It is surprising how little is known about disability in patients with inflammatory bowel disease (IBD). There are sparse data on IBD-related disability compared with other chronic inflammatory diseases such as multiple sclerosis. Even advocacy organizations such as the Crohn and Colitis Foundation of America (CCFA) have little information on the extent of disability of its membership. Perhaps the reason for this shortage relates to the lack of a standardized instrument to evaluate disability as well as multiple challenges in defining disability in these patients. Although defining disability may be important in research that provides a better understanding of the impact of disease and treatment on those with IBD, the definition has real-world implications for those individuals in terms of their financial security, access to medical care, and the ability to work and function in society.
Defining Disability
There are major differences in how disability is defined. Disability generally implies chronic limitations that preclude the ability to resume normal daily activities. In this sense, individuals with acute and relatively short-term flares of ulcerative colitis (UC) or Crohn disease (CD) may not be considered disabled. Several large population-based studies suggest that disease activity may be greatest in the first 2 years after diagnosis of IBD and then plateau for many patients. Delineating the differences between sick leave and disability may be an important component of the process. Another corollary includes the duration of disability and the expectation that an individual with IBD will shed a disabled status. Thus, setting an appropriate time frame is a necessary component of defining IBD disability.
Most disability studies have traditionally focused on work and employment. There are aspects of work force disability, which can be defined as unemployment versus employment, which can be divided further into full-time versus part-time or even occupation-specific disability. For example, almost all physicians in the United States carry occupation-specific disability, which provides benefits when they are unable to perform adequately in their own specialty or subspecialty. This system contrasts with other disability insurance systems, which may be focused on whether the individual can perform any job. Disability benefits from a private insurer may have different criteria compared with a governmental organization. Besides work disability, specific physical and psychosocial factors of disability can exist as well.
There are no generally accepted measures of disability for IBD patients. Development of such an index would be useful for evaluation of several aspects of IBD care. A major effort to create an index has been undertaken by a World Health Organization initiative, based on the International Classification of Functioning, Disability, and Health (ICF) Core Sets. Its development was based on information from several preparatory studies (a systematic literature review, a qualitative study, an expert survey, and a cross-sectional study) and an international consensus conference of 20 experts in the field of IBD from 17 countries.
The advantages include the establishment of an international standard and the ability to compare results between various institutions and different countries, potentially identify environmental factors that impact disability, implement and evaluate medical interventions in a more patient-oriented way, and establish a common language between the different health care professionals, patients, and policy makers and thereby disburden the life of the patients and improve their health and functioning. The ICF approach includes components of community support and governmental rules/regulations in defining disability. Including factors of activities and participation from a social setting to employment and education as well as attitudes of the patient creates some overlap with the Inflammatory Bowel Disease Questionnaire (IBDQ). This broad approach in evaluation of disability increases the potential of the ICF to become a valuable research tool but makes it more difficult to be applied to making “insurance” decisions about one individual’s disability in Peoria.
Although the bulk of disability research has focused on what patients with IBD cannot do, there is a flip side: can medical or surgical intervention significantly reduce the burden of the disease. Bernstein points out several benefits in utilizing this newly standardized tool to evaluate disability outcomes in IBD patients: Showing reduced disability in prescription drug users could help the pharmaceutical industry convince those who pay for health care of the long-term benefits of treatments, especially the expensive biologic therapies. Knowing potential short-term and long-term disability after surgery could help clinicians and patients decide on the potential benefit of surgery. If research shows no difference in disability for IBD patients with quiescent disease compared with the general population, this information may increase access to affordable health insurance. Although not a focus of this article, the question of health care insurability after a diagnosis of IBD is a major concern of patients, at least in the United States. A better understanding of the frequency and degree of IBD-related disability may have an effect on insurability, which, in either subtle or not-so-subtle ways, may alter the balance between working and disability.
In Spain, Vergara and colleagues have validated a questionnaire to assess disability in CD patients. In this CD perceived work disability questionnaire (CPWDQ), individuals with CD estimate the impact on their ability to function. It showed good correlations (r = 0.59, P <.01) to clinical activity and overall work impairment, r = 0.66 ( P <.01). The investigators found that CPWDQ scores were higher in patients with active disease versus those with inactive disease ( P <.001), prior sick leave versus none ( P <.01), and in those requiring hospitalization versus none ( P <.01).
