Using a Physician Survey to Estimate the Economic Burden of Fibromyalgia in China


 Background: Fibromyalgia (FM) is a chronic pain disorder with a global prevalence estimated to be between 2 and 3%. In addition to the chronic pain incurred by patients, FM is commonly associated with comorbidities and complications such as depression, anxiety, and sleep disturbances. This study estimates the economic burden of patients with FM in China using a physician survey. Methods: A burden of illness model was constructed using a micro-costing approach to estimate the direct cost associated with FM patients in China. FM-related comorbidities of anxiety, depression, and sleep disturbance were included in the model. Treatment utilization and costs for FM and FM-related comorbidities were included as well as FM-related healthcare resource utilization (physician visits, hospitalizations, blood tests, and radiologic tests). FM treatments included nonsteroidal anti-inflammatory drugs, pregabalin, duloxetine, amitriptyline, tramadol, Chinese medicine, physiotherapy, and acupuncture. The model leveraged the results of a physician survey, which targeted 6 rheumatologists and pain experts each with 5-10 FM patients per month in China. All costs are presented in Renminbi (¥) using spot exchange rates as of May 1, 2020.Results: From the physician survey, the prevalence rate of FM in China was estimated to be 2.8% with 75.8% as female. The economic model estimated the annual per patient direct medical cost of FM to be ¥17,377. Within these costs, FM-medication and treatment costs (¥11,216), healthcare resource utilization (¥4,297), and costs for medications treating FM-related comorbidities (¥1,863) were the highest contributors. Healthcare resource utilization costs were driven by physician visits (¥2,787) followed by radiographic tests (¥808), blood tests (¥508), and hospitalizations (¥194). Conclusion: The prevalence and gender distribution of FM patients in China is similar to those of other countries. The economic model estimates patients with fibromyalgia in China to incur significant economic costs.

contributors. Healthcare resource utilization costs were driven by physician visits (¥2,787) followed by radiographic tests (¥808), blood tests (¥508), and hospitalizations (¥194). Background Fibromyalgia (FM) is a chronic pain disorder affecting muscles and soft tissue while causing signi cant health and economic burden to patients [1]. The American College of Rheumatology (ACR) has published guidelines to de ne the criteria for diagnosing bromyalgia in adult patients. However, in clinical practice in China, the majority (> 60%) of physicians are unfamiliar with the ACR guidelines. Due to this lack of familiarity, which is not only a factor in China but globally, it is estimated that most cases take over 2 years to diagnosis [2].
The overall prevalence of bromyalgia globally is estimated to be between 2 and 3% [2][3]. It is more than three times as common in females as males [3]. Prevalence rates also vary signi cantly from study to study depending on the criteria and sample, with very few national studies being conducted. Patients with FM experience a high rate of comorbid conditions compared to their non-FM counterparts. Common comorbidities include sleep disturbance/insomnia, anxiety, and depression [6]. Rates of depressive symptoms and anxiety were positively correlated with FM severity. Sleep disturbance/insomnia was highly prevalent regardless of FM severity with a reported prevalence of 52.4% in mild patients, 71.4% in moderate patients, and 69.2% in severe patients. The average number of comorbid conditions among mild patients was 2.9 compared to 4.1 in moderate patients and 4.4 in severe patients [6].
In China, a study of 107 con rmed FM patients reported over 20% had lumbar disk herniation or suspected or misdiagnosed spondyloarthritis, and 14% had osteoarthritis. Furthermore, 12.15% had either anxiety or depression [7].
There currently is no cure for FM and the majority of Chinese rheumatologists believe the goal of treatment should be to focus on relieving symptoms [8]. In China the preferred treatments for FM patients cared for by rheumatologists include antidepressants (79.1%), nonsteroidal anti-in ammatory drugs (NSAIDs) (61.2%), physical therapy (56.0%), and exercise (52.6%). The majority of rheumatologists (95.3%) were prescribing pharmacotherapy to patients with a focus on relieving symptoms of FM, while 71.8% believed there was no effective bromyalgia therapy [8].
Patients with bromyalgia have a signi cant economic and humanistic burden. In the United States, patients with bromyalgia were founded to have costs that were three-times higher than their non-FM counterparts [9]. This trend in higher costs has held true in global studies as well, with heightened costs for FM patients [10][11]. The economic impact has been described as similar to rheumatoid arthritis [12]. In addition to the high economic burden patients also experience a considerable humanistic burden with lower rates of employment, reduced productivity, and lower quality of life compared to non-FM patients [10,13,14].
The primary objective of this study was to estimate the nancial burden of bromyalgia in China through the development of an economic model. The secondary objective was to conduct a survey of physicians to understand the prevalence, severity, and treatment patterns of patients with FM in China.

Model Overview
A model was developed to estimate the direct costs associated with FM in China. The model utilized a micro-costing approach and considered costs related to FM medications, medications for FM-related comorbidities, physician visits, hospitalizations, blood tests, and radiologic tests. This type of model has been used in previous FM studies to estimate the burden of disease within a health system [15]. Data for the model was sourced from a physician survey, a literature review, and publically available data.

