Incidence of juvenile idiopathic arthritis in Finland, 2000-2020.

OBJECTIVE: Previous epidemiological data of JIA in Finland are from the turn of the millennium. We aimed to determine the recent annual incidence of JIA in several consecutive years in Finland and to explore the differences in incidence between sexes, age groups, and regions. METHODS: We analyzed all children <16 years of age who met the ILAR classification criteria for JIA. Cases from 2000-2020 were identified from two national registers: the Care Register for Health Care of the Finnish Institute for Health and Welfare and the Reimbursement Register containing medication data from the Social Insurance Institution of Finland; cases from 2016-2020 were identified from the Finnish Rheumatology Quality Register. RESULTS: The incidence of JIA was 31.7 per 100 000 (95% CI 30.2, 33.1), according to the Care Register in 2000-2020 and peaked in 2010-2014. No considerable differences in incidence rates were observed among registers. In all age groups, incidence in girls was predominant compared with boys. The incidence in girls peaked at the ages of 2 years and 14-15 years. Decreasing incidence was observed among boys 0-3 years old during the entire study period, whereas increasing incidence was observed among teenage girls and boys 4-7 years old in 2000-2013. CONCLUSION: The incidence of JIA is not only very high with respect to that in other parts of the world but also higher than previously reported in Finland. The incidence varied by region and year but was not higher at the end than the beginning of the study period.

Disease burden measured by patient-reported outcomes: does psoriatic arthritis feel worse than rheumatoid arthritis? A cross-sectional nationwide study.

OBJECTIVES: To study the subjective disease burden of patients with psoriatic arthritis (PsA) and rheumatoid arthritis (RA), using patient-reported outcomes (PROs) cross-sectionally. METHODS: Data of 3598 patients with PsA and 13913 with RA were extracted from the database. Measures included the VAS-values of pain, fatigue and patient global assessment (PGA), HAQ, and disease activity at the most recent visit/remote contact in the period 1.2020 to 9.2021. Values were compared between patients with PsA and RA overall, and by sex and age (<50, 50-59, 60-69 and ≥70 years). Regression analyses were applied. RESULTS: The overall median (IQR)-values for pain were 29 (10, 56) for PsA and 26 (10, 51) for RA, 29 (9, 60) and 28 (8, 54) for fatigue, 28 (10, 52) and 29 (11, 51) for PGA, 0.4 (0, 0.9) and 0.5 (0, 1.0) for HAQ (p<0.001 for all comparisons; adjusted for sex and age). The median (IQR)-values for pain, fatigue, PGA and HAQ were higher for PsA vs. RA in most age groups for males and females. All PROs were higher in older patients with both diagnoses. The median values for DAS28, doctor global assessment, ESR and CRP were 1.9 vs. 2.0, 8 vs. 8, 7 vs. 8 and 2 vs. 3 in PsA and RA, respectively. CONCLUSIONS: Overall, both PsA and RA groups showed moderate disease control by patients' perspective, but the burden of disease was higher especially in women with PsA compared to RA. Disease activity was similar and low in both diseases.

Finding specific 10-joint Juvenile Arthritis Disease Activity Score (JADAS10) and clinical JADAS10 cut-off values for disease activity levels in non-systemic juvenile idiopathic arthritis: a Finnish multicentre study.

OBJECTIVES: To establish the cut-off values for inactive disease, as well as low disease activity (LDA), moderate disease activity (MDA) and high disease activity (HDA) in non-systemic JIA based on the Juvenile Arthritis Disease Activity Score (JADAS) and assessed with the 10-joint JADAS (JADAS10) and clinical JADAS10 (cJADAS10). METHODS: In a multicentre cross-sectional study consisting of ∼20% of all patients with JIA in Finland (n = 509), we obtained data on their most recent registered visits between January 2013 and January 2014. We calculated the JADAS10 and cJADAS10 and established the cut-off values of both of these scores using two different receiver operating characteristics-based statistical methods. RESULTS: Of the 509 patients studied, 65.8% were females and 53.8% had polyarticular disease. The most suitable method for determining cut-off values was the Youden index. In oligoarticular patients, a JADAS10 score of 0-0.5 represented inactive disease, 0.6-2.7 LDA and ≥2.8 MDA. In polyarticular disease, a JADAS10 score of 0-0.7 represented inactive disease, 0.8-3.9 LDA and ≥4.0 MDA. The cut-off values for HDA were not possible to establish because only two visits fulfilled HDA criteria. CONCLUSION: We established cut-off values for LDA and MDA. A reliable definition for HDA will require more patients. In the clinical setting, both the cJADAS10 and JADAS10 serve equally well both for research and quality control purposes. In the future, uniform clinical disease activity levels should be established. We also suggest revising and validating the criteria for HDA. Valid and robust cut-off values for disease activity levels can guide both clinicians and researchers and equip them for quality control.

