Disease-modifying antirheumatic drugs and risk of thyroxine-treated autoimmune thyroid disease in patients with rheumatoid arthritis.

BACKGROUND: Autoimmune thyroid disease (AITD) and rheumatoid arthritis (RA) share a genetic background, and the prevalence of AITD in RA patients is increased. Whereas immunomodulatory treatments are used in RA, they are rarely used in AITD. OBJECTIVES: We hypothesized that disease-modifying antirheumatic drugs (DMARDs) as used in RA might lower the risk of incident AITD. METHODS: A nationwide cohort study including 13,731 patients with new-onset RA from the Swedish Rheumatology Quality Register 2006-2018 and 63,201 matched general population comparators linked to national registers to identify AITD. We estimated relative risks (hazard ratios) of AITD after RA diagnosis in RA patients compared to the general population, and in relation to DMARD treatment, using Cox regression. RESULTS: Following RA diagnosis, 321 (2.3%) of the RA patients and 1838 (2.9%) of the population comparators developed AITD, corresponding to an incidence of 3.7 versus 4.6 per 1000 person-years, hazard ratio, 0.81; 95% CI, 0.72-0.91. The decreased risk of incident AITD among RA patients compared to the general population was most pronounced among biologic DMARD (bDMARD) treated patients, with a hazard ratio of 0.54; 95% CI, 0.39-0.76. Among RA patients, subgrouped by bDMARD use, TNF-inhibitors were associated with the most pronounced decrease, hazard ratio, 0.67; 95% CI, 0.47-0.96. CONCLUSIONS: In contrast to the increased prevalence of AITD in RA patients at diagnosis, our results indicate that the risk of AITD decreases following RA diagnosis. This decrease is especially pronounced in RA patients treated with bDMARDs. These findings support the hypothesis that DMARDs might have a preventive effect on AITD.

Venous thromboembolism with JAK inhibitors and other immune-modulatory drugs: a Swedish comparative safety study among patients with rheumatoid arthritis.

OBJECTIVE: To assess and compare the incidence of venous thromboembolism (VTE) in patients with rheumatoid arthritis (RA) treated with Janus kinase inhibitors (JAKi), tumour necrosis factor inhibitors (TNFi) or other biological disease modifying antirheumatic drugs (bDMARDs). For contextualisation, to assess VTE incidences in the Swedish general population and in the RA source population. METHODS: We performed a nationwide register-based, active comparator, new user design cohort study in Sweden from 2010 to 2021. The Swedish Rheumatology Quality Register was linked to national health registers to identify treatment cohorts (exposure) of initiators of a JAKi, a TNFi, or a non-TNFi bDMARD (n=32 737 treatment initiations). We also identified a general population cohort (matched 1:5, n=92 108), and an 'overall RA' comparator cohort (n=85 722). Outcome was time to first VTE during the follow-up, overall and by deep vein thrombosis (DVT) and pulmonary embolism (PE). We calculated incidence rates (IR) and multivariable-adjusted HRs using Cox regression. RESULTS: Based on 559 incident VTE events, the age- and sex-standardised (to TNFi) IR (95% CI) for VTE was 5.15 per 1000 person-years (4.58 to 5.78) for patients treated with TNFi, 11.33 (8.54 to 15.04) for patients treated with JAKi, 5.86 (5.69 to 6.04) in the overall RA cohort and 3.28 (3.14 to 3.43) in the general population. The fully adjusted HR (95% CI) for VTE with JAKi versus TNFi was 1.73 (1.24 to 2.42), the corresponding HR for PE was 3.21 (2.11 to 4.88) and 0.83 (0.47 to 1.45) for DVT. CONCLUSIONS: Patients with RA treated with JAKi in clinical practice are at increased risk of VTE compared with those treated with bDMARDs, an increase numerically confined to PE.

Safety of biological and targeted synthetic disease-modifying antirheumatic drugs for rheumatoid arthritis as used in clinical practice: results from the ARTIS programme.

