Population-based Matched Cohort Study Research Articles

Absence of Association between Previous Mycoplasma pneumoniae Infection and Subsequent Myasthenia Gravis: A Nationwide Population-Based Matched Cohort Study.

Mycoplasma pneumoniae (M. pneumoniae) is not only one of the most common pathogenic bacteria for respiratory infection but also a trigger for many autoimmune diseases. Its infection process shared many similarities with the pathogenesis of myasthenia gravis (MG) at cellular and cytokine levels. Recent case reports demonstrated patients present with MG after M. pneumoniae infection. However, no epidemiological studies ever looked into the association between the two. Our study aimed to investigate the relationship between M. pneumoniae infection and subsequent development of MG. In this population-based retrospective cohort study, the risk of MG was analyzed in patients who were newly diagnosed with M. pneumoniae infection between 2000 and 2013. A total of 2428 M. pneumoniae patients were included and matched with the non-M. pneumoniae control cohort at a 1:4 ratio by age, sex, and index date. Cox proportional hazards regression analysis was applied to analyze the risk of MG development after adjusting for sex, age, and comorbidities, with hazard ratios and 95% confidence intervals. The incidence rates of MG in the non-M. pneumoniae and M. pneumoniae cohorts were 0.96 and 1.97 per 10,000 person-years, respectively. Another case–control study of patients with MG (n = 515) was conducted to analyze the impact of M. pneumoniae on MG occurrence as a sensitivity analysis. The analysis yielded consistent absence of a link between M. pneumoniae and MG. Although previous studies have reported that M. pneumoniae infection and MG may share associated immunologic pathways, we found no statistical significance between M. pneumoniae infection and subsequent development of MG in this study.

Variability in end-of-life healthcare use in patients with osteoarthritis: a population-based matched cohort study

To investigate the patterns of healthcare use (HCU) at the last year of life in persons with osteoarthritis (OA). Using linked registers, we identified persons aged≥ 65 years who died during 2003-2014 and were resided in the Skåne region during 5-year prior to death. Among these, we randomly matched decedents with a principal OA diagnosis prior to the last year of life (OA cohort, n=17,993) with up to 4 comparators without OA by sex, age at death, and year of death (n=59,945). We measured monthly HCU for each decedent during last year of life and applied two-part regression models to estimate HCU attributable to OA. Group-based trajectory modelling (GBTM) was used to detect distinct trajectories of HCU within the OA cohort. During last 12-month of life, each person with OA had, on average, 2.5 (95% CI 2.2, 2.7) excess healthcare consultations and 1.8 (95% CI 1.3, 2.2) more inpatient days than those without OA. While both cohorts observed increasing trends in HCU towards death, excess healthcare consultations attributable to OA declined and inpatient days increased as death approached. For both healthcare consultations and inpatient days, GBTM identified four distinct trajectory classes. While underlying cause of death and age were the most important predictors of class membership, the overall predictive accuracy was poor. OA was associated with excess HCU especially hospital-based care during the last year of life. However, there seem to be distinct trajectory classes within the OA patient population.

Irritable bowel syndrome and subsequent risk of Parkinson's disease: a nationwide population-based matched-cohort study.

Gastrointestinal dysfunction (GI) is the most prevalent non-motor symptom of Parkinson's disease (PD), and its role in the risk of PD has been studied. In this study, we tried to evaluate whether irritable bowel syndrome (IBS) increased the risk of PD development stratified by sex, age, and IBS duration using a large nationwide cohort in Korea. Patients aged ≥ 20years with a primary diagnosis of IBS (ICD-10 codes: G56) more than three times were selected. A randomly matched cohort without IBS was enrolled by exact matching patients for sex, age, socioeconomic status, comorbidities, and year of enrollment to the IBS group with a ratio of 1:3. Cause-specific Cox regression models were used to identify hazards associated with PD development depending on the presence of IBS during the 11-year follow-up period. In total, 285,064 patients were enrolled in the study: 71,806 in the IBS cohort and 213,258 in the comparison cohort. Cause-specific Cox regression model showed a hazard ratio of 1.436 (95% CI, 1.226-1.682) for PD development in the IBS cohort, which is consistent in both male and female sexes. Subgroup analyses according to age groups showed that IBS increased PD risk only in individuals ≥ 65years (HR = 1.449, 95% CI, 1.207-1.741). We found temporal relationship between IBS and PD at aged ≥ 65years. There might be a possibility that IBS was an early manifestation of PD, and future studies for causal link between the two diseases to elucidate biomechanism are warranted.

