Reliability of patient self-reports to clinician-assigned functional scores of inclusion body myositis.

BACKGROUND: Sporadic inclusion body myositis (IBM) is a debilitating disease which leads to impaired ambulation and loss of hand function. Yale IBM Registry (IBMR) was launched in November 2016 to address the knowledge gap in IBM natural history data. The registry interface provides an IBM personalized index calculator (IBM-PIC) based on the IBM-functional rating scale (IBM-FRS). While the calculator is based on the IBM-FRS, it has not been directly compared to the IBM-FRS score. Therefore, in this study, we compared the patient-reported IBM-PIC score from this calculator with the physician-obtained IBM-FRS score. METHOD: IBM-FRS was administered over the phone within two weeks of their most recent IBM-PIC entry in the IBMR to 35 participants. To compare the agreement between IBM-FRS and IBM-PIC scores, Interrater Correlation Coefficient (ICC) analysis was performed. For individual questions, Fleiss Kappa statistics was used. RESULTS: Thirty-five active IBM-PIC users participated. Eighty percent of the participants were men, and 91% were White Caucasians. The reported IBM-FRS score of this group was 23.5 ± 7.4 (range 1-38). The Interrater Correlation Coefficient (ICC) between the physician-administered IBM-FRS score and the IBM-PIC was 0.98 (0.96-0.99). There was moderate to substantial agreement on all the questions on IBM-FRS except for handwriting and fine motor skills. DISCUSSION: IBM-PIC is a reliable indicator of the IBM-FRS score obtained by the physician. It is anticipated that this online platform will be a valuable tool for assessing IBM severity and monitoring disease progression remotely both in clinical practice and research studies.

Demographic and clinical features of inclusion body myositis in North America.

INTRODUCTION: Few studies of the demographics, natural history, and clinical management of inclusion body myositis (IBM) have been performed in a large patient population. To more accurately define these characteristics, we developed and distributed a questionnaire to patients with IBM. METHODS: A cross-sectional, self-reporting survey was conducted. RESULTS: The mean age of the 916 participants was 70.4 years, the male-to-female ratio was 2:1, and the majority reported difficulty with ambulation and activities of daily living. The earliest symptoms included impaired use and weakness of arms and legs. The mean time from first symptoms to diagnosis was 4.7 years. Half reported that IBM was their initial diagnosis. A composite functional index negatively associated with age and disease duration, and positively associated with participation in exercise. CONCLUSIONS: These data are valuable for informing patients how IBM manifestations are expected to impair daily living and indicate that self-reporting could be used to establish outcome measures in clinical trials.