Interstitial Lung Disease in Patients With Rheumatoid Arthritis or Psoriatic Arthritis Initiating Biologics and Controls: Data From 5 Nordic Registries.

OBJECTIVE: Interstitial lung disease (ILD) is one of the most common pulmonary manifestations of rheumatoid arthritis (RA), but its prevalence has not been investigated in psoriatic arthritis (PsA). The role of methotrexate (MTX) in ILD development remains under debate. This study (1) compares the incidences of ILD in patients with RA or PsA initiating a first biologic disease-modifying antirheumatic drug (bDMARD) to that in the general population, and (2) investigates the role of MTX comedication on ILD incidence. METHODS: Patients were identified in 5 rheumatology registries. Demographics, MTX use, and disease activity were retrieved. Matched subjects from the general population were available from 4 countries. Incidence of ILD during follow-up of up to 5 years was assessed through national patient registries. Subjects with prior ILD were excluded. Adjusted hazard ratios (HRs) were calculated for ILD incidence in patients vs the general population, and for MTX users vs nonusers. RESULTS: During follow-up of 29,478 patients with RA and 10,919 patients with PsA initiating a first bDMARD and 362,087 population subjects, 225, 23, and 251 cases of ILD were identified, respectively. HRs for ILD (vs population subjects) were 9.7 (95% CI 7.97-11.91) in RA and 4.4 (95% CI 2.83-6.97) in PsA. HRs for ILD with MTX comedication (vs nonuse) were 1.0 (95% CI 0.72-1.25) in RA and 0.9 (95% CI 0.38-2.05) in PsA. CONCLUSION: Among patients with RA and PsA initiating a bDMARD, the risk of ILD was higher than in the general population, and was highest in RA. MTX comedication was not a risk determinant for ILD.

Incidence of Clinically Diagnosed Psoriatic Arthritis in Sweden.

OBJECTIVE: Prior incidence estimates of psoriatic arthritis (PsA) vary considerably. We aimed to assess the annual incidence of clinically diagnosed PsA among adults in Sweden in 2014-2016, overall and stratified by age/sex/education/geography, and to investigate potential time trends in incidence in 2006-2018. Use of disease-modifying antirheumatic drugs (DMARDs) during the 2 years after diagnosis was also examined. METHODS: Patients (aged ≥ 18 years) with incident clinically diagnosed PsA in Sweden were identified from the National Patient Register (NPR) and/or the Swedish Rheumatology Quality Register (SRQ). Population statistics, stratification variables, and DMARD information were retrieved from other nationwide registers. Incidence was estimated according to a base case (BC) definition (ie, ≥ 1 main International Classification of Diseases, 10th revision, diagnosis of PsA [L40.5/M07.0-M07.3] from rheumatology/internal medicine in NPR, or a PsA diagnosis in SRQ during the relevant year, and no prior such diagnoses) and 4 different sensitivity analysis case definitions. RESULTS: The mean annual incidence of clinically diagnosed PsA among adults in Sweden in 2014-2016 was estimated at 21.77 per 100,000 person-years (PYs) at risk, according to the BC definition; 17.41 per 100,000 PYs at risk after accounting for diagnostic misclassification; and 15.78 to 28.83 per 100,000 PYs at risk across all sensitivity analyses. Incidence was slightly higher in female individuals, was lower in those with higher education (aged > 12 years), and peaked during the ages of 50 to 59 years. No apparent increasing or decreasing time trend was observed in 2006-2018. Within 2 years of diagnosis, 71.03% of patients had received DMARD therapy (22.37% biologic or targeted synthetic DMARDs). CONCLUSION: From 2014 to 2016, the annual incidence of clinically diagnosed PsA in the adult Swedish population was approximately 20 per 100,000 PYs at risk. Two years after diagnosis, almost three-quarters of patients had received DMARD therapy.

Effectiveness of JAK Inhibitors Compared With Biologic Disease-Modifying Antirheumatic Drugs on Pain Reduction in Rheumatoid Arthritis: Results From a Nationwide Swedish Cohort Study.

