General Population Comparison Cohort Research Articles

Risk of cardiovascular disease after hospital-diagnosed overweight or obesity.

The aim was to examine the association between hospital-diagnosed overweight/obesity and incident CVD according to the time period of the overweight/obesity diagnosis. This is a cohort study. From Danish national health registries, we identified all residents with a first-time hospital-based overweight/obesity diagnosis code, 1977-2018 (n = 195,221), and an age and sex-matched general population comparison cohort (n = 1,952,210). We computed adjusted hazard ratios (aHRs) with 95% confidence intervals (CIs) using Cox regression. We adjusted for comorbidities and educational level and applied 10 years of follow-up. The overall incidence rate was 10.1 (95% CI 10.0-10.1) per 1000 person-years for the comparison cohort and 25.1 (95% CI 24.8-25.4) per 1000 person-years for the overweight/obesity cohort, corresponding to an aHR of 2.5 (95% CI 2.4-2.5). The aHR was elevated for all subtypes of CVD: heart failure: 3.9 (95% CI 3.7-4.1), bradyarrhythmia: 2.9 (95% CI 2.7-3.1), angina pectoris: 2.7 (95% CI 2.7-2.8), atrial fibrillation or flutter: 2.6 (95% CI 2.5-2.6), acute myocardial infarction: 2.4 (95% CI 2.3-2.4), revascularization procedure: 2.4 (95% CI 2.2-2.5), valvular heart disease: 1.7 (95% CI 1.6-1.8), ischemic stroke: 1.6 (95% CI 1.4-1.7), transient ischemic attack: 1.6 (95% CI 1.5-1.7), and cardiovascular death: 1.6 (95% CI 1.5-1.6). The 1-10-year aHR of any CVD associated with an overweight/obesity diagnosis decreased from 2.8 (95% CI 2.7-2.9) in 1977-1987 to 1.8 (95% CI 1.8-1.9) in 2008-2018. Patients with hospital-diagnosed overweight/obesity had high rates of ischemic heart disease, heart failure, structural heart disease, arrhythmia, stroke, and death, although the strength of the association decreased in recent years. Obesity is linked to metabolic abnormalities that predispose individuals to an increased risk of subtypes of CVD. In this population-based nationwide 40-year cohort study, we found that of 195,221 patients with an overweight/obesity diagnosis, more than 31,000 (15.9%) were admitted to hospital within 10 years because of CVD; corresponding to a 2.5-fold greater relative risk of any CVD associated with overweight/obesity than in the general population. We observed an increased risk for most CVD subtypes, including ischemic heart disease, heart failure, structural heart disease, arrhythmia, stroke, and cardiovascular death, although the strength of the association decreased in recent years. Our study emphasizes the importance of improved clinical handling of obesity and underscores the need to prevent associated complications to alleviate the burden of obesity.

Diverticular disease and risk of dementia: a Danish population-based cohort study.

Patients with diverticular disease (DD) have ongoing chronic inflammation associated with changes in the gut microbiome, which might contribute to the development of dementia. Using Danish medical and administrative registries from 1980 to 2013, we conducted a nationwide population-based cohort study including all DD patients and a matched (5:1) general population comparison cohort without DD. A nested case-control analysis was then conducted using a risk set sampling, matching four DD controls without dementia to each DD patient with dementia. Clinical severity was categorized as uncomplicated DD (outpatient), conservatively treated DD (inpatient), and surgically treated DD. 149 527 DD patients and 747 635 general population comparators were identified. The 30-year cumulative incidence of dementia among DD patients and general population comparators were 12.4 (95% confidence interval [CI] 12.1-12.7) and 13.73% (95% CI 13.6-13.9), respectively. This corresponded to a 30-year hazard ratio (HR) of 1.10 (95% CI 1.1-1.1). The highest HRs were found in the conservatively treated DD group (1.15 95% CI 1.1-1.2) and the group with young onset of DD (1.52 95% CI 1.2-2.0). In the nested case-control analysis, we identified 8875 dementia cases and 35 491 matched controls. The adjusted odds ratio (OR) for conservatively treated DD was increased (1.08, 95% CI; 1.0-1.2) compared to the reference of uncomplicated DD. We observed a slight increased risk of dementia in patients with young onset DD and conservatively treated DD. Findings suggest an association between disease duration, perhaps reflecting the duration of gut inflammation, and the risk of developing dementia.