OBJECTIVE: Longitudinal clinical registry-infrastructures such as Anti-Rheumatic Therapies in Sweden (ARTIS) allow simultaneous comparison of the safety of individual immunomodulatory drugs used in clinical practice, with consistent definitions of treatment cohorts, follow-up and outcomes. Our objective was to assess and compare incidence rates of key safety outcomes for individual targeted synthetic or biological disease-modifying antirheumatic drugs (b/ts DMARDs) in rheumatoid arthritis (RA), updating previous reports and including newer treatments including Janus Kinase inhibitors (JAKi). METHODS: Nationwide register-based cohort study including all patients with RA in Sweden registered as starting any b/tsDMARD 1 January 2010 through 31 December 2020, followed until 30 June 2021 (N=20 117). The incidence rates of selected outcomes, identified through national healthcare registers, were compared between individual b/tsDMARDs, adjusted for confounding by demographics, RA disease characteristics and comorbidity. RESULTS: There were marked differences in treatment discontinuations due to adverse events (rates per 1000 person-years ranged from 18 on rituximab to 57 on tofacitinib), but few significant differences were observed for the serious adverse events under study. Neither cardiovascular events nor general serious infections were more frequent on baricitinib or tofacitinib versus bDMARDs, but JAKi were associated with higher rates of hospital-treated herpes zoster (HR vs etanercept, 3.82 (95% CI 2.05 to 7.09) and 4.00 (1.59 to 10.06)). Low number of events limited some comparisons, in particular for sarilumab and tofacitinib. CONCLUSION: Data from ARTIS supports that the b/tsDMARDs currently used to treat RA have acceptable and largely similar safety profiles, but differences exist in particular concerning tolerability and specific infection risks.

Glucocorticoid exposure and the risk of serious infections in rheumatoid arthritis: a marginal structural model application.

OBJECTIVE: Observational studies have reported an increased risk of infections associated with glucocorticoids in RA, not supported by evidence from randomized controlled trials. Inappropriately accommodating time-varying exposure and confounding in observational studies might explain the conflicting results. Therefore, we compared the incidence of serious infections between different oral glucocorticoid dose patterns over three years in a prospective inception cohort, adjusting for time-varying confounders in marginal structural models. METHODS: We included 9654 newly diagnosed RA patients from the Swedish Rheumatology Quality Register between 2007-2018 and followed them for three years after the first rheumatology visit. Follow-up was divided into 90-day periods. A mean oral prednisone daily dose was calculated for each period and categorized into 'no use', 'low' (≤10 mg/day) and 'high' (>10 mg/day) doses. The incidence of serious infections (hospitalization for infection) over follow-up periods was modelled by pooled logistic regression allowing separate effects for recent and past exposure. RESULTS: An increased incidence of serious infections was associated with higher compared with lower doses and with more recent compared with past glucocorticoid exposure. Over 3 years of follow-up, the marginal structural models predicted one additional serious infection for every 83 individuals treated with low GC doses for the first 6 months, and for every 125 individuals treated with high GC doses for the first 3 months, compared with no GC use. CONCLUSION: Our results broadly agree with previous observational studies showing a dose dependent increased risk of infection associated with (recent) use of oral glucocorticoids.

Federated analyses of multiple data sources in drug safety studies.

PURPOSE: Studies of rare side effects of new drugs with limited exposure may require pooling of multiple data sources. Federated Analyses (FA) allow real-time, interactive, centralized statistical processing of individual-level data from different data sets without transfer of sensitive personal data. METHODS: We review IT-architecture, legal considerations, and statistical methods in FA, based on a Swedish Medical Products Agency methodological development project. RESULTS: In a review of all post-authorisation safety studies assessed by the EMA during 2019, 74% (20/27 studies) reported issues with lack of precision in spite of mean study periods of 9.3 years. FA could potentially improve precision in such studies. Depending on the statistical model, the federated approach can generate identical results to a standard analysis. FA may be particularly attractive for repeated collaborative projects where data is regularly updated. There are also important limitations. Detailed agreements between involved parties are strongly recommended to anticipate potential issues and conflicts, document a shared understanding of the project, and fully comply with legal obligations regarding ethics and data protection. FA do not remove the data harmonisation step, which remains essential and often cumbersome. Reliable support for technical integration with the local server architecture and security solutions is required. Common statistical methods are available, but adaptations may be required. CONCLUSIONS: Federated Analyses require competent and active involvement of all collaborating parties but have the potential to facilitate collaboration across institutional and national borders and improve the precision of postmarketing drug safety studies.

Influenza outcomes in patients with inflammatory joint diseases and DMARDs: how do they compare to those of COVID-19?

