Background

Sarcoidosis generally occurs among the relatively young, working population. Sarcoidosis is a heterogeneous multi-organ system disease whereby the immune system launches a response to an unknown antigen resulting in granulomatous lesions occurring most anywhere in the body interfering with resident organ function. The lungs, eyes, and skin are the most commonly recognised; but cardiac, brain, spinal cord, and hepatic involvement are not uncommon [1].

Depending on granuloma burden, location, and sensitivity of the organ involved (e.g. eye, heart, brain and spinal cord require little granuloma volume to have devastating clinical effects); symptoms related to sarcoidosis vary in type, severity, and extent of disability [2]. Apart from major organ involvement, sarcoidosis can involve reduced muscle strength, loss of physical condition, pain, extreme fatigue, and memory- and concentration problems. Disease chronicity correlates to higher number and degree of reported impairment [3, 4].

These impairments can be organ-related, such as dyspnoea or exercise intolerance related to pulmonary or cardiac involvement; but might also be non-organ related, non-specific. Apart from major organ involvement, sarcoidosis can involve reduced muscle strength, loss of physical condition, pain, extreme fatigue, and small fiber neuropathy (SFN)-associated symptoms. Psychological factors are pervasive including anxiety, concentration and memory difficulties, and depressive symptoms; and may not correspond with inflammatory disease activity nor respond to sarcoidosis treatment [5, 6]. These symptoms are disabling, persisting after other signs of sarcoidosis activity resolve, and adversely impact major life areas, including quality of life (QOL) and work ability [7, 8].

Sarcoidosis is associated with a high number of illness and health visit related sick-days and associated with large yearly income loss [9,10,11] that persists beyond 5 years from diagnosis [9]. Patients undergo mental and physical employment assessments that depend upon lung function as the main indicator for work capacity, despite sarcoidosis being a systemic multi-organ disease with many patients having severe disease without significant lung impairment [6, 12,13,14,15,16,17,18,19,20]. The Dutch Sarcoidosis society (www.sarcoidose.nl) [21] reported a need for educational enhancement of sarcoidosis among decision-making authorities and medical examiners performing work capacity assessments in sarcoidosis patients, particularly in regard to extent and severity of extra-pulmonary symptoms.

The aim of this study was to assess difficulties sarcoidosis patients may have experienced regarding their work including performance, absenteeism, environment, employer policies, and disability evaluations. These experiences were examined in relation to disease burden.

Methods

Study Design

In cooperation with the Dutch Sarcoidosis Society, Sarcoidose.nl [21] and the ILD care foundation, the authors designed a cross-sectional web-based anonymous questionnaire that broadly investigated potential work-related issues experienced by patients with sarcoidosis in correlation to symptom and disease burden. Recruitment occurred from October 2017 to April 2018 and was designed to engage large representative samples of sarcoidosis patients.

Study Subjects and Procedure

Patients were recruited through membership of the Dutch Sarcoidosis Society, Sarcoidose.nl [21] via the society’s newsletter and advertisement through ILD Center of Excellence at Nieuwegein. No incentives were offered. Patients participating were proficient in Dutch and had internet access.

Patients were provided the specific link to the survey through the online questionnaire tool Surveymonkey (www.surveymonkey.com) [22] which queried disease and symptom burden, experiences regarding employers and disability evaluations, as well as demographics (gender, age, disease duration), medication use, and two sarcoidosis-validated questionnaires; the Fatigue Assessment Scale (FAS) [23] and the Small Fiber Neuropathy Screening List (SFNSL) [24].

Questionnaires

The FAS is a ten-item self-report fatigue questionnaire rated on a five-point scale (1 never to 5 always) providing a total score ranging between 10 and 50, and mental and physical sub-scores. A score > 21 indicates fatigue with > 34 indicating extreme fatigue. The FAS demonstrated good reliability and validity in sarcoidosis [23].

The SFNSL is a 21-item self-administered screening questionnaire for SFN-related symptoms on a five-point scale (0 never to 4 always). Scores range from 0 to 84, with scores between 11 and 48 indicating probable to highly probable SFN and > 48 indicating SFN [24].

Statistical Analysis

All statistical analyses were performed using SPSS version 20 for Windows. Standard descriptive statistics were computed. After subdivision into assessed- and non-assessed for disability benefits, these two sarcoidosis patient samples were compared using Chi-square test and independent t tests, depending on type of variables (continuous or dichotomous). A probability (p) value of < 0.05 was considered to be statistically significant.