Physical Disability
Previous studies that evaluated physical disability looked at the physical component summary (PCS) of the short form (SF-36) scale. In Lichtenstein and colleagues’ study, patients in CD activity index (CDAI) remission at week 54 had a mean PCS score 46.6, which is close to the general US population and higher than the mean score for patients who are not in CDAI remission (37.4) ( P <.0001).
Interestingly, Walker and colleagues found IBS patients had significantly higher medically unexplained physical symptoms and disability ratings than patients with IBD. Feagan and colleagues found significant differences in those with SF-36 PCS scores who were unemployed, employed part-time, or employed full-time ranging from lower to higher scores, respectively ( P <.0001).
Psychosocial Disability
Our current best estimates for psychosocial disability are through quality of life measurements. A study of CD patients in CDAI remission had mean mental component summary (MCS) score of 49.8, essentially the same as the general US population. But those patients not in CDAI remission at week 54 had an MCS score 41.3, much lower than that of the general US population ( P <.0001).
In Feagan and colleagues’ study, the IBDQ total score and the emotional, social, and systemic dimensions of the IBDQ, along with SF-36 MCS scores, were each significantly different ( P <.05), with the lowest scores in patients unemployed, higher scores in patients employed part-time, and the highest scores in patients employed full-time. The total score and the social dimension score were most significantly affected and had the greatest difference ( P <.0001).
Work/Financial Disability
Most disability studies have traditionally focused on work and employment. Employment status may be affected by disease severity and/or activity, but a host of other factors may come into play. The Americans with Disability Act addresses this issue by attempting to minimize those logistics that may preclude an individual with some disabilities from continuing to work. Individuals may consider themselves disabled, in other words self-reported disability, but may not qualify for disability insurance. Also, disability status for most insurance programs is a binary calculation: either disabled or not disabled. There is no partial disability status.
There is a considerable range of estimates of the incidence of work disability in IBD. Using data from the National Health Interview Survey, an estimated 31.5% of individuals with IBD were out of the labor force, which was twice as high as the non-IBD population. Another study found that at 10 years following IBD diagnosis, over 70% of patients were fully capable of work capacity, where less than 10% were partially capable and about 20% were incapable. Lichtenstein and colleagues’ study showed 49% of patients were employed full time, 12% part time, and 39% unemployed.
Several small case-control studies on work status in IBD reported almost similar employment rates in patients and controls. Comparable employment rates in Crohn patients relative to control subjects were found in the Netherlands.
Other studies did find increased work disability in IBD patients: A fourfold increased risk of chronic work disability in Crohn disease compared with controls was found in a study in England and Wales (odds ratio [OR]: 4.0; 95% confidence interval [CI]: 2.2–7.3). Another case-control study showed that patients with CD had significantly more long-term unemployment compared with controls, and up to 30% of the patients actively concealed their illness from their employers. A study of 106 patients reported significantly more patients (80%) than controls (24%) had experienced periods of unemployment and missed more work days than those without CD. Compared with the general population, patients with IBD were twice as likely to be unemployed, however, had a low rate of reporting themselves as disabled (1.3%). In a postal questionnaire conducted in the Netherlands where 69% of IBD patients and 48% of controls responded, employment was 6.5% lower compared with controls (95% CI: 4.0–9.0), and chronic work disability was 17.1% higher than expected (95% CI: 15.1–19.1). For those who were employed, 62% of patients versus 53% of controls had one or more episodes of sick leave during the past year ( P = .002).
Baseline data from the ACCENT I trial showed that 48% of CD patients were employed full time, 13% employed part time, and 39% were unemployed. Based on the TREAT registry report of September 2000, 16% of patients were not working due to CD. Full-time workers missed an average of 3.3 workdays per month compared with 2.4 workdays missed by part-time workers, and an overall disability rate of 25%. Given that this was an international study, it is interesting to note that there was a large variation in disability rates depending on the country, ranging from a low of 20% in the United States to a high of 34% in Europe.
