Low-frequency and rare genetic variants associated with rheumatoid arthritis risk

Rheumatoid arthritis (RA) has an estimated heritability of nearly 50%, which is particularly high in seropositive RA. HLA alleles account for a large proportion of this heritability, in addition to many common single-nucleotide polymorphisms with smaller individual effects. Low-frequency and rare variants, such as those captured by next-generation sequencing, can also have a large role in heritability in some individuals. Rare variant discovery has informed the development of drugs such as inhibitors of PCSK9 and Janus kinases. Some 34 low-frequency and rare variants are currently associated with RA risk. One variant (19:10352442G>C in TYK2) was identified in five separate studies, and might therefore represent a promising therapeutic target. Following a set of best practices in future studies, including studying diverse populations, using large sample sizes, validating RA and serostatus, replicating findings, adjusting for other variants and performing functional assessment, could help to ensure the relevance of identified variants. Exciting opportunities are now on the horizon for genetics in RA, including larger datasets and consortia, whole-genome sequencing and direct applications of findings in the management, and especially treatment, of RA.

Comorbidity clusters in patients with rheumatoid arthritis identify a patient phenotype with a favourable prognosis

OBJECTIVES

We aimed to cluster patients with rheumatoid arthritis (RA) based on comorbidities and then examine the association between these clusters and RA disease activity and mortality.

METHODS

In this population-based study, residents of an eight-county region with prevalent RA on 1 January 2015 were identified. Patients were followed for vital status until death, last contact or 31 December 2021. Diagnostic codes for 5 years before the prevalence date were used to define 55 comorbidities. Latent class analysis was used to cluster patients based on comorbidity patterns. Standardised mortality ratios were used to assess mortality.

RESULTS

A total of 1643 patients with prevalent RA (72% female; 94% white; median age 64 years, median RA duration 7 years) were studied. Four clusters were identified. Cluster 1 (n=686) included patients with few comorbidities, and cluster 4 (n=134) included older patients with 10 or more comorbidities. Cluster 2 (n=200) included patients with five or more comorbidities and high prevalences of depression and obesity, while cluster 3 (n=623) included the remainder. RA disease activity and survival differed across the clusters, with cluster 1 demonstrating more remission and mortality comparable to the general population.

CONCLUSIONS

More than 40% of patients with prevalent RA did not experience worse mortality than their peers without RA. The cluster with the worst prognosis (<10% of patients with prevalent RA) was older, had more comorbidities and had less disease-modifying antirheumatic drug and biological use compared with the other clusters. Comorbidity patterns may hold the key to moving beyond a one-size-fits-all perspective of RA prognosis.

Association between sinusitis and incident rheumatic diseases: a population-based study

OBJECTIVES

To determine whether antecedent sinusitis is associated with incident rheumatic disease.

METHODS

This population-based case-control study included all individuals meeting classification criteria for rheumatic diseases between 1995 and 2014. We matched three controls to each case on age, sex and length of prior electronic health record history. The primary exposure was presence of sinusitis, ascertained by diagnosis codes (positive predictive value 96%). We fit logistic regression models to estimate ORs for incident rheumatic diseases and disease groups, adjusted for confounders.

RESULTS

We identified 1729 incident rheumatic disease cases and 5187 matched controls (mean age 63, 67% women, median 14 years electronic health record history). After adjustment, preceding sinusitis was associated with increased risk of several rheumatic diseases, including antiphospholipid syndrome (OR 7.0, 95% CI 1.8 to 27), Sjögren's disease (OR 2.4, 95% CI 1.1 to 5.3), vasculitis (OR 1.4, 95% CI 1.1 to 1.9) and polymyalgia rheumatica (OR 1.4, 95% CI 1.0 to 2.0). Acute sinusitis was also associated with increased risk of seronegative rheumatoid arthritis (OR 1.8, 95% CI 1.1 to 3.1). Sinusitis was most associated with any rheumatic disease in the 5-10 years before disease onset (OR 1.7, 95% CI 1.3 to 2.3). Individuals with seven or more codes for sinusitis had the highest risk for rheumatic disease (OR 1.7, 95% CI 1.3 to 2.4). In addition, the association between sinusitis and incident rheumatic diseases showed the highest point estimates for never smokers (OR 1.7, 95% CI 1.3 to 2.2).

CONCLUSIONS

Preceding sinusitis is associated with increased incidence of rheumatic diseases, suggesting a possible role for sinus inflammation in their pathogenesis.

Gene-respiratory disease interactions for rheumatoid arthritis risk

OBJECTIVE

We aimed to identify gene by respiratory tract disease interactions that increase RA risk.

METHODS

In this case-control study using the Mass General Brigham Biobank, we matched incident RA cases, confirmed by ACR/EULAR criteria, to four controls on age, sex, and electronic health record history. Genetic exposures included a validated overall genetic risk score (GRS) for RA, a Human Leukocyte Antigen (HLA) GRS for RA, and the MUC5B promoter variant, an established risk factor for RA-associated interstitial lung disease (ILD). Preceding respiratory tract diseases came from diagnosis codes (positive predictive value 86%). We estimated attributable proportions (AP) and multiplicative odds ratios (OR) with 95% confidence intervals (CI) for RA for each genetic and respiratory exposure using conditional logistic regression models, adjusting for potential confounders.

RESULTS

We identified 653 incident RA cases and 2,607 matched controls (mean 54 years, 76% female). The highest tertile of the overall GRS and the HLA GRS were both associated with increased RA risk (OR 2.28, 95% CI 1.89,2.74; OR 2.02, 95% CI 1.67-2.45). ILD and the HLA GRS exhibited a synergistic relationship for RA risk (OR for both exposures 4.30, 95% CI 1.28,14.38; AP 0.51, 95% CI-0.16,1.18). Asthma and the MUC5B promoter variant also exhibited a synergistic interaction for seropositive RA (OR for both exposures 2.58, 95% CI 1.10,6.07; AP 0.62, 95% CI 0.24,1.00).

CONCLUSION

ILD-HLA GRS and asthma-MUC5B promoter variant showed synergistic interactions for RA risk. Such interactions may prove useful for RA prevention and screening.

Gut Microbiome Wellness Index 2 for Enhanced Health Status Prediction from Gut Microbiome Taxonomic Profiles

Recent advancements in human gut microbiome research have revealed its crucial role in shaping innovative predictive healthcare applications. We introduce Gut Microbiome Wellness Index 2 (GMWI2), an advanced iteration of our original GMWI prototype, designed as a robust, disease-agnostic health status indicator based on gut microbiome taxonomic profiles. Our analysis involved pooling existing 8069 stool shotgun metagenome data across a global demographic landscape to effectively capture biological signals linking gut taxonomies to health. GMWI2 achieves a cross-validation balanced accuracy of 80% in distinguishing healthy (no disease) from non-healthy (diseased) individuals and surpasses 90% accuracy for samples with higher confidence (i.e., outside the "reject option"). The enhanced classification accuracy of GMWI2 outperforms both the original GMWI model and traditional species-level α-diversity indices, suggesting a more reliable tool for differentiating between healthy and non-healthy phenotypes using gut microbiome data. Furthermore, by reevaluating and reinterpreting previously published data, GMWI2 provides fresh insights into the established understanding of how diet, antibiotic exposure, and fecal microbiota transplantation influence gut health. Looking ahead, GMWI2 represents a timely pivotal tool for evaluating health based on an individual's unique gut microbial composition, paving the way for the early screening of adverse gut health shifts. GMWI2 is offered as an open-source command-line tool, ensuring it is both accessible to and adaptable for researchers interested in the translational applications of human gut microbiome science.

Disparities in multimorbidity and comorbidities in rheumatoid arthritis by sex acrossthe lifespan

OBJECTIVES

Multimorbidity is burdensome for people with rheumatoid arthritis (RA). We investigated differences in multimorbidity and comorbidities by sex and age in the RA population.

METHODS

This cross-sectional analysis used national administrative claims (OptumLabs® Data Warehouse) from people with RA and non-RA comparators (matched on age, sex, race, census region, index year, and length of baseline insurance coverage) from 2010-2019. RA was determined using a validated algorithm. Multimorbidity was defined as ≥ 2 (MM2+) or ≥ 5 (MM5+) comorbidities from a validated set of 44 chronic conditions. We used logistic regression to assess associations between characteristics and multimorbidity.