OBJECTIVE: To compare the effectiveness of JAK inhibitors (JAKis) and biologic disease-modifying antirheumatic drugs (bDMARDs) on pain in patients with rheumatoid arthritis. METHODS: In this retrospective study, we investigated patients with a diagnosis of rheumatoid arthritis, starting treatment with a JAKi (n = 1,827), a tumor necrosis factor inhibitor (TNFi; n = 6,422), an interleukin-6 inhibitor (n = 887), abatacept (n = 1,102), or rituximab (n = 1,149) in 2017 to 2019, using data from several linked Swedish national registers. Differences in change in pain, assessed with a visual analogue scale (0-100 mm), from baseline to 3 months, as well as proportions of patients remaining on initial treatment with low pain (visual analogue scale pain <20) at 12 months, were compared between treatments. Comparisons of treatment responses between JAKis and bDMARDs were evaluated using multivariable linear regression, adjusted for patient characteristics, comorbidities, current comedication, and previous treatment. RESULTS: JAKi treatment was associated with a greater decrease in pain at 3 months compared with TNFi treatment (adjusted mean additional decrease 4.0 mm; 95% confidence interval 1.6-6.3), with similar trends in comparisons with non-TNFi bDMARDs. More patients achieved low pain at 12 months on JAKis compared with TNFis, in particular among those previously treated with at least two bDMARDs (adjusted change contrast 5.3 percentage points; 95% confidence interval 1.0-9.6). CONCLUSION: JAKis had a slightly better effect on pain outcomes at 3 and 12 months compared with TNFis, with significantly greater differences in patients previously treated with at least two bDMARDs. The effect of JAKis on pain reduction was at least similar to that of non-TNFi bDMARDs.

Comparing DAPSA, DAPSA28, and DAS28-CRP in Patients With Psoriatic Arthritis Initiating a First Tumor Necrosis Factor Inhibitor Across Nine European Countries.

OBJECTIVE: Because 66/68 joint counts are not always performed in routine care, we aimed to determine which of the modified 28-joint disease activity index for psoriatic arthritis (DAPSA28) or 28-joint disease activity score with C-reactive protein (DAS28-CRP) should be preferred for monitoring disease activity in psoriatic arthritis (PsA) when the original DAPSA (66/68 joints) is not available. METHODS: Prospectively collected real-world data of European bionaive patients with PsA initiating a first tumor necrosis factor inhibitor were pooled. Remission and response status were evaluated at 6 months by remission (DAPSA ≤ 4, DAPSA28 ≤ 4, and DAS28-CRP < 2.6), response (75% improvement for DAPSA and DAPSA28), and combined EULAR good/moderate responses for DAS28-CRP. Logistic regression analyses on multiple imputed data were used to identify baseline predictors. RESULTS: Remission and response cohorts included 3,159 and 1,866 patients, respectively. The 6-month proportions achieving remission/response were DAPSA (27%/44%), DAPSA28 (28%/44%), and DAS28-CRP (59%/80%). Of 14 possible baseline predictors, 11 predicted both DAPSA and DAPSA28 remission (8 of which also predicted their response, indicated by "*"): longer disease duration*, male sex*, and higher CRP* were positive, whereas older age*, higher body mass index*, patient fatigue*, and global, physician global, health assessment questionnaire score*, and tender and swollen* joint counts were negative predictors. Eight and five of these predicted DAS28-CRP remission and response, respectively. CONCLUSION: In patients with PsA, DAPSA28 should be preferred over DAS28-CRP as a substitute for DAPSA when 66/68 joint counts are not available because of the large overlap in remission and response status and in predictors between DAPSA and DAPSA28.

Association between inflammatory joint disease and severe or treatment-resistant depression: population-based cohort and case-control studies in Sweden.

OBJECTIVE: To investigate whether the association between depression and inflammatory joint disease (IJD; rheumatoid arthritis [RA], psoriatic arthritis [PsA], ankylosing spondylitis/spondyloarthropathies [AS], and juvenile idiopathic arthritis [JIA]) is affected by the severity or treatment-resistance of depression. METHOD: Parallel cohort studies and case-control studies among 600,404 patients with a depressive episode identified in Swedish nationwide administrative registers. Prospective and retrospective risk for IJD in patients with depression was compared to matched population comparators, and the same associations were investigated in severe or treatment-resistant depression. Analyses were adjusted for comorbidities and sociodemographic covariates. RESULTS: Patients with depression had an increased risk for later IJD compared to population comparators (adjusted hazard ratio (aHR) for any IJD 1.34 [95% CI 1.30-1.39]; for RA 1.27 [1.15-1.41]; PsA 1.45 [1.29-1.63]; AS 1.32 [1.15-1.52]). In case-control studies, patients with depression more frequently had a history of IJD compared to population controls (adjusted odds ratio (aOR) for any IJD 1.43 [1.37-1.50]; RA 1.39 [1.29-1.49]; PsA 1.59 [1.46-1.73]; AS 1.49 [1.36-1.64]; JIA 1.52 [1.35-1.71]). These associations were not significantly different for severe depression or TRD. CONCLUSION: IJD and depression are bidirectionally associated, but this association does not seem to be influenced by the severity or treatment resistance of depression.

Spondyloarthritis in First-Degree Relatives and Spouses of Patients with Inflammatory Bowel Disease: A Nationwide Population-based Cohort Study from Sweden.