OBJECTIVES: To estimate absolute and relative risks for seasonal influenza outcomes in patients with inflammatory joint diseases (IJDs) and disease-modifying antirheumatic drugs (DMARDs). To contextualise recent findings on corresponding COVID-19 risks. METHODS: Using Swedish nationwide registers for this cohort study, we followed 116 989 patients with IJD and matched population comparators across four influenza seasons (2015-2019). We quantified absolute risks of hospitalisation and death due to influenza, and compared IJD to comparators via Cox regression. We identified 71 556 patients with IJD on active treatment with conventional synthetic DMARDs and biological disease-modifying antirheumatic drugs (bDMARDs)/targeted synthetic disease-modifying antirheumatic drug (tsDMARDs) at the start of each influenza season, estimated risks for the same outcomes and compared these risks across DMARDs via Cox regression. RESULTS: Per season, average risks for hospitalisation listing influenza were 0.25% in IJD and 0.1% in the general population, corresponding to a crude HR of 2.38 (95% CI 2.21 to 2.56) that decreased to 1.44 (95% CI 1.33 to 1.56) following adjustments for comorbidities. For death listing influenza, the corresponding numbers were 0.015% and 0.006% (HR=2.63, 95% CI 1.93 to 3.58, and HR=1.46, 95% CI 1.07 to 2.01). Absolute risks for influenza outcomes were half (hospitalisation) and one-tenth (death) of those for COVID-19, but relative estimates comparing IJD to the general population were similar. CONCLUSIONS: In absolute terms, COVID-19 in IJD outnumbers that of average seasonal influenza, but IJD entails a 50%-100% increase in risk for hospitalisation and death for both types of infections, which is largely dependent on associated comorbidities. Overall, bDMARDs/tsDMARDs do not seem to confer additional risk for hospitalisation or death related to seasonal influenza.

Short-term, intermediate-term and long-term risks of acute coronary syndrome in cohorts of patients with RA starting biologic DMARDs: results from four Nordic countries.

OBJECTIVES: To compare the 1-year, 2-year and 5-year incidences of acute coronary syndrome (ACS) in patients with rheumatoid arthritis (RA) starting any of the biologic disease-modifying antirheumatic drugs (bDMARDs) currently available in clinical practice and to anchor these results with a general population comparator. METHODS: Observational cohort study, with patients from Denmark, Finland, Norway and Sweden starting a bDMARD during 2008-2017. Time to first ACS was identified through register linkages. We calculated the 1-year, 2-year and 5-year incidence rates (IR) (on drug and ever since treatment start) and used Cox regression (HRs) to compare ACS incidences across treatments taking ACS risk factors into account. Analyses were further performed separately in subgroups defined by age, number of previous bDMARDs and history of cardiovascular disease. We also compared ACS incidences to an individually matched general population cohort. RESULTS: 24 083 patients (75% women, mean age 56 years) contributing 40 850 treatment courses were included. During the maximum (5 years) follow-up (141 257 person-years (pyrs)), 780 ACS events occurred (crude IR 5.5 per 1000 pyrs). Overall, the incidence of ACS in RA was 80% higher than that in the general population. For all bDMARDs and follow-up definitions, HRs were close to 1 (etanercept as reference) with the exception of the 5-year risk window, where signals for abatacept, infliximab and rituximab were noted. CONCLUSION: The rate of ACS among patients with RA initiating bDMARDs remains elevated compared with the general population. As used in routine care, the short-term, intermediate-term and longer-term risks of ACS vary little across individual bDMARDs.

Comparison of treatment retention of originator vs biosimilar products in clinical rheumatology practice in Sweden.

OBJECTIVES: To compare treatment retention between biosimilars and their originator products among first starters (etanercept, infliximab, adalimumab and rituximab), as well as after non-medical switch. METHODS: Patients with rheumatic diseases starting, for the first time, an originator or biosimilar etanercept, infliximab, adalimumab or rituximab were identified in the national Swedish Rheumatology Quality Register. Moreover, patients switching from an originator to its biosimilar were identified and individually matched to patients continuing on the originator. One-year treatment retention was calculated and hazard ratios (HR) for discontinuation with 95% CIs were estimated, adjusting for comorbidities and socio-economic factors. RESULTS: In total, 21 443 first treatment courses were identified. The proportion of patients still on the drug at 1 year and the HR for discontinuation revealed no differences across adalimumab (Humira, Imraldi, Amgevita and Hyrimoz) nor across rituximab products (Mabthera, Ritemvia/Truxima and Rixathon). The proportions on the drug at 1 year were similar for Benepali (77%) and Enbrel (75%) and the adjusted HR for Benepali compared with Enbrel was 0.91 (95% CI 0.83, 0.99). For infliximab, the proportion still on the drug at 1 year was 67% for Remicade and 66% for Remsima/Inflectra and the HR compared with Remicade was 1.16 (95% CI 1.02, 1.33). Among 2925 patients switching from an originator drug to one of its biosimilars, we noted no statistically significant or clinically relevant differences in drug survival compared with those who remained on originator therapy. CONCLUSION: This large observational study supports the equivalence of biologic DMARD biosimilar products and originators when used in routine rheumatology care.