RESULTS

The sample included 154,391 RA patients and 154,391 non-RA comparators. For people aged 18-50 years, RA women (vs RA men) had 7.5 and 4.4 (vs 3.2 and 0.9 in non-RA women vs non-RA men) percentage point increases for MM2+ and MM5+, respectively. For people aged 51+ years, RA women (vs RA men) had 2.1 and 2.5 (vs 1.2 and 0.3 in non-RA women vs non-RA men) percentage point increases for MM2+ and MM5+, respectively. Interactions revealed that differences in multimorbidity between women and men were exacerbated by RA (vs non-RA) (p < 0.05), with more pronounced effects in people aged 18-50. Men had more cardiovascular-related conditions, whereas RA women had more psychological, neurological, and general musculoskeletal conditions. Other comorbidities varied by sex and age.

CONCLUSION

Multimorbidity disproportionately impacts women with RA. Research, clinical, and policy agendas for rheumatic diseases should acknowledge and support the variation in care needs by sex and gender across the lifespan.

Time Trends in Glucocorticoid Use in Rheumatoid Arthritis During the Biologics Era: 1999-2018

OBJECTIVES

To examine time trends in glucocorticoid (GC) use among patients diagnosed with rheumatoid arthritis (RA) during the biologic era.

METHODS

A population-based inception cohort of RA patients diagnosed during 1999 - 2018 was followed longitudinally through their medical records until death, migration or 12/31/2020. All patients fulfilled 1987 American College of Rheumatology classification criteria for RA. GC start and stop dates were collected along with dosages in prednisone equivalents. The cumulative incidence of GC initiation and discontinuation adjusted for the competing risk of death was estimated. Cox models adjusted for age and sex were used to compare trends between time periods.

RESULTS

The study population included 399 patients (71% female) diagnosed in 1999 - 2008 and 430 patients (67% female) diagnosed in 2009 - 2018. GC use was initiated within 6 months of meeting RA criteria in 67% of patients in 1999-2008 and 71% of patients in 2009-2018, corresponding to a 29% increase in hazard for initiation of GC in 2009-2018 (adjusted hazard ratio [HR]: 1.29; 95% confidence interval [CI]: 1.09-1.53). Among GC users, similar rates of GC discontinuation within 6 months after GC initiation were observed in patients with RA incidence in 1999 - 2008 and 2009 - 2018 (39.1% versus 42.9%, respectively), with no significant association in adjusted Cox models (HR: 1.11; 95% CI: 0.93-1.31).

CONCLUSION

More patients are initiating GCs early in their disease course now compared to previously. The rates of GC discontinuation were similar, despite the availability of biologics.

Using Unsupervised Machine Learning Methods to Cluster Comorbidities in a Population-Based Cohort of Patients With Rheumatoid Arthritis

OBJECTIVE

To identify clusters of comorbidities in patients with rheumatoid arthritis (RA) using 4 methods and to compare to patients without RA.

METHODS

In this retrospective, population-based study, residents of 8 Minnesota counties with prevalent RA as of January 1, 2015 were identified. Age-, sex-, and county-matched non-RA comparators were selected from the same underlying population. Diagnostic codes were retrieved for 5 years before January 1, 2015. Using 2 codes ≥30 days apart, 44 previously defined morbidities and 11 nonoverlapping chronic disease categories based on Clinical Classifications Software were defined. Unsupervised machine learning methods of interest included hierarchical clustering, factor analysis, K-means clustering, and network analysis.

RESULTS

Two groups of 1,643 patients with and without RA (72% female; mean age 63.1 years in both groups) were studied. Clustering of comorbidities revealed strong associations among mental/behavioral comorbidities and among cardiovascular risk factors and diseases. The clusters were associated with age and sex. Differences between the 4 clustering methods were driven by comorbidities that are rare and those that were weakly associated with other comorbidities. Common comorbidities tended to group together consistently across approaches. The instability of clusters when using different random seeds or bootstrap sampling impugns the usefulness and reliability of these methods. Clusters of common comorbidities between RA and non-RA cohorts were similar.

CONCLUSION

Despite the higher comorbidity burden in patients with RA compared to the general population, clustering comorbidities did not identify substantial differences in comorbidity patterns between the RA and non-RA cohorts. The instability of clustering methods suggests caution when interpreting clustering using 1 method.

Incidence, Prevalence, and Mortality of Dermatomyositis: A Population-Based Cohort Study

OBJECTIVE

We aimed to determine the population-based incidence, prevalence, and mortality of dermatomyositis (DM) using European Alliance of Associations for Rheumatology (EULAR)/American College of Rheumatology (ACR) criteria.

METHODS

This population-based cohort study included incident DM from January 1, 1995 to December 31, 2019. We manually reviewed all individuals with at least 1 code for DM or polymyositis to determine if they met EULAR/ACR criteria, subspecialty physician diagnosis, and/or Bohan and Peter criteria. We age- and sex-adjusted incidence and prevalence estimates to the US non-Hispanic White year 2000 population and estimated prevalence on January 1, 2015. Standardized mortality ratios (SMRs) with 95% confidence intervals (95% CIs) compared observed to expected mortality adjusting for age, sex, and year.

RESULTS

We identified 40 cases of verified DM, with 29 cases incident in Olmsted County from 1995 to 2019. The mean age was 57 years, 26 (90%) were female, and 12 (41%) had clinically amyopathic DM (CADM). The median follow-up time was 8.2 years. The overall adjusted incidence of DM was 1.1 (95% CI 0.7-1.5) per 100,000 person-years, and prevalence was 13 (95% CI 6-19) per 100,000. The SMR was significantly elevated among the myopathic DM cases (3.1 [95% CI 1.1-6.8]) but not CADM cases (1.1 [95% CI 0.2-3.3]). The positive predictive value of ≥2 DM codes was only 40 of 82 (49%).

CONCLUSION

This population-based study found that DM incidence and prevalence were higher than previously reported. Mortality was significantly elevated for myopathic DM but not for CADM.

Autoantibodies against citrullinated and native proteins and prediction of rheumatoid arthritis-associated interstitial lung disease: A nested case-control study

Background

To identify fine specificity anti-citrullinated protein antibodies (ACPA) associated with incident rheumatoid arthritis-associated interstitial lung disease (RA-ILD).

Methods

This nested case-control study within the Brigham RA Sequential Study matched incident RA-ILD cases to RA-noILD controls on time of blood collection, age, sex, RA duration, and rheumatoid factor status. A multiplex assay measured ACPA and anti-native protein antibodies from stored serum prior to RA-ILD onset. Logistic regression models calculated odds ratios (OR) with 95% confidence intervals (CI) for RA-ILD, adjusting for prospectively-collected covariates. We estimated optimism-corrected area under the curves (AUC) using internal validation. Model coefficients generated a risk score for RA-ILD.

Findings

We analyzed 84 incident RA-ILD cases (mean age 67 years, 77% female, 90% White) and 233 RA-noILD controls (mean age 66 years, 80% female, 94% White). We identified six fine specificity antibodies that were associated with RA-ILD. The antibody isotypes and targeted proteins were: IgA2 to citrullinated histone 4 (OR 0.08 per log-transformed unit, 95% CI 0.03-0.22), IgA2 to citrullinated histone 2A (OR 4.03, 95% CI 2.03-8.00), IgG to cyclic citrullinated filaggrin (OR 3.47, 95% CI 1.71-7.01), IgA2 to native cyclic histone 2A (OR 5.52, 95% CI 2.38-12.78), IgA2 to native histone 2A (OR 4.60, 95% CI 2.18-9.74), and IgG to native cyclic filaggrin (OR 2.53, 95% CI 1.47-4.34). These six antibodies predicted RA-ILD risk better than all clinical factors combined (optimism-corrected AUC=0·84 versus 0·73). We developed a risk score for RA-ILD combining these antibodies with the clinical factors (smoking, disease activity, glucocorticoid use, obesity). At 50% predicted RA-ILD probability, the risk scores both without (score=2·6) and with (score=5·9) biomarkers achieved specificity ≥93% for RA-ILD.

Interpretation

Specific ACPA and anti-native protein antibodies improve RA-ILD prediction. These findings implicate synovial protein antibodies in the pathogenesis of RA-ILD and suggest clinical utility in predicting RA-ILD once validated in external studies.

Funding

National Institutes of Health.

