Aims/hypothesisParenting a child with type 1 diabetes has been associated with stress-related symptoms. This study aimed to elucidate the potential impact on parental risk of major cardiovascular events (MCE) and death.MethodsIn this register-based study, we included the parents of 18,871 children, born 1987–2020 and diagnosed with type 1 diabetes in Sweden at <18 years. The median parental age at the child's diagnosis was 39.0 and 41.0 years for mothers and fathers, respectively. The cohort also encompassed 714,970 population-based matched parental control participants and 12,497 parental siblings. Cox proportional hazard regression models were employed to investigate the associations between having a child with type 1 diabetes and incident MCE and all-cause death, and, as secondary outcomes, acute coronary syndrome and ischaemic heart disease (IHD). We adjusted for potential confounders including parental type 1 diabetes and country of birth.ResultsDuring follow-up (median 12 years, range 0–35), we detected no associations between parenting a child with type 1 diabetes and MCE in mothers (adjusted HR [aHR] 1.02; 95% CI 0.90, 1.15) or in fathers (aHR 1.01; 95% CI 0.94, 1.08). We noted an increased hazard of IHD in exposed mothers (aHR 1.21; 95% CI 1.05, 1.41) with no corresponding signal in fathers (aHR 0.97; 95% CI 0.89, 1.05). Parental sibling analysis did not confirm the association in exposed mothers (aHR 1.01; 95% CI 0.73, 1.41). We further observed a slightly increased hazard of all-cause death in exposed fathers (aHR 1.09; 95% CI 1.01, 1.18), with a similar but non-significant estimate noted in exposed mothers (aHR 1.07; 95% CI 0.96, 1.20). The estimates from the sibling analyses of all-cause death in fathers and mothers were 1.12 (95% CI 0.90, 1.38) and 0.73 (95% CI 0.55, 0.96), respectively.Conclusions/interpretationHaving a child diagnosed with type 1 diabetes in Sweden was not associated with MCE, but possibly with all-cause mortality. Further studies are needed to disentangle potential underlying mechanisms, and to investigate parental health outcomes across the full lifespan.Graphical

Parental death and initiation of antidepressant treatment in surviving children and youth: a national register-based matched cohort study.

Population-based longitudinal studies on bereaved children and youth's mental health care use are scarce and few have assessed the role of surviving parents' mental health status. Using register data of individuals born in Sweden in 1992-1999, we performed a matched cohort study (n=117,518) on the association between parental death and subsequent initiation of antidepressant treatment among individuals bereaved at ages 7-24 years. We used flexible parametric survival models to estimate the hazard ratios (HRs) over time after bereavement, adjusting for individual and parental factors. We further examined if the association varied by age at loss, sex, parental sociodemographic factors, cause of death, and the surviving parents' psychiatric care. The bereaved were more likely to initiate antidepressants treatment than the nonbereaved matched individuals during follow-up (incidence rate per 1000 person years 27.5 [26.5-28.5] vs. 18.2 [17.9-18.6]). The HRs peaked in the first year after bereavement and remained higher than the nonbereaved individuals until the end of the follow-up. The average HR over the 12 years of follow-up was 1.48 (95% confidence interval [1.39-1.58]) for father's death and 1.33 [1.22-1.46] for mother's death. The HRs were particularly high when the surviving parents received psychiatric care before bereavement (2.11 [1.89-2.56] for father's death; 2.14 [1.79-2.56] for mother's death) or treated for anxiety or depression after bereavement (1.80 [1.67-1.94]; 1.82 [1.59-2.07]). The risk of initiating antidepressant treatment was the highest in the first year after parental death and remained elevated over the next decade. The risk was particularly high among individuals with surviving parents affected by psychiatric morbidity. The Swedish Research Council.

Healthcare Costs in the Year Before and After Alzheimer's Disease Diagnosis: A Danish Register-Based Matched Cohort Study.

