Updates in psoriasis diagnosis and treatment status in China: results from the National Psoriasis Center Registry.

Abstract

To the Editor: Psoriasis is a common chronic immune-mediated systemic inflammatory disease[1] characterized by irritating skin erythema, reduced quality of life, and associated systemic diseases including cardiovascular disease, diabetes, and metabolic syndrome. In 2017, 0.5% of China's population was diagnosed with psoriasis.[2] To improve the overall diagnosis and treatment level of psoriasis in China, the National Clinical Research Center for Skin and Immune Disease launched a national collaborative project called the Psoriasis Standardized Diagnosis and Treatment Center (also named Psoriasis Center) project, [3] in which the first national real-world big data collection platform, Psoriasis Center Registry, was established with more than 300 medical centers across China by 2022. This study aimed to update the current general characteristics and treatment distribution of patients with psoriasis in China by describing the registry data at enrollment. Baseline data of all patients with psoriasis who were enrolled in the registry between August 2020 and March 2022 were extracted in this cross-sectional study. The registry was approved by the Human Genetic Resources Management Office of the Ministry of Science and Technology of China (No. 2022-CJ0021) and the study protocol was approved by the Ethics Committee of Peking University First Hospital (No. 2020-scientific research-255). All patients signed informed consent forms before enrollment. At enrollment, the registry collects data on demographics; personal and family medical history; clinical manifestations including disease phenotype and severity; treatment strategies; and self-reported questionnaires. Moreover, the diagnosis of psoriasis and classification of phenotypes are made primarily based on medical history and clinical manifestations. Disease severity was assessed using the Psoriasis Area and Severity Index (PASI), which is the product of the affected area and the degree of redness, thickness, and scaling, with a total range of 0 to 72; Body Surface Area (BSA), which is the percentage of body surface covered by psoriatic lesions, ranges from 0% to 100%; and Investigator's Global Assessment (IGA), which is a 5-point Likert scale from 0 to 4, representing the overall psoriatic lesion severity as clear, almost clear, mild, moderate, and severe, respectively. Obesity was defined as body mass index (BMI) ≥ 27.5 kg/m2, according to the definition of obesity for the Chinese population suggested by the World Health Organization. Other comorbidities, including hypertension, diabetes, coronary artery disease, and malignancies, were primarily recorded according to the patients’ recall. The self-reported questionnaires included information on work status, education, medical insurance, smoking habits, Psoriasis Epidemiology Screening Tool (PEST) screening for psoriatic arthritis (PsA), and quality of life assessed using the Dermatology Life Quality Index (DLQI), which includes ten questions reflecting influences on patients’ symptoms and feelings, daily activities, leisure, work and study, personal relationships, and treatment burden in the last 7 days, and has a range of 0 to 30. According to the 2018 Chinese guideline,[4] disease severity was classified as mild (PASI<3, BSA<3%, IGA=2, DLQI<6), moderate (PASI 3–<10, BSA 3%–<10%, IGA=3, DLQI 6–<10), and severe (PASI ≥10, BSA ≥10%, IGA=4, DLQI ≥10). All treatment decisions were jointly made by the dermatologists and patients at each collaboration center. Statistical analyses were performed using STATA/SE (StataCorp LLC 2021, Release 17, College Station, TX, USA). Continuous data were analyzed using the Mann-Whitney U test, whereas categorical data were analyzed using the chi-squared test. P values <0.05 were considered statistically significant. Until March 2022, 55,402 baseline observations were collected from 282 collaborations across China [Supplementary Table 1, https://links.lww.com/CM9/B410]. The overall male-to-female ratio was 1.8:1, and the median age was 38.7 (29.2–52.9) years, with 93.8% (50,730/54,056) adults. The national urban employee and rural resident basic medical insurance covered 49.2% (26,319/53,499) and 42.3% (22,638/53,499) of patients with psoriasis, respectively, and only 3.5% (1867/53,499) of patients were on out-of-pocket expenses. The prevalence of obesity (BMI ≥27.5 kg/m2) was 19.0% (9483/50,050) among Chinese adult patients, who generally endured the disease for a median duration of 