BACKGROUND AND AIMS: Register-based research suggests a shared pathophysiology between inflammatory bowel disease [IBD] and spondyloarthritis [SpA], but the role of familial [genetic and environmental] factors in this shared susceptibility is largely unknown. We aimed to compare the risk of SpA in first-degree relatives [FDRs] and spouses of IBD patients with FDRs and spouses of matched, population-based, reference individuals. METHODS: We identified 147 080 FDRs and 25 945 spouses of patients with incident IBD [N = 39 203] during 2006-2016, and 1 453 429 FDRs and 258 098 spouses of matched reference individuals [N = 390 490], by linking nationwide Swedish registers and gastrointestinal biopsy data. Study participants were followed 1987-2017. Cox regression was used to estimate hazard ratios [HRs] of SpA. RESULTS: During follow-up, 2430 FDRs of IBD patients [6.5/10 000 person-years] and 17 761 FDRs of reference individuals [4.8/10 000 person-years] were diagnosed with SpA, corresponding to an HR of 1.35 [95% CI:1.29, 1.41]. In subgroup analyses, the increased risk of SpA was most pronounced in FDRs of Crohn's disease patients [HR = 1.44; 95% CI:1.34,1.5 6] and of IBD patients aged <18 years at diagnosis [HR = 1.46; 95% CI: 1.27, 1.68]. IBD patients' spouses also had a higher SpA rate than reference individuals' spouses, but the difference was less pronounced [4.3 vs 3.5/10 000 person-years; HR = 1.22; 95% CI:1.09, 1.37]. No subgroup-specific risk pattern was identified among spouses. CONCLUSIONS: The observed shared familial risks between IBD and SpA support shared genetic factors in their pathogenesis. However, spouses of IBD patients were also at increased risk for SpA, reflecting the influence of environmental exposures or similarities in health-seeking patterns.

Malignancy outcomes in patients with rheumatoid arthritis treated with abatacept and other disease-modifying antirheumatic drugs: Results from a 10-year international post-marketing study.

OBJECTIVE: To evaluate the risk of malignancy (overall, breast, lung, and lymphoma) in patients with rheumatoid arthritis treated with abatacept, conventional synthetic (cs) disease-modifying antirheumatic drugs (DMARDs), and other biologic/targeted synthetic (b/ts)DMARDs in clinical practice. METHODS: Four international observational data sources were included: ARTIS (Sweden), RABBIT (Germany), FORWARD (USA), and BC (Canada). Crude incidence rates (IRs) per 1000 patient-years of exposure with 95% confidence intervals (CIs) for a malignancy event were calculated; rate ratios (RRs) were estimated and adjusted for demographics, comorbidities, and other potential confounders. RRs were then pooled in a random-effects model. RESULTS: Across data sources, mean follow-up for patients treated with abatacept (n = 5182), csDMARDs (n = 73,755), and other b/tsDMARDs (n = 37,195) was 3.0-3.7, 2.9-6.2, and 3.1-4.7 years, respectively. IRs per 1000 patient-years for overall malignancy ranged from 7.6-11.4 (abatacept), 8.6-13.2 (csDMARDs), and 5.0-11.8 (other b/tsDMARDs). IRs ranged from: 0-4.4, 0-3.3, and 0-2.5 (breast cancer); 0.1-2.8, 0-3.7, and 0.2-2.9 (lung cancer); and 0-1.1, 0-0.9, and 0-0.6 (lymphoma), respectively, for the three treatment groups. The numbers of individual cancers (breast, lung, and lymphoma) in some registries were low; RRs were not available. There were a few cases of lymphoma in some of the registries; ARTIS observed an RR of 2.8 (95% CI 1.1-6.8) with abatacept versus csDMARDs. The pooled RRs (95% CIs) for overall malignancy with abatacept were 1.1 (0.8-1.5) versus csDMARDs and 1.0 (0.8-1.3) versus b/tsDMARDs. CONCLUSIONS: This international, post-marketing observational safety study did not find any statistically significant increase in the risk of overall malignancies in pooled data in patients treated with abatacept compared with csDMARDs or with other b/tsDMARDs. Assessment of larger populations is needed to further evaluate the risks for individual cancers, especially lymphoma.

Mortality in patients with psoriatic arthritis in Sweden: a nationwide, population-based cohort study.