Alzheimer's disease (AD) carries a significant economic burden, with costs peaking around the time of diagnosis. However, the cost of diagnosis, including the time leading up to it, has not been studied thoroughly. Furthermore, regionalized healthcare structure could result in differences in the pre-diagnostic costs for people with suspected AD. This study set out to estimate the excess healthcare costs before and after AD diagnosis compared to a matched non-AD population and to investigate regional variation in AD healthcare costs in Denmark. We used a register-based cohort of 25,523 matched pairs of new cases of AD and non-AD controls. The healthcare costs included costs on medication, and inpatient-, outpatient-, and primary care visits. Generalized estimating equations were employed to estimate the excess healthcare cost attributable to diagnosing AD, and the variation in costs across regions. Mean excess costs attributable to AD were € 3,284 and € 6,173 in the year before and after diagnosis, respectively. Regional differences in healthcare costs were identified in both the AD and control groups and were more pronounced in patients with AD (PwAD). PwAD incur higher healthcare costs across all cost categories in the year before and after diagnosis. Regional differences in healthcare utilization by PwAD may reveal potential variation in access to healthcare. These findings suggest that a more standardized and targeted diagnostic process may help reduce costs and variation in access to healthcare.

Traumatic brain injury during pregnancy is associated with increased rate of cesarean section: a nationwide multi-register study in Finland

Objective The literature on the incidence of traumatic brain injury (TBI) during pregnancy is lacking. Furthermore, only studies with small sample size have analyzed the impact of TBI during pregnancy to maternal and fetal outcomes. Thus, we aim to report the incidence of TBIs during pregnancy and study the pregnancy outcomes using nationwide high-quality registers. Methods This nationwide retrospective register-based matched cohort study utilized two national registers. All fertile-aged (15–49 years) women with a TBI hospitalization period during pregnancy were retrieved the Care Register for Health Care. Data were then linked with the data from the National Medical Birth Register (MBR). Propensity score matching was conducted according to maternal age during pregnancy, previous cesarean section (CS), maternal smoking status, maternal body mass index, and maternal gestational diabetes. The matching was conducted using the nearest neighbor methods with a caliber width if 0.15, and with a ratio 1:3 (patients/references). Adverse maternal and fetal outcomes were compared between patient group and reference group using Chi-squared tests. Results A total of 392 women having a TBI during pregnancy were found. The control group consisted of 722,497 women without TBI during pregnancy. Of the TBIs occurring during pregnancy, the most common types of TBIs were concussion (S06.0) (n = 359, 91.6%), diffuse traumatic brain injury (S06.2) (n = 11, 2.8%), traumatic subdural hemorrhage (n = 7, 1.8%), and unspecified intracranial injury S06.9 (n = 6, 1.5%). The incidence rates of pregnancies with a TBI have remained similar during pregnancy in Finland, peaking at 0.8 per 1000 pregnancies in 2016. The Chi-squared test showed higher rate for CS among women with TBI than for their matched references (21.4% vs. 15.5%, p = .008). Especially, women with TBI during 3rd trimester had higher rate for CS (29.0 vs. 15.0%, p = .016). Conclusions The main findings of this study were that the incidence rates for TBI during pregnancy have remained similar during our study period (2004–2018). TBI during pregnancy, even a mild one, is associated with an increased rate for CS. Especially, TBI during the 3rd trimester was associated with high rate for CS, but the etiology behind this remains unknown. In addition, we found no evidence of difference in fetal outcomes, such as preterm birth, low birth weight, or need for intensive care unit. Future studies should focus on the indications for elective CS, and reasons for unplanned CS among women with TBI during pregnancy, as these could possibly provide important information on the effects of TBI on the course of childbirth.

Directionality of the Association Between Epilepsy and Depression: A Nationwide Register-Based Cohort Study.

Epilepsy and depression share a bidirectional relationship; however, its magnitude and long-term temporal association remain to be elucidated. This study investigates the magnitude and long-term association between epilepsy and depression, comparing with the risks of the 2 disorders after another chronic medical illness (asthma). In a nationwide register-based matched cohort study, we identified all individuals who received a first diagnosis of epilepsy, depression, and asthma from January 1, 1980, to December 31, 2016. We used a Cox regression model to estimate the risk of epilepsy after depression and vice versa and the risk of epilepsy or depression after asthma, compared with healthy references matched on age and sex, adjusting for medical comorbidity, substance abuse, and calendar time. Results were stratified by epilepsy subtype. We furthermore investigated the risk of admission with acute seizures for persons with epilepsy who became depressed. In a population of 8,741,955 individuals, we identified 139,014 persons with epilepsy (54% males, median age at diagnosis 43 years [inter quartile range (IQR) 17-65 years]), 219,990 persons with depression (37% males, median age at diagnosis 43 years [IQR 29-60 years]), and 358,821 persons with asthma (49% males, median age at diagnosis 29 years [IQR 6-56 years]). The adjusted hazard ratio (aHR) of depression after epilepsy was 1.88 (95% CI 1.82-1.95), and the aHR of epilepsy after depression was 2.35 (95% CI 2.25-2.44). The aHR of depression after asthma was 1.63 (95% CI 1.59-1.67) and that of epilepsy after asthma, 1.48 (95% CI 1.44-1.53). The risk of depression was highest in the few years preceding and after an epilepsy diagnosis, and vice versa, but remained elevated during the entire follow-up period for both directions of the association. There was no evidence of a stronger association with depression for any epilepsy subtype. Receiving a diagnosis of depression subsequent to an epilepsy diagnosis was associated with a 1.20-fold (95% CI 1.07-1.36) increased HR of acute hospital admission with seizures. We identified a long-term bidirectional relationship between depression and epilepsy in a large-scale cohort study. Risk estimates were higher than those of epilepsy or depression after asthma.