Increased risk of shoulder calcific tendinopathy in diabetes mellitus: A nationwide, population-based, matched cohort study.

Calcific tendinopathy of the rotator cuff is a common cause of painful disability in the shoulder with unclear aetiology. Diabetes mellitus (DM) is associated with calcific tendinopathy; however, large epidemiological data are lacking. Thus, we conducted a nationwide population-based matched cohort study to investigate the risk for calcific tendinopathy of the shoulder in diabetic patients. The National Health Insurance Research Database of Taiwan was used to include 42915 patients newly diagnosed with DM between 1 January 2000 and 31 December 2015 and randomly extract the data of 171660 individuals, as a matched control group. All individuals were followed-up until the development of calcific tendinopathy or the end of 2015. Overall, 122 patients from the DM group (0.284%) developed calcific tendinopathy compared with 340 individuals from the non-DM group (0.198%). The Kaplan-Meier analysis indicated that patients with DM had a higher risk of calcific tendinopathy since the eighth year of follow-up (log-rank test, P=.006). Cox proportional hazard regression revealed that the adjusted hazard ratio of calcific tendinopathy in diabetic patients to that in non-diabetic patients was 1.276 (95% confidence interval 1.037-1.571, P=.002). Moreover, the stratified analysis disclosed that DM was a strong independent risk factor for calcific tendinopathy irrespective of the existing comorbidities. This study demonstrated that patients with DM had a 27% increased risk of developing calcific tendinopathy of the shoulder, 8years after initially being diagnosed with DM.

Characteristics and Outcomes of Women Developing Heart Failure After Early Stage Breast Cancer Chemotherapy: A Population-Based Matched Cohort Study.

The prognosis of heart failure (HF) after early stage breast cancer (EBC) treatment with anthracyclines or trastuzumab is not well-characterized. Using administrative databases, women diagnosed with HF after receiving anthracyclines or trastuzumab for EBC in Ontario during 2007 to 2017 (the EBC-HF cohort) were categorized by cardiotoxic exposure (anthracycline alone, trastuzumab alone, sequential therapy with both agents) and matched on age with ≤3 cancer-free HF controls to compare baseline characteristics. To study prognosis after HF onset, we conducted a second match on age plus important HF prognostic factors. The cumulative incidence function was used to describe risk of hospitalization or emergency department visits (hospital presentations) for HF and cardiovascular death. A total of 804 women with EBC developed HF after anthracyclines (n=312), trastuzumab (n=112), or sequential therapy (n=380); they had significantly fewer comorbidities than 2411 age-matched HF controls. After the second match, the anthracycline-HF cohort had a similar 5-year incidence of HF hospital presentations (16.5% [95% CI, 12.0%-21.7%]) as controls (17.1% [95% CI, 14.4%-20.1%]); the 5-year incidence was lower than matched controls for the trastuzumab-HF (9.7% [95% CI, 4.7%-16.9%]; controls 16.4% [95% CI, 12.1%-21.3%]; P=0.03) and sequential-HF cohorts (2.7% [95% CI, 1.4%-4.8%]; controls 10.8% [95% CI, 8.9%-13.0%]; P<0.001). At 5 years, the incidence of cardiovascular death was 2.9% (95% CI, 1.2%-5.9%) in the anthracycline-HF cohort vs. 9.5% (95% CI, 6.9%-12.6%) in controls, and 1.7% (0.6%-3.7%) for women developing HF after trastuzumab vs. 4.3% (95% CI, 3.1-5.8%) for controls. Women developing HF after cardiotoxic EBC chemotherapy have fewer comorbidities than cancer-free women with HF; trastuzumab-treated women who develop HF have better prognosis than matched HF controls.

Inflammatory Bowel Disease Increases the Risk of Venous Thromboembolism in Children: A Population-Based Matched Cohort Study.