6 (1–14) years [Supplementary Table 2, https://links.lww.com/CM9/B410]. Plaque psoriasis was the most prevalent phenotype (84.5%, 46,809/55,368), followed by guttate psoriasis (12.3%, 6792/55,368), pustular psoriasis (3.0%, 1680/55,368), and erythrodermic psoriasis (3.6%, 2008/55,368). Arthropathic psoriasis (i.e., psoriasis with PsA) was diagnosed in 2.3% (1290/55,368) of patients with psoriasis, although 7.1% (3725/52,781) reported a PEST score ≥3. Impactful areas were commonly affected by psoriasis lesions in Chinese patients (70.9%, 38,553/54,378), including the scalp (63.9%, 34,567/54,112), nails (20.4%, 10,894/53,292), palms/soles (17.8%, 9575/53,714), and genitals (12.1%, 6423/53,141). In terms of disease severity, the median PASI, BSA, and DLQI were 6.8 (3.0–14.0), 10% (3–26%), and 8 (3–12), respectively, in the overall psoriasis population. Furthermore, 37.4% of patients had severe psoriasis according to PASI (20,356/54,444), while the proportion was 53.2% using BSA (28,981/54,455), 14.8% using IGA (8058/54,449), and 37.9% using DLQI (20,152/53,182) [Supplementary Table 3, https://links.lww.com/CM9/B410]. Regarding comorbidities, 5.5% (2567/46,741), 3.4% (1742/50,768), 0.9% (435/46,524), and 0.3% (153/50,768) of patients had previously been diagnosed with hypertension, diabetes, coronary artery disease, and malignancies, respectively, and the prevalences of above comorbidities were 19.5% (1073/5517), 10.6% (662/6241), 4.7% (257/5420), 1.1% (66/6241) among aged patients (≥60 years) [Supplementary Table 4, https://links.lww.com/CM9/B410]. Additional auxiliary examination results are presented in Supplementary Table 5, https://links.lww.com/CM9/B410. Overall, at enrollment, topical therapy was prescribed for 59.3% (32,792/55,291) of patients, with glucocorticoids (35.0%, 19,358/55,291) and Vitamin D3 analogues (21.8%, 12,042/55,291) being the most commonly used topical agents. A total of 37.7% (20,853/55,283) of patients were prescribed non-biological systemic therapy, including phototherapy (11.4%, 6305/55,283) and oral systemic drugs, most of which were oral Chinese herbs (13.4%, 7415/55,283) and acitretin (6.8%, 3759/55,283) [Supplementary Table 6, https://links.lww.com/CM9/B410]. Additionally, 15,862 patients (28.7%, 15,862/55,276) were on biologics at baseline, among whom 80.8% (12,811/15,862) were on secukinumab and 10.1% (1597/15,862) were on adalimumab. More adult patients chose biological therapy, whereas more children chose topical or non-biological systemic therapies (all P < 0.001). Among those on biological therapies, 12,119 patients (76.4%, 12,119/15,862) initiated biological therapy at enrollment, of whom 88.0% (10,658/12,112) were diagnosed with plaque psoriasis, 6.9% (833/12,112) with guttate psoriasis, 2.8% (228/12,112) with pustular psoriasis, 5.8% (707/12,112) with erythrodermic psoriasis, and 3.2% (389/12,112) with arthropathic psoriasis. Furthermore, most patients with plaque psoriasis who initiated biological therapy at enrollment had a PASI ≥10 (63.3%, 6529/10,321) or had PsA with at least one impactful area being affected (74.6%, 7701/10,321), while 1116 patients (10.8%) had neither a PASI≥10 nor an impactful area affected (Supplementary Figure 1A, https://links.lww.com/CM9/B410). Detailed information on impactful area involvement and PsA stratified by PASI severity in patients with plaque psoriasis initiating biological therapy at enrollment is shown in Supplementary Figure 1B, https://links.lww.com/CM9/B410. To showcase the changes in treatment distribution in recent years, this study further exclusively classified each enrolled patient into one treatment group with a higher rank (i.e., biological treatment > non-biological systemic therapy > simple topical therapy), and compared the treatment distribution between August 2020 to February 2021 and March 2021 to March 2022 [Supplementary Figure 2A and B, https://links.lww.com/CM9/B410]. Before secukinumab was covered by the National Medical Insurance in March 2021, non-biological systemic therapy (with or without topical therapy, 45.4%, 4487/9881) and simple topical therapy (without systemic therapy, 26.9%, 2657/9881) were the major therapies for the general population of patients with psoriasis in China, while biological therapy was prescribed in 18.3% (1813/9881) of the patients. Secukinumab (50.7%, 919/1813) and adalimumab (26.7%, 484/1813) were the major biological agents prescribed. In comparison, since March 2021, non-biological systemic therapy (31.2%, 14,217/45,521) and biological therapy (with or without non-biological therapy, 30.8%, 