OBJECTIVES: To compare all-cause mortality and causes of death between patients with psoriatic arthritis (PsA) and the general population in Sweden. METHODS: Adults with at least one main PsA diagnosis (International Classification of Diseases-10: L40.5/M07.0-M07.3) from outpatient rheumatology/internal medicine departments 2001-2017 were identified from the National Patient Register. Each case was matched to five population comparator-subjects on sex/county/age at the case's first arthritis diagnosis. Follow-up ran from 1 January 2007, or from first PsA diagnosis thereafter, until death, emigration or 31 December 2018. Mortality was assessed overall, and stratified by sex and duration since diagnosis (diagnosis before/after 1 January 2007), using matched Cox proportional hazard regression (excluding/including adjustments for comorbidity) or Breslow test, as appropriate. Incidence rate ratios (IRR) of death, overall and stratified by sex/duration since diagnosis/age, as well as causes of death in PsA cases and comparator-subjects were also described. RESULTS: All-cause mortality was elevated in PsA (HR: 1.11 (95% CI: 1.07 to 1.16); IRR: 1.18 (95% CI: 1.13 to 1.22)), mainly driven by increased risks in women (HR: 1.23 (95% CI: 1.16 to 1.30)) and cases with longer time since diagnosis (HR: 1.18 (95% CI: 1.12 to 1.25)). IRR of death were significantly increased for all ages except below 40 years, with the numerically highest point-estimates for ages 40-59 years. When adjusted for comorbidity, however, the elevated mortality risk in PsA disappeared. Causes of death were similar among PsA cases/comparator-subjects, with cardiovascular disease and malignancy as the leading causes. CONCLUSIONS: Mortality risk in PsA in Sweden was about 10% higher than in the general population, driven by excess comorbidity and with increased risks mainly in women and patients with longer disease duration.

Abatacept and non-melanoma skin cancer in patients with rheumatoid arthritis: a comprehensive evaluation of randomised controlled trials and observational studies.

OBJECTIVES: This study aims to evaluate non-melanoma skin cancer (NMSC) risk associated with abatacept treatment for rheumatoid arthritis (RA). METHODS: This evaluation included 16 abatacept RA clinical trials and 6 observational studies. NMSC incidence rates (IRs)/1000 patient-years (p-y) of exposure were compared between patients treated with abatacept versus placebo, conventional synthetic (cs) disease-modifying antirheumatic drugs (DMARDs) and other biological/targeted synthetic (b/ts)DMARDs. For observational studies, a random-effects model was used to pool rate ratios (RRs). RESULTS: ~49 000 patients receiving abatacept were analysed from clinical trials (~7000) and observational studies (~42 000). In randomised trials (n=4138; median abatacept exposure, 12 (range 2-30) months), NMSC IRs (95% CIs) were not significantly different for abatacept (6.0 (3.3 to 10.0)) and placebo (4.0 (1.3 to 9.3)) and remained stable throughout the long-term, open-label period (median cumulative exposure, 28 (range 2-130 months); 21 335 p-y of exposure (7044 patients over 3 years)). For registry databases, NMSC IRs/1000 p-y were 5-12 (abatacept), 1.6-10 (csDMARDs) and 3-8 (other b/tsDMARDs). Claims database IRs were 19-22 (abatacept), 15-18 (csDMARDs) and 14-17 (other b/tsDMARDs). Pooled RRs (95% CIs) from observational studies for NMSC in patients receiving abatacept were 1.84 (1.00 to 3.37) vs csDMARDs and 1.11 (0.98 to 1.26) vs other b/tsDMARDs. CONCLUSIONS: Consistent with the warnings and precautions of the abatacept label, this analysis suggests a potential increase in NMSC risk with abatacept use compared with csDMARDs. No significant increase was observed compared with b/tsDMARDs, but the lower limit of the 95% CI was close to unity.

Predictors of DAPSA28 remission in patients with psoriatic arthritis initiating a first TNF inhibitor: results from 13 European registries.

OBJECTIVES: In bio-naïve patients with PsA initiating a TNF inhibitor (TNFi), we aimed to identify baseline predictors of Disease Activity index for PsA in 28 joints (DAPSA28) remission (primary objective) and DAPSA28 moderate response at 6 months, as well as drug retention at 12 months across 13 European registries. METHODS: Baseline demographic and clinical characteristics were retrieved and the three outcomes investigated per registry and in pooled data, using logistic regression analyses on multiply imputed data. In the pooled cohort, selected predictors that were either consistently positive or negative across all three outcomes were defined as common predictors. RESULTS: In the pooled cohort (n = 13 369), 6-month proportions of remission, moderate response and 12-month drug retention were 25%, 34% and 63% in patients with available data (n = 6954, n = 5275 and n = 13 369, respectively). Five common baseline predictors of remission, moderate response and 12-month drug retention were identified across all three outcomes. The odds ratios (95% CIs) for DAPSA28 remission were: age, per year: 0.97 (0.96-0.98); disease duration, years (<2 years as reference): 2-3 years: 1.20 (0.89-1.60), 4-9 years: 1.42 (1.09-1.84), ≥10 years: 1.66 (1.26-2.20); men vs women: 1.85 (1.54-2.23); CRP of >10 vs ≤10 mg/l: 1.52 (1.22-1.89) and 1 mm increase in patient fatigue score: 0.99 (0.98-0.99). CONCLUSION: Baseline predictors of remission, response and adherence to TNFi therapy were identified, of which five were common for all three outcomes, indicating that the predictors emerging from our pooled cohort may be considered generalizable from country level to disease level.