Long-term risk of atrial fibrillation or flutter after transcatheter patent foramen ovale closure: a nationwide Danish study.

Transcatheter closure of patent foramen ovale (PFO) is the recommended stroke prevention treatment in patients ≤60 years with cryptogenic ischemic stroke and PFO. Atrial fibrillation or flutter (AF) is a known potential procedure-related complication, but long-term risk of developing AF remains unknown. This paper studied the long-term risk of developing AF following PFO closure. A Danish nationwide cohort study was conducted. During 2008-2020, this study identified a PFO closure cohort, a PFO diagnosis cohort without PFO closure, and a general population comparison cohort matched 10:1 to the PFO closure cohort on age and sex. The outcome was first-time AF diagnosis. Risk of AF and multivariable-adjusted hazard ratio (HR) of the association between PFO closure or PFO diagnosis and AF were calculated. A total of 817 patients with PFO closure, 1224 with PFO diagnosis, and 8170 matched individuals were identified. The 5 year risk of AF was 7.8% [95% confidence interval (CI): 5.5-10] in the PFO closure cohort, 3.1% (95% CI: 2.0-4.2) in the PFO diagnosis cohort, and 1.2% (95% CI: 0.8-1.6) in the matched cohort. The HR of AF comparing PFO closure with PFO diagnosis was 2.3 (95% CI: 1.3-4.0) within the first 3 months and 0.7 (95% CI: 0.3-1.7) thereafter. The HR of AF comparing PFO closure with the matched cohort was 51 (95% CI: 21-125) within the first 3 months and 2.5 (95% CI: 1.2-5.0) thereafter. Patent foramen ovale closure was not associated with any substantial increased long-term risk of developing AF beyond the well-known procedure-related short-term risk.

Long-term Risk of Epilepsy Following Invasive Group B Streptococcus Disease in Neonates in Denmark

The risk of epilepsy after neonatal invasive Group B Streptococcus (iGBS) disease, particularly iGBS sepsis, is poorly understood. To examine the association between neonatal iGBS (sepsis or meningitis) and long-term risk of epilepsy, stratified by sex, prematurity, and maternal socioeconomic position (SEP). This population-based cohort study was conducted in Denmark with an inclusion period from 1997 through 2017 and follow-up until the end of 2018. A general population comparison cohort was randomly sampled and matched up to 10:1 to the exposed cohort. Linkage between Danish national registers were applied for data collection. Participants were infants aged 0 to 89 days. The general population comparison cohort was matched by sex, the child's year and month of birth, and gestational age. SEP was defined by maternal income and education. Hospital-diagnosed iGBS (sepsis or meningitis) during the first 89 days after birth. Epilepsy was defined by International Statistical Classification of Diseases and Related Health Problems, Tenth Revision codes and/or prescription codes for antiepileptic drugs using Danish medical registry data. Cumulative risk (CR) of epilepsy was calculated by treating death as a competing event. Cox proportional hazards regression was used to estimate hazard ratios with 95% CIs. Effect modification by sex, prematurity, and maternal SEP was assessed on an additive scale. A total of 1432 children (792 [55.3%] boys; 1126 [78.6%] with gestational age ≥37 weeks) were identified with iGBS disease: 1264 with sepsis and 168 with meningitis. In the comparison cohort, there were 14 211 children (7869 [55.4%] boys; 11 260 [79.2%] with gestational age ≥37 weeks). The overall (0 to 22 years) CR of epilepsy was 3.6% (95% CI, 2.6%-5.0%) in children with iGBS disease and 2.3% (95% CI, 1.9%-2.7%) in the comparison cohort. The overall CR of epilepsy for iGBS meningitis was 15.1% (95% CI, 8.9%-22.8%) and 2.2% (95% CI, 1.4%-3.4%) for iGBS sepsis. The adjusted hazard ratio for epilepsy in children with iGBS disease was 2.04 (95% CI, 1.46-2.85). Being a boy, born premature, or born to a mother belonging to a low SEP group was associated with an increased risk of epilepsy in later childhood. In this population-based cohort study of 1432 neonates, iGBS disease was associated with a higher incidence of epilepsy in later childhood, notably after meningitis. Premature birth, sex, and low maternal SEP modified the association.