Do patient-reported measures of disease activity in rheumatoid arthritis vary between countries? Results from a Nordic collaboration.

OBJECTIVES: To investigate whether patient-reported outcomes vary across countries and are influenced by cultural/contextual factors. Specifically, we aimed to assess inter-country differences in tender joint count (TJC), pain and patient's global health assessment (PGA), and their impact on disease activity (DAS28-CRP) in RA patients from five Nordic countries. METHODS: We collected data (baseline, 3- and 12-months) from rheumatology registers in the five countries comprising RA patients starting a first ever MTX or a first ever TNF inhibitor (TNFi). In order to assess the role of context (=country), we separately modelled TJC, pain and PGA as functions of objective variables (CRP, swollen joint count, age, sex, calendar period and disease duration) with linear models. Analyses were performed at each time point and for both treatments. We further assessed the impact of inter-country differences on DAS28-CRP. RESULTS: A total of 27 645 RA patients started MTX and 19 733 started a TNFi. Crude inter-country differences at MTX start amounted to up to 4 points (28 points scale) for TJC, 10 and 27 points (0-100 scale) for pain and PGA, respectively. Corresponding numbers at TNFi start were 3 (TJC), 27 (pain) and 24 (PGA) points. All differences were reduced at 3- and 12-months, and attenuated when adjusting for the objective variables. The variation in predicted DAS28-CRP across countries amounted to <0.5 units. CONCLUSIONS: Inter-country differences in TJC, pain and PGA are greater than expected based on differences in objective measures, but have a small clinical impact on DAS28-CRP across countries.

The impact of a csDMARD in combination with a TNF inhibitor on drug retention and clinical remission in axial spondyloarthritis.

OBJECTIVES: Many axial spondylarthritis (axSpA) patients receive a conventional synthetic DMARD (csDMARD) in combination with a TNF inhibitor (TNFi). However, the value of this co-therapy remains unclear. The objectives were to describe the characteristics of axSpA patients initiating a first TNFi as monotherapy compared with co-therapy with csDMARD, to compare one-year TNFi retention and remission rates, and to explore the impact of peripheral arthritis. METHODS: Data was collected from 13 European registries. One-year outcomes included TNFi retention and hazard ratios (HR) for discontinuation with 95% CIs. Logistic regression was performed with adjusted odds ratios (OR) of achieving remission (Ankylosing Spondylitis Disease Activity Score (ASDAS)-CRP < 1.3 and/or BASDAI < 2) and stratified by treatment. Inter-registry heterogeneity was assessed using random-effect meta-analyses, combined results were presented when heterogeneity was not significant. Peripheral arthritis was defined as ≥1 swollen joint at baseline (=TNFi start). RESULTS: Amongst 24 171 axSpA patients, 32% received csDMARD co-therapy (range across countries: 13.5% to 71.2%). The co-therapy group had more baseline peripheral arthritis and higher CRP than the monotherapy group. One-year TNFi-retention rates (95% CI): 79% (78, 79%) for TNFi monotherapy vs 82% (81, 83%) with co-therapy (P < 0.001). Remission was obtained in 20% on monotherapy and 22% on co-therapy (P < 0.001); adjusted OR of 1.16 (1.07, 1.25). Remission rates at 12 months were similar in patients with/without peripheral arthritis. CONCLUSION: This large European study of axial SpA patients showed similar one-year treatment outcomes for TNFi monotherapy and csDMARD co-therapy, although considerable heterogeneity across countries limited the identification of certain subgroups (e.g. peripheral arthritis) that may benefit from co-therapy.

Impact of the COVID-19 pandemic on morbidity and mortality in patients with inflammatory joint diseases and in the general population: a nationwide Swedish cohort study.