14,012/45,521) have become equally prevalent, and secukinumab (84.9%, 11,891/14,012) has become the first choice for those receiving biological therapy. In this cross-sectional study, we summarized the demographics, clinical characteristics, and current treatment status of patients with psoriasis in China between August 2020 and March 2022 based on the first national real-world registry for psoriasis in China. Compared with the nationwide hospital-based survey conducted by Chen et al[5] in 2009 to 2010, the overall disease severity significantly improved in this study, as the percentage of patients with a PASI ≥10 dropped from more than 71.1% to 37.4%. Despite the differences caused by different study populations and medical environments, the results suggest an overall improvement in psoriasis treatment within over 10 years. Before the 2010s, most patients were treated with topical glucocorticoids (75.7%) and oral traditional Chinese medicine (72.0%), while no previous use of biologics was reported due to its rarity.[5] Although topical glucocorticoids (35.0%) and oral traditional Chinese medicine (13.4%) were still used in 2020 to 2022, the proportion decreased significantly, and 28.7% of patients were on biological treatment at enrollment in this study. Since the national resident medical insurance covers over 90% of patients with psoriasis, the proportion of patients on biologics has further increased from 18.3% in 2020–2021 to 30.8% in 2021–2022 after secukinumab was added to the National Reimbursement Drug List. Furthermore, although biologics were only recommended in patients with severe plaque psoriasis determined by PASI≥10, with arthropathic psoriasis or impactful areas affected in the Chinese guideline,[4] 10.8% of patients with plaque psoriasis who initiated biologics at enrollment satisfied none of these requirements. Hence, in addition to objective skin lesions, previous responses to traditional therapy, subjective demands, and economic aspects of patients were also considered in the current treatment model in China. In addition to skin lesions, increasing evidence has revealed that psoriasis is a systemic inflammatory disease. PsA is the most notably associated disease, and is observed in 10% to 40% of the psoriasis population.[1] However, in real-world surveys, only 1.3% of Chinese patients with psoriasis had been previously diagnosed with PsA in the 2010s as per Kun Chen's study[5] and 2.3% in the 2020s as per this study. Furthermore, the diagnosis rates of other comorbidities in this study population were even lower than those of the general adult residents of China, including those of hypertension and diabetes. Our findings indicate poor awareness regarding psoriasis as a systemic inflammatory disease in the current diagnostic status in China, and emphasize the importance of regular comorbidity screening for patients with psoriasis. The main limitation of this study is missing data. Because missing at random was considered as the mechanism of missing data, a complete case analysis was applied to present real-world patient conditions. Additionally, the patients were primarily enrolled at dermatology clinics in tertiary hospitals, and thus may not fully represent the general population of patients with psoriasis in China. Future studies with data from more hospitals and medical alliances are needed to investigate the changes in patients’ clinical characteristics over the years and to explore psoriasis trigger factors and treatment effectiveness based on longitudinal data. In summary, this national real-world study showed a high overall disease severity and high prevalence of impactful areas affected, however, a low report rate of comorbid systemic disorders in Chinese patients with psoriasis, which requires more intensive treatment, mental support, and enhanced awareness of screening for comorbid systemic disorders. More preference was given to biological therapy in those with severe psoriasis, PsA, or lesions in impactful areas, especially after the medical insurance support was strengthened. As treatment approaches may continue to progress in the future, the results of this study could serve as a baseline reference for future studies. Funding The study was supported by a grant from the National Key Research & Development Program of China (No. 2021YFF1201100). Acknowledgements The authors would like to acknowledge the contributions made by all the collaborating units of the Psoriasis Center with data collection. The authors would also like to thank all the patients who participated in this study. Conflicts of interest None.