Risk Factors for Dementia in Patients With Incident Rheumatoid Arthritis: A Population-Based Cohort Study

OBJECTIVE

Growing evidence suggests that patients with rheumatoid arthritis (RA) have increased risk for dementia. We assessed risk factors for incident dementia in an inception cohort of patients with RA.

METHODS

This retrospective population-based cohort study included residents of 8 counties in Minnesota who were ≥ 50 years of age when they met 1987 American College of Rheumatology criteria for incident RA between 1980 and 2014 and were followed until death/migration or December 31, 2019. Patients with dementia before RA incidence were excluded. Incident dementia was defined as 2 relevant International Classification of Diseases, 9th or 10th revision codes at least 30 days apart. Data on sociodemographics, disease characteristics, cardiovascular/cerebrovascular disease (CVD) risk factors, and comorbidities were abstracted from medical records.

RESULTS

The study included 886 patients with RA (mean age 65.1 yrs, 65.2% female). During the follow-up period (median 8.5 yrs), 103 patients developed dementia. After adjusting for age, sex, and calendar year of RA incidence, older age at RA incidence (HR 1.14 per 1 year increase, 95% CI 1.12-1.17), rheumatoid nodules (HR 1.76, 95% CI 1.05-2.95), hypertension (HR 1.84, 95% CI 1.19-2.85), presence of large joint swelling (HR 2.03, 95% CI 1.14-3.60), any CVD (HR 2.25, 95% CI 1.38-3.66), particularly ischemic stroke (HR 3.16, 95% CI 1.84-5.43) and heart failure (HR 1.82, 95% CI 1.10-3.00), anxiety (HR 1.86, 95% CI 1.16-2.97), and depression (HR 2.63, 95% CI 1.76-3.93) were associated with increased risk of dementia. After adjusting for CVD risk factors and any CVD, all covariates listed above were still significantly associated with risk of dementia.

CONCLUSION

Apart from age, hypertension, depression, and anxiety, all of which are universally recognized risk factors for dementia, clinically active RA and presence of CVD were associated with an elevated risk of dementia incidence among patients with RA.

Racial Differences in Multimorbidity and Comorbidities in Rheumatoid Arthritis

OBJECTIVE

To identify differences in multimorbidity and individual comorbidities among individuals with rheumatoid arthritis (RA), separated by race and ethnicity.

METHODS

This case-control study within OptumLabs Data Warehouse from 2010 to 2019 matched RA cases (defined by 2 codes plus prescription of an RA drug) to non-RA controls 1:1 on age, sex, race and ethnicity, region, index date of RA, and insurance coverage duration. We defined multimorbidity as the presence of ≥2 or ≥5 validated comorbidities. Logistic regression models calculated adjusted odds of multimorbidity with 95% confidence intervals (95% CIs) within each race and ethnicity.

RESULTS

We identified 154,391 RA cases and 154,391 controls (mean age 59.6, 76% female). Black enrollees had the most multimorbidity ≥2/≥5 (73.1%, 34.3%); Asian enrollees had the least (52.4%, 17.3%). Adjusted odds of multimorbidity ≥2 and ≥5 in RA cases versus controls was 2.19 (95% CI 2.16-2.23) and 2.06 (95% CI 2.02-2.09), respectively. This increase was similar across race and ethnicity. However, we observed elevated occurrence of certain comorbidities by race and ethnicity versus controls (P < 0.001), including renal disease in White enrollees (4.7% versus 3.2%) and valvular heart disease in Black and White enrollees (3.2% and 2.8% versus 2.6% and 2.2%).

CONCLUSION

Multimorbidity is a problem for all RA patients. Targeted identification of certain comorbidities by race and ethnicity may be a helpful approach to mitigate multimorbidity.

Incidence, Risk Factors, and Mortality of Clinical and Subclinical Rheumatoid Arthritis-Associated Interstitial Lung Disease: A Population-Based Cohort

OBJECTIVE

To identify the incidence, risk factors, and outcomes of rheumatoid arthritis-associated interstitial lung disease (RA-ILD) and to assess time trends in the incidence and mortality in RA-ILD.

METHODS

We included adult residents of Olmsted County, Minnesota with incident RA between 1999 and 2014. Subjects were followed until death, emigration, or April 30, 2019. ILD was defined as the presence of a radiologist-defined pattern consistent with ILD on chest computed tomography (CT). When chest CT was absent, the combination of chest radiograph abnormalities compatible with ILD and restrictive pattern on pulmonary function testing was considered consistent with ILD. Potential risk factors included age, sex, smoking, obesity, seropositivity, extraarticular manifestations (EAMs), and medications. For survival analysis, we matched RA-ILD patients to RA-non-ILD comparators. The frequency and mortality from clinician-diagnosed RA-ILD from 1999 to 2014 was compared against a cohort from 1955 to 1994.

RESULTS

During the 1999-2014 time period, 645 individuals (70% women) had incident RA, were a median age of 55.3 years, and 53% never smoked. Twenty-two patients had ILD before RA, and 51 (67% women) developed ILD during follow-up. The 20-year cumulative incidence of RA-ILD was 15.3%. Ever-smoking (hazard ratio [HR] 1.92), age at RA onset (HR 1.89 per 10-year increase), and severe EAMs (HR 2.29) were associated with incident RA-ILD. The RA-ILD cases had higher mortality than their matched RA comparators (HR 2.42). Incidence of RA-ILD was non-significantly lower from 1999 to 2014 than from 1955 to1994, but mortality was improved.

CONCLUSIONS

RA-ILD occurs in nearly 1 in 6 patients with RA within 20 years and is associated with shorter survival. Lack of significant change in RA-ILD incidence over 6 decades deserves further investigation.

Association between work physical activity, dietary factors, and risk of rheumatoid arthritis

OBJECTIVE

We aimed to determine the association of physical activity and dietary factors on RA risk.

METHODS

This case-control study within the Mayo Clinic Biobank matched incident RA cases (two codes plus disease-modifying anti-rheumatic drug, PPV 95%) to controls 1:3 on age, sex, and recruitment year/location. A baseline questionnaire assessed activity and dietary exposures. Logistic regression models calculated adjusted odds ratios (aOR) with 95% confidence intervals (CI) of RA for each of 45 activity/dietary exposures.

RESULTS

We identified 212 incident RA cases and 636 controls (mean age 64, 70% female). Active work physical activity was associated with elevated risk of RA (aOR 3.00, 95% CI 1.58-5.69 vs. sedentary); leisure activity was not (aOR 0.96, 95% CI 0.64-1.42 sedentary vs. active). Three or more servings high-fat food and 5+ servings fruits/vegetables daily showed non-significant associations with RA (aOR 1.22, 95% CI 0.74-2.00 vs. 0-1 time; aOR 0.75, 95% CI 0.51-1.11 vs. 0-3 times), especially in sensitivity analyses with at least five years between questionnaire and RA (aOR 1.80, 95% CI 0.69-4.71; aOR 0.54, 95% CI 0.27-1.08). Alcohol binging was not associated with RA risk (aOR 1.28, 95% CI 0.56-2.96). Finally, sensitivity (versus primary) analyses showed a nonsignificant increase in RA risk for most vitamins and supplements.

CONCLUSION

Active work physical activity and some nutritional profiles (increased high-fat, reduced fruit/vegetable consumption) may be associated with increased risk of RA. Confirmatory studies are needed.

Associations of the MUC5B promoter variant with timing of interstitial lung disease and rheumatoid arthritis onset

OBJECTIVES

To investigate the associations of the common MUC5B promoter variant with timing of RA-associated interstitial lung disease (RA-ILD) and RA onset.

METHODS

We identified patients with RA meeting 2010 ACR/EULAR criteria and available genotype information in the Mass General Brigham Biobank, a multihospital biospecimen and clinical data collection research study. We determined RA-ILD presence by reviewing all RA patients who had CT imaging, lung biopsy or autopsy results. We determined the dates of RA and RA-ILD diagnoses by manual records review. We examined the associations of the MUC5B promoter variant (G>T at rs35705950) with RA-ILD, RA-ILD occurring before or within 2 years of RA diagnosis and RA diagnosis at age >55 years. We used multivariable logistic regression to estimate odds ratios (ORs) for each outcome by MUC5B promoter variant status, adjusting for potential confounders including genetic ancestry and smoking.

