Exploring Patient-Reported Outcomes Measures in Atopic Dermatitis

Atopic dermatitis (AD), or eczema, is a common inflammatory skin disorder marked by the recurrence of pruritic, eczematous patches, skin infections, and often pain. Eczema has a significant impact on quality of life with decreased self-esteem, impaired work productivity, and sleep disturbances.¹ Approximately 15% to 30% of children and 2% to 10% of adults are affected in industrialized countries—where eczema prevalence grew two- to threefold in the 3 decades before 2008.² Because AD is a dynamic disease—sometimes even changing by the day—and symptoms and signs may not be perfectly correlated, its severity is difficult to evaluate and, to some degree, troublesome to define. Many validated tools used in research settings are not suitable for clinical patient care applications. Moreover, by the very fact that they are rarely used in isolation in clinical studies, these tools generally are understood to capture only a limited aspect of the disease on their own. As a result, patient-reported outcome (PRO) instruments for eczema are increasingly being recognized as having a crucial role in understanding disease burden and AD treatment outcomes. In this brief narrative review, we examine some of the most commonly used instruments for eczema severity and disease control with a focus on those that incorporate PROs and might be best suited for use in clinical practice.

Challenges to Defining Eczema Severity and Control

One of the greatest challenges in measuring eczema severity is the dynamic nature of the disease. An individual patient’s symptoms not only vary in distribution and morphology but also fluctuate day to day.³ Assessing symptoms during the patient’s clinic visit simply cannot provide an accurate picture of the relapsing and remitting course of the disease. This is akin to the mechanic’s problem in which the car never seems to make the concerning noise when brought into the shop. Many patients report that, on the day of their clinic appointment, things are better (or sometimes far worse) than they have been and are thus not a good representation of their disease. Additionally, the objective clinical measures of AD severity in adults do not adequately capture the emotional and psychosocial burden for the patient. In fact, current literature findings suggest that objective eczema scores are not significantly correlated with quality-of-life outcomes.⁴ How a patient looks—especially at one appointment visit—may not capture the burden of disease.

Furthermore, patients’ differential responses to treatment complicate the definition of severity. How do we define AD severity when a patient initially diagnosed with severe eczema achieves full remission with topical steroids, whereas a patient with mild to moderate eczema requires the use of powerful systemic agents to maintain a slightly improved state? Similarly, how does treatment success affect how we label disease severity after treatment? If a medication is indicated for moderate to severe AD and, after 3 months of treatment, the disease is now mild, does that mean the medication is no longer indicated? Rather than simply defining severity, measuring AD control may be a more appropriate measure for chronic AD.

Patient-Centered Approach: Importance of PROs Measures in AD

PROs may solve some of the challenges with measuring the physical and psychosocial manifestations of AD. The growing use of PROs has directed health care practice and clinical research trials toward a more patient-centered approach. PROs encompass an individual’s experience with their health condition from their own perspective.⁵ The use of PRO measures (PROMs) for AD may afford greater insight for both the patient and the clinician over time. As an added bonus, the results from these questionnaires also facilitate patient-clinician discussion and decision-making.⁶

Harmonising Outcome Measures for Eczema (HOME) is a global initiative that focuses on standardizing and validating the numerous tools available to measure eczema outcomes (symptoms, quality of life, and control) for clinical trials as well as, more recently, clinical practice.⁷ Over the years, HOME has released guidelines and recommendations for evaluating eczema outcomes based on scientific validity and discussion of PROMs.

