Introduction

Ankylosing spondylitis (AS)/axial spondyloarthritis (axial SpA) typically affects people from a young age, it often has a detrimental impact on health and well-being and it is associated with significant risk of limiting work productivity over the life course. Despite this, relatively little attention has been paid to issues regarding work productivity in this condition. Consequently, there is an urgent need not only to understand better the different perspectives of people with AS/axial SpA, of health professionals, of health service managers and of employers but also to embed issues pertinent to work productivity as a routine element of health care. Exciting opportunities now exist to bring together the key sectors to develop innovative solutions and processes to drive such advances, and to enable the potential of people with AS/axial SpA to succeed in workplace settings to be fully realised.

Key clinical features

AS/axial SpA is a chronic systemic inflammatory condition that primarily affects the axial skeleton . Inflammation of the spinal joints and adjacent structures, with localised enthesitis, creates pain, stiffness and limitations in spinal movement and it may lead to bony fusion of the spine . Recent refinement in diagnosis has followed the introduction of the term ‘axial SpA’ by the Assessment of SpondyloArthritis International Society (ASAS) . In axial SpA, the predominant symptom is chronic inflammatory back pain, but X-ray features of sacroiliitis may or may not be present. The new classification criteria enable earlier diagnosis of pre-radiographic axial SpA, compared to the previous modified New York criteria , in which X-ray changes at the sacroiliac joint were required. Previous dependence on radiographic changes contributed to people often experiencing long delays in diagnosis .

The prevalence of AS/axial SpA ranges from 0.5% to 1.8% in Caucasians . It is likely that approximately 200,000 people have AS in the UK . Among people with chronic back pain, the prevalence of AS/Axial SpA is only 5% , and many years may pass between the first symptoms and a definitive diagnosis . About 50% of people with AS develop associated disorders, including episodic iritis (40%), psoriasis (16%) and inflammatory bowel disease (10%) . The strong genetic association with HLA-B27 is well established , and much effort continues to be focussed upon identifying other key biomarkers.

Key clinical features

AS/axial SpA is a chronic systemic inflammatory condition that primarily affects the axial skeleton . Inflammation of the spinal joints and adjacent structures, with localised enthesitis, creates pain, stiffness and limitations in spinal movement and it may lead to bony fusion of the spine . Recent refinement in diagnosis has followed the introduction of the term ‘axial SpA’ by the Assessment of SpondyloArthritis International Society (ASAS) . In axial SpA, the predominant symptom is chronic inflammatory back pain, but X-ray features of sacroiliitis may or may not be present. The new classification criteria enable earlier diagnosis of pre-radiographic axial SpA, compared to the previous modified New York criteria , in which X-ray changes at the sacroiliac joint were required. Previous dependence on radiographic changes contributed to people often experiencing long delays in diagnosis .

The prevalence of AS/axial SpA ranges from 0.5% to 1.8% in Caucasians . It is likely that approximately 200,000 people have AS in the UK . Among people with chronic back pain, the prevalence of AS/Axial SpA is only 5% , and many years may pass between the first symptoms and a definitive diagnosis . About 50% of people with AS develop associated disorders, including episodic iritis (40%), psoriasis (16%) and inflammatory bowel disease (10%) . The strong genetic association with HLA-B27 is well established , and much effort continues to be focussed upon identifying other key biomarkers.

Managing AS/axial SpA

ASAS/European League Against Rheumatism (EULAR) recommendations aim to maximise long-term health-related quality of life (HRQoL) through control of symptoms and inflammation, prevention of progressive structural damage and preservation/normalisation of function and social participation . Education and physical exercise are key elements. People are encouraged to take responsibility for their own programmes, and physiotherapists play a key role in this. A recent Cochrane review concluded there is ‘silver’-level evidence that exercise programmes, either home based or supervised, can improve movement and physical function.