Comorbidities and chance of remission in patients with early rheumatoid arthritis receiving methotrexate as first-line therapy: a Swedish observational nationwide study.

OBJECTIVES: This study aims to examine whether comorbidities affect the likelihood of reaching primary remission on methotrexate monotherapy as the first disease-modifying antirheumatic drug (DMARD) in early rheumatoid arthritis (RA). METHODS: We used nationwide Swedish clinical and quality registers to collect RA disease activity measures and comorbidity data for patients diagnosed with RA 2007-2020 (n=11 001). The primary outcome was failure to reach 28-joint Disease Activity Score (DAS28) remission at 3 months. Secondary outcomes included Boolean, Simplified Disease Activity Index/Clinical Disease Activity Index remission, European Alliance of Associations for Rheumatology response and no swollen joint count at 3 and 6 months. For each comorbidity, and for combinations thereof, we calculated adjusted relative risks (RRs) of failure to reach remission, using modified Poisson regression. RESULTS: In total, 53% (n=4019/7643) failed to reach DAS28 remission after 3 months of methotrexate monotherapy, ranging from 66% (n=25/38) among patients with chronic kidney disease to 48% (n=154/319) in patients with previous cancer. The risk of not reaching DAS28 remission at 3 months (RR adjusted for sex and age) was increased among patients with endocrine (RR 1.08, 95% CI 1.01 to 1.15), gastrointestinal (RR 1.16, 95% CI 1.03 to 1.30), infectious (RR 1.21, 95% CI 1.06 to 1.38), psychiatric (RR 1.24, 95% CI 1.15 to 1.35) and respiratory comorbidities (RR 1.16, 95% CI 1.01 to 1.32). Having three or more comorbidity categories was associated with a 27% higher risk of DAS28 remission failure at 3 months. A similar pattern was observed for the secondary outcomes. CONCLUSIONS: Comorbidities decrease the chance of reaching remission on methotrexate as DMARD monotherapy in patients with early RA and are important to consider when assessing treatment outcomes.

Are JAKis more effective among elderly patients with RA, smokers and those with higher cardiovascular risk? A comparative effectiveness study of b/tsDMARDs in Sweden.

OBJECTIVES: To investigate whether the relative effectiveness of janus kinase inhibitors (JAKis) versus tumour necrosis factor inhibitors (TNFi) or other biological disease-modifying antirheumatic drugs in rheumatoid arthritis differ by the presence or absence of risk factors for cardiovascular (CV) disease, age, sex and smoking. METHODS: Through Swedish registers, we identified 13 493 individuals with 3166 JAKi, 5575 non-TNFi and 11 286 TNFi treatment initiations 2016-2022. All lines of therapy were included, with the majority in second line or higher. Treatment response was defined as the proportion reaching European Alliance of Associations for Rheumatology (EULAR) good response and Clinical Disease Activity Index (CDAI) remission, respectively, within 6 months. Crude percentage point differences in these proportions (JAKis, and non-TNFis, vs TNFis) overall and by risk factors were observed, and adjusted for confounders using linear regression models. Predicted probabilities of response and remission were estimated from adjusted Poisson models, and presented across CV risk and age. RESULTS: Overall, adjusted percentage point differences indicated higher response (+5.0%, 95% CI 2.2% to 7.9%) and remission (+5.8%, 95% CI 3.2% to 8.5%) with JAKis versus TNFis. The adjusted percentage point differences for response in those above 65, at elevated CV risk, and smokers were +5.9% (95% CI 2.7% to 9.0%), +8.3% (95% CI 5.3% to 11.4%) and +6.0% (95% CI 3.3% to 8.7%), respectively. The corresponding estimates for remission were +8.0% (95% CI 5.3% to 10.8%), +5.6% (95% CI 3.0% to 8.2%) and +7.6% (95% CI 5.5% to 9.7%). CONCLUSIONS: As used in clinical practice, response and remission at 6 months with JAKis are higher than with TNFi. Among patients with risk factors of concern, effectiveness is similar or numerically further increased. For individualised benefit-to-risk ratios to guide treatment choice, safety and effectiveness in specific patient segments should be considered.

Comparative cardiovascular safety with janus kinase inhibitors and biological disease-modifying antirheumatic drugs as used in clinical practice: an observational cohort study from Sweden in patients with rheumatoid arthritis.