Similar levels of disease activity and remission rates in patients with psoriatic arthritis and rheumatoid arthritis-results from the Finnish quality register.

OBJECTIVES: To compare the current disease activity and remission rates, and their regional variation in patients with psoriatic arthritis (PsA) and rheumatoid arthritis (RA) in Finland. METHODS: Data of patients' most recent visit in 1/2020-9/2021 were extracted from the Finnish Rheumatology Quality Register. Measures for disease activity and remission included joint counts, DAS28, cDAPSA, CDAI, the Boolean definition, and physician assessment. Regression analyses were applied, adjusted for age and sex. RESULTS: Data of 3598 patients with PsA (51% female, mean age 54 years) and 13,913 patients with RA (72% female, 74% ACPA-positive, mean age 62 years) were included. The median (IQR) DAS28 was 1.9 (1.4, 2.6) in PsA and 2.0 (1.6, 2.7) in RA (p = 0.94); for cDAPSA, the median (IQR) values were 7.7 (3.1, 14) in PsA and 7.7 (3.3, 14) in RA (p < 0.001). In all regions in both diseases, the median DAS28 was ≤ 2.6 and the median cDAPSA < 13. Remission rates included DAS28 < 2.6 in 73% in PsA and 69% in RA (p = 0.17) and Boolean remission in 17% in PsA and 15% in RA (p < 0.001). By other definitions of remission, the rates ranged between 30% and 46%. Methotrexate was currently used by 49% in PsA and 57% in RA (p < 0.001). Self-administered bDMARDs were currently used by 37% in PsA and 21% in RA (p < 0.001). CONCLUSION: The overall disease activity was low and similar in patients with PsA and RA across the country. Remission rates varied between 15 and 73%, depending on the definition but were similar in PsA and RA. Key Points • The disease activity and clinical picture was similar between patients with PsA and RA, in a cross-sectional setting in 1.2020-9.2021. • A significant majority of patients with PsA had low disease activity or were in remission according to cDAPSA. Majority of patients with RA were in remission according to DAS28. • Patients with PsA and RA used methotrexate similarly. The utilization of bDMARDs was more prevalent in patients with PsA.

Intense symptoms of pain are associated with poor sleep, fibromyalgia, depression and sleep apnea in patients with rheumatoid arthritis and psoriatic arthritis. A register-based study.

OBJECTIVES: To study whether poor sleep and comorbidities are associated with high symptom levels of patient-reported outcomes (PROs) pain, patient global assessment and fatigue in patients with rheumatoid arthritis (RA) and psoriatic arthritis (PsA), in a nation-wide cross-sectional setting. METHODS: Clinical data were extracted from The Finnish Rheumatology Quality Register between 1.2021 and 9.2022. Self-reported sleep was categorized as "good" (little/no difficulties) or "poor" (great difficulties/can't) sleep. Data concerning comorbidities were collected from national registers. Descriptive statistics were used. Regression analyses were applied to analyze independent associations of sleep status, comorbidities and disease activity with pain in RA and PsA, adjusting for age and sex. RESULTS: Among 13,512 patients with RA, 6052 [mean (SD) age 62 (13), 71% female] had sleep status reported; in PsA 1861/3636 [age 55 (13), 48% female]. In RA, 5072 (84%) reported good and 980 (16%) poor sleep; the corresponding numbers in PsA were 1460 (78%) and 401 (22%). Median values for objective disease activity were low and similar in patients with poor sleep and good sleep in both diseases. Among patients with no swollen joints, the median values for PROs were approximately three times higher for patients with poor sleep vs. good sleep in both diagnoses (P<0.001). In regression analyses, "poor" sleep was independently associated with higher symptoms in pain [B (95%CI) 20 (18,22) in RA and 23 (19, 26) in PsA], followed by comorbid fibromyalgia, as well as depression in RA and sleep apnea in PsA. CONCLUSION: "Poor" sleep quality and comorbidities are independently associated with pain. Patient's sleep status is important to know especially in patients with severe symptoms without objective disease activity.