Results

Of the 870 patients with sarcoidosis who participated in the survey, 755 had paid work. Of these 755, 43% (n = 328) reported having undergone disability assessments by the benefits authorities; 427 patients reported no assessment (Fig. 1; Table 1). The remaining 115 patients were not included due to being homemakers, informal caregivers, self-employed, or previously declared unfit for work due to illnesses other than sarcoidosis.

Fig. 1
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Flowchart of survey participants

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Table 1 Characteristics of patients with sarcoidosis, who were assessed or not assessed by the benefits authority
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Of those assessed, 75% were on treatment compared to almost two-thirds of the non-assessed sample (p < 0.01), and also had significantly more extra-pulmonary symptoms, extreme fatigue, reduced exercise capacity, and memory and concentration problems. Moreover, mean FAS and SFNSL-scores were significantly higher in the assessed group.

At the time of the survey 17% of the total study sample were on sick leave, 28% were declared fully unfit for work, and 13% declared partially unfit for work. Among those employed (n = 267) at the time of the survey, 69% reported frequently finding work too strenuous, and reported sarcoidosis-related absence for shorter or longer periods. Among those assessed (n = 328), 37% perceived not having been listened to or taken seriously during assessment, while 10% had mixed experiences. Thirty-eight percent (n = 124) of those assessed disagreed with the assessment outcome; of which 75% (n = 93) appealed or requested re-assessment. Table 2 summarises the respondents’ perceptions of the assessment encounter [25].

Table 2 Ten statements by patients with sarcoidosis, who had been assessed by the Dutch benefits authority UWV
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Discussion

This is the first study assessing difficulties sarcoidosis patients may have experienced regarding work capacity in relation to disability claims. Sarcoidosis patients who had undergone evaluation for disability were significantly more likely to experience extra-pulmonary symptoms, extreme fatigue, reduced exercise capacity, and cognitive difficulties.

At the time of the survey, a high rate of participants were on sick leave, or declared fully or partially unfit for work demonstrating the great impact of sarcoidosis on work ability. Moreover, a remarkably high proportion of assessed patients perceived they were not taken seriously or listened to during assessments resulting in a high level of outcome disagreement, suggesting the need to improve quality of assessments better informed by the scope of sarcoidosis.

Absenteeism Related to Sarcoidosis

Sarcoidosis-related absenteeism has previously been demonstrated to impair work attendance and livelihood [9,10,11], imposing significant economic burden on both patients and employers. Polish social insurance data reported sarcoidosis-related absence or disability averaged 30 sick-days per person annually [11]. In the U.S. Sarcoidosis patients had significantly more sick-days (15.9 vs. 11.3) and income loss than non-sarcoidosis controls [10]. In Sweden, impaired sarcoidosis-related work ability persisted beyond 5 years after diagnosis, averaging 45 sick-days annually compared with 34 days in non-sarcoidosis disease comparators. Older patients and patients receiving treatment upon diagnosis registered the highest number of sick-days and largest income loss during the study period [9].

Combining results from our and these few other studies, as most patients want to continue working, attention on the causes of absenteeism and strategies to improve work accommodations is needed. Also, health systems approaches that consolidate travel to clinical appointments and use home-based therapies as well as innovative applications such as sick-day donation and work from home infrastructures are worth taking a closer look at [26,27,28,29,30].

Beyond optimisation of work maintenance, disability assessments for sarcoidosis should be conducted by examiners well-educated in the scope of the disease.

Assessing Claims and Collecting Information

The first step in evaluating claims for work capacity is data collection of diagnoses, physical examinations, laboratory findings, workload, and self-evaluation using questionnaires, performance tests, and interview procedures. Evaluation of disability is a complex process that is affected by the skills set, attitudes and beliefs of the examiner; few countries enforce standards of practice [31, 32], which presents considerable challenges to reliability of assessments [33, 34].

A recent systematic review by Barth et al. [35] supported this hypothesis demonstrating a high variation in judgements on work disability among medical examiners; using standardised assessment methods, like rating instruments for functional limitations or structured interview methods (such as the disability assessment structured interview (DASI) [36]), demonstrated a reduction in “inter-rater variability” and improved the reproducibility among examiners.

However, only few of these standardised methods are available and being used to measure impairments in claim assessments. The aforementioned systemic review demonstrated that only six of thirteen insurance-based studies administered one or more specific work-ability instruments; with no instrument reported as validated. Most studies (n = 10) used only medical examiner perceptions to generate a global rating of workability [35].

In our study, a large percentage felt their complaints were not taken seriously. One could speculate that medical examiners erroneously regard sarcoidosis as a pulmonary disease, basing functional capacity mainly on the presence of pulmonary symptoms and lung function tests results. Recent research by Marcellis et al. [16] and Strookappe et al. [17] showed that generally used medical assessments, like lung function tests results and chest radiographs, only poorly correlate with commonly reported physical impairments such as muscle weakness, exercise intolerance, and fatigue.