The association between migraine and dementia – a national register-based matched cohort study

ObjectivesMigraine and dementia, two major public health challenges, are associated, but more knowledge is needed to understand their relationship. Objectives of this study were to investigate 1) the association between non–self-reported measures of migraine and dementia, and whether dementia was associated with 2) migraine without aura (MO) and with aura (MA) in combination with migraine medication use, and 3) migraine severity operationalized as the number of migraine prescriptions. Study designMatched cohort study. MethodsNational register data were obtained from individuals born between 1934 and 1958. Migraine cases (aged 25–58 years) were identified by migraine diagnoses and redeemed migraine medication. Migraine cases were matched with non-cases (N = 340,850) and date of diagnosis or medication redemption was defined as index year. Dementia was identified by dementia diagnoses and redeemed dementia medication. ResultsWe observed a 1.46 (95% CI: 1.26–1.69) times higher dementia rate in individuals with a migraine diagnosis and a 0.86 (95% CI: 0.76–0.97) times lower rate when using migraine medication. We found the highest dementia rate among individuals with MA, who also used migraine medication (HR = 2.23; 95% CI: 1.19–4.17), and the lowest rate among individuals with MO, who also used medication (HR = 1.25; 95% CI: 0.75–2.10). The number of migraine medication prescriptions was not associated with dementia. ConclusionsBeing registered with a migraine diagnosis was associated with a higher dementia rate, while use of prescribed migraine medication was not. The differences in the dementia rate among migraine cases identified via diagnoses versus medications warrants further investigation.

Association of maternal psoriasis and small for gestational age or preterm birth: a nationwide matched cohort study in 69 080 singleton infants.

Women with certain inflammatory diseases have an increased risk of giving birth to infants who are small for gestational age (SGA) or preterm birth (PTB), with maternal disease activity being the most important risk factor. However, previous studies investigating an association between psoriasis and SGA are scarce and have shown conflicting results. To investigate the association between maternal psoriasis and risk of SGA infants and PTB, respectively, both overall and stratified by psoriasis severity. This was a nationwide register-based matched cohort study of women with psoriasis matched 1 : 10 to women without psoriasis on age at delivery, body mass index and smoking status and with their first singleton infant born during the period 2004-2017. Odds ratio (OR) and 95% CI were calculated in conditional logistic regression models adjusted for known risk factors. From 516 063 deliveries, we identified 6282 women with psoriasis and 62 798 matched women without psoriasis. The risk of SGA and PTB was similar in women with psoriasis and matched controls: adjusted OR (aOR) = 1.07 (95% CI 0.98-1.17) and aOR = 1.05 (95% CI 0.93-1.19), respectively. The risk of term SGA was increased in women with psoriasis (aOR 1.11; 95% CI 1.01-1.22) compared with matched controls. Maternal psoriasis was not associated with increased risk of SGA or PTB. Risk of term SGA was slightly increased in women with a history of psoriasis compared with matched controls, however; these infants are likely to be constitutionally small with no increased risk of perinatal morbidity and mortality.