Background and AimsAlthough venous thromboembolism [VTE] is a well-known complication of inflammatory bowel disease [IBD] in adults, limited data exist on the risk in children. We report the incidence of VTE among children with and without IBD.MethodsWe conducted a matched cohort study within a distributed network of population-based Canadian provincial health administrative databases. Children <16 years diagnosed with IBD were identified using validated algorithms from administrative data in Alberta, Manitoba, Nova Scotia, Ontario and Québec and compared to age- and sex-matched children without IBD. Hospitalizations for VTE within 5 years of IBD diagnosis were identified. Generalized linear mixed-effects models were used to pool province-specific incidence rates and incidence rate ratios [IRR] with 95% confidence intervals [CI]. Hazard ratios [HR] from Cox proportional hazards models were pooled with fixed-effects meta-analysis.ResultsThe 5-year incidence of VTE among 3593 children with IBD was 31.2 [95% CI 23.7–41.0] per 10 000 person-years [PY] compared to 0.8 [95% CI 0.4–1.7] per 10 000 PY among 16 289 children without IBD [unadjusted IRR 38.84, 95% CI 16.59–90.83; adjusted HR 22.91, 95% CI 11.50–45.63]. VTE was less common in Crohn’s disease than ulcerative colitis [unadjusted IRR 0.47, 95% CI 0.27–0.83; adjusted HR 0.52, 95% CI 0.29–0.94]. The findings were similar for deep vein thrombosis and pulmonary embolism when comparing children with and without IBD.ConclusionsThe risk of VTE is much higher in children with IBD than controls without IBD. While the absolute risk is low, we found a higher incidence rate than previously described in the pediatric literature.Conference Presentation: An abstract based on the data included in this paper was presented at Canadian Digestive Diseases Week [Montréal, Canada] in March 2020.

Divergent Roles of Induction Chemotherapy in Patients with Unresectable Locally Advanced Head and Neck Squamous Cell Carcinoma: A Population-Based Matched Cohort Study

Background: Induction chemotherapy (IC) has a proven role in organ preservation and reducing distant failure. However, its ability to prolong survival remains controversy. Herein, we conducted a nationwide population‐based matched cohort study to investigate the association of primary tumor location with the role of IC in patients with locally advanced head and neck squamous cell carcinoma (LA-HNSCC) Methods: In this population based study, we retrospectively identified patients who aged 18 years and older with newly diagnosed LA-HNSCC between 2007 and 2016 from Taiwan National Health Insurance Research Database and Taiwan Cancer Registry. Patients were categorized into two group : IC group and definitive CCRT group. The primary tumor locations were classified into four part : oral cavity, oropharynx, hypopharynx and larynx. In order to reduce the selection bias, IC patients were individually matched at a ratio of 1 : 1 with the CCRT patients. The oncologic outcomes were presented with overall survival (OS). Findings: A total of 5547 patients were identified. After 1:1 matching, 1564 patients were analyzed for outcomes comparison, including 782 patients in each group. In general, median OS were 27.3 months versus 28.5 months in IC and CCRT group, respectively (p=0.6151). Patients were thereafter stratified by primary tumor location. For patients with oral cavity and laryngeal cancers, the median OS was significantly inferior in IC group than those in CCRT group, while for patients with oropharyngeal and hypopharyngeal cancer, the median OS was superior in IC group than those in CCRT group. Interpretation: IC has a divergent role in patients with different primary tumor location. Primary tumor location should be taken into consideration when facing the dilemma of IC followed by CCRT or definitive CCRT. Further prospective trials are warranted to confirm our results. Funding: This work was supported by the Room for Database Research of E-DA HEALTHCARE GROUP (grant no. EDCD2001) Declaration of Interest: The authors have nothing to declare Ethical Approval: This study was approved by the Institutional Review Board of the E-Da Cancer Hospital in Taiwan (EMRP-108-061), and the requirements for informed consent were waived.

Risk of Reinfection After Seroconversion to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2): A Population-based Propensity-score Matched Cohort Study.