Incident Herpes Zoster and Risk of Dementia: A Population-Based Danish Cohort Study.

Herpes zoster (HZ) is caused by reactivation of the neurotrophic varicella-zoster virus (VZV). Zoster may contribute to development of dementia through neuroinflammation, cerebral vasculopathy, or direct neural damage, but epidemiologic evidence is limited. We used data from linked nationwide Danish registries to conduct a cohort study of the association between zoster and dementia during 1997-2017. As secondary aims, we examined whether associations were more pronounced for zoster involving cranial nerves (mainly ophthalmic zoster) or the CNS and Alzheimer disease as an outcome. We included people aged ≥40 years with zoster and a general population comparison cohort matched 5:1 by sex and birth year. We identified zoster and dementia in the registries using prescription records in the community and hospital diagnoses. We used Cox regression to compute confounder-adjusted hazard ratios (HRs) with 95% CIs for dementia associated with zoster during 0-1 year and 1-21 years of follow-up. We compared the cumulative incidence of dementia, inverse probability weighted for confounders. The study included 247,305 people with zoster and 1,235,890 matched general population comparators (median age 64 years; 61% female). The HR of all-cause dementia was 0.98 (95% CI 0.92-1.04) during the first year and 0.93 (95% CI 0.90-0.95) thereafter in people with zoster vs matched comparators. Dementia was diagnosed in 9.7% of patients with zoster and 10.3% of matched comparators by the end of follow-up. We observed no increased long-term risk of dementia in subgroup analyses, except possibly in people with CNS infection (HR 1.94; 95% CI 0.78-4.80). Analyses of Alzheimer disease as a separate outcome showed similar results. HZ is not associated with an increased risk of dementia, and contrary to expectation, we found a small decrease in the risk. The explanation for this finding is unclear, and systematic errors should be considered. Patients with CNS involvement had an almost 2-fold increased relative risk of dementia. The population attributable fraction of dementia due to this rare complication is estimated at 0.014%. Therefore, universal vaccination against VZV in the elderly is unlikely to reduce dementia risk.

Mortality Among Danish Patients with a Hospital Diagnosis of Overweight or Obesity Over a 40-Year Period.

PurposeData on long-term mortality among patients with hospital-diagnosed overweight/obesity are limited. Thus, we aim to examine 40-year mortality among patients with hospital-diagnosed overweight/obesity, including cause-specific deaths, secular time trends, and potential effect modification by age, comorbidity, and socioeconomic factors.Patients and MethodsFrom national registries, we identified all Danes with a first hospital-based overweight/obesity diagnosis (N=331,185), 1979–2018, and constructed an age- and gender-matched general population comparison cohort (N=1,655,925). We computed mortality rates (MRs) per 1000 person-years and adjusted mortality rate ratios (aMRRs) with 95% confidence intervals (CIs), using Cox regression with adjustment for comorbidities and educational level. We performed stratified analyses on age, comorbidities, and socioeconomic factors.ResultsThe overall aMRR was 1.70 (95% CI: 1.68–1.72) for patients with overweight/obesity, mainly due to diabetes and other endocrine diseases (aMRR=2.68 [95% CI: 2.57–2.81]), cardiovascular (aMRR=1.95 [95% CI: 1.91–1.98]), and respiratory diseases (aMRR=1.83 [95% CI: 1.77–1.89]). The 1–10-year aMRR decreased from 2.06 (95% CI: 2.01–2.11) in 1979–1989 to 1.29 (95% CI: 1.26–1.32) in 2000–2009. We found effect modification by age: age 18 to <30 years: aMRR=2.44 (95% CI: 2.24–2.66) vs age ≥70 years: 1.35 (95% CI: 1.33–1.37); comorbidities: baseline comorbidities: aMRR=1.13 (95% CI: 1.10–1.15) vs no comorbidities: aMRR=1.83 (95% CI: 1.80–1.85); and educational level: high educational level: aMRR=1.81 (95% CI: 1.74–1.88) vs low educational level: aMRR=1.70 (95% CI: 1.67–1.72).ConclusionPatients with overweight/obesity had a substantially increased long-term mortality, mainly due to diabetes, cardiovascular, and respiratory diseases. The excess mortality decreased during recent decades. Age, comorbidities, and socioeconomic factors modified the association.

