How scoring limits the usability of minimal important differences (MIDs) as responder definition (RD): an exemplary demonstration using EORTC QLQ-C30 subscales

Minimally important differences for interpreting EORTC QLQ-C30 change scores over time: A synthesis across 21 clinical trials involving nine different cancer types

“…For example, a patient can only change by 33 points for QLQ-C30 single-item scales, such as diarrhoea, whereas multi-item scales (e.g. physical functioning) have many more intermediate values and hence more continuous change scores [33]. Thus, selection of within-patient thresholds should be done with knowledge of the underlying score distribution.…”

Introduction to the special section: “Methodologies and considerations for meaningful change”

“…The team combined the use of a longitudinal graded response model with a transition item to measure latent change. The method produced tighter estimates of meaningful change when compared to traditional methods, with the methods overlapping most when the proportion of responders was [23] N/A Individual Change over time N/A Griffiths et al [24] Meaningful change Group, Individual Change over time Minimal Ho et al [33] Distribution-based Individual, Group Change over time N/A Jones et al [21] Meaningful change Individual Change over time Not specified Lee et al [32] Both Individual Change over time Minimal Li [18] Distribution-based Individual Change over time N/A Peipert et al [30] Distribution-based Individual Change over time N/A Poon et al [29] Meaningful change Individual Change over time (hypothetical) Minimal Qin et al [27] Meaningful change Individual Change over time Not specified Smit et al [16] Both Individual Change over time Meaningful a Wyrwich & Norman [22] Meaningful change General General General Wyrwich et al [19] Meaningful change Individual Change over time (hypothetical) Meaningful b about 50% of participants. Extensions of this approach show promise for a range of applications [25,26].…”

“…This article serves as a helpful collection of methodological issues to consider when reading the collected papers. The third paper illustrates a fundamental practical question when determining meaningful change thresholds, but likely also for any threshold determination [23]: how scoring rules and ranges limit the usability of group-level minimal important differences in individual-level responder definitions. Based on the example of the EORTC QLQ-C30 subscales, the authors illustrate how the commonly used 10-point change may be misleading, as due to scaling, an individual cannot actually be measured with a 10-point change on any scale.…”

Synergy of de-walled Ganoderma Lucidum spore powder (GLSP) on targeted therapy in advanced non-squamous non-small cell lung cancer with epidermal growth factor receptor (EGFR) mutant: protocol for a randomized, double-blind, placebo-controlled study

“…In the FLAURA patient-reported outcome using the same scale, a mean fatigue score of 32.2 ± 24.9 was observed in patients with advanced EGFR-mutated NSCLC treated with Osimertinib [14]. Referring to previous literature, it is considered that the minimum clinically important difference (MID) in fatigue subscale is 11.1 and there exists a range of change between 11.1 and 22.2 points within this threshold value range for clinical significance assessment purposes [15]. The use of de-walled GLSP is assumed to result in at least a 15-point increase in fatigue score, indicating potential clinical significance for this drug intervention approach.…”