RESULTS

We identified 1005 RA patients with available genotype data for rs35705950 (mean age 45 years, 79% female, 81% European ancestry). The MUC5B promoter variant was present in 155 (15.4%) and was associated with RA-ILD [multivariable OR 3.34 (95% CI 1.97, 5.60)], RA-ILD before or within 2 years of RA diagnosis [OR 4.01 (95% CI 1.78, 8.80)] and RA onset after age 55 years [OR 1.52 (95% CI 1.08, 2.12)].

CONCLUSIONS

The common MUC5B promoter variant was associated with RA-ILD onset earlier in the RA disease course and older age of RA onset. These findings suggest that the MUC5B promoter variant may impact RA-ILD risk early in the RA disease course, particularly in patients with older-onset RA.

Demographic, Lifestyle, and Serologic Risk Factors for Rheumatoid Arthritis (RA)-associated Bronchiectasis: Role of RA-related Autoantibodies

OBJECTIVE

To investigate demographic, lifestyle, and serologic risk factors for isolated rheumatoid arthritis (RA)-associated bronchiectasis (RA-BR) that is not a result of interstitial lung disease (ILD).

METHODS

We performed a case-control study using patients with RA from the Mass General Brigham Biobank. We reviewed the records of all patients with RA meeting the 2010 American College of Rheumatology/European Alliance of Associations for Rheumatology criteria with computed tomography (CT) chest imaging to identify RA-BR cases and controls with RA and RA-related lung disease. For each patient, the CT chest imaging that was performed closest to enrollment was independently reviewed by 2 radiologists for the presence of RA-related lung diseases. Cases had clinical and radiologic evidence of RA-BR without interstitial lung abnormalities on imaging. Controls had RA and no evidence of bronchiectasis or ILD. We examined the associations between demographic, lifestyle, and serologic factors with RA-BR using multivariable logistic regression.

RESULTS

We identified 57 cases of isolated RA-BR and 360 RA controls without RA-related lung disease. In multivariable models, RA-BR was associated with older age at RA onset (OR 1.37 per 10 years, 95% CI 1.02-1.82), lower BMI at RA diagnosis (OR 0.94 per kg/m2, 95% CI 0.89-0.99), seropositive RA (OR 3.96, 95% CI 1.84-8.53), positive rheumatoid factor (OR 4.40, 95% CI 2.14-9.07), and positive anticyclic citrullinated peptide (OR 3.47, 95% CI 1.65-7.31). Higher titers of RA-related autoantibodies were associated with higher odds of RA-BR.

CONCLUSION

Seropositivity, older age at RA diagnosis, and lower BMI at RA onset were associated with isolated bronchiectasis in RA that was not a result of ILD. These findings expand the list of potential risk factors for RA-BR and suggest a pathogenic link between airway inflammation and RA-related autoantibodies.

Allergic conditions and risk of rheumatoid arthritis: a Swedish case-control study

Objective

To determine the association of allergic conditions with incident rheumatoid arthritis (RA), especially in relation to smoking history and anti-citrullinated peptide antibody (ACPA) status.

Methods

This case–control study included 3515 incident RA cases and 5429 matched controls from the Epidemiological Investigation of Rheumatoid Arthritis study 1995 to 2016, including questionnaire-based information on eight allergic conditions composed from a list of 59 unique allergies. We used logistic regression and adjusted ORs (aOR) to assess the association between allergic conditions and risk of RA, adjusting for age, sex, residential area, body mass index, education, and smoking, and stratified by smoking and ACPA.

Results

A history of any reported allergy was equally common in RA (n=1047, 30%) as among population controls (n=1540, 29%), aOR 1.04, 95% CI 0.95 to 1.15. Metal, respiratory, food, plant/pollen and chemical allergies were not associated with risk of RA. By contrast, statistically significant associations were observed for animal dander allergy (6% vs 5%, aOR 1.37, 95% CI 1.03 to 1.82), especially in ACPA-positive RA (aOR 1.46 95% CI 1.06 to 2.01) and for atopic dermatitis, in particular for older and ACPA-negative RA (aOR 2.33, 95% CI 1.37 to 3.96 at age 80). Never smokers with allergic rhinitis also had increased risk of developing RA (aOR 1.30, 95% CI 1.00 to 1.68).

Conclusion

Most common allergies do not increase risk of RA, nor do they protect against RA. However, some allergic conditions, notably animal dander allergy, atopic dermatitis and allergic rhinitis, were associated with an increased risk for RA.

Timing of sinusitis and other respiratory tract diseases and risk of rheumatoid arthritis

OBJECTIVE

To investigate the association between timing of respiratory tract diseases and risk of rheumatoid arthritis (RA).

METHODS

This case-control study using the Mass General Brigham Biobank matched incident RA cases, confirmed by ACR/EULAR criteria, with at least seven years preceding electronic health record (EHR) data to three controls on age, sex, and EHR history from RA diagnosis (index date). We ascertained timing (>0-5 years/>5-10 years/>10 years) of the first documented respiratory tract disease prior to index date using diagnosis codes. We estimated odds ratios (OR) with 95% confidence intervals (CI) for RA for each respiratory exposure using logistic regression models, adjusting for potential confounders. We also conducted a stratified analysis by serostatus and smoking.

RESULTS

We identified 625 incident RA cases (median 56 years, 75% female, 57% seropositive) and 1,875 controls. Acute sinusitis was associated with RA only in the >5 to 10 years before RA (OR 3.90, 95% CI:1.90,8.01). In contrast, pneumonia was associated with RA only in the >0 to 5 years before RA (OR 1.73, 95% CI:1.00,3.00), and chronic respiratory tract diseases only >10 years before RA (OR 1.43, 95% CI:1.00,2.05). All respiratory tract diseases tended to show a stronger association with seronegative RA than seropositive RA, although the interaction was statistically significant only for chronic sinusitis (p=0.04). Respiratory diseases showed a nonsignificantly stronger association among smokers than nonsmokers.

CONCLUSION

Sinusitis and other respiratory diseases are associated with increased risk of RA, especially 5 years before RA onset. RA may begin many years before clinical onset.

Comprehensive assessment of multimorbidity burden in a population-based cohort of patients with rheumatoid arthritis

Objective

To comprehensively assess multimorbidity burden in patients with rheumatoid arthritis (RA) in order to unify the multimorbidity definition for RA research and clinical practice.

Methods

In this population-based study, residents of eight Minnesota counties with prevalent RA on 1 January 2015 were identified. Age, sex and county-matched non-RA comparators were selected from the same population. Diagnostic codes were retrieved for 5 years before 1 January 2015. Using two codes ≥30 days apart, 44 previously defined morbidities and 78 non-overlapping chronic disease categories based on Clinical Classification Software were defined. Prevalence of each morbidity in the RA versus non-RA cohorts was compared using false discovery rate to adjust for multiple comparisons. Morbidities more common in RA than non-RA and those with prevalence ≥5% were retained.

Results

1643 patients with RA and 1643 non-RA subjects (72% women; mean age 63.1 years) were studied. Using the 44 morbidities, multimorbidity (defined as 2+ morbidities) was present in 1411 (86%) of RA and 1164 (71%) of non-RA subjects (p<0.001) with 5+ morbidities present in 907 (55%) of RA and 619 (38%) of non-RA (p<0.001). Patients with RA had significantly higher prevalence of 24 of the 44 morbidities compared with non-RA, especially interstitial lung disease, fibromyalgia, osteoarthritis and osteoporosis. Among the additional 78 categories, 7 were significantly higher in RA than non-RA, including organic sleep disorders, vitamin D deficiency and foot ulcers.

Conclusion

Patients with RA have a higher prevalence of multimorbidity compared with non-RA subjects. These results confirm the list of 44 morbidities and add several other morbidities of interest in RA.

Association of sinusitis and upper respiratory tract diseases with incident rheumatoid arthritis: A case-control study

OBJECTIVE

We aimed to determine whether specific respiratory tract diseases are associated with increased rheumatoid arthritis (RA) risk.

METHODS

This case-control study within the Mass General Brigham Biobank matched newly diagnosed RA cases to three controls on age, sex, and electronic health record history. We identified RA using a validated algorithm and confirmed by medical record review. Respiratory tract disease exposure required one inpatient or two outpatient codes at least two years before index date of RA clinical diagnosis or matched date. Logistic regression models calculated odds ratios (OR) for RA with 95% confidence intervals (CI), adjusting for confounders. We then stratified by serostatus ("seropositive" was positive rheumatoid factor and/or anti-citrullinated protein antibodies) and smoking.