This suggests that the inclusion of metrics such as 6-minute walk distance (6MWD), or other muscle and exercise testing in assessment guidelines may increase the accuracy of these assessment outcomes. A recent patient survey reinforced the need for clinical indicators to be used in tandem with patient-centred healthcare, including attention to work ability and other supportive measures [7].

Knowledge About Symptom Burden in Sarcoidosis

Furthermore, this discordance underscores the limited knowledge that clinicians generally possess regarding sarcoidosis as a disease of extra-pulmonary involvement. Fatigue is a central concern in sarcoidosis [6, 15], our data demonstrated 35% and 61% with fatigue and extreme fatigue respectively in the assessed group; mirroring that found in many other chronic disorders [37,38,39,40,41]. Furthermore, sarcoidosis patients often struggle with memory and concentration problems [6, 20] (30% and 69% respectively in the assessed group), although these factors pose challenges in objective assessment, they are recognised illness-related symptoms meriting formal consideration with validated instruments like the FAS [23], the SFNSL [24] and the subjective Cognitive Failure Questionnaire (CFQ) [42].

Sarcoidosis patient organisations are an immense and rich resource to provide integral guidance on and development of effective methods of measuring and incorporating QoL and functionality outcomes with a view to improve sarcoidosis outcomes and management strategies [7]. In line with recent studies [7, 43], the results of this study suggest an urgent need for education among medical examiners supported by formal guidelines that consider all aspects of sarcoidosis.

The development of a disease specific core set for sarcoidosis under the framework of “the International Classification of Functioning, Disability and Health (ICF)” [44] with input from patients as well as physicians, rehabilitation specialists, specialist nurses, and so on, could hereby be a first step in examining and structuring the multi-faced functional impact of sarcoidosis on employment. As a preliminary step, this study investigated the merit of pre-study concerns expressed by the sarcoidosis patient community regarding experiences and perceptions of disability claims. This paper establishes that merit. Evaluation of disability is a complex process that is affected by the skills set, attitudes and beliefs of the examiner, which presents considerable challenges to the reliability of disability claims assessments. Future goals in addition, to correlation of disability claims with objective disease severity assessments, would investigate the spectrum of reliable and feasible evaluation measures to accurately quantify extent of sarcoid-related disability and investigate perspectives of disability officers in relation to sarcoidosis. The synthesis of these investigative efforts will ultimately help to inform the revision of national disability assessment protocols. The results of this paper once again highlight that non-pulmonary symptoms and measures should be acknowledged in the management of sarcoidosis in general, and more specifically by those who are responsible for rating workability.

Limitations

A major limitation of the study might be selection bias with symptomatic patients being more likely to be members of a patients’ society or referred to a sarcoidosis clinic, and thus possibly influencing the rate of symptomatic respondents. To date, we recently published a study evaluating self-reported symptoms in three European Countries: Denmark, Germany, and the Netherlands whereby the German and Dutch cohorts were gathered through patient associations, the Danish cohort were patients from a sarcoidosis clinic. The German and Dutch cohorts had similar patient-reported severity as the Danish cohort, that had detailed objective severity data. This finding provides some reassurance regarding the Netherlands self-reported patient association data in this study [45].

Another limitation is that data is self-reported and without verification of diagnosis nor correlation to other objective functional measures. Having hospital established severity data would have enhanced the design—but this is a preliminary study that founds the need for more involved studies. However, symptom burden and perceptions of disability evaluations processes are both intrinsically patient experiences and never before quantified.

Although this study was based on self-reported symptoms and data on functional status was not collected, it is clear patients are plagued by multiple symptoms, most prominently fatigue. Earlier studies identified discordance between fatigue and lung function testing or 6MWD.

The present study only scratches the surface of many important aspects of work ability, setting the stage for future studies delving into work accommodations, clinical operations and disability assessments [46]. Future studies will correlate other functional testing to these patient-reported measures in relation to work capacity.

Conclusion

Sarcoidosis patients may be more severely disabled than current disability claims assessment protocols for sarcoidosis are equipped to measure; a sufficient extent of objective parameters appear to be lacking. This study showed that a high proportion of the sarcoidosis patients who had undergone a disability evaluation felt their concerns dismissed with many disagreeing with the assessment outcome. Medical examiners’ lack of education regarding scope of sarcoidosis disease burden beyond being a pulmonary disease could explain these perceptions. There is an urgent need for sarcoidosis-related education enhancing work-related medical examinations supported by guidelines that account for extent of sarcoidosis impact on functionality, and therefore work capacity.