Ringing in the Patient Voice: Measuring Patients’ Lived Experience of Dermatomyositis Symptoms

The development and validation of measures of disease activity, damage, and health-related quality of life (HRQOL) over the past 30 years has been fundamental in advancing research and care for patients with adult and juvenile idiopathic inflammatory myopathies (IIMs).¹ These efforts have resulted in the development of core set measures of disease activity and damage for myositis, and the American College of Rheumatology (ACR)/European Alliance of Associations for Rheumatology (EULAR)–endorsed Myositis Response Criteria, which have been successfully implemented in IIM clinical trials and which recently facilitated the US Food and Drug Administration licensure of intravenous immunoglobulin for dermatomyositis (DM).^2-5 IIM core set activity measures include several patient-reported outcome measures (PROMs), specifically patient/parent global assessments of disease activity and physical disability measures (ie, Health Assessment Questionnaire and Childhood Health Assessment Questionnaire [CHAQ]). In the Paediatric Rheumatology International Trials Organisation core set, the CHAQ is also included as a measure of HRQOL.⁶ The Myositis Disease Activity Assessment Tool (MDAAT) is focused on the assessment of extramuscular disease activity. It includes several symptoms commonly experienced by patients, such as fatigue, arthralgia, myalgia, dyspnea, and gastrointestinal symptoms, although these are assessed from the physician’s viewpoint.⁷ HRQOL assessment has also been advanced by validation of generic PROMs for assessing overall (eg, Patient-Reported Outcomes Measurement Information System [PROMIS]) and organ-specific HRQOL impact (eg, Skindex).^8-11 However, most PROMs administered to patients with IIMs were not developed specifically for this population and assess only a subset of IIM-related experiences.^1,12 To better represent the voice of patients who live with IIMs in studies, the limitations of currently available disease activity measures and PROMs must be addressed.

In this issue of The Journal of Rheumatology, Christopher-Stine et al report on the development of the Dermatomyositis Disease Symptom Questionnaire (DM-DSQ), with a design process that aims to address the limitations of existing PROMs.¹³ The DM-DSQ is meant to capture patients’ DM-related symptoms from their own perspective. The emphasis on a symptom report differentiates this PROM from others that assess related yet distinct constructs, such as HRQOL, physical function, or global health. With patient input, the investigators employed primarily qualitative methods (eg, concept elicitation and cognitive debriefing interviews) to develop and refine a conceptual model of patient-reported symptoms of DM, along with corresponding DM-DSQ survey items intended to measure patients’ self-reported symptoms, to generate a tool specific to patients with DM. Thirty adults with DM were sampled to ensure representation of patients with wide-ranging disease severity and treatment histories. Qualitative coding focused on symptoms of DM, patients’ definition of DM disease activity, and aspects of HRQOL affected by DM, including muscle and skin symptoms, muscle fatigability, physical dysfunction, and difficulty swallowing or breathing. Most DM-DSQ items were well understood by participants, except for an item assessing photosensitivity, which was subsequently removed. The authors also confirmed that an ordinal, rather than continuous, patient global assessment of disease activity was comprehensible to participants. Importantly, the authors note that although these efforts provide preliminary evidence of content validity, full psychometric assessment of the DM-DSQ is planned in the context of an ongoing larger phase II clinical trial that will examine construct validity and responsiveness of the measure. Further psychometric evaluation should also aid in widening the demographic profile of included patients and ensuring the DM-DSQ’s applicability to more diverse populations’ experiences.

The authors are commended for developing the DM-DSQ,¹³ which holds great promise as an innovative tool with the potential to enhance clinical care and research by directly incorporating patients’ lived experiences of DM symptoms. A symptom-based PROM that captures both the major elements of disease activity and HRQOL brings much-needed innovation to the assessment of systemic autoimmune disease. There is a strong need to represent the patient experience in clinical trials and registries. Studies show that physicians and patients may often differ in their assessment of disease impact, and that such discordance may be associated with worse outcomes.^14,15 A symptom-based PROM such as DM-DSQ provides unique information, distinct from physician-scored measures, that can help ensure often-overlooked symptoms (eg, fatigue and pain) are addressed effectively in clinical and research settings.

Further, the DM-DSQ is innovative, insofar as it may enhance the quality of decentralized clinical care and research for patients with DM. Telehealth is now central to the clinical care of patients with rheumatic disease.¹⁶ However, much work remains to be done to optimize the use of telehealth modalities, such as mobile apps and remote clinical encounters, for patients with DM and other rheumatic diseases.¹⁷ The DM-DSQ may enable remote monitoring of patients between in-person clinic visits, such that meaningful patient-reported changes in disease activity—indicative of disease flare or of significant improvement—could be identified in real time, followed by commensurate changes in therapy. Decentralized clinical trials and research registries also require valid, patient-centered measures of disease activity. They have the potential to improve participant recruitment and retention and enable innovative therapies to reach a wider range of participants than traditional clinical trial and registry settings.¹⁸ One recent example, the Myositis Interstitial Lung Disease Nintedanib Trial (MINT; ClinicalTrials.gov: NCT05799755) for myositis-associated interstitial lung disease, relies primarily on the remote collection of patient data from their homes.¹⁹ A well-validated, comprehensive outcome measure such as the DM-DSQ that captures patient symptoms would be an essential component of such innovative decentralized studies. A tool like the DM-DSQ, if found to be sensitive to change, also increases the feasibility of a time-to-improvement design in therapeutic studies, facilitated by more frequent follow-up evaluations that monitor how symptoms are changing over time.