Mood and neurotic disorders among youth with prenatal substance exposure: A longitudinal register-based cohort study

BackgroundPrenatal substance exposure is associated with mood and neurotic disorders but this association is complex and understudied. This study investigated the recorded use of specialised healthcare services for mood and neurotic disorders among youth with prenatal substance exposure in comparison with an unexposed matched cohort. Furthermore, the influence of adverse maternal characteristics and out-of-home care (OHC) is investigated. MethodsThis longitudinal register-based matched cohort study included 594 exposed and 1735 unexposed youth. Cox proportional hazard regression models were applied to study the first episode of mood and neurotic disorders in specialised healthcare from 13 years of age, and the influence of adverse maternal characteristics and OHC. Mediation analysis was applied to study the mediating effect of OHC on the association between prenatal substance exposure and the disorders. ResultsThe exposed cohort had a two-fold higher likelihood of being treated at specialised healthcare for mood and neurotic disorders compared with the unexposed cohort (HR 2.34, 95% CI 1.86–2.95), but this difference was attenuated to non-significant levels (AHR 1.29, 95% CI 0.92–1.81) following adjustments with adverse maternal characteristics and OHC. OHC mediated 61% (95% CI 0.41–0.94) of the association between prenatal substance exposure and youth's mood and neurotic disorders. LimitationsRegister data likely include more severe cases of disorders, and as an observational study, causality cannot be assessed. ConclusionMood and neurotic disorders are more common following prenatal exposure to substances and interlinked with significant adversities in the postnatal caregiving environment and OHC.

Risk of heart disease following treatment for breast cancer - results from a population-based cohort study.

There is a rising concern about treatment-associated cardiotoxicities in breast cancer patients. This study aimed to determine the time- and treatment-specific incidence of arrhythmia, heart failure, and ischemic heart disease in women diagnosed with breast cancer. A register-based matched cohort study was conducted including 8015 breast cancer patients diagnosed from 2001 to 2008 in the Stockholm-Gotland region and followed up until 2017. Time-dependent risks of arrhythmia, heart failure, and ischemic heart disease in breast cancer patients were assessed using flexible parametric models as compared to matched controls from general population. Treatment-specific effects were estimated in breast cancer patients using Cox model. Time-dependent analyses revealed long-term increased risks of arrhythmia and heart failure following breast cancer diagnosis. Hazard ratios (HRs) within the first year of diagnosis were 2.14 (95% CI = 1.63-2.81) for arrhythmia and 2.71 (95% CI = 1.70-4.33) for heart failure. HR more than 10 years following diagnosis was 1.42 (95% CI = 1.21-1.67) for arrhythmia and 1.28 (95% CI = 1.03-1.59) for heart failure. The risk for ischemic heart disease was significantly increased only during the first year after diagnosis (HR = 1.45, 95% CI = 1.03-2.04). Trastuzumab and anthracyclines were associated with increased risk of heart failure. Aromatase inhibitors, but not tamoxifen, were associated with risk of ischemic heart disease. No increased risk of heart disease was identified following locoregional radiotherapy. Administration of systemic adjuvant therapies appears to be associated with increased risks of heart disease. The risk estimates observed in this study may aid adjuvant therapy decision-making and patient counseling in oncology practices. This work was supported by the Swedish Research Council (grant no: 2018-02547); Swedish Cancer Society (grant no: CAN-19-0266); and FORTE (grant no: 2016-00081).

Neurological symptoms and disorders following electrical injury: A register-based matched cohort study.

IntroductionElectric shocks may have neurological consequences for the victims. Although the literature on the neurological consequences of electric shocks is limited by retrospective designs, case studies and studies of selected patient groups, previous research provides some evidence of a link between electric shocks, and diseases and symptoms of the central nervous system (CNS)(e.g. epilepsy, migraine and vertigo) and the peripheral nervous system (PNS)(e.g. loss of sensation, neuropathy and muscle weakness). This study aims to employ a register-based, matched cohort study, to investigate whether individuals demonstrate a greater risk of neurological diseases and symptoms of the CNS or PNS in the years following an electrical injury.Materials and methodsWe identified 14,112 electrical injuries over a period of 19 years in two Danish registries, and matched these with three different groups of persons in a prospective matched cohort study: (1) patients with dislocation/sprain injuries, (2) patients with eye injuries and (3) persons employed in the same occupation. Year of injury, sex and age were used as matching variables. The outcomes we identified comprised neurological disorders and central or peripheral nervous system symptoms that covered a range of diagnoses in the Danish National Patient Register. The associations were analysed using conditional logistic regression for a range of time periods (six months to five years) and conditional Cox regression for analyses of the complete follow-up period (up to 20 years).ResultsFor victims of electric shock, the CNS sequelae we identified included an increased risk of epilepsy, convulsions, abnormal involuntary movements, headache, migraine and vertigo. We also identified an uncertain, increased risk of spinal muscular atrophy and dystonia, whereas we identified no increased risk of Parkinson’s disease, essential tremor, multiple sclerosis or other degenerative diseases of the nervous system. For victims of electric shock, the PNS sequelae we identified included an increased risk of disturbances of skin sensation, mononeuropathy in the arm or leg and nerve root and plexus disorders. We also identified an uncertain, increased risk of facial nerve disorders, other mononeuropathy, and polyneuropathy.ConclusionOur results confirm that electrical injuries increase the risk of several neurological diseases and symptoms of the CNS or PNS in the years following the injury. Most often the diseases and symptoms are diagnosed within the first six months of the injury, but delayed onset of up to 5 years cannot be ruled out for some symptoms and diagnoses. Some of the conditions were rare in our population, which limited our ability to identify associations, and this warrants cautious interpretation. Therefore, further studies are needed to confirm our findings, as are studies that examine the mechanisms underlying these associations.