Non-steroidal anti-inflammatory drugs (NSAIDs) together with physiotherapy are used to treat symptomatic inflammatory back pain . Anti-tumour necrosis factor (TNF) therapy in people with high disease activity who have not responded to NSAIDs may reduce disease activity but not radiographic progression . In some people, joint replacement surgery or spinal corrective osteotomy for severe deformity may be required .

Assessment and monitoring

The National Ankylosing Spondylitis Society (NASS) ‘Looking Ahead’ document provides guidance for diagnosis and management, and a benchmark for accessing local services. All individuals with AS/axial SpA should be assessed by a physiotherapist at the time of diagnosis and at least annually thereafter , and these individuals should have regular contact with a multidisciplinary team (MDT) . These principles are reiterated within the ‘2020 Health Report’ which recommends that every person diagnosed with AS should receive an annual appointment with a specialist to review medication, range of movement, impact on work and social activities, co-morbidities and mental health. To inform regular monitoring, a range of composite indices and questionnaires are currently available. Disease status scores have been found to correlate with anxiety, depression and health status, which should be taken into account when interpreting Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and Bath Ankylosing Spondylitis Functional Index (BASFI) data .

Impact on personal development and attainment

AS/axial SpA has a significant impact on many areas of personal development and attainment. Symptoms commonly begin in adolescence or early adulthood, which is a critical time in terms of education, work and establishment of social frameworks and relationships . The condition typically advances slowly, often leading to insidious decline in physical and social abilities, whilst co-morbidities may also develop. The outcome is largely unpredictable, and the degree of disability ranges from minimal to devastating . This may pose problems in relation to the person’s career, family and social life . Pain, stiffness, fatigue and sleep problems are important concerns along with changes in mood or personality, low self-esteem, stigma and worry about the future . A recent study showed that patients experience a wide range of problems, including the psychological distress of having to ‘fight’ to get a diagnosis, and that this may be associated with lack of familiarity and knowledge of AS/axial SpA among health-care professionals.

Impact on work productivity

Given the features of AS/axial SpA described above, it is perhaps unsurprising that it is responsible for substantial direct and indirect socio-economic costs, work disability and impact on quality of life . Withdrawal from work is three times more common in people with AS than in the general population, increasing from 5% during the first year of diagnosis to over 20% at 10 years and 30% at 20 years . One-third of hospital attenders with AS give up work before retirement age and others modify or reduce their work . Fifty percent of people with AS experience work instability, whilst 15% reduce or change their work because of AS. Both physical and psychosocial factors have an important role, such that loss of employment is associated with being older, longer disease duration, lower educational achievement, co-morbidity, greater physical impairment, pain, fatigue, stiffness, anxiety, depression and lower self-esteem . This leads to significant personal and societal costs that rise substantially with decreasing function . Moreover, people with non-radiographic axial SpA experience a similar burden of disease and impact on HRQoL as those with established AS .

There is a paucity of literature addressing the key determinants of work productivity in AS. To date, most studies have been framed as questionnaire surveys , and they have concluded that the determinants are complex and multifactorial. Issues identified encompass a range of sociocultural, psychological, coping, lifestyle and occupational factors.

The major physical features pertinent to a person’s ability to remain in work are loss of spinal mobility and chest expansion. Many people with AS experience continuing decline in spinal mobility even after 20 years of disease independently of disease duration and reported frequency of unsupervised exercise . Moreover, failure to prevent disease progression leads to about 40% of people eventually developing severe spinal restriction . People may therefore have concerns about their appearance, which has a negative impact on body image . In addition, psychological factors influence body image, potentially representing an important difference between adults with AS and healthy adults . Fears for the future have been reported, centred around the uncertainty of disease progression such as fear of being in a wheelchair, self-consciousness and ugly appearance associated with the postural changes of the ‘ bent back’, which create poor self-esteem, less self-confidence and poor self-image .

