1 Introduction
Atopic dermatitis (AD), a systemic inflammatory disease with autoimmune components, is a severe form of eczema pathologically characterized by skin barrier disruption mediated by a type 2 helper T-cell immune response [
1]. Atopic dermatitis is part of the atopic march that may result from underlying biologic mechanisms [
2], and while AD can develop in adults, onset is generally during early childhood and may extend into adult life in approximately half of the cases [
3]; it has been estimated that the lifetime prevalence of AD in adults is 2–10% [
4,
5]. In the absence of a cure, AD requires treatment over the lifetime of the patient.
In addition to the hallmark clinical symptoms of eczema and intense pruritus, AD is associated with a substantial and multi-faceted patient-reported burden that encompasses sleep disturbances, anxiety/depression, reduced function/productivity, and a lower quality of life (QoL) [
6‐
14]. The presence of these effects of AD highlights the importance of understanding disease severity and impact from the patient’s perspective and the need to ensure that disease management is tailored to the needs of the individual patient.
Although AD presents in moderate and severe forms in 20–37% and 10–34% of patients, respectively [
15,
16], there is limited understanding on how physicians assess the severity of AD in routine clinical practice and its relationship to how patients self-report their disease severity. This challenge of appropriately and consistently assessing disease severity is exacerbated by the availability of more than 20 measures that can be used to assess severity, which are mainly used in clinical trials [
17,
18], and the lack of a consensus on how to define the severity of AD. While cut-off values for defining severity have been suggested for multi-component clinical scales such as the Eczema Area and Severity Index (EASI) [
19] and Scoring Atopic Dermatitis (SCORAD) [
20], these scales are predominantly based on specific clinical signs, and the use of these measures may not necessarily be appropriate for daily clinical practice, nor may they adequately capture factors that patients use to define severity. Simpler global impression scales may be more readily interpretable, but the wide variability in content and use in the absence of standardization limits their value in defining severity and making comparisons across populations and studies [
21].
There is a need to better understand how AD severity is rated in clinical practice, and the objective of this study was to evaluate the level of agreement between physician- and patient-rated AD severity, and to identify factors that may be associated with discordance between these severity ratings. The study also evaluated physician awareness of clinical and patient-reported outcome measures available to assess disease severity and the impact of AD on QoL.
4 Discussion
Results from this study show a discordance between patient- and physician-reported AD severity, with an inter-rater agreement that was only of moderate magnitude (weighted kappa = 0.52); almost one-third of patients rated severity of their AD differently from how their physicians rated severity. These results are consistent with Torrelo et al. [
35] who also found only moderate agreement between patient and physician perceptions of AD severity and a kappa coefficient that was identical to that of the current study. Such discordance between patient and physician perceptions of disease is common in the clinical setting and has been previously reported in other chronic conditions including osteoarthritis [
36], rheumatoid arthritis [
37], painful diabetic peripheral neuropathy [
38], and psoriasis [
39].
The use of bivariate analysis in this study was important not only for initially identifying significant variables that contribute to the observed disparity, but also for showing which variables were not significant. The patterns of agreement did not appear to be dependent on physician specialty, suggesting that physicians may have a similar misunderstanding of the patient’s perspective regardless of their specialty. Additionally, three key objective clinical measures also did not appear to influence pattern of agreement, i.e., the extent of AD as measured by body surface area, use of IMs, and EASI score, which itself has been proposed as a measure of disease severity [
19]. In contrast, variables that evaluated the impact on the patient demonstrated significance, including sleep disturbance, QoL using both a dermatology-specific measure and a generic measure, and work productivity.