Unspecified pain and other soft tissue disorders following electrical injuries: a register-based matched cohort study

ObjectiveThis study investigates whether individuals who have sustained an electrical injury (EI) are diagnosed with unspecified pain or pain related to the musculoskeletal system in the years following the injury.MethodsIndividuals listed in Danish registers as having sustained EIs were matched for sex, age, and year of injury in a cohort study with individuals having experienced dislocations/sprains (match 1), eye injuries (match 2), and a sample of individuals with the same occupation without a history of electrical injuries (match 3). Outcomes were unspecified pain and unspecified soft tissue disorders. Conditional logistic regression and conditional Cox regression were applied.ResultsWe identified 14,112 individuals who sustained EIs. A higher risk of both outcomes was observed for all three matches, and was highest at the 6- and 12-month follow-ups. The risk of both outcomes was considerably higher for match 3.ConclusionsThis study confirms that exposure to EIs increases the risk of being diagnosed with unspecified pain or unspecified soft tissue disorders both at short and long terms. Our results also showed that the risk of unspecified pain as sequelae is related to the severity of the injury.

Completed secondary education among youth with prenatal substance exposure: A longitudinal register-based matched cohort study

IntroductionThe dual impact of prenatal substance exposure (i.e. alcohol/drugs) and adverse postnatal caregiving environment on offspring secondary education completion is an understudied research area. The aim was to investigate the influence of childhood adversities, out-of-home care, and offspring's mental and/or behavioural disorders on secondary education completion among prenatally exposed offspring in comparison to matched unexposed offspring. MethodsThis is a longitudinal register-based matched cohort study in Finland including offspring with a history of prenatal substance exposure and a matched unexposed cohort. The study sample included 283 exposed and 820 unexposed offspring aged 18–23 years. ResultsThe results showed a time lag in secondary education completion and lower educational attainment overall among exposed compared with unexposed (37.8% vs. 51.0%, respectively). The results from the multivariate logistic regression models showed that the differences in the secondary education completion between exposed and unexposed were diminished in the presence of covariates. A cumulative childhood adversity score and out-of-home care were not associated with secondary education completion in the multivariate models, whereas the different domains of offspring's mental and/or behavioural disorders including psychiatric disorders (AOR 0.65, 95% CI 0.45–0.96), neuropsychological disorders (AOR 0.35, 95% CI 0.23–0.54) and dual psychiatric and neuropsychological disorder (AOR 0.29, 95% CI 0.18–0.48) showed an independent negative effect on secondary education completion. ConclusionsInferior educational outcomes may not be directly linked with prenatal substance exposure but may rather reflect the extent of evolving offspring's mental and/or behavioural disorders over time influenced by childhood adversities.

Prenatal substance exposure, adverse childhood experiences and diagnosed mental and behavioral disorders - A longitudinal register-based matched cohort study in Finland.

Both prenatal substance exposure (PSE, alcohol/drugs) and experiences during the first years of life have powerful effects on brain development. However, only a few studies have investigated the combined effect of PSE and adverse childhood experiences (ACEs) on mental and behavioral disorders among exposed adolescents and adults. This longitudinal register-based cohort study 1) compared the nature and extent of diagnosed mental and behavioral disorders among youth with PSE and matched unexposed controls, and 2) investigated the influence of PSE, health in infancy and ACEs (maternal risk factors and out-of-home care, OHC) on diagnoses of mental and behavioral disorders. The data consisted of 615 exposed youth aged 15–24 years and 1787 matched unexposed controls. Data from hospital medical records and nine registers were merged for the analysis. Descriptive analysis methods and Cox regression were used. The results showed that the prevalence of mental and behavioral disorders was twice as high among exposed compared with controls. The highest levels of mental and behavioral disorders and ACEs were found among exposed with at least one OHC episode. The difference in the risk of mental and behavioral disorders between exposed and controls diminished after controlling for the effect of ACEs. Low birth weight, maternal risk factors, and OHC were the strongest predictors of mental and behavioral disorders. The results suggest that PSE alone does not explain poorer mental health among exposed youth. Risk factors accumulate, and low birth weight and ACEs are strongly associated with increased risk of mental and behavioral disorders.