RESULTS

We identified 741 RA cases and 2,223 controls (both median age 55, 76% female). Acute sinusitis (OR 1.61, 95% CI:1.05,2.45), chronic sinusitis (OR 2.16, 95% CI:1.39,3.35), and asthma (OR 1.39, 95% CI:1.03,1.87) were associated with increased risk of RA. Acute respiratory tract disease burden during the pre-index exposure period was also associated with increased RA risk (OR 1.30 per 10 codes, 95% CI:1.08,1.55). Acute pharyngitis was associated with seronegative (OR 1.68, 95% CI:1.02,2.74) but not seropositive RA; chronic rhinitis/pharyngitis was associated with seropositive (OR 2.46, 95% CI:1.01,5.99) but not seronegative RA. Respiratory tract diseases tended towards higher associations in smokers, especially >10 packyears (OR 1.52, 95% CI:1.02,2.27; p=0.10 for interaction).

CONCLUSION

Acute/chronic sinusitis and pharyngitis and acute respiratory burden increased RA risk. The mucosal paradigm of RA pathogenesis may involve the upper respiratory tract.

Trends in incidence of dementia among patients with rheumatoid arthritis: A population-based cohort study

OBJECTIVE

We aimed to assess the incidence of dementia over time in patients with incident rheumatoid arthritis (RA) as compared to non-RA referents.

METHODS

This population-based, retrospective cohort study included Olmsted County, Minnesota residents with incident RA by ACR 1987 criteria, diagnosed between 1980 and 2009. We matched non-RA referents 1:1 on age, sex, and calendar year and followed all individuals until 12/31/2019. Incident dementia was defined as two codes for Alzheimer's disease and related dementias (ADRD) at least 30 days apart. Cumulative incidence of ADRD was assessed, adjusting for the competing risk of death. Cox proportional hazards models calculated hazard ratios (HR) with 95% confidence intervals (CI) for incident ADRD by decade.

RESULTS

After excluding individuals with prior dementia, we included 897 persons with incident RA (mean age 56 years; 69% female) and 885 referents. The 10-year cumulative incidence of ADRD in individuals diagnosed with RA during the 1980s was 12.7% (95%CI:7.9-15.7%), 1990s was 7.2% (95%CI:3.7-9.4%), and 2000s was 6.2% (95%CI:3.6-7.8%). Individuals with RA diagnosed in 2000s had insignificantly lower cumulative incidence of ADRD than those in the 1980s (HR 0.66; 95%CI:0.38-1.16). The overall HR of ADRD in individuals with RA was 1.37 (vs. referents; 95%CI:1.04-1.81). When subdivided by decade, however, the risk of ADRD in individuals diagnosed with RA was higher than referents in the 1990s (HR 1.72, 95%CI:1.09-2.70) but not 2000s (HR 0.86, 95%CI:0.51-1.45).

CONCLUSIONS

The risk of dementia in individuals with RA appears to be declining over time, including when compared to general population referents.

Associations of baseline use of biologic or targeted synthetic DMARDs with COVID-19 severity in rheumatoid arthritis: Results from the COVID-19 Global Rheumatology Alliance physician registry

Objective

To investigate baseline use of biologic or targeted synthetic (b/ts) disease-modifying antirheumatic drugs (DMARDs) and COVID-19 outcomes in rheumatoid arthritis (RA).

Methods

We analysed the COVID-19 Global Rheumatology Alliance physician registry (from 24 March 2020 to 12 April 2021). We investigated b/tsDMARD use for RA at the clinical onset of COVID-19 (baseline): abatacept (ABA), rituximab (RTX), Janus kinase inhibitors (JAKi), interleukin 6 inhibitors (IL-6i) or tumour necrosis factor inhibitors (TNFi, reference group). The ordinal COVID-19 severity outcome was (1) no hospitalisation, (2) hospitalisation without oxygen, (3) hospitalisation with oxygen/ventilation or (4) death. We used ordinal logistic regression to estimate the OR (odds of being one level higher on the ordinal outcome) for each drug class compared with TNFi, adjusting for potential baseline confounders.

Results

Of 2869 people with RA (mean age 56.7 years, 80.8% female) on b/tsDMARD at the onset of COVID-19, there were 237 on ABA, 364 on RTX, 317 on IL-6i, 563 on JAKi and 1388 on TNFi. Overall, 613 (21%) were hospitalised and 157 (5.5%) died. RTX (OR 4.15, 95% CI 3.16 to 5.44) and JAKi (OR 2.06, 95% CI 1.60 to 2.65) were each associated with worse COVID-19 severity compared with TNFi. There were no associations between ABA or IL6i and COVID-19 severity.

Conclusions

People with RA treated with RTX or JAKi had worse COVID-19 severity than those on TNFi. The strong association of RTX and JAKi use with poor COVID-19 outcomes highlights prioritisation of risk mitigation strategies for these people.

Relationship between rheumatoid arthritis and pulmonary function measures on spirometry in the UK Biobank

OBJECTIVE

We investigated the independent relationship of rheumatoid arthritis (RA) with type and severity of pulmonary patterns on spirometry compared to general population controls.

METHODS

This cross-sectional study investigated the association of RA and pulmonary function measures on spirometry among subjects who had spirometry performed for research purposes in the UK Biobank. RA cases were identified by self-report and current DMARD/glucocorticoid use. General population controls denied RA. Outcomes included continuous % predicted forced expiratory volume in 1 second (FEV₁ ) and forced vital capacity (FVC), type of spirometric pattern (restrictive or obstructive), and severity. We used multivariable regression to estimate the effects of RA cases versus controls, adjusting for age, sex, body mass index (BMI), and smoking status/pack-years.

RESULTS

Among 350,776 analyzed subjects with spirometry performed (mean age 56.3 years, 55.8% female, and 45.5% ever smokers), we identified 2,008 cases of treated RA. In multivariable analyses, RA was associated with lower % predicted FEV₁ (β -2.93, 95%CI -3.63,-2.24), % predicted FVC (β -2.08, 95%CI -2.72,-1.45), and FEV₁ /FVC (β -0.008, 95%CI -0.010,-0.005) than controls. RA was associated with restrictive (OR 1.36, 95%CI 1.21,1.52) and obstructive (OR 1.21, 95%CI 1.07,1.37) patterns independent of confounders. RA had the strongest associations for severe restrictive and obstructive patterns.

CONCLUSION

RA was associated with increased odds of restrictive and obstructive patterns, and this relationship was not explained by confounders including smoking. In addition to restrictive lung disease, clinicians should also be aware that airflow obstruction may be a pulmonary manifestation of RA.

Investigating the impact of disease and health record duration on the eMERGE algorithm for rheumatoid arthritis

OBJECTIVE

The study sought to determine the dependence of the Electronic Medical Records and Genomics (eMERGE) rheumatoid arthritis (RA) algorithm on both RA and electronic health record (EHR) duration.

MATERIALS AND METHODS

Using a population-based cohort from the Mayo Clinic Biobank, we identified 497 patients with at least 1 RA diagnosis code. RA case status was manually determined using validated criteria for RA. RA duration was defined as time from first RA code to the index date of biobank enrollment. To simulate EHR duration, various years of EHR lookback were applied, starting at the index date and going backward. Model performance was determined by sensitivity, specificity, positive predictive value, negative predictive value, and area under the curve (AUC).

RESULTS

The eMERGE algorithm performed well in this cohort, with overall sensitivity 53%, specificity 99%, positive predictive value 97%, negative predictive value 74%, and AUC 76%. Among patients with RA duration <2 years, sensitivity and AUC were only 9% and 54%, respectively, but increased to 71% and 85% among patients with RA duration >10 years. Longer EHR lookback also improved model performance up to a threshold of 10 years, in which sensitivity reached 52% and AUC 75%. However, optimal EHR lookback varied by RA duration; an EHR lookback of 3 years was best able to identify recently diagnosed RA cases.

CONCLUSIONS

eMERGE algorithm performance improves with longer RA duration as well as EHR duration up to 10 years, though shorter EHR lookback can improve identification of recently diagnosed RA cases.