There are several factors that may explain this considerable variability among studies. Patient selection may be a major determinant. The more community-based patient population will have a lower rate of disease severity and disability than a tertiary referral center. The ACCENT 1 data and the TREAT registry may have selected for a large proportion of patients with more severe disease. However, the geographic variations within TREAT probably reflect socioeconomic factors and government regulations that affect the ability to obtain disability in one country versus another. Thus, similar disease severity may entitle an individual to disability in one country but not another.
Another estimate from a health insurance claims database stated that 15% to 25% of patients with CD require hospitalization in a given year. Rogala and colleagues showed that despite similar employment rates in IBD and non-IBD populations, there was a three times increased short-term disability in IBD population reported as reduced activity at work/home, having been confined to bed, and requiring extra effort due to illness, than those in the community sample.
Disability as a Function of Governmental Policy/Economics
In the United States individuals may purchase private disability insurance or rely on Social Security Disability Insurance (SSDI). There are significantly different standards for defining what qualifies as disability between the two (see later discussion). In the United States, at least, the most widely applicable definition of IBD disability is that embodied in the SSDI regulations. The Americans with Disabilities Act forbids disability discrimination in the workplace, with a goal to keep disabled individuals working.
In studies, considerable variety in rates of disability were found. Procaccini and Bickston reported that 20.4% of individuals were disabled but that approximately one-third of these (7%) had been denied disability. Anathakrishnan and colleagues found that 5.3% of CD patients at a university referral center were receiving SSDI. In a Norwegian cohort, the average disability pension in 1995 to 1999 in IBD patients was 8.8%, identical to the general population. An earlier study in Germany found that 3% of all German employees with IBD were granted a disability pension.
Predictors of Disability
Certain factors can predict an increased risk of disability.
CD Versus UC
In general, CD seemed to affect employment more than UC. The OR of chronic work disability in CD was 5.4 (95% CI: 3.7–7.8) compared with 2.6 (95% CI: 1.8–3.6) in UC. CD patients reported somewhat more frequent sick leave than UC patients ( P = .04), and days absent at work were higher in CD compared with UC patients ( P = .04). The sick leave numbers for those with CD were twice as high, whereas UC patients were only slightly higher than the background Norwegian population. In Sweden, patients with CD received an early pension threefold more frequently than patients with UC.
Disease Characteristics
Interestingly, shorter disease duration predicted a higher likelihood of unemployment. No studies have evaluated medications specifically as a marker of disability. Certain clinical courses suggest a greater risk, including more than two operations, more than two medical hospitalizations, and a lower quality of life. Prior bowel resection predicted a higher likelihood of unemployment and of receiving disability compensation.
Not surprisingly, patients in remission are more likely to be working than those with active disease. Thirty-one percent of the IBD population who experienced symptoms in the past 12 months were not in the labor force. This rate was greater than for the IBD group without symptoms (18.5%) and the non-IBD group (14.8%). Other variables of disease severity such as number of visits to the specialist, taking IBD-related drugs, hospitalization, or surgery in the past year were also significantly associated with sick leave ( P <.001). Within IBD patients, the risk of sick leave was associated with self-reported disease severity during the past year (OR for no episode of bowel symptoms compared with continuous disease 0.07 (95% CI: 0.02–0.22), OR for one episode of disease compared with continuous disease 0.17 (95% CI: 0.05–0.55), and OR for several episodes of disease activity compared with continuous disease activity 0.3 (95% CI: 0.1–0.7).
This statement is somewhat self-evident: more severe disease leads to a greater chance of disability. However, some studies have not found a strong correlation between disease activity indices and disability. This result raises the possibility that there may be cumulative morbidity associated with disease that leads to disability. In the ACCENT I trial data, a higher number of patients went from unemployed status to employed status (31%) if they were in remission at week 54 of the study, compared with only 16% if they were not in remission at that time. Patients’ mean work hours lost decreased the longer the patients were in remission per CDAI criteria.
Quality of Life
IBD-related sick leave turned out to be the variable with the strongest association to the patient’s health-related quality of life (HRQOL) as measured by the SF-36 and Norwegian-IBDQ. Both disability pension and sick leave were significantly associated with the patients’ HRQOL. Quality of life (IBDQ SF-36) scores were significantly higher in employed patients.