Risk of Parkinson Disease and Secondary Parkinsonism in Myocardial Infarction Survivors.

BackgroundIn addition to primary neurodegenerative processes, vascular disorders, such as stroke, can lead to parkinsonism. However, some cardiovascular risk factors, such as smoking and elevated cholesterol levels, are associated with reduced risk of Parkinson disease. We examined the risk of Parkinson disease and secondary parkinsonism in 1‐year survivors of myocardial infarction (MI).Methods and ResultsWe conducted a nationwide population‐based matched cohort study using Danish medical registries from 1995 to 2016. We identified all patients with a first‐time MI diagnosis and sampled a sex‐, age‐, and calendar year–matched general population comparison cohort without MI. Cox regression analysis was used to compute adjusted hazard ratios (aHRs) for Parkinson disease and secondary parkinsonism, controlled for matching factors and adjusted for relevant comorbidities and socioeconomic factors. We identified 181 994 patients with MI and 909 970 matched comparison cohort members (median age, 71 years; 62% men). After 21 years of follow‐up, the cumulative incidence was 0.9% for Parkinson disease and 0.1% for secondary parkinsonism in the MI cohort. Compared with the general population cohort, MI was associated with a decreased risk of Parkinson disease (aHR, 0.80; 95% CI, 0.73–0.87) and secondary parkinsonism (aHR, 0.72; 95% CI, 0.54–0.94).ConclusionsMI was associated with a 20% decreased risk of Parkinson disease and 28% decreased risk of secondary parkinsonism. Reduced risk may reflect an inverse relationship between cardiovascular risk factors and Parkinson disease.

Swedish Covid-19 Investigation for Future Insights - A Population Epidemiology Approach Using Register Linkage (SCIFI-PEARL).

BackgroundIn response to the Covid-19 pandemic, we designed and initiated a nationwide linked multi-register, regularly updated, observational study for timely response to urgent scientific questions.AimTo describe the SCIFI-PEARL (Swedish Covid-19 Investigation for Future Insights – a Population Epidemiology Approach using Register Linkage) linked database encompassing essentially all known diagnosed Swedish Covid-19 patients plus a large general population comparison cohort and outline its utility in the current and future phases of the pandemic.MethodsIndividuals with Covid-19 from the entire country are identified on a regularly updated basis, from different sources: all individuals from SmiNet, the national database of notifiable diseases, with positive SARS-CoV-2 polymerase chain reaction (PCR) test results; patients identified in the healthcare system by condition (ICD-10) or procedure codes in the National Patient Register or Cause-of-Death Register; patients identified through several disease-specific national quality registers (NQRs); and in two regions additionally patients identified in primary care. A comparison population was obtained by stratified random sampling from Swedish national population registers. Data from all these registers plus the National Prescribed Drug Register, the Cancer Register, national sociodemographic registers, some additional NQRs, the National Vaccination Register, and further data sources, are then linked to all study subjects (Covid-19 cases and population cohort). New cases in the study population and all data for all subjects are updated every few months, as required.Conclusion and UtilityThe SCIFI-PEARL study cohort captures Swedish residents with Covid-19 on an ongoing basis, includes a representative general population comparison cohort, and links to a broad range of national and regional healthcare data for a comprehensive longitudinal view of the Covid-19 pandemic. By combining high-quality national registers with short time delay and continuous repeated linkage and updating, the project brings timely and internationally relevant data for epidemiological research on SARS-CoV-2. Our efforts provide an example and important learnings for similar efforts internationally in the future.