OBJECTIVES: To compare the incidence of cardiovascular (CV) events in rheumatoid arthritis (RA) treated with janus kinase inhibitors (JAKi), tumour necrosis factor inhibitors (TNFi), or other biological disease-modifying antirheumatic drugs (bDMARDs), in clinical practice, and to contextualise these findings by comparing to the Swedish RA population and general population at large. METHODS: Patients with RA initiating JAKi, TNFi and non-TNFi bDMARDs were identified in the Swedish Rheumatology Quality Register between 2016 and 2021. Through linkages to national registers, a cohort of patients with RA, general population comparators, as well as covariates and incident major acute CV event (MACE, including myocardial infarction, stroke and fatal CV events) were identified until 2022. Crude and age-sex standardised rates were calculated and HRs estimated from multivariable Cox regression models using TNFi as reference. RESULTS: We identified 13 492 patients with RA initiating a JAKi, non-TNFi bDMARD or TNFi treatment. Among 3037 JAKi-initiators, 59 MACE events were observed. The age-sex standardised rates for MACE were similar in the JAKi (0.88 per 100 person years) and TNFi (0.91) cohorts. Fully adjusted models showed no increased rate of MACE with JAKi (HR=0.71, 95% CI 0.51 to 0.99), or non-TNFi bDMARD (HR=0.98; 95% CI 0.78 to 1.23) in comparison to TNFi. We found no evidence that this HR changed over time since treatment initiation. In a CV-enriched subset, we observed higher rates but similar HRs. CONCLUSIONS: As used in present clinical practice in Sweden, we found no evidence that CV risk is higher with JAKis than TNFis in RA.

Remission, response, retention and persistence to treatment with disease-modifying agents in patients with rheumatoid arthritis: a study of harmonised Swedish, Danish and Norwegian cohorts.

OBJECTIVE: Precision medicine in rheumatoid arthritis (RA) requires a good understanding of treatment outcomes and often collaborative efforts that call for data harmonisation. We aimed to describe how harmonisation across study cohorts can be achieved and investigate how the observed proportions reaching remission vary across remission criteria, study types, disease-modifying antirheumatic drugs (DMARDs) and countries, and how they relate to other treatment outcomes. METHODS: We used data from eight existing large-scale, clinical RA registers and a pragmatic trial from Sweden, Denmark and Norway. In these, we defined three types of treatment cohorts; methotrexate monotherapy (as first DMARD), tumour necrosis factor inhibitors (TNFi) (as first biological DMARD) and rituximab. We developed a harmonised study protocol defining time points during 36 months of follow-up, collected clinical visit data on treatment response, retention, persistence and six alternative definitions of remission, and investigated how these outcomes differed within and between cohorts, by treatment. RESULTS: Cohort sizes ranged from ~50 to 22 000 patients with RA. The proportions reaching each outcome varied across outcome metric, but with small to modest variations within and between cohorts, countries and treatment. Retention and persistence rates were high (>50% at 1 year), yet <33% of patients starting methotrexate or TNFi, and only 10% starting rituximab, remained on drug without other DMARDs added and achieved American Congress of Rheumatology/European Alliance of Associations for Rheumatology or Simplified Disease Activity Index remission at 1 year. CONCLUSION: Harmonisation of data from different RA data sources can be achieved without compromising internal validity or generalisability. The low proportions reaching remission, point to an unmet need for treatment optimisation in RA.

Microscopic colitis and risk of incident rheumatoid arthritis: A nationwide population-based matched cohort study.

BACKGROUND: Microscopic colitis (MC) has been linked to several autoimmune conditions. Results from previous studies on the association with rheumatoid arthritis (RA) have been inconsistent. AIM: To assess the risk of future RA in MC. METHODS: We conducted a nationwide matched cohort study in Sweden of 8179 patients with biopsy-verified MC (diagnosed in 2007-2017), 36,400 matched reference individuals and 8202 siblings without MC, with follow-up until 2021. Information on MC was obtained from all of Sweden's regional pathology registers (n = 28) through the ESPRESSO cohort. Data on incident RA were collected from the National Patient Register. Using Cox regression, we calculated adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs). RESULTS: During a median follow-up of 9.1 years (interquartile range = 6.7-11.7), 73 MC patients and 183 reference individuals from the general population were diagnosed with RA (99 vs. 55 events per 100,000 person-years), equivalent to one extra case of RA in 226 patients with MC followed for 10 years. These rates corresponded to an aHR of 1.83 (95% CI = 1.39-2.41). The aHR was highest during the first year of follow-up (2.31 [95% CI = 1.08-4.97]) and remained significantly elevated up to 5 years after MC diagnosis (aHR 2.16; 95% CI = 1.42-3.30). Compared to siblings, without MC, the aHR was 2.04 (95% CI = 1.18-3.56). CONCLUSION: Patients with MC are at a nearly two-fold risk of developing RA compared to the general population. Knowledge of this increased risk may expedite evaluation for RA in patients with MC presenting with joint symptoms and/or arthralgia, thus preventing delay until RA diagnosis.