Initial presentation of early rheumatoid arthritis.

OBJECTIVES: To study the joint distribution and clinical picture of rheumatoid arthritis (RA) at the initial presentation in seropositive (anti-citrullinated protein antibody (ACPA) and/or rheumatoid factor (RF) positive) and negative patients and the effect of duration of symptoms on the clinical picture. METHODS: Data of patients who received reimbursement for DMARDs for newly diagnosed RA in 1/2019 to 9/2021 were extracted from the national databases. Joint counts, presence of symmetrical swelling, other disease activity measures, and patient reported outcomes (PROs) were compared in seropositive and negative patients. Regression analyses were applied to compare clinical variables in patients with duration of symptoms of <3, 3-6, and >6 months, adjusted for age, sex, and seropositivity. RESULTS: Data of 1816 ACPA and RF-tested patients were included. Symmetrical swelling was present in 75% of patients. Seronegative versus positive patients had higher value for all disease activity measures and PROs including median swollen joint count (SJC46 10 versus 5) and DAS28 (4.7 versus 3.7), (p<0.001). Patients diagnosed in <3 months had higher median pain VAS (62 versus 52 and 50, p<0.001) and HAQ (1.1 versus 0.9 and 0.75, p = 0.002) compared to those with a duration of symptoms of 3-6 and >6 months. Patients diagnosed >6 months were ACPA-positive more frequently (77% versus 70% in other groups, p = 0.045). CONCLUSION: Incident RA presents mainly as symmetric arthritis. Seronegative patients have higher disease burden at the initial presentation. Patients experiencing more severe pain and decreased functional ability are diagnosed earlier, regardless of ACPA- status.

Etanercept for patients with juvenile idiopathic arthritis: drug levels and influence of concomitant methotrexate: observational study.

BACKGROUND: Etanercept (ETN) is widely used tumour necrosis factor (TNF) blocker in the treatment of juvenile idiopathic arthritis (JIA) when traditional synthetic disease modifying antirheumatic drug (sDMARD) therapy is not sufficient. There is limited information about the effects of methotrexate (MTX) on serum ETN concentration in children with JIA. We aimed to investigate whether ETN dose and concomitant MTX would effect ETN serum trough levels in JIA patients, and whether concomitant MTX have an influence on the clinical response in patients with JIA receiving ETN. METHODS: In this study, we collected the medical record data of 180 JIA patients from eight Finnish pediatric rheumatological centres. All these patients were treated with ETN monotherapy or combination therapy with DMARD. To evaluate the ETN concentrations, blood samples of the patients were collected between injections right before the subsequent drug. Free ETN level was measured from serum. RESULTS: Ninety-seven (54%) of the patients used concomitant MTX, and 83 (46%) received either ETN monotherapy or used sDMARDs other than MTX. A significant correlation was noted between ETN dose and drug level [r = 0.45 (95% CI: 0.33-0.56)]. The ETN dose and serum drug level were correlated (p = 0.030) in both subgroups - in MTX group [r = 0.35 (95% CI: 0.14-0.52)] and in non-MTX group [r = 0.54 (95% CI: 0.39-0.67)]. CONCLUSION: In the present study, we found that concomitant MTX had no effect on serum ETN concentration or on clinical response. In addition, a significant correlation was detected between ETN dose and ETN concentration.

Pain-coping scale for children and their parents: a cross-sectional study in children with musculoskeletal pain.