Ten-year cardiovascular risk in patients with stable angina pectoris but without coronary artery disease by coronary angiography

Abstract Background Patients with stable angina pectoris who do not have obstructive coronary artery disease (CAD) by coronary angiography are presumed to have a continued high cardiovascular risk despite no CAD. Purpose We examined the 10-year risk of myocardial infarction (MI), major adverse cardiovascular events (MACE), and death in elective patients with stable angina pectoris, but without CAD by coronary angiography compared to an age and sex matched general population cohort from Western Denmark. Methods We performed a cohort study of patients with stable angina pectoris without obstructive CAD by elective CAG examined between 2003 and 2016 in Western Denmark. Patients were compared to an age and sex matched general population comparison cohort without previous MI or coronary revascularization. Outcomes were MI, MACE (a composite of MI, ischemic stroke, and cardiac death), and death. Maximum follow-up was 10 years. Adjusted incidence rate ratios (IRRs) were computed using conditional Poisson regression. We also did a stratified analysis by sex and levels of comorbidity. Results A total of 18,491 patients suspected of angina pectoris without obstructive CAD, and 92,387 individuals from the general population were included in the study. Median follow-up was 8.6 years. Patients with chest pain but without CAD had reduced risk of MI (adjusted IRR 0.59, 95% CI 0.50–0.70, Figure), MACE (adjusted IRR 0.64, 95% CI 0.57–0.80), and death (adjusted IRR 0.62, 95% CI 0.59–0.67) compared to the general population when adjusting for potential confounders. Results were consistent when stratifying by sex and levels of comorbidity. Conclusions Absence of angiographic obstructive CAD in patients with symptoms of stable angina pectoris was associated with favorable low 10-year cardiovascular risk and mortality compared to the general population without known coronary status. Figure 1 Funding Acknowledgement Type of funding source: Public hospital(s). Main funding source(s): Department of Cardiology, Aarhus University Hospital

Associations between adjustment disorder and hospital-based infections in the Danish population

ObjectiveThere is some evidence that posttraumatic stress disorder (PTSD) is associated with increased risk of infections, and it is unknown whether adjustment disorder is as well. We assessed the association between adjustment disorder and subsequent infections, and assessed additive interaction with sex. MethodsThe study population included a nationwide cohort of all Danish-born residents of Denmark diagnosed with adjustment disorder between 1995 and 2011, and an age- and sex-matched general population comparison cohort. We compared rates of infections requiring inpatient or outpatient hospitalization in the two cohorts. We fit Cox proportional hazards models to compute adjusted hazard ratios (aHR) for the associations between adjustment disorder and 32 types of infections, and calculated interaction contrasts to assess interaction between adjustment disorder and sex. ResultsAdjustment disorder was associated with increased rates of infections overall (n = 19,838 infections, aHR = 1.8, 95% confidence interval = 1.8. 1.9), and increased rates of each individual infection type (aHRs for 30 infections ranged from 1.5 to 2.3), adjusting for baseline psychiatric and somatic comorbidities and marital status. For many infection types (e.g., skin infections, pneumonia), interaction contrasts indicated rate differences were greater among men than women, while for two (urinary tract infections and sexually transmitted infections), rate differences were greater for women. ConclusionsThese findings are consistent with studies examining the relationship between psychological stress and infections, and between PTSD and infections. They may be explained by a combination of the triggering of unhealthy behaviors as well as immune responses to stress.

Initiation of statins and risk of venous thromboembolism: Population-based matched cohort study

BackgroundThe effects of statins in prevention of venous thromboembolism (VTE) is not well established. ObjectivesTo examine the risks of first-time VTE in a cohort of patients initiating statin treatment and in a matched general population comparison cohort. MethodsWe conducted a nationwide, population-based, matched cohort study based on data from Danish health registries. The study period was 1 January 2005–31 December 2015. We identified statin initiators (without VTE, myocardial infarction, or ischemic stroke) and sex-, age-, and calendar year-matched (1,3) individuals from the general population (without statin use, VTE, myocardial infarction, or ischemic stroke). We computed cumulative risks and comorbidity-adjusted hazard ratios (HRs) of VTE, myocardial infarction, and ischemic stroke. ResultsAmong 601,011 statin initiators and 1,803,033 matched population cohort members during 2005–2015, the cumulative risk after 11 years was 2.8% for VTE (both cohorts), 4.7% vs. 2.9% for myocardial infarction, and 7.1% vs. 5.2 for ischemic stroke. After adjustment, statin use was associated with a slightly decreased risk of VTE (adjusted HR: 0.95 [95% CI: 0.92–0.97]), driven by a reduced risk of unprovoked VTE (adjusted HR: 0.92 [95% CI: 0.89–0.95]). The reduced risks of VTE were more pronounced among patients who had an imaging examination performed. The adjusted HRs were elevated for myocardial infarction and ischemic stroke. ConclusionStatin initiation was associated with a reduced risk of VTE, with no indication of a healthy-user effect. Based on available evidence, statins have weak thromboprophylactic effects.