Why women have more autoimmune diseases than men: An evolutionary perspective

Women have up to a fourfold increase in risk for autoimmune disease compared to men. Many explanations have been proposed, including sex hormones, the X chromosome, microchimerism, environmental factors, and the microbiome. However, the mechanism for this autoimmune sex bias remains obscure. In this manuscript, we evaluate the hypothesis that qualitative or quantitative differences in circulating antibodies may explain, at least in part, the pathogenesis of autoimmune disease and its sex bias-especially when considering an evolutionary perspective. Indeed, women have higher absolute levels of antibodies than men, and (auto)antibodies are also associated with most autoimmune diseases. Several facts suggest differences in antibodies may cause increased prevalence of autoimmune disease in women. First, the association between increased quantities of serum antibodies and increased prevalence of autoimmunity is found not only in women, but also in men with Klinefelter syndrome. Second, both serum antibody levels and autoimmunity spike in the postpartum period. Third, a dose-response effect exists between parity and both serum antibodies and prevalence of autoimmune disease. Fourth, many biologically plausible mechanisms explain the association, such as T cell-dependent activation of B cells and/or VGLL3. The evolutionary underpinning of increased antibodies in women is likely to be protection of offspring from infections. Overall, this evolutionary paradigm can help explain why the phenomenon of autoimmunity occurs preferentially in women and raises the possibility of new treatment options.

Lack of Association of Spontaneous Coronary Artery Dissection With Autoimmune Disease

BACKGROUND

Case reports and referral-based studies suggest spontaneous coronary artery dissection (SCAD) is associated with autoimmune diseases and causes 2% to 4% of acute coronary syndromes.

OBJECTIVES

This study determined the association of SCAD with autoimmune diseases, together with incidence and recurrence, in a population-based study.

METHODS

This case-control study took place from 1995 to 2018 within the Rochester Epidemiology Project. The study identified cases with SCAD from diagnosis codes and verified them using coronary angiography images, matching each case to 3 control subjects on age, sex, county, and years of medical history. Autoimmune disease history came from a validated, code-based definition. A multivariable logistic regression model calculated the odds ratio (OR) for SCAD among patients with a history of autoimmune disease, adjusting for race and body mass index.

RESULTS

The study identified 114 cases with SCAD (mean age 51 years and 90% women) and 342 matched control subjects. Autoimmune disease occurred in 13 (11%) cases with SCAD and 40 (12%) control subjects (p = 0.93). Even after adjustment, autoimmune diseases were not associated with SCAD (OR: 0.81; 95% confidence interval [CI]: 0.40 to 1.66). SCAD incidence between 2010 and 2018 (2.7 per 100,000; 95% CI: 1.7 to 3.7) was 10-fold higher than the incidence between 1995 and 2009 (0.3 per 100,000; 95% CI: 0.0 to 0.6). SCAD recurrence was 10% (95% CI: 3% to 16%) at 5 years.

CONCLUSIONS

These findings suggested SCAD pathogenesis is noninflammatory and screening for autoimmune diseases based on SCAD alone is not warranted. The code-based incidence of SCAD has increased over time, highlighting the importance of considering SCAD among patients with acute coronary syndromes.

Family History of Rheumatic, Autoimmune, and Nonautoimmune Diseases and Risk of Rheumatoid Arthritis

OBJECTIVE

Since comorbidities such as autoimmune diseases may be associated with rheumatoid arthritis (RA) risk, we hypothesized that a family history of these other conditions might also predict RA. Therefore, we aimed to determine the association between family history of 79 comorbidities and RA.

METHODS

This case-control study identified 821 cases of RA in the Mayo Clinic Biobank (positive predictive value 95%) and matched 3 controls to each case based on age, sex, recruitment year, and location. Patients self reported family history and characteristics (adjusted). Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs) for RA risk according to the presence of family history for each comorbidity, adjusted for body mass index, race, and smoking.

RESULTS

Family history of several conditions was associated with developing RA, including rheumatic autoimmune diseases (ORadj 1.89 [95% CI 1.41-2.52]), pulmonary fibrosis (ORadj 2.12 [95% CI 1.16-3.80]), inflammatory bowel disease (ORadj 1.45 [95% CI 1.05-1.98]), hyper/hypothyroidism (ORadj 1.34 [95% CI 1.10-1.63]), and obstructive sleep apnea (ORadj 1.28 [95% CI 1.05-1.55]). Parkinson's disease and type 2 diabetes mellitus were associated with a statistically decreased risk of RA that did not reach the prespecified significance threshold of P < 0.01 (ORadj 0.70 [95% CI 0.49-0.98] and ORadj 0.81 [95% CI 0.67-0.97], respectively). Analyses among 143 cases of incident RA were similar and also suggested an association with a family history of autism (OR 10.5 [95% CI 2.51-71.3]).

CONCLUSION

Family history of several autoimmune and nonautoimmune comorbidities was associated with increased risk of RA, providing an opportunity to identify novel populations at risk for RA.

Respiratory Diseases as Risk Factors for Seropositive and Seronegative Rheumatoid Arthritis and in Relation to Smoking

OBJECTIVE

The link and interplay between different airway exposures and rheumatoid arthritis (RA) risk are unclear. This study was undertaken to determine whether respiratory disease is associated with development of RA, and specifically to examine this relationship by RA serostatus and smoking exposure.

METHODS

Using data from the Epidemiological Investigation of Rheumatoid Arthritis study, this analysis included 1,631 incident RA cases and 3,283 matched controls recruited from 2006 to 2016. Linking these individuals to the National Patient Register provided information on past acute or chronic, upper or lower respiratory disease diagnoses. For each disease group, we estimated adjusted odds ratios (OR_adj ) with 95% confidence intervals (95% CI) for RA, using logistic regression models adjusted for age, sex, residential area, body mass index, and education both overall and stratified by anti-citrullinated protein antibody (ACPA)/rheumatoid factor (RF) status and by smoking status.

RESULTS

Respiratory disease diagnoses were associated with risk of RA, with an OR_adj of 1.2 for acute upper respiratory disease (95% CI 0.8-1.7), 1.4 for chronic upper respiratory disease (95% CI 1.1-1.9), 2.4 for acute lower respiratory disease (95% CI 1.5-3.6), and 1.6 for chronic lower respiratory disease (95% CI 1.5-3.6). These associations were present irrespective of RF or ACPA status, though the association was somewhat stronger for ACPA/RF-positive than ACPA/RF-negative RA. The association between any respiratory disease and RA was stronger for nonsmokers (OR_adj 2.1 [95% CI 1.5-2.9]) than for smokers (OR_adj 1.2 [95% CI 0.9-1.5]).

CONCLUSION

Respiratory diseases increase the risk for both seropositive and seronegative RA, but only among nonsmokers. These findings raise the hypothesis that smoking and airway disease are associated with RA development through partly different mechanisms.

Lifestyle and Clinical Risk Factors for Incident Rheumatoid Arthritis-associated Interstitial Lung Disease

OBJECTIVE

To determine the association between novel lifestyle factors on risk of rheumatoid arthritis (RA)-associated interstitial lung disease (ILD), define the threshold at which smoking increases RA-ILD risk, and calculate the degree to which known lifestyle and clinical factors predict RA-ILD.

METHODS

This nested case-control study matched incident RA-ILD cases to RA non-ILD controls on age, sex, RA duration, rheumatoid factor, and time from exposure assessment to RA-ILD. Exposures included education, BMI, smoking, anticyclic citrullinated peptide antibodies, race, joint erosions, rheumatoid nodules, C-reactive protein (CRP), disease activity score, functional status, disease-modifying antirheumatic drug use, and glucocorticoid use. OR for each exposure on risk of RA-ILD were obtained from logistic regression models. Area under the curve (AUC) was calculated based on all lifestyle and clinical exposures.

RESULTS

We identified 84 incident RA-ILD cases and 233 matched controls. After adjustment, obesity, high-positive CRP (≥ 10 mg/L), and poor functional status (multidimensional Health Assessment Questionnaire [MDHAQ] ≥ 1) were associated with increased risk of RA-ILD (OR 2.42, 95% CI 1.11-5.24 vs normal BMI; OR 2.61, 95% CI 1.21-5.64 vs CRP < 3 mg/L; OR 3.10, 95% CI 1.32-7.26 vs MDHAQ < 0.2). Smoking 30 pack-years or more was strongly associated with risk of RA-ILD compared to never smokers (OR 6.06, 95% CI 2.72-13.5). Together, lifestyle and clinical risk factors for RA-ILD had an AUC of 0.79 (95% CI 0.73-0.85).