BACKGROUND: In a chronic pain-causing disease such as juvenile idiopathic arthritis, the quality of coping with pain is crucial. Parents have a substantial influence on their children's pain-coping strategies. This study aimed to develop scales for assessing parents' strategies for coping with their children's pain and a shorter improved scale for children usable in clinical practice. METHODS: The number of items in the Finnish version of the pain-coping questionnaire for children was reduced from 39 to 20. A corresponding reduced scale was created for parental use. We recruited consecutive patients from nine hospitals evenly distributed throughout Finland, aged 8-16 years who visited a paediatric rheumatology outpatient clinic and reported musculoskeletal pain during the past week. The patients and parents rated the child's pain on a visual analogue scale from 0 to 100 and completed pain-coping questionnaires and depression inventories. The selection process of pain questionnaire items was performed using factor analyses. RESULTS: The average (standard deviation) age of the 130 patients was 13.0 (2.3) years; 91 (70%) were girls. Four factors were retained in the new, improved Pain-Coping Scales for children and parents. Both scales had 15 items with 2-5 items/factor. The goodness-of-fit statistics and Cronbach's alpha reliability coefficients were satisfactory to good in both scaled. The criterion validity was acceptable as the demographic, disease related, and the depression and stress questionnaires correlated with the subscales. CONCLUSIONS: We created a shorter, feasible pain-coping scale for children and a novel scale for caregivers. In clinical work, the pain coping scales may serve as a visualisation of different types of coping strategies for paediatric patients with pain and their parents and facilitate the identification of families in need of psychological support.

Validating 10-joint juvenile arthritis disease activity score cut-offs for disease activity levels in non-systemic juvenile idiopathic arthritis.

Objectives: To validate cut-offs of the Juvenile Arthritis Disease Activity Score 10 (JADAS10) and clinical JADAS10 (cJADAS10) and to compare them with other patient cohorts. Methods: In a national multicentre study, cross-sectional data on recent visits of 337 non-systemic patients with juvenile idiopathic arthritis (JIA) were collected from nine paediatric outpatient units. The cut-offs were tested with receiver operating characteristic curve-based methods, and too high, too low and correct classification rates (CCRs) were calculated. Results: Our earlier presented JADAS10 cut-offs seemed feasible based on the CCRs, but the cut-off values between low disease activity (LDA) and moderate disease activity (MDA) were adjusted. When JADAS10 cut-offs for clinically inactive disease (CID) were increased to 1.5 for patients with oligoarticular disease and 2.7 for patients with polyarticular disease, as recently suggested in a large multinational register study, altogether 11 patients classified as CID by the cut-off had one active joint. We suggest JADAS10 cut-off values for oligoarticular/polyarticular disease to be in CID: 0.0-0.5/0.0-0.7, LDA: 0.6-3.8/0.8-5.1 and MDA: >3.8/5.1. Suitable cJADAS10 cut-offs are the same as JADAS10 cut-offs in oligoarticular disease. In polyarticular disease, cJADAS10 cut-offs are 0-0.7 for CID, 0.8-5.0 for LDA and >5.0 for MDA. Conclusion: International consensus on JADAS cut-off values is needed, and such a cut-off for CID should preferably exclude patients with active joints in the CID group.

Defining new clinically derived criteria for high disease activity in non-systemic juvenile idiopathic arthritis: a Finnish multicentre study.

OBJECTIVES: To redefine criteria for high disease activity (HDA) in JIA, to establish HDA cut-off values for the 10-joint Juvenile Arthritis Disease Activity Score (JADAS10) and clinical JADAS10 (cJADAS10) and to describe the distribution of patients' disease activity levels based on the JADAS cut-off values in the literature. METHODS: Data on 305 treatment-naïve JIA patients were collected from nine paediatric units treating JIA. The median parameters of the JADAS were proposed to be the clinical criteria for HDA. The cut-off values were assessed by using two receiver operating characteristics curve-based methods. The patients were divided into disease activity levels based on currently used JADAS cut-off values. RESULTS: We proposed new criteria for HDA. At least three of the following criteria must be satisfied in both disease courses: in oligoarthritis, two or more active joints, ESR above normal, physician global assessment (PGA) of disease activity ≥2 and parent/patient global assessment (PtGA) of well-being ≥2; in polyarthritis, six or more active joints, ESR above normal, PGA of overall disease activity ≥4 and PtGA of well-being ≥2. The HDA cut-off values for JADAS10 (cJADAS) were ≥6.7 (6.7) for oligoarticular and ≥15.3 (14.1) for polyarticular disease. The distribution of the disease activity levels based on the JADAS cut-off values in the literature varied markedly based on which cut-offs were used. CONCLUSION: New clinically derived criteria for HDA in JIA and both JADAS and cJADAS cut-off values for HDA were proposed.