Other features that may affect people within the workplace are pain and stiffness, sitting in a static position, problems with mobility – sometimes involving peripheral joints – and tiredness due to sleep disturbance and/or fatigue with a consequent impact on the ability to concentrate. Psychological features are also very important. Healey and colleagues identified a range of factors related to work status in AS, among which depression was strongly associated with unemployment outcomes including absenteeism and presenteeism. Moreover, the ‘stigmatisation’ of having ‘back pain’ may negatively influence willingness to disclose symptoms and working difficulties to managers and work colleagues alike. The workplace is a difficult arena in which to maintain relationships by trying to remain ‘normative in the face of disruption’. For example, work colleagues may be reluctant to redistribute workloads, and they may be poorly tolerant of frequent absences from the workplace .

It has been suggested that the work capacity of people with AS in the middle decades of life is similar to that of people with rheumatoid arthritis . Moreover, inability to work has important consequences for the individual and his/her family through both loss of earnings and the loss of self-esteem that a career and income provide. Financial and personal costs of living with AS are substantial including the cost of drugs and other treatments, regular exercise, increased insurance premiums, and reduced earnings and pension rights, which can ultimately lead to financial disadvantage.

There is also a cost to society due to a potential loss of up to one-third of people with AS from the workplace. Many individuals with AS may fail to achieve their chosen career or to fulfil their potential . Financial costs include the loss of tax revenue from those patients and carers unable to work, and the cost of paying disability benefits and/or benefits to carers’ allowance. The direct costs of treatment include primary- and secondary-care costs, drug costs and social care costs with societal costs rising steeply as physical function deteriorates.

Raising awareness about work productivity

In the UK, the National Ankylosing Spondylitis Society (NASS) has campaigned for many years to raise awareness of AS/Axial SpA, and it made a significant contribution to best practice in its ‘Looking Ahead’ document . Within this document, the burden of living and working with AS is highlighted as being a major problem. NASS has sought to raise awareness of the impact of living with AS has on the ability to work, and it has emphasised the role of delay in diagnosis and lack of awareness of the condition from family, friends and employers. To quote Jane Skerrett, a former director of NASS

‘ These anxieties often focus most acutely on the impact of AS on work: will you be able to carry on in your current role? How will your employer and fellow employees react? Will you have to change your job completely or even worse, have to give up work altogether ?’

In 2009, NASS published a survey of their members on working with AS in response to their expressed concerns about employment. NASS distributed a questionnaire to 1000 members, receiving 324 responses from people with a current diagnosis of AS. Only 12% reported that AS had made no discernible impact on their working lives, whilst one-third reported that they were able to perform less physical or manual tasks at work than before the onset of AS. The findings showed that people were not receiving useful advice from health-care professionals or employers on how to cope with their condition at work and that work-related issues were often not even discussed. Many felt they had waited too long to receive a diagnosis, and this had an impact on their productivity, whereas effective treatment made a significant difference to being able to remain in work. In addition, people with more severe AS reported more impact on their working lives, and those with higher disease activity were twice as likely to report that their working life had been affected. Sixty-one percent were concerned about the impact of the deterioration of their condition on their job or employment prospects, and 30% had concerns about discrimination because of their AS, from employers or colleagues. Two-thirds reported that they occasionally went to work despite feeling unwell. Those who found their treatments helpful had fewer perceived barriers to remaining in employment than those whose treatment was not working well. They were less likely to report pain and fatigue affecting their ability to work and were less likely to need time off sick.

In response to the survey, NASS invited a panel of experts to develop recommendations and a call to action for key stakeholders, which included the government, general practitioners (GPs), rheumatologists and employers. The ‘2020 Health’ report recommends that employers be encouraged to develop strategies for getting people back into work. Within this, small businesses should be encouraged to work with larger organisations to exchange ideas and best practice. The report suggests that ‘Rather than employers being dismissive of complaints about back pain or viewing them with suspicion as an excuse for poor performance, it is important for them to seek to improve the working lives of people with long term conditions so that they remain in work.’