Widowhood and mortality: a Danish nationwide register-based cohort study.

Widowed people have increased mortality compared to married people of the same age. Although most widowed people are of older age, few studies include the oldest old. As life expectancy is increasing, knowledge of widowhood into older age is needed. This study aimed to examine mortality and widowhood in older age by comparing mortality in widowed and married people by sex, age, time since spousal loss and cause of death. A Danish register-based matched cohort study of 10% of widowed persons ⩾65 years in the years 2000-2009. For each randomly drawn widowed person, five married persons were matched on sex and age. Mortality rate ratios (MRR) were calculated using Poisson regression, and stratified according to sex and 5-year age intervals. MRRs were furthermore calculated by time since spousal loss and by specific cause of death. The study included 82 130 persons contributing with 642 914.8 person-years. The overall MRR between widowed and married persons with up to 16 years of follow-up was 1.25 (95% CI 1.23-1.28). At age ⩾95 years for men, and ⩾90 years for women, no differences in mortality rates were seen between widowed and married persons. Mortality in widowed persons was increased for most specific causes of death, with the highest MRR from external causes (MRR 1.53 [1.35-1.74]) and endocrine diseases (MRR 1.51 [1.34-1.70]). Widowhood was associated with increased mortality in older age for both men and women until age ⩾95 and ⩾90 years, respectively. Increased mortality was observed for almost all causes of death.

Cohort profile: ADEF Helsinki - a longitudinal register-based study on exposure to alcohol and drugs during foetal life.

Purpose:The need for longitudinal studies on prenatal substance exposure (PSE) extending into adulthood is widely recognised. In particular, studies on the dual effect of exposure to substances and adverse childhood experiences are needed. This register-based matched cohort study investigates the effect of this dual exposure on the health and development of youth with PSE. The follow-up is from birth to young adulthood.Participants:The exposed youth were born in 1992–2001 to mothers with a significant substance misuse problem during pregnancy. The mothers were identified in primary care maternity clinics in the Helsinki metropolitan area and referred for intensified pregnancy follow-up in a tertiary care setting (HAL-clinics). Data from hospital medical records were collected for the mothers during the pregnancy follow-up and linked with register data from multiple national health and social welfare registers obtained for each mother–child dyad from birth until the end of 2015–2018. Similar register data were gathered for three matched mother–child dyads without any evidence of the mother’s substance misuse in national health and social welfare registers. The study consists of 615 exposed and 1787 unexposed youth aged 15–24 years.Findings to date:A majority of the exposed youth (64%) had been in out-of-home care at least once compared with 8% among the unexposed. Outpatient and inpatient hospital care due to mental or behavioural disorders were two to three times more common among the exposed than among the unexposed. The exposed had less often completed secondary school education and had more often needed social assistance.Future plans:The data comprise a wide range of information on infant health, youth’s mental and somatic health and development, out-of-home care history, and mother’s life situation at the delivery and later health. Risk and protective factors for different long-term developmental outcomes in adolescence or in young adulthood will be studied.

Educational inequalities in all-cause and cause-specific mortality among people with gout: a register-based matched cohort study in southern Sweden