BackgroundSerological assays detecting anti-SARS-CoV-2 antibodies are being widely deployed in studies and clinical practice. However, the duration and effectiveness of the protection conferred by the immune response remains to be assessed in population-based samples. To estimate the incidence of newly acquired SARS-CoV-2 infections in seropositive individuals as compared to seronegative controls we conducted a retrospective longitudinal matched study.MethodsA seroprevalence survey including a representative sample of the population was conducted in Geneva, Switzerland between April and June 2020, immediately after the first pandemic wave. Seropositive participants were matched one-to-two to seronegative controls, using a propensity-score including age, gender, immunodeficiency, BMI, smoking status and education level. Each individual was linked to a state-registry of SARS-CoV-2 infections. Our primary outcome was confirmed infections occurring from serological status assessment to the end of the second pandemic wave (January 2021).ResultsAmong 8344 serosurvey participants, 498 seropositive individuals were selected and matched with 996 seronegative controls. After a mean follow-up of 35.6 (SD 3.2) weeks, 7 out of 498 (1.4%) seropositive subjects had a positive SARS-CoV-2 test, of whom 5 (1.0%) were classified as reinfections. In contrast, the infection rate was higher in seronegative individuals (15.5%, 154/996) during a similar follow-up period (mean 34.7 [SD 3.2] weeks), corresponding to a 94% (95%CI 86% to 98%, P<0.001) reduction in the hazard of having a positive SARS-CoV-2 test for seropositives.ConclusionsSeroconversion after SARS-CoV-2 infection confers protection against reinfection lasting at least 8 months. These findings could help global health authorities establishing priority for vaccine allocation.

Myocardial infarction in diffuse large B-cell lymphoma patients - a population-based matched cohort study.

The outcome for diffuse large B-cell lymphoma (DLBCL) patients has improved with the immunochemotherapy combination R-CHOP. An increased rate of heart failure is well documented following this treatment, whereas incidence and outcome of other cardiac complications, for example myocardial infarction, are less well known. We identified 3548 curatively treated DLBCL patients in Sweden diagnosed between 2007 and 2014, and 35474 matched lymphoma-free general population comparators. The incidence, characteristics and outcome of acute myocardial infarctions (AMIs) were assessed using population-based registers up to 11years after diagnosis. The rate of AMI was estimated using flexible parametric models. Overall, a 33% excess rate of AMI was observed among DLBCL patients compared with the general population (HR: 1.33, 95% CI: 1.14-1.55). The excess rate was highest during the first year after diagnosis and diminished after 2years. High age, male sex and comorbidity were the strongest risk factors for AMI. Older patients (>70years) with mild comorbidities (i.e. hypertension or diabetes) had a 61% higher AMI rate than comparators (HR: 1.61, 95% CI: 1.10-2.35), whereas the corresponding excess rate was 28% for patients with severe comorbidities (HR: 1.28, 95% CI: 1.01-1.64). Among younger patients (≤70), a short-term excess rate of AMI was limited to those with severe comorbidities. There was no difference in AMI characteristics, pharmacological treatment or 30-day survival among patients and comparators. DLBCL patients have an increased risk of AMI, especially during the first 2years, which calls for improved cardiac monitoring guided by age and comorbidities. Importantly, DLBCL was not associated with differential AMI management or survival.

Unemployment Insurance and Mortality Among the Long-Term Unemployed: A Population-Based Matched-Cohort Study.

Unemployment insurance is hypothesized to play an important role in mitigating the adverse health consequences of job loss. In this prospective cohort study, we examined whether receiving unemployment benefits is associated with lower mortality among the long-term unemployed. Census records from the 2006 Canadian Census Health and Environment Cohort (n=2,105,595) were linked to mortality data from 2006-2016. Flexible parametric survival analysis and propensity score matching were used to model time-varying relationships between long-term unemployment (≥20 weeks), unemployment-benefit recipiency, and all-cause mortality. Mortality was consistently lower among unemployed individuals who reported receiving unemployment benefits, relative to matched nonrecipients. For example, mortality at 2 years of follow-up was 18% lower (95% confidence interval (CI): 9, 26) among men receiving benefits and 30% lower (95% CI: 18, 40) among women receiving benefits. After 10 years of follow-up, unemployment-benefit recipiency was associated with 890 (95% CI: 560, 1,230) fewer deaths per 100,000 men and 1,070 (95% CI: 810, 1,320) fewer deaths per 100,000 women. Our findings indicate that receiving unemployment benefits is associated with lower mortality among the long-term unemployed. Expanding access to unemployment insurance may improve population health and reduce health inequalities associated with job loss.

