IBD-Disk as a tool estimating the prevalence of inflammatory bowel disease-related disability and associated influencing factors in Saudi Arabia: A cross-sectional study

Abstract

Background:

Inflammatory bowel disease (IBD) disk is an easy tool to use in clinical practice to measure IBD-related disability, with a score >40 correlating with high daily-life burden. Its use has been limited mainly to the western world. We aimed to estimate the prevalence of IBD-related disability and evaluate the associated risk factors in Saudi Arabia.

Methods:

In this cross sectional study conducted at a tertiary referral center for IBD, the English IBD disk was translated into Arabic, and patients with IBD were approached to complete it. Total IBD disk score (0 = no disability; 100 = severe disability) was documented and a score of >40 was set as a threshold to estimate the prevalence of disability.

Results:

Eighty patients with a mean age of 32.5 ± 11.9 years and disease duration of 6 years, including 57% females, were analyzed. The mean IBD-disk total score was 20.70 ± 18.69. The mean subscores for each function within the disk ranged from 0.38 ± 1.69 for sexual functions to 3.61 ± 3.29 for energy. The overall prevalence of IBD-related disability was 19% (15/80 scoring >40) and was much higher in active disease, in males and in IBD of long duration (39%, 24%, and 26%, respectively). A clinically active disease, high CRP, and high calprotectin were strongly associated with higher disk scores.

Conclusion:

Although the overall mean IBD disk score was low, nearly 19% of our population had high scores signifying a high prevalence of disability. As demonstrated by other studies, active disease and high biomarkers were significantly associated with higher IBD-disk scores.

INTRODUCTION

Inflammatory bowel disease (IBD), comprising of Crohn’s disease (CD) and ulcerative colitis (UC) is a long-term condition that predominantly affects the digestive system, with a consequential broader impact on other parts of the body. A recent report has highlighted the rising incidence and prevalence of IBD worldwide.[1] The global distribution of this disease is anticipated to impose a significant societal and economic burden on governments and health care systems in the coming years.[2] This is primarily due to the disabling nature of IBD, which is marked by chronic restrictions, impeding the capacity to participate in everyday activities.[3] Patients with IBD frequently suffer debilitating symptoms with reported disability rates ranging between 1.3% to 34%.[3] Acknowledging this, the focus of IBD therapy has shifted substantially from symptom management to complete disease control (clinical and endoscopic remission), with the objective of avoiding organ damage and incapacity.[4] As a result, the Selecting Therapeutic Targets in IBD, an international initiative, has added the absence of disability and restoration of quality of life, to the long-term aims of clinical remission and endoscopic healing.[5]

To formulate a standardized method to assess disability in patients with IBD, the IBD disability index (IBD-DI) was developed as a validated instrument to assess the four categories of body functioning, activity participation, body structures, and environmental variables.[6] However, IBD-DI consisting of 28 questions remains more of a research tool. To simplify and make it more patient-friendly and clinician-friendly, IBD-DI has been adapted into a shortened questionnaire called IBD disk.[7]

The IBD disk consists of 10 questions, exploring abdominal pain, defecation, social life, professional life, sleep, energy, anxiety, self-image, sexual functions, and joint pain. Answers range from “absolutely disagree” to “absolutely agree” on an 11-point visual analogue scale. The points can be joined to form a polygon, which gives a quick overview of the disease-related burden.[8] IBD disk has been validated to be a reliable tool for clinical practice and a cut-off of 40 from the total score of 100 has been reported to be associated with a high IBD daily-life burden.[8,9]

IBD-related disability had been rarely measured outside the western world. Likewise, despite the rising incidence of IBD in Saudi Arabia, very little is known about the associated burden of disability to realize the economic implications and develop tools to address them.[10] Hence, we aimed to look at the prevalence and associated risk factors of disability among patients with IBD in the western region of Saudi Arabia.

PATIENTS AND METHODS

Study design and population

This was a cross-sectional study conducted at a single hospital in the western region of Saudi Arabia and the study was approved by the local Institutional Review Board that has been accredited by the Association for the Accreditation of Human Research Protection Program. From November 2021 till May 2022, patients aged 18 years and more with confirmed diagnosis of IBD based on standard clinical, imaging, endoscopic, and histopathologic findings for at least 6 months, attending the gastroenterology outpatient clinic and/or day care for biologic infusion, were approached to fill in the IBD disk. The patients filled in the electronic version of the questionnaire with the help of a research nurse.

The English IBD disk was translated into Arabic through the process of forward and backward translation by bilingual gastroenterology physicians and nurses fluent in both English and Arabic. It was proofread by a local Arabic speaker and tested on 10 patients with IBD for comprehension. The final version was confirmed by a gastroenterologist with an interest in IBD.