The key areas for employers to give greater attention to were identified as follows:

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  Appropriate training is to be provided for co-workers to enable them to support employees with long-term conditions.

  
  
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  A flexible approach to job design and responsibilities is to be adapted, which may include flexible working hours, amended job descriptions and inclusive recruitment policies and procedures. The benefits of allowing employees with AS to take regular short breaks from work to stretch out and exercise was highlighted.

  
  
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  Health-care professionals (such as GPs and occupational health) are to be proactively engaged with when an employee notifies them of their condition, so that the individual is able to remain an effective member of the workforce without feeling isolated.

The Work Foundation also published a recent report on the impact of AS on work in the UK , which highlighted the potential for AS/axial SpA to significantly disrupt or even curtail the participation of younger people in the labour market, adding further to the case that there are important clinical, social and economic benefits of keeping people with AS/axial SpA in work.

Tools to measure impact of AS/axial SpA on work

Although work plays a key role in the lives of people with AS/axial SpA, capturing the impact of the condition on a person’s work ability is not currently a core component of health assessment, partly because there is a paucity of tools to measure its impact on working lives. International guidelines, such as those from the Canadian Rheumatology Association and the Spondyloarthritis Research Consortium of Canada, recommend that disease monitoring not only include assessments of function, disability and handicap but that social, leisure, education, community and work activities also be integral measures . OMERACT has also reinforced the importance of work productivity through the Worker Productivity Special Interest Group .

The Work Productivity and Activity Impairment questionnaire in AS (WPAI:SpA) was modified from the Work Productivity and Activity Impairment (WPAI) , which is a self-administered questionnaire for assessing the impact of disease on productivity, and which was validated for use in many long-term conditions including asthma, dermatitis and Crohn’s disease. The WPAI:SpA assesses the impact of AS on work and other daily activities during the previous 7 days. It comprises six questions to determine employment status, hours missed from work due to AS, hours missed from work for other reasons, hours actually worked, the degree to which AS affected work productivity while at work and the degree to which AS affected activities outside of work. Four scores are derived: percentage of absenteeism, percentage of presenteeism (reduced productivity while at work), an overall work impairment score that combines absenteeism and presenteeism and percentage of impairment in activities performed outside of work. Higher scores indicate more impairment. However, questions related to absenteeism and presenteeism are only applicable to employed people.

Validation of the WPAI:SpA was undertaken in the context of a 24-week randomised, double-blind clinical trial of a biologic therapy in patients with AS . Discriminative validity of WPAI:SpA included absenteeism, presenteeism, overall work productivity loss and activity impairment scores, which were assessed relative to patient-reported outcomes.

This tool has been used mainly within clinical trials, but it has recently also been included as one of the outcome measures within the industry-sponsored ‘Talking AS’ online tool designed to make monitoring AS quicker and easier. Although providing data on absenteeism and productivity, this measure provides no indication of how the ability to work is being influenced by the condition, and it performs assessments over only a 1-week period. Furthermore, it was developed before the newer concept of non-radiographic Axial SpA evolved, and it is only valid if a person is in employment.

Work instability (WI) encompasses the period prior to work disability (WD), and it is defined as the consequences of a mismatch between a person’s functional ability and the demands of their job, which may threaten employment . Therefore, recognising WI early might reduce or eliminate the risk of work disability through the introduction of workplace or clinical interventions. The Work Instability Scale for Rheumatoid Arthritis (RA-WIS) was validated for AS (AS-WIS) as a self-administered questionnaire for identifying those at a risk of job retention problems and work disability, and also to indicate if biologic therapies are indicated. It is a 20-item questionnaire, many of the questions being shared with the original RA-WIS. There are cut-off points for defining low (<11), medium (11–18) and high (19–20) levels of work instability. However, the AS-WIS was only developed from a small sample size, and its predictive validity for job retention remains unknown .

