Defining the Minimal Important Change and Meaningful Change Value of the Disease Activity Index for Psoriatic Arthritis: A Chinese Longitudinal Study

Yijie Liu; Minjia Tan; Kun Hu; Sichun Deng; Lu Jian; Junchen Chen; Mi Zhang; Yehong Kuang

doi:10.3899/jrheum.2023-1085

Defining the Minimal Important Change and Meaningful Change Value of the Disease Activity Index for Psoriatic Arthritis: A Chinese Longitudinal Study

J Rheumatol. 2024 May 1:jrheum.2023-1085. doi: 10.3899/jrheum.2023-1085. Online ahead of print.

Authors

Yijie Liu¹, Minjia Tan², Kun Hu³, Sichun Deng⁴, Lu Jian⁵, Junchen Chen⁶, Mi Zhang⁷, Yehong Kuang⁸

Affiliations

¹ Y. Liu, BS, Department of Dermatology, Xiangya Hospital, Central South University, and National Clinical Research Center for Geriatric Disorders (Xiangya Hospital), and Hunan Engineering Research Center of Skin Health and Disease, Hunan Key Laboratory of Skin Cancer and Psoriasis (Xiangya Hospital), and Department of Network Information Center, Xiangya Hospital, Central South University, Changsha.
² M. Tan, BS, Department of Dermatology, Xiangya Hospital, Central South University, Changsha, and Department of Dermatology, the Eighth Affiliated Hospital of Sun Yat-sen University, Shenzhen, China.
³ K. Hu, BS, Department of Dermatology, Xiangya Hospital, Central South University, and National Clinical Research Center for Geriatric Disorders (Xiangya Hospital), and Hunan Engineering Research Center of Skin Health and Disease, Hunan Key Laboratory of Skin Cancer and Psoriasis (Xiangya Hospital), and Department of Network Information Center, Xiangya Hospital, Central South University, Changsha.
⁴ S. Deng, BS, Department of Dermatology, Xiangya Hospital, Central South University, and National Clinical Research Center for Geriatric Disorders (Xiangya Hospital), and Hunan Engineering Research Center of Skin Health and Disease, Hunan Key Laboratory of Skin Cancer and Psoriasis (Xiangya Hospital), and Department of Network Information Center, Xiangya Hospital, Central South University, Changsha.
⁵ L. Jian, BS, Department of Dermatology, Xiangya Hospital, Central South University, and National Clinical Research Center for Geriatric Disorders (Xiangya Hospital), and Hunan Engineering Research Center of Skin Health and Disease, Hunan Key Laboratory of Skin Cancer and Psoriasis (Xiangya Hospital), and Department of Network Information Center, Xiangya Hospital, Central South University, Changsha.
⁶ J. Chen, MD, Department of Dermatology, Xiangya Hospital, Central South University, and National Clinical Research Center for Geriatric Disorders (Xiangya Hospital), and Hunan Engineering Research Center of Skin Health and Disease, Hunan Key Laboratory of Skin Cancer and Psoriasis (Xiangya Hospital), and Department of Network Information Center, Xiangya Hospital, Central South University, Changsha.
⁷ M. Zhang, MD, Department of Dermatology, Xiangya Hospital, Central South University, and National Clinical Research Center for Geriatric Disorders (Xiangya Hospital), and Hunan Engineering Research Center of Skin Health and Disease, Hunan Key Laboratory of Skin Cancer and Psoriasis (Xiangya Hospital), and Department of Network Information Center, Xiangya Hospital, Central South University, Changsha.
⁸ Y. Kuang, MD, Department of Dermatology, Xiangya Hospital, Central South University, and National Clinical Research Center for Geriatric Disorders (Xiangya Hospital), and Hunan Engineering Research Center of Skin Health and Disease, Hunan Key Laboratory of Skin Cancer and Psoriasis (Xiangya Hospital), and Department of Network Information Center, Xiangya Hospital, Central South University, Changsha.

PMID: 38490673
DOI: 10.3899/jrheum.2023-1085

Abstract

Objective: To determine the minimal important change (MIC) and meaningful change value (MCV) of the Disease Activity Index for Psoriatic Arthritis (DAPSA) and the effect size (ES) of DAPSA.

Methods: This was a retrospective cohort study, recruiting 106 patients who agreed to participate in the research from the Department of Dermatology, Xiangya Hospital, between November 1, 2019, and April 1, 2023. An anchor-based method using linear regression analyses was used to determine the MICs and MCVs of the DAPSA. The anchor question assessed whether the patient's well-being had changed since their previous visit, employing a 5-point Likert scale that ranged from "much improved" to "much deteriorated."

Results: The overall MIC value was 8.4 (95% CI 0.01-16.75). The MIC improvement was 9.5 (95% CI 0.89-18.14) and MIC deterioration was 1.1 (95% CI -9.81 to 12.05). The overall MCV was 10.5 (95% CI 4.34-16.72). MCV improvement was 11.4 (95% CI 5.95-16.95) and MCV deterioration was 1.1 (95% CI -9.81 to 12.05). The ES was 0.6.

Conclusion: A change in DAPSA of 8.4 is indicative of an MIC, offering physicians an additional means to contextualize the patient's perception of disease activity during treatment, and a change in DAPSA of 10.5 is likely to be regarded as MCV. These values can enhance the utility of DAPSA in psoriatic arthritis clinical trials.