Posttraumatic Stress Disorder and Incident Infections: A Nationwide Cohort Study.

It is unknown whether posttraumatic stress disorder (PTSD) is associated with incident infections. This study's objectives were to examine (1) the association between PTSD diagnosis and 28 types of infections and (2) the interaction between PTSD diagnosis and sex on the rate of infections. The study population consisted of a longitudinal nationwide cohort of all residents of Denmark who received a PTSD diagnosis between 1995 and 2011, and an age- and sex-matched general population comparison cohort. We fit Cox proportional hazards regression models to examine associations between PTSD diagnosis and infections. To account for multiple estimation, we adjusted the hazard ratios (HRs) using semi-Bayes shrinkage. We calculated interaction contrasts to assess the presence of interaction between PTSD diagnosis and sex. After semi-Bayes shrinkage, the HR for any type of infection was 1.8 (95% confidence interval: 1.6, 2.0), adjusting for marital status, non-psychiatric comorbidity, and diagnoses of substance abuse, substance dependence, and depression. The association between PTSD diagnosis and some infections (e.g., urinary tract infections) were stronger among women, whereas other associations were stronger among men (e.g., skin infections). This study's findings suggest that PTSD diagnosis is a risk factor for numerous infection types and that the associations between PTSD diagnosis and infections are modified by sex.

Risk of thromboembolic and bleeding outcomes following hematological cancers: A Danish population‐based cohort study

BackgroundTherapeutic advances have improved survival after hematological cancers. In turn, patients may be at increased risk of thromboembolic and bleeding events. ObjectivesTo examine the risks of myocardial infarction (MI), ischemic stroke, venous thromboembolism (VTE), and bleeding requiring hospital contact in patients with hematological cancers. MethodsWe conducted a Danish population‐based cohort study (2000‐2013). We identified all adult hematological cancer patients and sampled a general population comparison cohort in a 1:5 ratio matched by age, sex, previous thromboembolic events, bleeding, and solid cancer. Ten‐year absolute risks of thromboembolism and bleeding were calculated and hazard ratios (HRs) were computed, controlling for matching factors. ResultsAmong 32 141 hematological cancer patients, the 10‐year absolute risk of any thromboembolic or bleeding complication following hematological cancer was 19%: 3.3% for MI, 3.5% for ischemic stroke, 5.2% for VTE, and 8.5% for bleeding. Except among patients with myeloid leukemia, acute lymphoid leukemia, or myelodysplastic syndrome, the risk of thromboembolic events surpassed that of bleeding. The hematological cancer cohort overall was at increased risk for MI [HR = 1.36, 95% confidence interval (CI): 1.25‐1.49], ischemic stroke (HR = 1.22, 95% CI: 1.12‐1.33), VTE (HR = 3.37, 95% CI: 3.13‐3.64), and bleeding (HR = 2.39, 95% CI: 2.26‐2.53) compared with the general population. ConclusionsApproximately 2 of 10 hematological cancer patients experienced MI, ischemic stroke, VTE, or bleeding requiring hospital contact within 10 years. The hematological cancer cohort had higher hazards of MI, ischemic stroke, VTE, and bleeding requiring hospital contact than a general population comparison cohort.

Ischemic Stroke in Adults With Congenital Heart Disease: A Population-Based Cohort Study.