OBJECTIVES: To estimate absolute and relative risks for all-cause mortality and for severe COVID-19 in inflammatory joint diseases (IJDs) and with antirheumatic therapies. METHODS: Through Swedish nationwide multiregister linkages, we selected all adult patients with rheumatoid arthritis (RA, n=53 455 in March 2020), other IJDs (here: spondyloarthropathies, psoriatic arthritis and juvenile idiopathic arthritis, n=57 112), their antirheumatic drug use, and individually matched population referents. We compared annual all-cause mortality March-September 2015 through 2020 within and across cohorts, and assessed absolute and relative risks for hospitalisation, admission to intensive care and death due to COVID-19 March-September 2020, using Cox regression. RESULTS: During March-September 2020, the absolute all-cause mortality in RA and in other IJDs was higher than 2015-2019, but relative risks versus the general population (around 2 and 1.5) remained similar during 2020 compared with 2015-2019. Among patients with IJD, the risks of hospitalisation (0.5% vs 0.3% in their population referents), admission to intensive care (0.04% vs 0.03%) and death (0.10% vs 0.07%) due to COVID-19 were low. Antirheumatic drugs were not associated with increased risk of serious COVID-19 outcomes, although for certain drugs, precision was limited. CONCLUSIONS: Risks of severe COVID-19-related outcomes were increased among patients with IJDs, but risk increases were also seen for non-COVID-19 morbidity. Overall absolute and excess risks are low and the level of risk increases are largely proportionate to those in the general population, and explained by comorbidities. With possible exceptions, antirheumatic drugs do not have a major impact on these risks.

Effectiveness and treatment retention of TNF inhibitors when used as monotherapy versus comedication with csDMARDs in 15 332 patients with psoriatic arthritis. Data from the EuroSpA collaboration.

BACKGROUND: Comedication with conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) during treatment with tumour necrosis factor inhibitors (TNFi) is extensively used in psoriatic arthritis (PsA), although the additive benefit remains unclear. We aimed to compare treatment outcomes in patients with PsA treated with TNFi and csDMARD comedication versus TNFi monotherapy. METHODS: Patients with PsA from 13 European countries who initiated a first TNFi in 2006-2017 were included. Country-specific comparisons of 1 year TNFi retention were performed by csDMARD comedication status, together with HRs for TNFi discontinuation (comedication vs monotherapy), adjusted for age, sex, calendar year, disease duration and Disease Activity Score with 28 joints (DAS28). Adjusted ORs of clinical remission (based on DAS28) at 12 months were calculated. Between-country heterogeneity was assessed using random-effect meta-analyses, combined results were presented when heterogeneity was not significant. Secondary analyses stratified according to TNFi subtype (adalimumab/infliximab/etanercept) and restricted to methotrexate as comedication were performed. RESULTS: In total, 15 332 patients were included (62% comedication, 38% monotherapy). TNFi retention varied across countries, with significant heterogeneity precluding a combined estimate. Comedication was associated with better remission rates, pooled OR 1.25 (1.12-1.41). Methotrexate comedication was associated with improved remission for adalimumab (OR 1.45 (1.23-1.72)) and infliximab (OR 1.55 (1.21-1.98)) and improved retention for infliximab. No effect of comedication was demonstrated for etanercept. CONCLUSION: This large observational study suggests that, as used in clinical practice, csDMARD and TNFi comedication are associated with improved remission rates, and specifically, comedication with methotrexate increases remission rates for both adalimumab and infliximab.

Comorbidities at diagnosis of rheumatoid arthritis: a population-based case-control study.

OBJECTIVES: Comorbidities contribute to the morbidity and mortality in RA, and are thus important to capture and treat early. In contrast to the well-studied comorbidity risks in established RA, less is known about the comorbidity pattern up until diagnosis of RA. We therefore compared whether the occurrence of defined conditions, and the overall comorbidity burden at RA diagnosis, is different from that in the general population, and if it differs between seropositive and seronegative RA. METHODS: Using Swedish national clinical and demographic registers, we identified new-onset RA patients (n = 11 086), and matched (1:5) to general population controls (n = 54 813). Comorbidities prior to RA diagnosis were identified in the Patient and Prescribed Drug Registers, and compared using logistic regression. RESULTS: At diagnosis of RA, respiratory (odds ratio (OR) = 1.58, 95% CI: 1.44, 1.74), endocrine (OR = 1.39, 95% CI: 1.31, 1.47) and certain neurological diseases (OR = 1.73, 95% CI: 1.59, 1.89) were more common in RA vs controls, with a similar pattern in seropositive and seronegative RA. In contrast, psychiatric disorders (OR = 0.87, 95% CI: 0.82, 0.92) and malignancies (OR = 0.88, 95% CI: 0.79, 0.97) were less commonly diagnosed in RA vs controls. The comorbidity burden was slightly higher in RA patients compared with controls (P <0.0001). CONCLUSION: We found several differences in comorbidity prevalence between patients with new-onset seropositive and seronegative RA compared with matched controls from the general population. These findings are important both for our understanding of the evolvement of comorbidities in established RA and for early detection of these conditions.