Intentional injury and violent death after intimate partner violence. A retrospective matched-cohort study

The incidence of intimate partner violence (IPV) varies according to IPV definitions and data collection approaches. The criminal Justice system assesses IPV through a review of the evidence gathered by the police and the court hearings. We aimed to determine the association between IPV, as identified in criminal Justice disposition records, and subsequent healthcare-identified intentional injury inflicted by others, including violent death. We conducted a retrospective population-based matched-cohort study using linked multisectoral databases. Female adult Manitoba residents identified as victims of IPV in provincial prosecution and disposition records 2004 to 2016 (n = 20,469) were matched to three non-victims (n = 61,407) of similar age, relationship status and place of residence at the date of the IPV incident. Outcomes were first healthcare use for intentional injury and violent death, assessed in Emergency Department visits, hospitalizations and Vital Statistics deaths records. Conditional Cox Regression was used to obtain Hazard Ratios (HR) with 95% confidence intervals (CI). The risk of intentional injury was 8.5 per 1000 women among non-victims of IPV and 55.8 per 1000 women among IPV victims. The Hazard Ratios associated with IPV were 3.8 (95% CI: 3.4, 4.3) for intentional injury and 4.6 (95% CI: 2.3, 9.2) for violent death, after adjustment. IPV victims experienced half the risk of subsequent intentional injury if the accused received a probation sentence. Our findings suggest that Justice involvement represents an opportunity for intersectoral collaborative prevention of subsequent intentional injury among IPV victims.

Association Between Bariatric Surgery and Major Adverse Diabetes Outcomes in Patients With Diabetes and Obesity

There are high-quality randomized clinical trial data demonstrating the effect of bariatric surgery on type 2 diabetes remission, but these studies are not powered to study mortality in this patient group. Large observational studies are warranted to study the association of bariatric surgery with mortality in patients with type 2 diabetes. To determine the association between bariatric surgery and all-cause mortality among patients with type 2 diabetes and severe obesity. This retrospective, population-based matched cohort study included patients with type 2 diabetes and body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) 35 or greater who underwent bariatric surgery from January 2010 to December 2016 in Ontario, Canada. Multiple linked administrative databases were used to define confounders, including age, baseline BMI, sex, comorbidities, duration of diabetes diagnosis, health care utilization, socioeconomic status, smoking status, substance abuse, cancer screening, and psychiatric history. Potential controls were identified from a primary care electronic medical record database. Data were analyzed in 2020. Bariatric surgery (gastric bypass and sleeve gastrectomy) and nonsurgical management of obesity provided by the primary care physician. The primary outcome was all-cause mortality. Secondary outcomes were cause-specific mortality and nonfatal morbidities. Groups were compared through a multivariable Cox proportional Hazards model. A total of 6910 patients (mean [SD] age at baseline, 52.04 [9.45] years; 4950 [71.6%] women) were included, with 3455 patients who underwent bariatric surgery and 3455 match controls and a median (interquartile range) follow-up time of 4.6 (3.22-6.35) years. In the surgery group, 83 patients (2.4%) died, compared with 178 individuals (5.2%) in the control group (hazard ratio [HR] 0.53 [95% CI, 0.41-0.69]; P < .001). Bariatric surgery was associated with a 68% lower cardiovascular mortality (HR, 0.32 [95% CI, 0.15-0.66]; P = .002) and a 34% lower rate of composite cardiac events (HR, 0.68 [95% CI, 0.55-0.85]; P < .001). Risk of nonfatal renal events was also 42% lower in the surgical group compared with the control group (HR, 0.58 [95% CI, 0.35-0.95], P = .03). Of the groups that had the highest absolute benefit associated with bariatric surgery, men had an absolute risk reduction (ARR) of 3.7% (95% CI, 1.7%-5.7%), individuals with more than 15 years of diabetes had an ARR of 4.3% (95% CI, 0.8%-7.8%), and individuals aged 55 years or older had an ARR of 4.7% (95% CI, 3.0%-6.4%). These findings suggest that bariatric surgery was associated with reduced all-cause mortality and diabetes-specific cardiac and renal outcomes in patients with type 2 diabetes and severe obesity.

Appendectomy and Non-Typhoidal Salmonella Infection: A Population-Based Matched Cohort Study.