BackgroundCongenital heart disease (CHD) is associated with risk factors for ischemic stroke including cardiac arrhythmias and heart failure. However, few long‐term follow‐up data exist on ischemic stroke risk and associated mortality in adults with CHD.Methods and ResultsUsing Danish nationwide registries, we identified individuals aged ≥18 years diagnosed with CHD, at any age, from 1963 to 2017 and a sex and birth year‐matched (1:10) general population comparison cohort. We computed risks, as well as sex and birth year‐adjusted hazard ratios (aHRs) for ischemic stroke and 30‐day post‐stroke mortality in CHD adults compared with the general population. Analyses were stratified according to age <60 years (young) and ≥60 years (older). We identified 16 836 adults with CHD. The risk of ischemic stroke at age 60 years was 7.4% in the CHD cohort and 2.9% in the general population cohort. The adjusted hazard ratios for ischemic stroke compared with the general population was 3.8 (95% CI: 3.3–4.3) in young CHD adults and 1.6 (95% CI: 1.4–1.9) in older CHD adults. The adjusted hazard ratios for post‐stroke mortality compared with the general population was 2.3 (95% CI: 1.2–4.4) in young CHD adults and 1.3 (95% CI: 0.9–1.9) in older CHD adults.ConclusionsBoth younger and older CHD adults have an increased risk of ischemic stroke and by 60 years of age 7.4% of CHD adults will have had an ischemic stroke. Post‐stroke mortality was also increased in CHD adults compared with the general population.

Risk of amyotrophic lateral sclerosis and other motor neuron disease among men with benign prostatic hyperplasia: a population-based cohort study

ObjectivesAmyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disorder. Sleep disturbance may interfere with clearance of abnormal proteins that aggregate in neurodegenerative diseases. The objective of this study was...

The Role of Comorbidity in Mortality After Hip Fracture: A Nationwide Norwegian Study of 38,126 Women With Hip Fracture Matched to a General-Population Comparison Cohort

Hip fracture patients often have comorbid conditions. We investigated whether the combination of comorbidity and hip fracture could explain the previously observed excess mortality among hip fracture patients as compared with the general population. Using a population-based matched study design with 38,126 Norwegian women who suffered a hip fracture during the period 2009–2015 and the same number of women in a matched comparison cohort, we matched participants on prefracture comorbidity, age, and education. We estimated relative survival and additive and multiplicative comorbidity–hip fracture interactions. An additive comorbidity–hip fracture interaction of 4 or 9 additional deaths per 100 patients, depending on Charlson Comorbidity Index (CCI) score, was observed 1 year after hip fracture. Among women with a CCI score of ≥3, 15 additional deaths per 100 patients were observed; of these, 9 deaths could be attributed to the interaction and 6 to the hip fracture per se. On the relative scale, we observed increasing heterogeneity in survival by comorbidity over time; survival was reduced by 39% after 6 years among patients with a CCI score of ≥3, while among women with no comorbidity, survival was reduced by 17% (hip fracture vs. no hip fracture). In summary, prefracture comorbidity was associated with short-term absolute excess mortality and long-term relative excess mortality.

Increased risk of acute coronary syndrome in patients with bronchiectasis: A population-based cohort study.

There are few studies on the relationship between bronchiectasis and acute coronary syndrome (ACS). We conducted a population-based cohort study to assess whether bronchiectasis was associated with an increased risk of ACS. We identified 3521 patients diagnosed with bronchiectasis between 2000 and 2010 (bronchiectasis cohort) and frequency matched them with 14 084 randomly selected people without bronchiectasis from the general population (comparison cohort) according to sex, age and index year using the Longitudinal Health Insurance Database. Both cohorts were followed until the end of 2010 to determine the ACS incidence. Hazard ratios of ACS were measured. Based on 17 340 person-years for bronchiectasis patients and 73 639 person-years for individuals without bronchiectasis, the overall ACS risk was 40% higher in the bronchiectasis cohort (adjusted hazard ratio (HR) = 1.40; 95% CI: 1.20-1.62). Compared with those in the comparison cohort with one respiratory infection-related emergency room (ER) visit per year, the ACS risk was 5.46-fold greater in bronchiectasis patients with three or more ER visits per year (adjusted HR = 5.46, 95% CI: 4.29-6.96). Patients with bronchiectasis and three or more respiratory infection-related hospitalizations per year had an 8.15-fold higher ACS risk (adjusted HR = 8.15, 95% CI: 6.27-10.61). Bronchiectasis patients, particularly those experiencing frequent exacerbations with three or more ER visits and consequent hospitalization per year, are at an increased ACS risk.

Tonsillectomy and risk of Parkinson's disease: A danish nationwide population-based cohort study.