Increasing healthcare costs in inflammatory bowel disease 2007-2020 in Sweden.

BACKGROUND: Inflammatory bowel disease has been linked to increasing healthcare costs, but longitudinal data on other societal costs are scarce. AIM: To assess costs, including productivity losses, in patients with prevalent Crohn's disease (CD) or ulcerative colitis (UC) in Sweden between 2007 and 2020. METHODS: We linked data from national registers on all patients with CD or UC and a matched (sex, birthyear, healthcare region and education) reference population. We assessed mean costs/year in Euros, inflation-adjusted to 2020, for hospitalisations, out-patient visits, medications, sick leave and disability pension. We defined excess costs as the mean difference between patients and matched comparators. RESULTS: Between 2007 and 2020, absolute mean annual societal costs in working-age (18-64 years) individuals decreased by 17% in CD (-24% in the comparators) and by 20% in UC (-27% in comparators), due to decreasing costs from sick leave and disability, a consequence of stricter sick leave regulations. Excess costs in 2007 were dominated by productivity losses. In 2020, excess costs were mostly healthcare costs. Absolute and excess costs increased in paediatric and elderly patients. Overall, costs for TNF inhibitors/targeted therapies increased by 274% in CD and 638% in UC, and the proportion treated increased from 5% to 26% in CD, and from 1% to 10% in UC. CONCLUSION: Between 2007 and 2020, excess costs shifted from productivity losses to direct healthcare costs; that is, the patients' compensation for sickness absence decreased, while society increased its spending on medications. Medication costs were driven both by expanding use of TNF inhibitors and by high costs for newer targeted therapies.

Calprotectin, a sensitive marker of inflammation, is robustly assessed in plasma from patients with early or established rheumatoid arthritis by use of different laboratory methods.

Calprotectin (S100A8/S100A9, MRP8/MRP14) is a major leukocyte protein found to be more sensitive than C-Reactive Protein (CRP) and Erythrocyte Sedimentation Rate (ESR) as a marker of inflammation in patients with rheumatoid arthritis (RA). The present objective was to explore the robustness of calprotectin assessments by comparing two different laboratory methods assessing calprotectin in plasma samples from patients with early or established RA. A total of 212 patients with early RA (mean (SD) age 52(13.3) years, disease duration 0.6(0.5) years) and 177 patients with established RA (mean (SD) age 52.9(13.0) years, disease duration 10.0(8.8) years) were assessed by clinical, laboratory, and ultrasound examinations. Frozen plasma samples (-80 °C) were analysed for calprotectin levels at baseline, 1, 2, 3, 6 and 12 months by use of either enzyme-linked immunosorbent assay (ELISA) or fluoroenzyme immunoassay (FEIA). The ELISA technique used kits from Calpro AS and the FEIA technology was assessed on an automated Thermo Fisher Scientific instrument. The results showed high correlations between the two methods at baseline and during follow-up, with Spearman correlation at baseline 0.93 (p < 0.001) in the early and 0.96 (p < 0.001) in the established RA cohorts. The correlations between each of the two calprotectin assessments and clinical examinations had similar range. Calprotectin correlated well with clinical examinations, with at least as high correlations as CRP and ESR. The present study showed similar results for the two analytical methods, supporting the robustness of calprotectin analyses, and suggest calprotectin in plasma to be included in the assessments offered by clinical routine laboratories.

Methotrexate treatment in early psoriatic arthritis in comparison to rheumatoid arthritis: an observational nationwide study.

INTRODUCTION: We aimed to compare the proportions of patients with newly diagnosed psoriatic arthritis (PsA) and rheumatoid arthritis (RA) remaining on methotrexate (regardless of other disease-modifying antirheumatic drug (DMARD)-changes), and proportions not having started another DMARD (regardless of methotrexate discontinuation), within 2 years of starting methotrexate, as well as methotrexate effectiveness. METHODS: Patients with DMARD-naïve, newly diagnosed PsA, starting methotrexate 2011-2019, were identified from high-quality national Swedish registers and matched 1:1 to comparable patients with RA. Proportions remaining on methotrexate and not starting another DMARD were calculated. For patients with disease activity data at baseline and 6 months, response to methotrexate monotherapy was compared through logistic regression, applying non-responder imputation. RESULTS: In total, 3642/3642 patients with PsA/RA were included. Baseline patient-reported pain and global health were similar, whereas patients with RA had higher 28-joint scores and evaluator-assessed disease activity. Two years after methotrexate start, 71% of PsA vs 76% of patients with RA remained on methotrexate, 66% vs 60% had not started any other DMARD, and 77% vs 74% had not started specifically a biological or targeted synthetic DMARD. At 6 months, the proportions of patients with PsA versus RA achieving pain-scores ≤15 mm were 26% vs 36%; global health ≤20 mm: 32% vs 42%; evaluator-assessed 'remission': 20% vs 27%, with corresponding adjusted ORs (PsA vs RA) of 0.63 (95% CI 0.47 to 0.85); 0.57 (95% CI 0.42 to 0.76) and 0.54 (95% CI 0.39 to 0.75). DISCUSSION: In Swedish clinical practice, methotrexate use is similar in PsA and RA, both regarding initiation of other DMARDs and methotrexate retention. On a group level, disease activity improved during methotrexate monotherapy in both diseases, although more so in RA.