A more recent example is the arthritis-specific Work Productivity Survey (WPS), which has been validated to assess productivity limitations associated with arthritis both within and outside the home . This instrument assesses productivity limitations in axial SpA, including non-radiographic axial SpA and AS, and as with the WPAI and AS-WIS it has followed on from its initial validation in other conditions (rheumatoid and psoriatic arthritis). Psychometric properties were assessed using data from the RAPID-axSpA trial. The WPS is a disease-specific questionnaire designed to assess the impact of arthritis on workplace and household productivity, as well as daily activities during the preceding month. It is interviewer-administered or self-reported, and it covers a 1-month period . The first item of the WPS addresses current labour market participation (employment outside the home), as well as providing normative and comparative data on employment status (not working implying complete loss of paid productivity). Two items capture self-reported absenteeism (days of work missed) and presenteeism (days with productivity reduced by at least half) due to arthritis, and two items capture the same concepts but apply to nonpaid (household) work. Additional items capture the respondent’s estimate of the extent to which arthritis has interfered with work productivity (paid and nonpaid) on a scale of 0–10 (0 = no interference and 10 = complete interference), the number of days in the past month that outside help was hired because of arthritis, and the number of days in the past month that family, social or leisure activities were missed because of arthritis. Although recommended for use in both clinical trials and clinical practice, the authors point out that there is no gold standard for assessing worker productivity in axial SpA. They do, however, state that the validation results are in line with previous work carried out for the WPAI questionnaire in the AS subpopulation. In this study, people with greater disease severity (BASDAI) were seen to experience greater work impairment, presenteeism and impairment in daily activities; however, absenteeism was not significantly different between people with worse health and those with better health . A caveat in the WPS validation is that the group studied probably had more active disease than a more representative population-recruited group would have.

Generic outcome measures that have been used in research studies include the Work Limitations Questionnaire (WLQ) . This was developed to measure how health problems are interfering with specific aspects of job performance and the productivity impact of these work limitations. The questionnaire is recommended for use in clinical studies, by employers and health professionals for employed individuals with chronic conditions. There are five scales: time management (consisting of five items addressing the difficulty in managing time and scheduling demands), physical demands (contains six items covering a person’s ability to perform job tasks that involve physical strength, stamina, movement, coordination and flexibility), mental/interpersonal (nine items that assess cognitive job tasks and on-the-job social interactions) and output demands (five items concerning reduced work quantity and quality). Scale scores range from 0 (limited none of the time) to 100 (limited all of the time). The score represents the amount of time in the last 2 weeks that people were limited whilst working. In addition to the scale score, a total WLQ index score can be calculated and converted into an estimate of productivity loss, and this can be compared to the ‘healthy’ employee (normative scores).

Although tools are available to measure the loss of paid productivity, they are associated with important methodological limitations, especially in the context of clinical trials of biologic therapies . Verstappen et al. suggested how clinical trials might more robustly investigate the impact of therapies on the capacity to work, for example, by adjusting outcomes for possible confounders and through mandatory use of control groups in observational studies. They emphasised the importance of contextual factors relating to work characteristics and the organisation in understanding work participation.

The World Health Organization’s proposition of the bio-psychosocial model may more adequately address the impact of chronic conditions within the workplace in terms of productivity loss and disability . Within this model, the consequence of disease symptomatology and the impact on functional ability are complemented by psychosocial aspects including personal factors (educational level, helplessness, coping, beliefs about health and work and job satisfaction) and also by environmental factors (job type, social support, sick leave compensation, adaptation of the workplace, flexible working hours and potential help from colleagues). Contextual factors are complex, and they vary greatly across occupations and individuals, but validated questionnaires exist such as job content questionnaire based on the effort-demand model , and the effort-reward imbalance questionnaire based on the eponym model . Indeed, a recent study to understand the role of work-related contextual factors in AS suggested that both health-related and contextual factors contribute to work limitations in patients with AS and that additional opportunities for improvement should be addressed within the working environment .