BackgroundGout is the most common inflammatory arthritis with a rising prevalence around the globe. While educational inequalities in incidence and prevalence of gout have been reported, no previous study investigated educational inequality in mortality among people with gout. The aim of this study was to assess absolute and relative educational inequalities in all-cause and cause-specific mortality among people with gout in comparison with an age- and sex-matched cohort free of gout in southern Sweden.MethodsWe identified all residents aged ≥30 years of Skåne region with doctor-diagnosed gout (ICD-10 code M10, n = 24,877) during 1998–2013 and up to 4 randomly selected age- and sex-matched comparators free of gout (reference cohort, n = 99,504). These were followed until death, emigration, or end of 2014. We used additive hazards models and Cox regression adjusted for age, sex, marital status, and country of birth to estimate slope and relative indices of inequality (SII/RII). Three cause-of-death attribution approaches were considered for RII estimation: “underlying cause”, “any mention”, and “weighted multiple-cause”.ResultsGout patients with the lowest education had 1547 (95% CI: 1001, 2092) more deaths per 100,000 person-years compared with those with the highest education. These absolute inequalities were larger than in the reference population (1255, 95% CI: 1038, 1472). While the contribution of cardiovascular (cancer) mortality to these absolute inequalities was greater (smaller) in men with gout than those without, the opposite was seen among women. Relative inequality in all-cause mortality was smaller in gout (RII 1.29 [1.18, 1.41]) than in the reference population (1.46 [1.38, 1.53]). The weighted multiple-cause approach generally led to larger RIIs than the underlying cause approach.ConclusionsOur register-based matched cohort study showed that low level of education was associated with increased mortality among gout patients. Although the magnitude of relative inequality was smaller in people with gout compared with those without, the absolute inequalities were greater reflecting a major mortality burden among those with lower education.

Patient-reported outcomes in hip resurfacing versus conventional total hip arthroplasty: a register-based matched cohort study of 726 patients

Background and purpose — The theoretical mechanical advantages of metal-on-metal hip resurfacing (MoM-HR) compared with conventional total hip arthroplasty (THA) have been questioned. Studies including measures of patient-reported function, physical activity, or health-related quality of life have been sparse. We compared patient-reported outcomes in MoM-HR patients with a matched group of patients with conventional THA at 7 years post-surgery.Patients and methods — Patients and patient data were retrieved from the Swedish Hip Arthroplasty Register. The case group, consisting of 363 patients with MoM-HR, was matched 1:1 with a control group, consisting of patients with a conventional THA. Patients were sent a postal patient-reported outcome measures (PROM) questionnaire including the Hip Disability and Osteoarthritis Outcome Score (HOOS), EQ-5D, and VAS pain. We used multivariable linear regression analyses to investigate the influence of prosthesis type.Results — 569 patients (78%) returned the questionnaire with complete responses (299 MoM-HRs and 270 conventional THAs). MoM-HR was associated with better scores in HOOS function of daily living (4 percentage units) and HOOS function in sport and recreation (8 percentage units) subscales. Type of prosthesis did not influence HOOS quality of life, HOOS pain, HOOS symptoms, EQ-5D index, hip pain, or satisfaction as measured with visual analog scales.Interpretation — At mean 7 years post-surgery, patients with hip resurfacing had somewhat better self-reported hip function than patients with conventional THA. The largest difference between groups was seen in the presumed most demanding subscale, i.e., function in sport and recreation.

Psychiatric disorders among children of parents with cancer: A Swedish register-based matched cohort study.

To investigate the risk of psychiatric disorders among children of parents with cancer in a nationwide population-based setting. Based on Swedish national registers, the study included 101339 children with parental cancer diagnosed either during pregnancy (N=1047) or after birth (N=100292) that were born during 1983 to 2000. For each exposed child, we randomly selected 10 unexposed children from the general population after individual matching by year of birth and sex. The matched cohort was followed during 2001 to 2010. Clinical diagnoses of psychiatric disorders and use of prescribed psychiatric medications were identified for all children. Cox regression and logistic regression were used to evaluate the associations of parental cancer with psychiatric disorder diagnosis and psychiatric medication use, respectively. Parental cancer during pregnancy was not associated with the risk of psychiatric disorders overall, although paternal cancer during pregnancy was associated with a higher risk of psychiatric medication use among females. Parental cancer after birth was associated with higher risks of psychiatric disorder diagnoses, particularly stress reaction and adjustment disorders (males: hazard ratio [HR]: 1.24, 95% confidence interval [CI], 1.08-1.43; females: HR: 1.27, 95% CI, 1.14-1.41), and use of psychiatric medication (males: odds ratio [OR]: 1.09, 95% CI, 1.04-1.13; females: OR: 1.14, 95% CI, 1.10-1.18). The positive associations were stronger for parental cancer with poor expected survival and for parental death after cancer diagnosis. Parental cancer, primarily the life-threatening cancer, might confer a higher risk of psychiatric disorders among children. These findings have potential implications for health care professionals in providing targeted support to children living with a parent with cancer.