Increasing Risk of Lymphoma Over Time in Crohn's Disease but Not in Ulcerative Colitis: A Scandinavian Cohort Study.

BACKGROUND & AIMS: Earlier studies have provided varying risk estimates for lymphoma in patients with inflammatory bowel disease (IBD), but often have been limited by detection biases (especially during the first year of follow-up evaluation), misclassification, and small sample size; and rarely reflect modern-day management of IBD. METHODS: We performed a binational register-based cohort study (Sweden and Denmark) from 1969 to 2019. We compared 164,716 patients with IBD with 1,639,027 matched general population reference individuals. Cox regression estimated hazard ratios (HRs) for incident lymphoma by lymphoma subtype, excluding the first year of follow-up evaluation. RESULTS: From 1969 to 2019, 258 patients with Crohn's disease (CD), 479 patients with ulcerative colitis (UC), and 6675 matched reference individuals developed lymphoma. This corresponded to incidence rates of 35 (CD) and 34 (UC) per 100,000 person-years in IBD patients, compared with 28 and 33 per 100,000 person-years in their matched reference individuals. Although both CD (HR, 1.32; 95% CI, 1.16-1.50) and UC (HR, 1.09; 95% CI, 1.00-1.20) were associated with an increase in lymphoma, the 10-year cumulative incidence difference was low even in CD patients (0.08%; 95% CI, 0.02-0.13). HRs have increased in the past 2 decades, corresponding to increasing use of immunomodulators and biologics during the same time period. HRs were increased for aggressive B-cell non-Hodgkin lymphoma in CD and UC patients, and for T-cell non-Hodgkin lymphoma in CD patients. Although the highest HRs were observed in patients exposed to combination therapy (immunomodulators and biologics) or second-line biologics, we also found increased HRs in patients naïve to such drugs. CONCLUSIONS: During the past 20 years, the risk of lymphomas have increased in CD, but not in UC, and were driven mainly by T-cell lymphomas and aggressive B-cell lymphomas.

The National Prevalence of Clinically Diagnosed Psoriatic Arthritis in Sweden in 2017.

OBJECTIVE: Psoriatic arthritis (PsA) prevalence estimates vary across studies; studies based on national data are few. We aimed to estimate the prevalence of clinically diagnosed PsA in Sweden in 2017, overall and stratified by sex, age, education, and geography, and to quantify disease-modifying antirheumatic drug (DMARD) use among those in contact with specialized rheumatology care between 2015 and 2017. METHODS: Individuals who were 18 to 79 years of age, alive and residing in Sweden on December 31, 2017, and had a prior PsA diagnosis were identified from the National Patient Register (NPR) and/or the Swedish Rheumatology Quality Register (SRQ). PsA prevalence was estimated according to a base case (BC) definition (ie, ≥ 1 main PsA International Classification of Diseases code from rheumatology or internal medicine departments in the NPR or a PsA diagnosis in the SRQ), according to 4 sensitivity analysis definitions, and for those seen in specialized rheumatology care between 2015 and 2017. In the latter group, DMARD use during 2017 was also assessed. Data for stratifications were retrieved from national registers. RESULTS: The crude national prevalence of PsA for adults, aged 18 to 79 years, was estimated at 0.39%, according to the BC definition; 0.34% after accounting for diagnostic misclassification; and 0.32% to 0.50% across all sensitivity analyses. The prevalence was lower in males and in those with a higher level of education. The prevalence for those seen in specialized rheumatology care between 2015 and 2017 was estimated at 0.24%. During 2017, 32% of patients in this population received biologic or targeted synthetic DMARDs, and 41% received conventional synthetic DMARDs only. CONCLUSION: The prevalence of clinically diagnosed PsA in adults, aged 18 to 79 years, in Sweden in 2017 was around 0.35%. Among PsA cases in recent contact with specialized rheumatology care, almost three-fourths received DMARD therapy in 2017.