HOME Recommendations for Eczema Tools

Currently, there are multiple PROM instruments recommended by HOME to assess both clinical signs and long-term control. The HOME international meeting in 2019 focused on reaching consensus for measuring eczema control in AD trials and agreed on the use of Atopic Dermatitis Control Tool (ADCT) and Recap of Atopic Eczema (RECAP).⁸ ADCT is a recently developed instrument that measures six patient-perceived AD symptoms over a weeklong period. Defined are overall severity of symptoms, days with intense episodes of itching, intensity of bother, problem with sleep, impact on daily activities, and impact on mood or emotions. ADCT demonstrated successful validity, reliability, and ability to detect change in real-world settings.⁹ RECAP also assesses an individual’s experience of eczema control over the past week with a seven-item questionnaire that includes a self-report version (for adults and older children) as well as a caregiver version (for younger children). The seven items are similar to ADCT; they touch on the acceptability of eczema, itchy skin, intensely itchy skin, sleep disturbance, getting in the way of daily activities, mood, and global assessment of disease.¹⁰ Originally, RECAP used a 4-week AD control evaluation. However, due to challenges with recall bias, a 1-week recall period was employed. In a study of patients with moderate to severe eczema, RECAP was able to show good construct validity, test-retest reliability, and responsiveness to change.¹¹

As mentioned earlier, eczema control is an incredibly important measurement for the long-term management of this chronic disease. RECAP and ADCT are validated tools administered not only to support clinical research but also to encourage a more comprehensive evaluation of eczema and promote insightful discussion between patient and clinician. Consequently, HOME officially added RECAP and ADCT to the list of guidelines for their clinical practice initiative in 2020.¹²

HOME recommendations for clinical practice further describe the use of Patient-Oriented Eczema Measure (POEM) and/or Patient-Oriented Scoring AD (PO-SCORAD) to assess clinical symptoms in routine care as well as the need for a peak itch numeric rating scale (NRS) for a 24-hour recall period.¹³ POEM has already been validated and is well established as HOME’s gold standard tool for AD in clinical trials.¹⁴ This patient-oriented questionnaire records the frequency of seven eczema symptoms (itch, sleep disturbance, dryness, flaking, weeping or oozing, bleeding, and cracking) and usually takes less than 2 minutes to complete. On the other hand, PO-SCORAD assesses affected body surface area, severity of itching and sleep disturbances, and severity of other clinical symptoms (dryness, redness, swelling, crusting/oozing, scratching, thickening).¹⁵ Both PO-SCORAD and POEM are available without cost, have mobile apps available, and come in multiple languages, providing great accessibility.¹³ PO-SCORAD also includes three different skin tones—fair, medium, and dark—to help patients better approximate their skin.¹⁶ It is worth noting that PO-SCORAD may take up to 15 minutes for new users to complete, making it less practical for quick clinical use.

Peak Pruritus NRS allows patients to report the worst itch on a scale of 0 to 10 (0 for “no itch” and 10 for “the worst possible itch”) in the past 24 hours. It became the first fully validated PRO for itch rating in randomized trials with patients who had moderate to severe AD.¹⁷ Average itch was also evaluated in these individuals, but the peak itch led to a more precise and consistent interpretation among patients. Peak Pruritus NRS is an easy score to obtain but lacks the symptoms and quality-of-life components. Therefore, it is generally used to complement other PROMs. (See Table.)

Other Eczema Tools

It is important to note that there are many AD outcome measures that have not been discussed here. Given that technology is progressing rapidly, there are now tools that take eczema monitoring to a convenient app platform. One such tool is Eczemawise.¹⁸ The National Eczema Association (NEA) recently developed a mobile app to encourage patients and caretakers to record triggers, symptoms, and treatments, which can help identify trends and monitor the disease cycle. Like the other PROs, Eczemawise may provide greater understanding and discussion, leading to better patient outcomes.

Conclusion

Unfortunately, there is no single, standard approach for assessing and rating eczema outcomes. Even the HOME initiative encourages the concurrent use of multiple PROMs that measure disease control, clinical symptoms, quality-of-life scores, and itch severity. This stems from the underappreciated complexity of eczema evaluation and treatment. Also, some of the PROMs may be difficult to implement in real practice owing to inconvenience and the required time commitment. For now, ADCT, POEM, and RECAP all offer very brief (generally under 2 minutes) testing and are surprisingly comprehensive tools that can easily be used in clinical practice to get a sense of the disease and perhaps facilitate discussion.

The authors have no relevant financial interests.

1. Eckert L, Gupta S, Amand C, Gadkari A, Mahajan P, Gelfand JM. Impact of atopic dermatitis on health-related quality of life and productivity in adults in the United States: an analysis using the National Health and Wellness Survey. J Am Acad Dermatol. 2017;77(2):274-279.e3.