CONCLUSION

Obesity, CRP, functional status, and extensive smoking may be novel risk factors for RA-ILD that may be useful for RA-ILD risk assessment and prevention. The overall ability to predict RA-ILD remains modest.

Comorbidities As Risk Factors for Rheumatoid Arthritis and Their Accrual After Diagnosis

OBJECTIVE

To determine the prevalence of comorbidities in rheumatoid arthritis (RA), discover which comorbidities might predispose to developing RA, and identify which comorbidities are more likely to develop after RA.

PATIENTS AND METHODS

We performed a case-control study using a single-center biobank, identifying 821 cases of RA (143 incident RA) between January 1, 2009, and February 28, 2018, defined as 2 diagnosis codes plus a disease-modifying antirheumatic drug. We matched each case to 3 controls based on age and sex. Participants self-reported the presence and onset of 74 comorbidities. Logistic regression models adjusted for race, body mass index, education, smoking, and Charlson comorbidity index.

RESULTS

After adjustment for confounders and multiple comparisons, 11 comorbidities were associated with RA, including epilepsy (odds ratio [OR], 2.13; P=.009), obstructive sleep apnea (OR, 1.49; P=.001), and pulmonary fibrosis (OR, 4.63; P<.001), but cancer was not. Inflammatory bowel disease (OR, 3.82; P<.001), type 1 diabetes (OR, 3.07; P=.01), and venous thromboembolism (VTE; OR, 1.80; P<.001) occurred more often before RA diagnosis compared with controls. In contrast, myocardial infarction (OR, 3.09; P<.001) and VTE (OR, 1.84; P<.001) occurred more often after RA diagnosis compared with controls. Analyses restricted to incident RA cases and their matched controls mirrored these results.

CONCLUSION

Inflammatory bowel disease, type 1 diabetes, and VTE might predispose to RA development, whereas cardiovascular disease, VTE, and obstructive sleep apnea can result from RA. These findings have important implications for RA pathogenesis, early detection, and recommended screening.

Frailty Phenotypes and Relations With Surgical Outcomes: A Latent Class Analysis

BACKGROUND

Frailty is an important concept in the care of older adults although controversy remains regarding its defining features and clinical utility. Both the Fried phenotype and the Rockwood deficit accumulation approaches cast frailty as a "burden" without exploring the relative salience of its cardinal markers and their relevance to the patient. New multifactorial perspectives require a reliable assessment of frailty that can validly predict postoperative health outcomes.

METHODS

In a retrospective study of 2828 unselected surgical patients, we used item response theory to examine the ability of 32 heterogeneous markers capturing limitations in physical, functional, emotional, and social activity domains to indicate severity of frailty as a latent continuum. Eighteen markers efficiently indicated frailty severity and were then subject to latent class analysis to derive discrete phenotypes. Next, we validated the obtained frailty phenotypes against patient-reported 30-day postoperative outcomes using multivariable logistic regression. Models were adjusted for demographics, comorbidity, type and duration of surgery, and cigarette and alcohol consumption.

RESULTS

The 18 markers provided psychometric evidence of a single reliable continuum of frailty severity. Latent class analyses produced 3 distinct subtypes, based on patients' endorsement probabilities of the frailty indicators: not frail (49.7%), moderately frail (33.5%), and severely frail (16.7%). Unlike the moderate class, severely frail endorsed emotional health problems in addition to physical burdens and functional limitations. Models adjusting for age, sex, type of anesthesia, and intraoperative factors indicated that severely frail (odds ratio, 1.89; 95% confidence interval, 1.42-2.50) and moderately frail patients (odds ratio, 1.31; 95% confidence interval, 1.03-1.67) both had higher odds of experiencing postoperative complications compared to not frail patients. In a 3-way comparison, a higher proportion of severely frail patients (10.7%) reported poorer quality of life after surgery compared to moderately frail (9.2%) and not frail (8.3%) patients (P < .001). There was no significant difference among these groups in proportions reporting hospital readmission (5.6%, 5.1%, and 3.8%, respectively; P = .067).

CONCLUSIONS

Self-report frailty items can accurately discern 3 distinct phenotypes differing in composition and their relations with surgical outcomes. Systematically assessing a wider set of domains including limitations in functional, emotional, and social activities can inform clinicians on what precipitates loss of physiological reserve and profoundly influences patients' lives. This information can help guide the current discussion on frailty and add meaningful clinical tools to the surgical practice.

Investigating Asthma, Allergic Disease, Passive Smoke Exposure, and Risk of Rheumatoid Arthritis

OBJECTIVE

Rheumatoid arthritis (RA) is postulated to originate at mucosal surfaces, particularly the airway mucosa. To investigate this hypothesis, we determined the association between RA and asthma, passive smoke exposure, and age at start of smoking.

METHODS

For this case-control study, we identified 1,023 cases of RA (175 incident) within a single-center biobank population, using a rules-based algorithm that combined self-report with 2 diagnostic codes. Exposures were self-reported on biobank questionnaires. Logistic regression models were used to calculate the association of exposures with RA, adjusting for potential confounders. Odds ratios (ORs) with 95% confidence intervals (95% CIs) were calculated.

RESULTS

After adjustment for allergies, urban environment, and passive smoke exposure, asthma was found to be associated with RA in the full cohort (OR 1.28 [95% CI 1.04-1.58; P = 0.02]) but not the incident RA cohort (OR 1.17 [95% CI 0.66-2.06; P = 0.60]). History of allergic disease was associated with RA in both the full cohort (OR 1.30 [95% CI 1.12-1.51; P < 0.001]) and the incident RA cohort (OR 1.61 [95% CI 1.11-2.33; P = 0.01]), especially food allergy, which was significantly associated with RA in the full cohort (OR 1.38 [95% CI 1.08-1.75; P = 0.01]) and showed a trend toward significance in the incident RA cohort (OR 1.83 [95% CI 0.97-3.45; P = 0.06]). Passive smoke exposure at home or work was not associated with RA. Finally, age at start of smoking was not associated with increased odds of developing RA in either the full cohort (OR 1.03 [95% CI 1.00-1.06; P = 0.03]) or the incident RA cohort (OR 1.00 [95% CI 0.92-1.08; P = 0.98]).

CONCLUSION

Asthma and allergies may be associated with increased risk of RA. Passive smoke exposure and early age at start of smoking do not appear to influence risk of RA.

Occurrence and aetiology of gastrointestinal perforation in patients with vasculitis

OBJECTIVES

This study aimed to characterise the presenting features and outcomes of patients with vasculitis and gastrointestinal perforation.

METHODS

Using a retrospective cohort design, this study included 20 cases with verified vasculitis and gastrointestinal perforation at Mayo Clinic, Rochester, USA, between 1998 and 2017.

RESULTS

Four of the twenty cases experienced vasculitis-induced perforation. Cases with perforations due to vasculitic involvement had more small bowel involvement, longer duration of abdominal pain prior to perforation (41 days vs. 0 days, p=0.005), and a higher proportion of active tobacco use (75% vs. 7%, p=0.01) compared to the cases with non-vasculitis perforation. A majority (88%) of the non-vasculitis perforations were associated with glucocorticoid use. The median cumulative glucocorticoid dose prior to perforation in patients with additional, non-vasculitic risk factors for perforation was 4,320 mg prednisone and was 22,170 mg for those without additional risk factors. Mortality rates for the whole cohort were higher than the general population (standardised mortality ratio: 2.19, 95% confidence interval 1.05 to 4.02). The cases with vasculitis-induced perforation tended to have increased number of surgeries and length of stay compared to the non-vasculitis cases; however, those differences failed to reach statistical significance.

CONCLUSIONS

Small bowel location and longer abdominal pain duration may help distinguish vasculitis-induced bowel perforation from other etiologies. Overall mortality in patients with vasculitis and bowel perforation is increased, highlighting the importance of prompt diagnosis and management.

