See the article by Dirven et al. pp. 1327–1336.
Patient-reported outcomes (PRO) are invaluable to many stakeholders. Patients would like to understand the experience associated with a disease and its treatment from other patients who previously had it. Clinicians would like to know how their patients feel and function to allow for proactive intervention. Regulatory agencies would like to have the patient’s perspective on personal harms and benefits of a potential treatment to inform their decisions. PRO provides critical information to patients, providers, regulators, and third-party payers for evaluating the tolerability of new therapies.1 Without PRO, clinicians, and regulators have an incomplete picture of how patients are affected by a new agent.2 A very important piece of information in the use of PRO is determining what constitute a minimally important difference (MID) when evaluating new therapies. No matter the terminology—minimal clinically important difference, clinically important difference, minimally detectable difference, or MID, MID refer to the change in scores that allow interpretation of the clinical relevance of PRO results.3
In this issue, Dirven and her coauthors performed a very comprehensive analysis of what constitutes MID for the EORTC QLQ-C30 (European Organization for Research and Treatment of Cancer Quality of Life Questionnaire) in glioma patients.4 Although a similar approach was used on the same PRO to determine MID for advanced breast cancer patients5 and malignant melanoma,6 Dirven and coauthors results are expressly made for neuro-oncologists. Glioma patients are neither breast cancer patients nor melanoma patients and fittingly so, there were slight variations in MIDs among the 3 cancer groups. With patient data from 3 large trials, these MIDs for the EORTC QLQ-C30 specifically for glioma patients are an opportune addition to neuro-oncologists who used EORTC QLQ-C30 either in clinical practice or research or to study sponsors who are planning to design clinical trials for potential interventional treatment for glioma patients.
Dirven and her coauthors’ manuscript has several strengths and unique features. They appropriately emphasized anchor-based approach rather than distribution-based approach though both results were presented. They ensure that they can combine data from 3 different trials by testing for interaction between trial indicator and anchor variable. To enhance readability, the authors provided 2 practical examples of how MID can be used for the interpretation of EORTC QLQ-C30 data and for sample size calculations.
The authors have acknowledged that these MID results are at the group level and not at the individual patient level. Nevertheless, this information are important and will contribute to our current understanding and interpretation of this measure in glioma patients.
Acknowledgments
Please note that the opinion expressed here is solely that of the author and that no third party had input or gave support to its writing.
References
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