Validity of clinical psoriatic arthritis diagnoses made by rheumatologists in the Swedish National Patient Register

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.

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.

Danish translation and cultural adaptation of the Psoriatic arthritis UnclutteRed screening Evaluation (PURE-4) scale

OBJECTIVES

Screening tools are needed to help to identify psoriatic arthritis in patients with psoriasis. The Psoriatic arthritis UnclutteRed screening Evaluation (PURE-4) questionnaire was developed for this purpose and has been shown to perform very well. The aim of this study was to translate and culturally adapt the PURE-4 scale into the Danish language.

METHOD

The translational process followed the guidelines provided by the Mapi Research Trust, which include the following steps: forward translation, backward translation, cognitive interviews, and proofreading. Following the guidelines helps to maintain the content validity of the questionnaire and secures a translation that is both literally and culturally appropriate for the target population.

RESULTS

All four items were modified throughout the translation process, involving mainly minor changes such as the addition of more colloquial words in the Danish version. The new Danish version of PURE-4 was reviewed and approved by the original developers.

CONCLUSIONS

A Danish version of the PURE-4 questionnaire was produced. The translation and cultural adaptation of PURE-4 constitute the first step in the validation of the questionnaire in Danish patients with psoriasis.

Health-related quality of life in gout, psoriatic arthritis, rheumatoid arthritis and ankylosing spondylitis, results from a cross-sectional survey in Western Sweden

OBJECTIVES

Inflammatory joint diseases (IJDs) substantially affect health-related quality of life (HRQoL). We aimed to compare HRQoL between patients with gout, psoriatic arthritis (PsA), rheumatoid arthritis (RA), and ankylosing spondylitis (AS): (i) overall; (ii) stratified by sex; and (iii) between women and men with the same IJD diagnosis.

METHOD

A survey including the RAND36-Item Health Survey for assessing HRQoL was sent to patients with a diagnosis of gout, PsA, RA, or AS, registered at a rheumatology clinic or primary care centre during 2015-2017. HRQoL was compared across IJDs. Because of age differences between diagnoses, age-matched analyses were performed.

RESULTS

In total, 2896/5130 (56.5%) individuals responded to the questionnaire. Of these, 868 had gout, 699 PsA, 742 RA, and 587 AS. Physical component summary (PCS) scores were more affected than mental component summary (MCS) scores for all diagnoses (PCS range: 39.7-41.2; MCS range: 43.7-48.9). Patients with gout reported better PCS scores than patients with PsA, RA, and AS, who reported similar scores in age-matched analysis. MCS scores were close to normative values for the general population and similar across IJDs. When comparing women and men with respective IJDs, women reported worse PCS (range, all IJDs: 34.5-37.4 vs 37.5-42.5) and MCS (PsA: 44.0 vs 46.8; RA: 46.1 vs 48.7) scores.

CONCLUSION

We found that patients with gout reported better PCS scores than patients with other IJDs, for whom the results were similar. Women reported overall worse PCS and MCS scores than men.

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.

MRI Findings in Axial Psoriatic Spondylarthritis

Psoriatic arthritis is a significant medical condition with a high prevalence, a wide variety of non-specific symptoms, and a high degree of overlap with other spondylarthritis disorders, particularly ankylosing spondylitis. Hence, knowledge of the magnetic resonance imaging (MRI) manifestations and a multidisciplinary strategy are required for the better management of these patients. We searched publications from the last 10 years and focused on the most relevant ones which discussed the classification criteria, the MRI characteristics of axial psoriatic arthritis, the importance of MRI for follow up, and the reliability of skin and synovial biopsy. Axial spondylarthritis can be diagnosed and followed up on using the well-established MRI technique and, additionally, a biopsy. The analysis and concordance between them can provide new directions for future studies.