TY - JOUR

T1 - Do patient-reported measures of disease activity in rheumatoid arthritis vary between countries? Results from a Nordic collaboration

AU - Delcoigne, Bénédicte

AU - Provan, Sella Aarrestad

AU - Hammer, Hilde Berner

AU - Di Giuseppe, Daniela

AU - Frisell, Thomas

AU - Glintborg, Bente

AU - Grondal, Gerdur

AU - Gudbjornsson, Bjorn

AU - Hetland, Merete Lund

AU - Michelsen, Brigitte

AU - Nordström, Dan

AU - Relas, Heikki

AU - Askling, Johan

N1 - Publisher Copyright: © The Author(s) 2022. Published by Oxford University Press on behalf of the British Society for Rheumatology.

PY - 2022

Y1 - 2022

N2 - 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.

AB - 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.

KW - disease activity

KW - inter-country comparison

KW - pain

KW - patient-reported outcome (PRO)

KW - rheumatoid arthritis

U2 - 10.1093/rheumatology/keac081

DO - 10.1093/rheumatology/keac081

M3 - Journal article

C2 - 35139178

AN - SCOPUS:85141889547

VL - 61

SP - 4286

EP - 4296

JO - Rheumatology

JF - Rheumatology

SN - 1462-0324

IS - 11

ER -