In the multi-variate model, day-to-day (baseline) symptoms of papules and permanent scarring were not significant, although a previous study using multiple regression analysis reported that the specific clinical signs of excoriations, erythema, and edema/papulation were independent predictors of patient-rated disease severity [
40]. However, in that study, these signs accounted only for 25% of the variation in patient-reported severity, with the patient-reported severity primarily based on the bothersomeness of the condition rather than overall disease activity. Additionally, in the present study, excoriations, erythema, and edema/papulation were captured as part of the EASI score rather than as individual symptoms. Of the variables that did demonstrate significance in bivariate analysis and were included in the multi-variate model, the only two that retained significance were patient-reported QoL assessed using a dermatology-specific measure (DLQI), and sleep disturbance, which is both a frequent complaint of patients with AD and a component of their disease perception [
11]. The finding that these two variables retained significance suggests that QoL-related issues contribute to patient perceptions of their overall disease severity and may likely be key drivers of discordance between the patient and physician perspectives. The importance of QoL and sleep is not surprising given the impact that AD, and the associated pruritus in particular, has on these outcomes [
12,
14,
41,
42], and that sleep disturbance has also been reported to be a significant predictor of QoL in patients with AD [
42].
Because QoL does not necessarily correlate with disease activity assessed using standard clinical measures [
43], its identification as a factor contributing to the discordance between physician and patient perceptions suggests a need for the incorporation of QoL evaluation when assessing patients with AD. Such QoL assessment is clinically relevant considering that awareness and use of clinical and patient-reported AD measures among physicians was generally low. To our knowledge, this is the first study to evaluate the extent of awareness and clinical use of these measures among physicians. The low awareness even among dermatologists for measures that evaluated pruritus was surprising, especially given the importance of itch to the burden of AD including daily effects on sleep disturbance and functional impairment [
10,
14]. Such low awareness of AD measures also indicates that physician estimation of severity may not necessarily be based on quantitative measures of disease activity, further suggesting that clinical assessment may be less than optimal. Importantly, these results also indicate that physicians may not be having meaningful conversations with patients about QoL or the impact of AD on the daily life of the patient. The patient impact likely represents an important indicator of a need for treatment because patients may be more concerned about what they can do and how they are perceived than by an estimated value on a severity scale.
To put the DSP physician-perceived severity findings into context, information regarding overall physician workload (from the same physicians that completed the DSP), in terms of the total numbers of AD patients seen over a 2-week period split into mild, moderate, and severe, was used to produce an estimate of the overall distribution of AD. This indicated proportions of patients with mild, moderate, and severe AD of 53.9, 42.0, and 4.1%, respectively. In addition, using information regarding total numbers of patients managed over a 12-month period by each physician included in the DSP, and taking into account the total number of physicians of each type in the USA, we estimated that the proportion of patients treated by PCPs, dermatologists, and allergists/immunologists was 66, 28, and 5% of patients with AD, respectively. Results indicate that when AD severity is projected to the total population, severe AD represents a smaller proportion of the overall AD population than the sample included in this analysis.
4.1 Strengths and Limitations
The strengths of this study are that the patients had a clinically confirmed diagnosis of AD, and that these patients reflect the consulting population from real-world clinical practice, providing insight into how patients who met the inclusion criteria and their consulting physician rate AD severity. However, interpretation and generalizability of these results should also take into account the study limitations, including that this analysis was limited only to patients with a history of moderate-to-severe AD. In addition, disease severity rating by the patient was based on personal judgment, rather than an objective measure such as POEM. Although this may limit the generalizability of the findings to other populations, this was considered important to determine patient perceptions in this real-world setting. Another limitation is that data acquisition was reliant on the accuracy of the physician’s report. There is also the potential for selection bias because those who agreed to participate may have characteristics different from those who did not agree. Last, the DSP is a cross-sectional study, and thus relationships should be considered associative rather than causal.
Acknowledgements
Medical writing support in the preparation of this publication, in accordance with good publication practice (GPP3), was provided by E. Jay Bienen, independent medical writer, and Valerie Moss ISMPP CMPP™ of PRIME, Knutsford, UK and funded by Sanofi and Regeneron Pharmaceuticals, Inc. The authors are responsible for all content and editorial decisions and received no honoraria related to the development of this publication.