The potential association between appendectomy and non-typhoidal Salmonella (NTS) infection has not been elucidated. We hypothesized that appendectomy may be associated with gut vulnerability to NTS. The data were retrospectively collected from the Taiwan National Health Insurance Research Database to describe the incidence rates of NTS infection requiring hospital admission among patients with and without an appendectomy. A total of 208,585 individuals aged ≥18 years with an appendectomy were enrolled from January 2000 to December 2012, and compared with a control group of 208,585 individuals who had never received an appendectomy matched by propensity score (1:1) by index year, age, sex, occupation, and comorbidities. An appendectomy was defined by the International Classification of Diseases, Ninth Revision, Clinical Modification Procedure Codes. The main outcome was patients who were hospitalized for NTS. Cox proportional hazards models were applied to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs). Two sensitivity analyses were conducted for cross-validation. Of the 417,170 participants (215,221 (51.6%) male), 208,585 individuals (50.0%) had an appendectomy, and 112 individuals developed NTS infection requiring hospitalization. In the fully adjusted multivariable Cox proportional hazards regression model, the appendectomy group had an increased risk of NTS infection (adjusted HR (aHR), 1.61; 95% CI, 1.20–2.17). Females and individuals aged 18 to 30 years with a history of appendectomy had a statistically higher risk of NTS than the control group (aHR, 1.92; 95% CI, 1.26–2.93 and aHR, 2.67; 95% CI, 1.41–5.07). In this study, appendectomy was positively associated with subsequent hospitalization for NTS. The mechanism behind this association remains uncertain and needs further studies to clarify the interactions between appendectomy and NTS.

Uptake of influenza vaccination among persons with inflammatory bowel disease, multiple sclerosis or rheumatoid arthritis: a population-based matched cohort study

Background:Individuals with immune-mediated inflammatory diseases, such as inflammatory bowel disease, multiple sclerosis and rheumatoid arthritis, are at increased risk for influenza and related complications. We examined and compared the uptake of influenza vaccination among people with and without these diseases, as well as the influence of psychiatric comorbidity on vaccine uptake.Methods:Using administrative data from Apr. 1, 1984, to Mar. 31, 2016, we conducted a retrospective matched cohort study in Manitoba, Canada. We matched persons 18 years of age or older who had a diagnosis of inflammatory bowel disease, multiple sclerosis or rheumatoid arthritis (the immune-mediated inflammatory disease cohorts) with persons who did not have these diagnoses (the control cohorts) on age, sex and region. We then identified cohort members with any mood or anxiety disorder (depression, anxiety disorders, bipolar disorder). We identified influenza vaccinations through billing codes. Using binomial regression, we modelled the difference in the proportion of the immune-mediated inflammatory disease and matched cohorts vaccinated annually, with adjustment for sociodemographic characteristics, comorbidity and immune therapy. We tested additive interaction effects between a person’s cohort and presence of a mood or anxiety disorder.Results:We identified 32 880 individuals with 1 or more immune-mediated inflammatory diseases (10 148 with inflammatory bowel disease, 6158 with multiple sclerosis and 16 975 with rheumatoid arthritis) and a total of 164 152 controls. In fiscal year 2015, 8668 (41.3%, 95% confidence interval [CI] 40.6% to 42.0%) of the 20 982 persons with an immune-mediated inflammatory disease received an influenza vaccination, a rate higher than among controls (35 238 of 104 634; 33.7%, 95% CI 33.4% to 34.0%). After adjustment, participants with an immune-mediated inflammatory disease but no mood or anxiety disorder had 6.44% (95% CI 5.79% to 7.10%) greater uptake of vaccination than participants without such a disease. Among participants without an immune-mediated inflammatory disease, having a mood or anxiety disorder was associated with 4.54% (95% CI 4.20% to 4.89%) greater uptake of vaccination. However, we observed a subadditive interaction between immune-mediated inflammatory disease and psychiatric status (−1.38%, 95% CI −2.26% to −0.50%).Interpretation:Uptake of influenza vaccination was consistently low in populations with immune-mediated inflammatory disease, and although psychiatric morbidity is associated with greater vaccine uptake by Manitobans, it negatively interacts with these diseases to reduce uptake. Changes in care delivery are needed to mitigate this gap in care.

PO-19 Initiation of low-dose aspirin and risk of colorectal neoplasms: a population-based matched cohort study in Denmark

PO-19 Initiation of low-dose aspirin and risk of colorectal neoplasms: a population-based matched cohort study in Denmark

Association of Nutritional Support With Clinical Outcomes in Malnourished Cancer Patients: A Population-Based Matched Cohort Study.