Physician Survey
In the absence of recent literature describing the local treatment patterns of patients with bromyalgia in China, a survey was administered to Chinese rheumatologists and pain physicians currently treating patients with FM. Their responses were based on their personal impressions based on their experience.
Since the average physician in China may not be familiar with FM, the physicians chosen had an average of 5-10 patients per month. The selected physicians regularly participated in advisory boards and patient education activities for a variety of stakeholders. The survey covered four areas including 1) epidemiology of FM; 2) FM-related treatment patterns; 3) treatment patterns for FM-related comorbidities; and 4) healthcare resource utilization and costs for FM patients. A total of six Chinese rheumatologists were targeted for the surveys, which was administered in-person/via phone. Ethics committee approval was not required because the data were based on the opinions of clinical experts without the aide of patient charts.

Model Inputs
The model inputs were sourced from a combination of the literature and the physician survey described above. Clinical inputs included the percentage of patients on FM-related medications/therapy (Table 1) and medication for FM-related comorbidities as reported in the physician survey. The cost per day of each included medication is based on publically-available information and can be provided upon request.

Physician Survey
The response rate to the survey was 100% with all physicians providing completed surveys. The physicians were rheumatologists and pain physicians located in the following hospitals: two physicians were from the Chinese PLA General Hospital and one each was from the Beijing Tsinghua Chang Gung  Globally the economic impact of bromyalgia has been extensively reported. While the difference in health systems and costs makes a direct comparison between the results from this analysis to analyses in other health settings di cult, the drivers of costs can be compared. The exact prevalence and incidence of FM in China are largely unknown. There have been few studies attempting to estimate the prevalence in different regions and cities, and no studies estimating nationally [4][5]. A 2015 study evaluating the prevalence of FM in a small sample of 4,056 residents of Shantou estimated a prevalence rate of 0.12% [4]. A similar study conducted in Hong Kong reported a prevalence of 0.82% [5].
In Taiwan, the direct cost per year for patients with FM was estimated to be ¥14,000. FM-related medications were responsible for 56.6% (¥7585) of costs, resource utilization was 14.1% (¥1885), and comorbid medication was due to 29.2% of costs [15] A study of Japanese patients with FM determined the per-patient direct costs were ¥126,500, which were signi cantly higher than a matched cohort of non-FM patients [13].
The average annual direct cost per FM patient in the United States with a diagnosis of FM diagnosis during the period of 2001-2004 was ¥77,000. Direct costs were driven by outpatient pharmaceuticals (28.8%), inpatient stays (14.8%), and physician visits (7.6%) [12]. A study in the United States compared the costs and healthcare resource utilization of patients with FM based on severity. Of all the direct costs to the payer, 76.2% were for prescription medications in mild patients compared to 62.1% and 62.2% in moderate and severe patients, respectively [6].
Other economic burden studies have been conducted in China for other chronic disease areas. A 2019 publication estimated the economic burden of postherpetic neuralgia in China using a similar method.
The study found total direct medical costs of ¥10,600. The costs were driven by higher hospitalization costs of ¥9300 compared to our study, which was driven mostly by higher drug costs [16]. The societal costs of patients with rheumatoid arthritis across 21 tertiary care hospitals between July 2009 and December 2010 were studied [17]. The total societal cost per patient-year was estimated to be ¥27,000, of which 90% (¥24,300) were direct costs. The primary driver (> 50%) of costs were drug costs, which was similar to our analysis [17]. Patients with diabetes were reported to have total annual medical costs of ¥19,600 and diabetes-related costs of ¥13,100, which was closely correlated with our estimated annual direct cost of ¥17,377 for FM patients [18].
The results of this analysis can be used by stakeholders in China to better understand the different sources of costs for FM patients in the healthcare system. While FM-related medications were the largest contributor to direct medical costs, the cost of treating comorbid conditions represented a signi cant 10.7% of direct medical costs. The optimal treatment selection to effectively treat FM and control comorbid conditions such as depression, anxiety, and sleep disturbance, could result in a reduction in treatment costs and healthcare resource utilization. Lastly, physician education is an important component of the effectiveness of treating FM. Physicians understanding the nature of the disease are able to more effectively treat it through the selection of the correct medication(s) for each individual patient and thus improve patient outcomes and perhaps lower the indirect costs associated with FM. Furthermore, treatments could include exercise and other healthy habits with minimal cost on the payer system.

Declarations
Ethics approval and consent to participate: Ethics committee approval was not required because the data were based on the opinions of clinical experts without the aide of patient charts. No individual, patient-level data was referenced for the work.
Please see the following link to support this statement: https://www.bu.edu/researchsupport/compliance/human-subjects/determining-if-irb-approval-is-needed/ Consent for Publication:

Not Applicable
Availability of data and materials: Data sharing is not applicable to this article as no datasets were generated or analyzed during the current study.
Competing interests: Bruce CM Wang, Wesley E Furnback, and Dongfeng Liang are paid consultants of P zer Upjohn Medical Trading Co., Ltd. Feifei Chen is an employee of P zer Upjohn Medical Trading Co., Ltd and Jim Z Li is an employee of Upjohn Division, P zer Inc. Funding: This study (including all publication fees) was funded by P zer Investment Co. Ltd.
Author's Contributions: BW and WF provided data analysis, interpretation of data, and drafting of the work. FC and JL contributed to the study conception, design of work, and drafting of the work. DL contributed to the design of the work, data acquisition, and substantial revisioin of the draft.