Risk of solid cancers overall and by subtypes in patients with psoriatic arthritis treated with TNF inhibitors - a Nordic cohort study.

OBJECTIVES: To investigate whether TNF inhibitors (TNFi) are associated with increased risk of solid cancer in patients with psoriatic arthritis (PsA). METHODS: From the Nordic clinical rheumatology registers (CRR) here: SRQ/ARTIS (Sweden), DANBIO (Denmark), NOR-DMARD (Norway), ROB-FIN (Finland) and ICEBIO (Iceland) we identified PsA patients who started a first TNFi 2001-2017 (n = 9655). We identified patients with PsA not treated with biologics from (i) the CRR (n = 14 809) and (ii) the national patient registers (PR, n = 31 350). By linkage to the national cancer registers, we collected information on incident solid cancer overall and for eight cancer types. We used Cox regression to estimate hazard ratio (HR) with 95% CI of cancer (per country and pooled) in TNFi-exposed vs biologics-naïve, adjusting for age, sex, calendar period, comorbidities and disease activity. We also assessed standardized incidence ratios (SIR) in TNFi-exposed PsA vs the general population (GP). RESULTS: We identified 296 solid cancers among the TNFi-exposed PsA patients (55 850 person-years); the pooled adjusted HR for solid cancer overall was 1.0 (0.9-1.2) for TNFi-exposed vs biologics-naïve PsA from the CRR, and 0.8 (0.7-1.0) vs biologics-naïve PsA from the PRs. There were no significantly increased risks for any of the cancer types under study. The pooled SIR of solid cancer overall in TNFi treated PsA vs GP was 1.0 (0.9-1.1). CONCLUSION: In this large cohort study from five Nordic countries, we found no increased risk of solid cancer in TNFi-treated PsA patients, neither for solid cancer overall nor for eight common cancer types.

Risk of neuroinflammatory events in arthritis patients treated with tumour necrosis factor alpha inhibitors: a collaborative population-based cohort study from Denmark and Sweden.

OBJECTIVES: To investigate whether tumour necrosis factor alpha inhibitors (TNFis) are associated with an increased risk of neuroinflammatory diseases among patients with arthritic diseases. METHODS: Cohorts of patients with rheumatoid arthritis (RA, n=25 796), psoriatic arthritis (PsA, n=8586) and ankylosing spondylitis (AS, n=9527) who initiated a TNFi treatment year 2000-2017 were identified from nationwide clinical rheumatology registers in Sweden and Denmark. Information on demyelinating disease and inflammatory neuropathy diagnoses was retrieved from prospective linkage to National Patients Register. A Cox proportional hazard model was used to estimate HRs and 95% CI comparing TNFi exposed and non-exposed, by disease and country. RESULTS: Among 111 455 patients with RA, we identified 270 (Sweden) and 51 (Denmark) events (all types of neuroinflammatory diseases combined), corresponding to crude incidence rates (per 1000 person-years) of 0.37 (Sweden) and 0.39 (Denmark) in TNFi-treated patients vs 0.39 (Sweden) and 0.28 (Denmark) in unexposed patients, and an age-sex-calendar-period-adjusted HR (95% CI) of 0.97 (0.72 to 1.33) (Sweden) and 1.45 (0.74 to 2.81) (Denmark) in TNFi exposed compared with non-exposed patients. For a total of 64 065 AS/PsA patients, the corresponding numbers were: 196 and 32 events, crude incidence rates of 0.59 and 0.87 in TNFi-treated patients vs 0.40 and 0.19 in unexposed patients, and HRs of 1.50 (1.07 to 2.11) and 3.41 (1.30 to 8.96), for Sweden and Denmark, respectively. For multiple sclerosis, the patterns of HRs were similar. CONCLUSIONS: Use of TNFi in AS/PsA, but not in RA, was associated with increased risk of incident neuroinflammatory disease, though the absolute risk was below one in 1000 patients/year.