Malnutrition is prevalent in hospitalized cancer patients and has been associated with poor therapy response and unfavorable clinical outcome. While recent studies have shown a survival benefit through nutritional support in a hospitalized malnourished medical population including cancer patients, we aimed to investigate the association of nutritional support with in-hospital mortality and other clinical outcomes in a nationwide inpatient cancer population. In this population-based cohort study, using a large Swiss administrative claims database from April 2013 to December 2018, we created two cohorts of malnourished cancer patients on medical wards. We generated two pairwise cohorts of malnourished patients who received nutritional support by 1:1 propensity-score matching to patients not receiving nutritional support. The primary outcome was all-cause in-hospital mortality. Secondary outcomes were 30-days all-cause hospital readmission and discharge to a post-acute care facility. To account for disease activity, we stratified patients either admitted for cancer as main diagnosis or admitted with cancer as comorbidity. Among 1,851,498 hospitalizations on medical ward, we identified a total of 32,038 malnourished cancer patients. After matching, 11,906 (37%) cases were included in the “cancer main diagnosis cohort” and 5,954 (18.6%) in the “cancer comorbidity cohort.” Patients prescribed a nutritional support showed a lower in-hospital mortality in both cohorts as compared to their respective matched controls not receiving nutritional support [cancer main diagnosis cohort: 15.4 vs. 19.4 %, OR 0.76 (95% CI 0.69–0.83); cancer comorbidity cohort: 7.4 vs. 10.2%, OR 0.71 (95% CI 0.59–0.85)]. While we found no difference in 30-days readmission rates, discharge to a post-acute care facility was less frequent in the nutritional support group of both cohorts. In this large cohort study, nutritional support in hospitalized patients with either cancer as main diagnosis or comorbidity was associated with a lower risk of in-hospital mortality and discharge to a post-acute care facility.

Effect of back problems on healthcare utilization and costs in Ontario, Canada: a population-based matched cohort study.

We assessed the effect of back problems on healthcare utilization and costs in a population-based sample of adults from a single-payer health system in Ontario. We conducted a population-based cohort study of Ontario respondents aged ≥18 years of the Canadian Community Health Survey (CCHS) from 2003 to 2012. The CCHS data were individually linked to health administrative data to measure healthcare utilization and costs up to 2018. We propensity score-matched (hard matched on sex) adults with self-reported back problems to those without back problems, accounting for sociodemographic, health-related, and behavioural factors. We evaluated cause-specific and all-cause healthcare utilization and costs adjusted to 2018 Canadian dollars using negative binomial and linear (log transformed) regression models. After propensity score matching, we identified 36,806 pairs (women: 21,054 pairs; men: 15,752 pairs) of CCHS respondents with and without back problems (mean age 51 years, standard deviation = 18). Compared with propensity score matched adults without back problems, adults with back problems had 2 times the rate of cause-specific visits (rate ratio [RR]women 2.06, 95% confidence interval [CI] 1.88-2.25; RRmen 2.32, 95% CI 2.04-2.64), slightly more all-cause physician visits (RRwomen 1.12, 95% CI 1.09-1.16; RRmen 1.10, 95% CI 1.05-1.14), and 1.2 times the costs (women: 1.21, 95% CI 1.16-1.27; men: 1.16, 95% CI 1.09-1.23). Incremental annual per-person costs were higher in adults with back problems than those without back problems (women: $395, 95% CI $281-$509; men: $196, 95% CI $94-$300). This corresponded to $532 million for women and $227 million for men (adjusted to 2018 Canadian dollars) annually in Ontario given the high prevalence of back problems. Given the high health system burden, new strategies to effectively prevent and treat back problems and thus potentially reduce the long-term costs are warranted.