Some limitations of the DM-DSQ need to be addressed when refining this PROM. First, most DM-DSQ items assess muscle symptoms, fatigue, or mobility, with fewer items assessing skin disease and other extramuscular manifestations. Cutaneous and other extramuscular manifestations are associated with significant morbidity, negative HRQOL impact, and treatment refractoriness, even in the setting of apparent control of muscle inflammation.^11,20 This suggests that future iterations of the DM-DSQ may require additional items or weighting to ensure that the lived experience of patients with predominantly extramuscular disease manifestations is accurately reflected. Relatedly, the DM-DSQ was developed solely for use in patients with DM, with the authors stating that this disease specificity would ensure that the included items best represent the experience of this subset of IIM. However, the exclusion of other IIM subtypes (eg, antisynthetase syndrome, immune-mediated necrotizing myopathy, overlap myositis, juvenile-onset IIMs) may also limit the usability of the DM-DSQ, given that many therapeutic trials and observational studies include multiple subtypes of IIMs. The DM-DSQ should also ensure representation of diverse patient perspectives, given guidance indicating the need for transparent reporting of participant representation in studies and inclusion of patients who are diverse across multiple sociodemographic dimensions.^21,22 Refinement of the DM-DSQ could also consider alternative survey formats, such as computerized adaptive testing–administered item banks or conditional branching logic, which can provide more individualized assessments across disease subtypes and organ involvement patterns while still keeping assessments brief.^10,23

Future versions of the DM-DSQ may also need to consider methods for ensuring that symptoms reported by patients are attributable directly to DM. Some symptoms assessed by DM-DSQ may be multifactorial or even unrelated to rheumatic disease, introducing measurement error and potentially decreasing the responsiveness of the DM-DSQ to clinically meaningful changes in disease activity. Additional cognitive interviewing and use of prompts and item wording to indicate that symptoms should be directly attributable to DM may help address these concerns. The authors also reported that certain symptoms elicited in interviews with patients with DM, such as brain fog, were not included among the DM-DSQ items per the authors’ judgment that these symptoms may not be related to the target of DM treatments.¹³ Recent work by systemic lupus erythematosus investigators has suggested that in addition to “type 1” symptoms amenable to immunosuppression, patients endorse such symptoms as brain fog, depression, and other “type 2” symptoms that may be less responsive to immunosuppression, but are nonetheless perceived as being related to their rheumatic disease.²⁴ Future work engaging with participants could determine if a similar framework of type 1 and type 2 symptoms would better address the full range of symptoms patients deem important, rather than focusing on a subset of symptoms based on physicians’ a priori conceptualization of the illness experience.

Finally, we strongly urge adaptation of the DM-DSQ for use in patients with juvenile-onset DM (JDM), building on the strong track record of collaboration between adult and pediatric myositis investigators^{1,3,4,12,25,26} and the availability of patient assessment tools for IIM (eg, PROMIS) that can be cross-linked for combined pediatric and adult studies.^8-10 The DM-DSQ could undergo adaptation to generate a child/family-centered conceptual model of JDM symptoms that would inform the development of pediatric self-report and parent proxy–report versions. The availability of an adapted pediatric DM-DSQ would allow for combined DM/JDM trials, including adaptive trial designs with staged recruitment of adults followed by pediatric patients and pediatric extrapolation studies. Collectively, these efforts would address the unmet needs of patients with juvenile-onset IIMs and aid in speeding the arrival of novel therapeutics to the pediatric population.

We applaud the authors for their accomplishment in centering the patient voice and their lived experience in the assessment of DM.¹³ We are optimistic that the DM-DSQ will prove useful to patients with DM and ultimately to patients with other IIMs, including juvenile-onset forms. The DM-DSQ can provide information that is complementary to established myositis core set measures and Outcomes Measures in Rheumatology (OMERACT) HRQOL domains. Although generic measures (eg, PROMIS) are accessible and may facilitate comparisons to other general and subspecialty patient populations, disease-specific measures such as the DM-DSQ can provide meaningful information unique to the DM patient population’s experiences and illness symptoms, which may not be well captured by generic tools. The DM-DSQ brings the patient voice front and center in disease assessment, in a much-needed role that will have broad applicability to future clinical care and new decentralized research settings for all patients with myositis. The DM-DSQ should stimulate a much-needed paradigm shift that will enhance disease assessment for all patients with autoimmune disease.

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