Review of perioperative falls

Falls are a known public health problem, and there is increasing recognition of the importance of perioperative falls for risk prediction and quality assessment. Our objective was to review existing literature regarding the occurrence, injuries, and risk factors of preoperative and postoperative falls. A systematized search of PubMed entries between 1947 and November 2015 produced 24 articles that met inclusion criteria. Most studied orthopaedic surgery patients older than 65 yr. Four were rated 'good' quality. Interrater reliability for the quality assessment was moderate (κ = 0.77). In the 3-12 months before surgery, the proportion of preoperative patients who fell ranged from 24 to 48%. Injuries were common (70%). The rate of postoperative falls ranged from 0.8 to 16.3 per 1000 person-days, with a gradual decline in the months after surgery. Injuries from postoperative falls occurred in 10-70% of fallers, and 5-20% experienced a severe injury. Risk factors were not well studied. Prospective studies reported a higher percentage of falls and fall-related injuries than retrospective studies, suggesting that there may be underdetection of falls and injuries with retrospective studies. Perioperative falls were more common than falls reported in the general community, even up to 12 months after surgery. Surgery-related falls may therefore occur beyond the hospitalization period. Future studies should use a prospective design, validated definitions, and broader populations to study perioperative falls. In particular, investigations of risk factors and follow-up after hospitalization are needed.

REGISTRY NUMBER

PROSPERO registration number CRD42015029971.

Protocol for an observational study of delirium in the post-anaesthesia care unit (PACU) as a potential predictor of subsequent postoperative delirium

INTRODUCTION

Postoperative delirium can be a serious consequence of major surgery, associated with longer hospital stays, readmission, cognitive and functional deterioration and mortality. Delirium is an acute, reversible disorder characterised by fluctuating course, inattention, disorganised thinking and altered level of consciousness. Delirium occurring in the hours immediately following anaesthesia and delirium occurring in the postoperative period of 1-5 days have been described as distinct clinical entities. This protocol describes an observational study with the aim of determining if delirium in the first hour following tracheal tube removal is a predictor of delirium in the 5 subsequent postoperative days. Improved understanding regarding the development of postoperative delirium would improve patient care and allow more effective implementation of delirium prevention measures.

METHODS AND ANALYSIS

Patients enrolled to the Electroencephalography Guidance of Anesthesia to Alleviate Geriatric Syndromes (ENGAGES) randomised controlled trial will be eligible for this substudy. A validated delirium assessment method, the 3-min Diagnostic Confusion Assessment Method and the Richmond Agitation and Sedation Scale will be used to assess 100 patients for delirium at 30 min and 60 min following tracheal tube removal. Patients will also be assessed for delirium over postoperative days 1-5 using three validated methods, the Confusion Assessment Method (CAM), CAM for the Intensive Care Unit and structured chart review. Logistic regression analysis will then be performed to test whether immediately postoperative delirium independently predicts subsequent postoperative delirium.

ETHICS AND DISSEMINATION

This observational substudy of ENGAGES has been approved by the ethics board of Washington University School of Medicine. Enrolment began in June 2016 and will continue until June 2017. Dissemination plans include presentations at scientific conferences and scientific publications.

TRIAL REGISTRATION NUMBER

NCT02241655.

Changes in quality of life after elective surgery: an observational study comparing two measures

PURPOSE

Our main objective was to compare the change in a validated quality of life measure to a global assessment measure. The secondary objectives were to estimate the minimum clinically important difference (MCID) and to describe the change in quality of life by surgical specialty.

METHODS

This prospective cohort study included 7902 adult patients undergoing elective surgery. Changes in the Veterans RAND 12-Item Health Survey (VR-12), composed of a physical component summary (PCS) and a mental component summary (MCS), were calculated using preoperative and postoperative questionnaires. The latter also contained a global assessment question for quality of life. We compared PCS and MCS to the global assessment using descriptive statistics and weighted kappa. MCID was calculated using an anchor-based approach. Analyses were pre-specified and registered (NCT02771964).

RESULTS

By the change in VR-12 scores, an equal proportion of patients experienced improvement and deterioration in quality of life (28% for PCS, 25% for MCS). In contrast, by the global assessment measure, 61% reported improvement, while only 10% reported deterioration. Agreement with the global assessment was slight for both PCS (kappa = 0.20, 57% matched) and MCS (kappa = 0.10, 54% matched). The MCID for the overall VR-12 score was approximately 2.5 points. Patients undergoing orthopedic surgery showed the most improvement in quality of life measures, while patients undergoing gastrointestinal/hepatobiliary or urologic surgery showed the most deterioration.

CONCLUSIONS

Subjective global quality of life report does not agree well with a validated quality of life instrument, perhaps due to patient over-optimism.

Ability of preoperative falls to predict postsurgical outcomes in non-selected patients undergoing elective surgery at an academic medical centre: protocol for a prospective cohort study

INTRODUCTION

Falls are increasingly recognised for their ability to herald impending health decline. Despite the likely susceptibility of postsurgical patients to falls, a detailed description of postoperative falls in an unselected surgical population has never been performed. One study suggests that preoperative falls may forecast postoperative complications. However, a larger study with non-selected surgical patients and patient-centred outcomes is needed to provide the generalisability and justification necessary to implement preoperative falls assessment into routine clinical practice. The aims of this study are therefore twofold. First, we aim to describe the main features of postoperative falls in a population of unselected surgical patients. Second, we aim to test the hypothesis that a history of falls in the 6 months prior to surgery predicts postoperative falls, poor quality of life, functional dependence, complications and readmission.

METHODS AND ANALYSIS

To achieve these goals, we study adult patients who underwent elective surgery at our academic medical centre and were recruited to participate in a prospective, survey-based cohort study called Systematic Assessment and Targeted Improvement of Services Following Yearlong Surgical Outcomes Surveys (SATISFY-SOS) (NCT02032030). Patients who reported falling in the 6 months prior to surgery will be considered 'exposed.' The primary outcome of interest is postoperative falls within 30 days of surgery. Secondary outcomes include postoperative functional dependence, quality of life (both physical and mental), in-hospital complications and readmission. Regression models will permit controlling for important confounders.

ETHICS AND DISSEMINATION

The home institution's Institutional Review Board approved this study (IRB ID number 201505035). The authors will publish the findings, regardless of the results.

Assessing change in patient-reported quality of life after elective surgery: protocol for an observational comparison study

Despite their widespread use, the two main methods of assessing quality of life after surgery have never been directly compared. To support patient decision-making and study design, we aim to compare these two methods. The first of these methods is to assess quality of life before surgery and again after surgery using the same validated scale. The second is simply to ask patients whether or not they think their post-operative quality of life is better, worse, or the same. Our primary objective is to assess agreement between the two measures. Secondary objectives are to calculate the minimum clinically important difference (MCID) and to describe the variation across surgical specialties. To accomplish these aims, we will administer surveys to patients undergoing elective surgery, both before surgery and again 30 days after surgery. This protocol follows detailed guidelines for observational study protocols.

Preoperative Falls Predict Postoperative Falls, Functional Decline, and Surgical Complications

Background

Falls are common and linked to morbidity. Our objectives were to characterize postoperative falls, and determine whether preoperative falls independently predicted postoperative falls (primary outcome), functional dependence, quality of life, complications, and readmission.

Methods

This prospective cohort study included 7982 unselected patients undergoing elective surgery. Data were collected from the medical record, a baseline survey, and follow-up surveys approximately 30 days and one year after surgery.

Results

Fall rates (per 100 person-years) peaked at 175 (hospitalization), declined to 140 (30-day survey), and then to 97 (one-year survey). After controlling for confounders, a history of one, two, and ≥ three preoperative falls predicted postoperative falls at 30 days (adjusted odds ratios [aOR] 2.3, 3.6, 5.5) and one year (aOR 2.3, 3.4, 6.9). One, two, and ≥ three falls predicted functional decline at 30 days (aOR 1.2, 2.4, 2.4) and one year (aOR 1.3, 1.5, 3.2), along with in-hospital complications (aOR 1.2, 1.3, 2.0). Fall history predicted adverse outcomes better than commonly-used metrics, but did not predict quality of life deterioration or readmission.

Conclusions

Falls are common after surgery, and preoperative falls herald postoperative falls and other adverse outcomes. A history of preoperative falls should be routinely ascertained.

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Postoperative falls are common during hospitalization and after discharge and may be more prevalent in certain specialties.

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Preoperative falls predict postoperative falls, postoperative functional decline, and in-hospital complications.

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Ascertaining fall history is practical and informative, and should become routine.

Surgery-related falls occur at a high rate both during hospitalization and after discharge, and they may be especially prevalent in certain surgical specialties. Preoperative falls are the main harbinger of postoperative falls, and also strongly predict postoperative functional decline and complications. Importantly, these findings appear to be true across all ages. Therefore, a history of falls before surgery is a useful tool that should be incorporated into routine preoperative assessment.