Response to De Paepe et al.

We thank De Paepe et al.2 for their letter and interest in our recent publication proposing a holistic composite outcome score across 5 core domains for the assessment of treatment response to chronic pain interventions.5 The authors raise important considerations regarding the personalisation of outcome measures and the role of patient involvement in defining meaningful change. We agree that the impact of pain is an individual experience, and that outcome measures should reflect this. Our 5 holistic outcome domains (pain intensity, health-related quality of life, sleep quality, physical, and emotional function) were selected on the basis of the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) recommendations and have been judged as important by patients with chronic pain and health care providers.4 The use of minimal clinically important differences (MCID) aims to balance the need for outcome standardisation in clinical trials. By averaging across domains (where baseline scores are worse than normative population thresholds) on an individual basis, we sought to develop a personalized composite outcome measure that reflects the domains deemed most relevant to people with pain. De Paepe et al.2 correctly highlight the limitations of nomothetic instruments, such as the EuroQol five-dimension (EQ-5D) instrument, in capturing individual patient nuances. We acknowledge that our group-level validation methodology does not directly address the outcome item-level relevance for specific individuals. However, the use of validated instruments remains essential for comparability across studies and populations. The challenge lies in integrating idiographic approaches, such as personalized item selection, without compromising psychometric rigor or feasibility in large-scale trials. Although the holistic MCID was developed to evaluate response to chronic pain interventions, we would note that the tool could be used in clinical practice and enable individual patients to identify the domains of most relevance to them. As discussed in our paper,5 the holistic MCID approach could be used with different sets of domains.1 In conclusion, we welcome the comments by De Paepe et al. in that our proposed holistic MCID represents a “significant advance” in pain outcome assessment. Holistic outcomes measures that allow patients to select their own domains, whilst conceptually appealing, can be challenging to use, especially in a clinical trial setting.3 Disclosures R.S.T. reports consultancy fees from Medtronic, Nevro and Saluda Medical outside the submitted work. R.V.D. is an employee of Saluda Medical. R.V.D. has previously received consultancy fees from Medtronic, and Saluda Medical.