We hypothesized that tonsillectomy modifies the risk of PD. To test the hypothesis in a nationwide population-based cohort study. We used Danish medical registries to construct a cohort of all patients in Denmark with an operation code of tonsillectomy 1980-2010 (n = 195,169) and a matched age and sex general population comparison cohort (n = 975,845). Patients were followed until PD diagnosis, death, censoring, or end of follow-up 30 November 2013. Using Cox regression, we computed hazard ratios for PD and corresponding 95% confidence intervals, adjusting for age and sex by study design, and potential confounders. We identified 100 and 568 patients diagnosed with PD among the tonsillectomy and general population comparison cohort, respectively, finding similar risks of PD (adjusted hazard ratio = 0.95 [95% confidence interval: 0.76-1.19]; for > 20 years' follow-up (adjusted hazard ratio = 0.96 [95% confidence interval: 0.64-1.41]). Tonsillectomy is not associated with risk of PD, especially early-onset PD. © 2017 International Parkinson and Movement Disorder Society.

Potential paraneoplastic syndromes and selected autoimmune conditions in patients with non-small cell lung cancer and small cell lung cancer: A population-based cohort study.

BackgroundLittle is known about the occurrence and distribution of types of paraneoplastic syndromes (PNS) in patients with lung cancer. Identification of autoimmune PNS is particularly important for discerning them from immune-related adverse events of novel immunotherapies. We estimated the occurrence of PNS among patients with lung cancer and compared it with that in the general population.MethodsIn this registry-based cohort study in Denmark, we identified all patients with incident primary lung cancer between 1997 and 2010, and in a general-population comparison cohort matched on calendar time, sex, age, and residence. Among patients with non-small cell lung cancer (NSCLC) and small-cell lung cancer (SCLC), we estimated prevalence of potential PNS and selected autoimmune conditions and compared their incidence rates with those of equivalent conditions in the general population cohort, using hazard ratios (HRs) adjusted for baseline comorbidity.ResultsThere were 35,319 patients with NSCLC and 6,711 patients with SCLC. The incidence rates per 1000 person-years (95% confidence interval) of any potential PNS or selected autoimmune disorders were 135.4 (131.9–139.1) among NSCLC patients and 237.3 (224.4–250.5) among SCLC patients. Adjusted HRs for any potential PNS or selected autoimmune disorders were 4.8 (4.7–5.0) for NSCLC and 8.2 (7.6–8.8) for SCLC.ConclusionIncidence rate of any potential PNS or selected autoimmune disorders among patients with lung cancer was greater than that in the general population and was greater after SCLC than after NSCLC.ImpactThese results provide context to discerning PNS from adverse effects of novel immunotherapies during the clinical course of NSCLC and SCLC.

The impact of comorbidity on mortality in multiple myeloma: a Danish nationwide population-based study.

To describe the prevalence of comorbidity and its impact on survival in newly diagnosed multiple myeloma patients compared with population controls. Cases of newly diagnosed symptomatic multiple myeloma during the 2005–2012 period were identified in the Danish National Multiple Myeloma Registry. For each myeloma patient, 10 members of the general population matched by age and sex were chosen from the national Civil Registration System. Data on comorbidity in the myeloma patients and the general population comparison cohort were collected by linkage to the Danish National Patient Registry (DNPR). Cox proportional hazards regression models were used to evaluate the prognostic significance of comorbidity. The study included 2190 cases of multiple myeloma and 21,900 population controls. The comorbidity was increased in multiple myeloma patients compared with population controls, odds ratio (OR) 1.4 (1.1–1.7). The registration of comorbidity was highly increased within the year preceding diagnosis of multiple myeloma (OR 3.0 [2.5–3.5]), which was attributable to an increased registration of various diseases, in particular, renal disease with OR 11.0 (8.1–14.9). The median follow‐up time from diagnosis of multiple myeloma for patients alive was 4.3 years (interquartile range 2.4–6.3). Patients with registered comorbidity had increased mortality compared with patients without comorbidity, hazard ratio 1.6 (1.5–1.8). Multiple myeloma patients have increased comorbidity compared with the background population, in particular during the year preceding the diagnosis of myeloma.