Family-related factors may also play a role. The mother’s positive affect was significantly inversely correlated with adolescent depression and functional disability described by the 15-item Functional Disability Index and frequency of bowel movements.
Extra-Intestinal Manifestations
Self-reported joint complaints were associated with sick leave (OR: 3.19; 95% CI: 1.15–8.86; P <.03). Although no significant differences in HRQOL scores were found between those with PSC-IBD and non-PSC IBD in Anathakrishnan and colleagues’ small retrospective study, permanent work disability defined by receipt of Social Security disability payments was found in 7.7% of PSC-IBD patients compared with 0% of non-PSC-IBD patients ( P = .013).
Employment Type
Sonnenberg reported that of all German employees, work-disabled IBD patients were more likely to have a white-collar job than all the other work-disabled subjects. However, the investigator states that this result may simply reflect the higher prevalence of IBD among white-collar workers.
Age
There are conflicting data for age as a risk factor for disability. Some studies find that younger patients are more likely to be disabled, others not. Whether this result reflects greater disease activity early in the disease, development of coping mechanisms over time, or national differences in societal benefit plans remains unclear. If younger age is a true risk, it would argue against the importance of cumulative morbidity.
A Norwegian study found that the patients receiving disability pension or unemployed patients had higher mean age (7% unemployed under 30 vs 43% unemployed in 60–67 years of age range) than those not receiving disability or employed. In contrast, patients reporting sick leave or IBD-related sick leave had lower mean age than those not reporting any sick leave ( P <.001). Relative to controls, the risk of chronic work disability was more increased in younger ( P = .02) and higher educated ( P = .02) patients compared with controls in Boonen and colleagues’ study as well. The IBD group with symptoms was a younger group (32.6% were aged 30–39 years) than the IBD group without symptoms (46.5% were aged 50–64 years). Younger age predicted a higher likelihood of unemployment, as well as part-time employment. Sonnenberg’s study from Germany found that in Crohn patients, the largest fraction of disability pensions was given to patients younger than 40 years, with a small peak at age 60 to 64 years. UC patients had similar distributions as well.
Gender
There has been conflicting information on gender as an influence on disability. Although some studies showed no differences, others found a female predominance. In Germany, female patients with IBD had an increased risk for disability than their male counterparts. Specifically, disability in CD was twice as common in women than men ( P <.001), whereas disability in UC was equal. In a Norwegian cohort, women with CD had a three to four times higher disability rate (22.5%) than men with CD and women and men with UC. Although no specific findings within their study explained this difference, the investigators suggested that differing coping mechanisms between genders may account for the difference.
Marital status and domestic arrangements may also be a determinant in employment status. However, marital status did not change the results of chronic work disability significantly. Smoking habits were not associated with increased disability.
Lower Educational Levels
Procaccini and Bickston found that, in the United States, the chance of maintaining employment was a function of level of education, with 91% of those with postgraduate education and 72% of those with a college degree continuing to work, whereas only 42% of high school graduates were still in the work force.
Longobardi and colleagues also concluded that a higher level of education, in the United States, was one of the most important factors in determining work status in patients with IBD. However, a study from the Netherlands found the opposite, that those with low education had an almost four times higher association of work disability than those with high education (OR 3.8; 95% CI: 2.4–6.2). However, the risk to be chronically work-disabled was higher among higher educated patients in this study. Thus, there may be important factors beyond the disease itself that impact disability status.
Related posts:
The Role of Capsule Endoscopy in Evaluating Inflammatory Bowel Disease
Health Maintenance in the Inflammatory Bowel Disease Patient
The Promise and Pitfalls of Serologic Testing in Inflammatory Bowel Disease
Evaluation for Postoperative Recurrence of Crohn Disease
Patient-Specific Approach to Combination Versus Monotherapy with the Use of Antitumor Necrosis Factor α Agents for Inflammatory Bowel Disease
Imaging for Luminal Disease and Complications: CT Enterography, MR Enterography, Small-Bowel Follow-Through, and Ultrasound
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