2. Bieber T. Atopic dermatitis. N Engl J Med. 2008;358(14):1483-1494.

3. Thestrup-Pedersen K. Clinical aspects of atopic dermatitis. Clin Exp Dermatol. 2000;25(7):535-543.

4. Drucker AM, Wang AR, Li WQ, Sevetson E, Block JK, Qureshi AA. The Burden of Atopic Dermatitis: Summary of a Report for the National Eczema Association. J Invest Dermatol. 2017;137(1):26-30.

5. Hughes S, Aiyegbusi OL, Lasserson D, Collis P, Glasby J, Calvert M. Patient-reported outcome measurement: a bridge between health and social care? J R Soc Med. 2021;114(8):381-388.

6. Leshem YA, Chalmers JR, Apfelbacher C, et al. Measuring Atopic Eczema Control and Itch Intensity in Clinical Practice: A Consensus Statement From the Harmonising Outcome Measures for Eczema in Clinical Practice (HOME-CP) Initiative. JAMA Dermatol. 2022; Dec 1;158(12):1429-1435. doi: 10.1001/jamadermatol.2022.4211

7. Schmitt J, Spuls PI, Thomas KS, et al. The Harmonising Outcome Measures for Eczema (HOME) statement to assess clinical signs of atopic eczema in trials. J Allergy Clin Immunol. 2014;134(4):800-807.

8. Thomas KS, Apfelbacher CA, Chalmers JR, et al. Recommended core outcome instruments for health‐related quality of life, long‐term control, and itch intensity in atopic eczema trials: results of the HOME VII consensus meeting. Br J Dermatol. 2021;185(1):139-146.

9. Simpson E, Eckert L, Gadkari A, et al. Validation of the Atopic Dermatitis Control Tool (ADCT©) using a longitudinal survey of biologic-treated patients with atopic dermatitis. BMC Dermatol. 2019;19(1):15.

10. Howells LM, Chalmers JR, Gran S, et al. Development and initial testing of a new instrument to measure the experience of eczema control in adults and children: recap of atopic eczema (RECAP). Br J Dermatol. 2020;183(3):524-536.

11. Bhanot A, Peters TJ, Ridd MJ. Assessing the validity, responsiveness, and reliability of the Recap measure of eczema control. Br J Dermatol. 2021;184(5):955-957.

12. HOME. Clinical Practice Set. Harmonising Outcome Measures for Eczema (HOME). Centre of Evidence Based Dermatology at University of Nottingham. Accessed February 12, 2023. http://www.homeforeczema.org/index.aspx

13. Leshem YA, Chalmers JR, Apfelbacher C, et al. Measuring atopic eczema symptoms in clinical practice: the first consensus statement from the Harmonising Outcome Measures for Eczema in clinical practice initiative. J Am Acad Dermatol. 2020;82(5):1181-1186.

14. Spuls PI, Gerbens LAA, Simpson E, et al. Patient-Oriented Eczema Measure (POEM), a core instrument to measure symptoms in clinical trials: a Harmonising Outcome Measures for Eczema (HOME) statement. Br J Dermatol. 2017;176(4):979-984.

15. Li A, Zhang M, Yang Y, et al. Patient-reported outcome (PRO) instruments for disease severity and quality of life in patients with atopic dermatitis: a systematic review of English and Chinese literature. Ann Transl Med. 2022;10(16):906-906.

16. PO-Scorad. 2020_PD-SCORAD_EN.pdf. 2020. Accessed February 10, 2023. https://www.pierrefabreeczemafoundation.org/sites/default/files/2021-01/2020_PO-SCORAD_EN.pdf

17. Yosipovitch G, Reaney M, Mastey V, et al. Peak Pruritus Numerical Rating Scale: psychometric validation and responder definition for assessing itch in moderate-to-severe atopic dermatitis. Br J Dermatol. 2019;181(4):761-769.

18. National Eczema Association. Turn your whys into wise with eczemawise. Accessed February 9, 2023. https://nationaleczema.org/turn-your-whys-into-wise-with-eczemawise/