@article{7fad2f481dce412b85b0ec707ad3cb48,
title = "Assessing deterioration using impairment and functional outcome measures in chronic inflammatory demyelinating polyneuropathy: A post-hoc analysis of the immunoglobulin overtreatment in CIDP trial",
abstract = "It is unclear whether frequently used cutoff values for outcome measures defining minimal clinically important differences (MCIDs) can accurately identify meaningful deterioration in chronic inflammatory demyelinating polyneuropathy (CIDP). We used data from the immunoglobulin overtreatment in CIDP (IOC) trial, in which 60 clinically stable patients with CIDP were randomized to intravenous immunoglobulin (IVIg) withdrawal or continuation. We calculated change scores of the Inflammatory Rasch-Built Overall Disability Scale (I-RODS), grip strength, and Medical Research Council-sum score (MRC-SS) and classified visits based on a treatment anchor (ie, decision to restart/increase treatment after reaching a predefined early endpoint of deterioration). The variability of scores in patients without deterioration was calculated using the limits of agreement. We defined optimized MCIDs for deterioration and specific combinations of MCIDs from different outcome measures, and subsequently calculated the accuracies of the (combined) MCIDs. Substantial variability was found in scores of the I-RODS, grip strength and MRC-SS in patients without deterioration over time, and most MCIDs were within the limits of the variability observed in patients without deterioration. Some MCID cut-offs were insensitive but highly specific for detecting deterioration, for example, the MCID-SE of -1.96 of the I-RODS and -2 point on the MRC-SS. Others were sensitive, but less specific, for example, -4 centiles of the I-RODS. Some combined MCIDs resulted in high specificities and moderate sensitivities. Our results suggest that clinically important deterioration cannot be distinguished from variability over time with currently used MCIDs on the individual level. Combinations of MCIDs might improve the accuracy of determining deterioration, but this needs validation.",
keywords = "chronic inflammatory demyelinating polyneuropathy, minimum important difference, outcome measures, GRIP STRENGTH, RESPONSIVENESS",
author = "{van Veen}, R. and L. Wieske and I. Lucke and M.E. Adrichem and I.S.J. Merkies and {van Schaik}, I.N. and F. Eftimov",
note = "Funding Information: Study was made possible by grants from ZonMw (836021010) and Prinses Beatrix Spierfonds (Dutch Charity for neuromuscular diseases). . provided the placebo, preparation, blinding and distribution of the study treatment. The funders had no role in the trial design, data collection, data analysis, data interpretation, or the writing of the report. Sanquin Plasma Products B.V Funding Information: Dutch Governmental grant (ZonMw), Grant/Award Number: 836021010; Prinses Beatrix Spierfonds; Sanquin Plasma Products B.V. Funding information Funding Information: We thank Janneke Zwiers and Mary Muijs from Sanquin plasma products B.V., the research nurses from Penthecilia B.V. and Margit Dros from Mediq Tefa for ensuring the blinding and distribution of the IMP. We also like to thank Michael Lunn, Joke Dijk and Brent Opmeer for participating in the DSMB. Funding Information: F. Eftimov report grants from ZonMw (Dutch governmental agency) for the IOC trial in which data was collected for this study, and a grant from Prinses Beatrix Spierfonds (Dutch charity) on clinimetrics in CIDP. Outside of the submitted work, he has received other grants from ZonMw and Prinses Beatrix Spierfonds for studies in CIDP. As principal investigator of INCbase, the also reports investigator‐initiated grants from Kedrion, Terumo BCT, CSL‐Behring, Grifols and Takeda Pharmaceutical Company. His institution has received fees from UCB Pharma, CSL Behring, Grifols and Takeda for advisory board membership and/or lectures. All grants and fees were paid to his institution. He is a member of the Cochrane Neuromuscular Editorial Board. L. Wieske received research grants from Grifols (2019) and the GBS/ CIDP Foundation (2020) outside the submitted word. I. van Schaik reports grants from Dutch Governmental grant (ZonMw/Rational Pharmacotherapy program, non‐financial support from Sanquin Plasma Products B.V., during the conduct of the study; other from CSL‐Behring, outside the submitted work. I. S. J. Merkies reports grants from GBS/CIDP Foundation International, grants from Talecris Talents program foundation, reports personal fees and other from Steering committee member of several studies: ICE trial, CSL Behring, LFB, Novartis, Baxter, UCB, Octapharma, Argenx, outside the submitted work. M. E. Adrichem, I. Lucke, and R. van Veen have nothing to disclose. Publisher Copyright: {\textcopyright} 2022 The Authors. Journal of the Peripheral Nervous System published by Wiley Periodicals LLC on behalf of Peripheral Nerve Society.",
year = "2022",
month = jun,
day = "1",
doi = "10.1111/jns.12497",
language = "English",
volume = "27",
pages = "144--158",
journal = "Journal of the Peripheral Nervous System",
issn = "1085-9489",
publisher = "Wiley",
number = "2",
}