Incidence of Psoriasis in Patients with Inflammatory Bowel Disease: A Nationwide Population-Based Matched Cohort Study

Background: Emerging data suggest that inflammatory bowel disease (IBD) and psoriasis are associated, sharing common genetic predispositions and immunological mechanisms. However, concrete data on psoriasis risk in IBD patients compared to the general population are limited. Objective: We investigated the risk of developing psoriasis in IBD patients compared to controls without IBD. Methods: Using the Korean National Health Insurance Database, patients diagnosed with Crohn’s disease (CD) or ulcerative colitis (UC) between 2005 and 2008 were age- and sex-matched 1:4 to non-IBD subjects from 2003 to 2018. IBD patients were defined by combining the International Classification of Diseases 10th revision code and at least one prescription of IBD-specific medications. Disease phenotypes, including psoriasis severity and psoriatic arthritis, were also identified. We investigated newly diagnosed psoriasis from 2009 to 2018. Incidence rates and risk of psoriasis were assessed with multivariate Cox regression models. Subgroup analyses for age and sex, and sensitivity analysis involving tumor necrosis factor (TNF) inhibitor-naïve patients were performed. Results: During nearly a decade of follow-up, 20,152 IBD patients were identified (14,619 [72.54%] UC and 5,533 [27.46%] CD). Among them, 439 patients were newly diagnosed with psoriasis (incidence rate of 217.68 per 100,000 person-years and 228.62 per 100,000 person-years for UC and CD, respectively). The psoriasis risk was higher in IBD patients than in the matched controls (adjusted hazard ratio, aHR, 2.95, 95% confidence interval, CI, 2.60–3.33). Moreover, IBD patients aged <30 years were at an increased risk (aHR 3.35, 95% CI 2.58–4.35), a trend that was unchanged across all psoriasis phenotypes. Sensitivity analysis of TNF inhibitor-naïve patients revealed consistent results. Conclusions: IBD patients were more likely to develop psoriasis compared to non-IBD subjects, including younger patients at an elevated risk regardless of TNF inhibitor use. This advocates the interplay between IBD and psoriasis; thus, inspection of cutaneous manifestation and dermatological consultation may be helpful in IBD patients at risk.

Dementia identified as a risk factor for infection-related hospital contacts in a national, population-based and longitudinal matched-cohort study

The aim of this study was to investigate the association between incident dementia and rates of infection-related hospital contacts. We conducted a registry- and population-based matched-cohort study of all Danish residents who were born in or before 1950, included from 1 January 2000 or their 65th birthday (whichever came later), who were alive and resided in Denmark at the start of the study, excluding those who had received a dementia diagnosis before 1 January 2000 or their 65th birthday (n = 1,712,100). A total of 129,660 people (403,744 person years) with incident dementia were matched with 297,476 people (1,918,784 person years) without dementia. Incidence rate ratios (IRRs) of infection-related hospital contacts were calculated using Poisson regression, by infection type, sex and age. The IRR for any infection-related contact in dementia was 1.5, was highest for nervous and urinary system infections and sepsis, decreased with increasing age and was higher in men. More people with than without dementia had contacts five years before the index date. Our findings show that dementia is a risk factor for infection-related hospital contacts and infections might be an early sign of dementia.

Atopic eczema in adulthood and mortality: UK population–based cohort study, 1998-2016

BackgroundAtopic eczema affects up to 10% of adults and is becoming more common globally. Few studies have assessed whether atopic eczema increases the risk of death.ObjectiveWe aimed to determine whether adults with atopic eczema were at increased risk of death overall and by specific causes and to assess whether the risk varied by atopic eczema severity and activity.MethodsThe study was a population-based matched cohort study using UK primary care electronic health care records from the Clinical Practice Research Datalink with linked hospitalization data from Hospital Episode Statistics and mortality data from the Office for National Statistics from 1998 to 2016.ResultsA total of 526,736 patients with atopic eczema were matched to 2,567,872 individuals without atopic eczema. The median age at entry was 41.8 years, and the median follow-up time was 4.5 years. There was limited evidence of increased hazard for all-cause mortality in those with atopic eczema (hazard ratio = 1.04; 99% CI = 1.03-1.06), but there were somewhat stronger associations (8%-14% increased hazard) for deaths due to infectious, digestive, and genitourinary causes. Differences on the absolute scale were modest owing to low overall mortality rates. Mortality risk increased markedly with eczema severity and activity. For example, patients with severe atopic eczema had a 62% increased hazard (hazard ratio = 1.62; 99% CI = 1.54-1.71) for mortality compared with those without eczema, with the strongest associations for infectious, respiratory, and genitourinary causes.ConclusionThe increased hazards for all-cause and cause-specific mortality were largely restricted to those with the most severe or predominantly active atopic eczema. Understanding the reasons for these increased hazards for mortality is an urgent priority.