Comparisons of risk prediction methods using nested case-control data.

Using both simulated and real datasets, we compared two approaches for estimating absolute risk from nested case-control (NCC) data and demonstrated the feasibility of using the NCC design for estimating absolute risk. In contrast to previously published results, we successfully demonstrated not only that data from a matched NCC study can be used to unbiasedly estimate absolute risk but also that matched studies give better statistical efficiency and classify subjects into more appropriate risk categories. Our result has implications for studies that aim to develop or validate risk prediction models. In addition to the traditional full cohort study and case-cohort study, researchers designing these studies now have the option of performing a NCC study with huge potential savings in cost and resources. Detailed explanations on how to obtain the absolute risk estimates under the proposed approach are given. Copyright © 2016 John Wiley & Sons, Ltd.

Risk of Psychiatric Disorders in Juvenile Idiopathic Arthritis: Population- and Sibling-Controlled Cohort and Cross-Sectional Analyses.

OBJECTIVE: The objective of this study was to examine the incidence and accumulated burden of psychiatric disorders in juvenile idiopathic arthritis (JIA) relative to the general population (GP) and to their same-sex siblings. METHODS: We performed an observational register-based study from July 1, 2006, to December 31, 2020, with three different study population contrasts: 1) patients with incident JIA versus five age- and sex-matched GP individuals (cohort), 2) patients with incident JIA versus full same-sex siblings (cohort), and 3) patients with prevalent JIA at age 18 versus matched GP individuals (cross-sectional). We investigated six groups of psychiatric disorders defined via International Classification of Diseases, Tenth Revision codes: mood and anxiety, suicidal behavior, eating, sleeping, substance use, psychotic, plus an overall combined outcome (ie, at least one of the six). Incidences rates were compared through Cox regression (contrasts 1 and 2) and logistic regression (contrast 3), all adjusted for demographics, comorbidities, and proxies for socioeconomic status. RESULTS: During 25,141 person-years of follow-up of 4939 incident patients with JIA, the incidence of the overall combined outcome was 20.1 per 1000 person-years in patients with JIA versus 13.1 per 1000 person-years in the GP (adjusted hazard ratio [HR] = 1.49 [95% confidence interval: 1.35-1.65]). The three most elevated HRs were obtained for sleeping disorder (1.91 [1.41-2.59]), suicidal behavior (1.60 [1.23-2.07]), and mood and anxiety disorders (1.46 [1.30-1.64]). The comparison of patients with JIA (n = 1815) with their siblings (n = 2050) for the overall combined outcome resulted in a nonstatistically significant HR (1.16 [0.82-1.64]). By age 18, patients with JIA were more likely to have been diagnosed with any psychiatric disorder (adjusted odds ratio = 1.37 [1.25-1.50]). CONCLUSION: There is an increased burden of psychiatric morbidity in JIA, which holds both individual and familial components.

How does current disease activity in rheumatoid arthritis affect the short-term risk of acute coronary syndrome? A clinical register based study from Sweden and Norway.

OBJECTIVES: To estimate short-term risks of acute coronary syndrome (ACS) in patients with rheumatoid arthritis (RA) as a function of current RA disease activity including remission. METHODS: Data from clinical visits of RA patients in Sweden (SE) and Norway (NO) between January 1st 2012 until December 31st 2020 were used. At each visit, patient's disease activity was assessed including remission status (measured with several metrics). Through linkage to national health and death registers, patients were followed up for incident ACS up to six months from each visit. We compared the short-term risk of ACS in patients not in remission vs. in remission using Cox regression analyses with robust standard errors, adjusted for country and covariates (e.g., age, sex, prednisolone use, comorbidities). We also explored disease activity categories as exposure. RESULTS: We included 212,493 visits (10,444 from Norway and 202,049 from Sweden) among 41,250 patients (72% women, mean age at visit 62 years). During the 6-month follow-ups, we observed 524 incident ACS events. Compared to patients in remission, patients currently not in remission had an increased rate of ACS: adjusted hazard ratio (95% confidence interval) 1.52 (1.24-1.85) with DAS28 metric. The crude absolute six-month risks were 0.2% for patients in remission vs. 0.4% for patients with DAS28 high disease activity. The use of alternative RA disease activity and remission metrics provided similar results. CONCLUSION: Failure to reach remission is associated with elevated short-term risks of ACS, underscoring the need for CV risk factor optimization in these patients.