The IBD disk consists of 10 questions and included a 11-point Likert scales (0 = no burden; 10 = maximal burden) assessing each component of the IBD-related disability: joint pain, abdominal pain, body image, education and work, emotions, energy, interpersonal interactions, regulating defecation, sexual function, and sleep. The final score ranges from 0 to 100.[7,9]

Demographics and clinical details including type of IBD, duration of disease, Montreal classification of IBD, extraintestinal manifestations (EIM), surgical history, and medications were recorded. Disease activity was classified for both UC and CD based on physician global assessment as evaluated by the gastroenterologist on a four-point scale of inactive disease, mildly active, moderately active, and severely active disease. Inactive disease was defined as presence of clinical remission and the composite of mild, moderate, and severe as absence of clinical remission. In addition, laboratory investigations like fecal calprotectin (FC), CRP, and a full blood count were documented.

The IBD-disk scores were compared according to patient and disease characteristics. The comparison was done between patients in clinical remission with those who were not, between the two types of IBD, the phenotype of IBD as defined by international societies and the presence/absence of EIM.[11,12] The other comparison of IBD-disk scores was done between patients who had IBD-related surgery with those who did not and between those who were taking biologics and those who were not. In addition, IBD-disk scores were compared between patients with high/low CRP and high/low fecal calprotectin. CRP of ≥5 mg/L and fecal calprotectin ≥200 μg/g were considered high.[13]

Statistical analysis

Data were analyzed using SPSS version 26.0. Qualitative data were presented as percentages and were compared using the Chi-squared test. Quantitative data were presented as mean ± standard deviation or as median and interquartile range and were compared between the two groups using the Student “t” test or the Mann-Whitney test, depending on their distribution type. A two-sided alpha was set at 0.05 for all hypothesis tests.

RESULTS

Participants’ characteristics

Of the 131 patients contacted, 30 declined to participate. Twenty one patients had incomplete information and were excluded. A total of 80 patients were included in the final analysis and their details are listed in Table 1. The mean age at the time of participation was 32.5 ± 11.9 years with a mean duration of disease of 6 years and 57% were females [Table 1]. Ninety one percent (20/22) of these who had surgery were patients with CD and of these 50% had colectomy, 35% had an ileocecal resection, and 15% had small bowel resection. The majority of the patients with IBD were on biologics (62/80, 78%) with more than one-third of these on infliximab (23/62, 37%). Conventional therapy alone was used in 22% (18/80) of the patients and included antibiotics, 5-aminosalicylic acid, azathioprine, and methotrexate. Only four patients were on systemic steroids and all of these patients were on biologics [Table 1].

Table 1.

Demographics, disease, and medication characteristics of 80 patients with Inflammatory bowel disease

Characteristics	Overall patients n=80
Age, years	32.5 ± 11.9
Male gender	34 (43)
BMI, kg/m2	24.36 ± 7.34
Duration of IBD, years	5.7 ± 3.9
Age at diagnosis (%)
A1: ≤16 years	2 (3)
A2: 17–40 years	60 (75)
A3: >40 years	18 (22)
Type of inflammatory bowel disease
Crohn’s disease	40 (50)
Ulcerative colitis	40 (50)
History of intestinal resection	22 (28)
EIM	11 (14)
Current treatment
Antibiotics	2 (3)
5-ASA	12 (15)
Immunomodulator alone	4 (5)
Corticosteroids	4 (5)
Infliximab	23 (29)
Adalimumab	13 (16)
Vedolizumab	14 (17)
Ustekinumab	12 (15)
Combination*	26 (33)
CRP
High	32 (40)
Low	48 (60)
Calprotectin
High	32 (40)
Low	48 (60)
Physician Global Assessment
Active disease	36 (45)
Inactive disease	44 (55)

Data presented as mean ± standard deviation, or n (%) as appropriate. *Combination of biologics with steroid, immunomodulators, or 5ASA

Clinically active IBD

At the time of the interview, 45% (36/80) of the patients with IBD had active disease, including active UC in 61% (22/36). CRP was above the upper limit of normal in 32% and calprotectin was ≥200 μg/g in 32% of IBD patients.

Disability scores on IBD-disk

The mean IBD-disk total score was 20.70 ± 18.69. The mean subscores for each function within the disk ranged from 0.38 ± 1.69 for sexual functions to 3.61 ± 3.29 for energy. The top five components that scored the highest on the IBD disk included energy, abdominal pain, sleep, joint pain, and emotions [Table 2]. The overall mean of the IBD disk was significantly worse in active disease compared to disease in remission. Similarly, the mean subscores for each component of the IBD disk increased notably with disease activity, except for body image and sexual functions.

Table 2.

IBD-disk score and sub scores for each component of the disk

	Overall study Population n=80	Presence of clinical remission n=44	Absence of clinical remission n=36	P
Joint pain	2.28 ± 3.17	1.05 ± 1.90	3.78 ± 3.74	<0.001
Abdominal pain	3.23 ± 2.83	2.23 ± 1.90	4.44 ± 3.29	0.002
Regulating defecation	1.94 ± 2.70	1.20 ± 1.89	2.83 ± 3.25	0.024
Interpersonal interactions	1.71 ± 2.57	0.61 ± 1.17	3.06 ± 3.14	0.001
Education and work	1.68 ± 2.69	0.68 ± 1.68	2.89 ± 3.19	0.001
Sleep	2.54 ± 3.16	0.86 ± 1.81	4.58 ± 3.26	<0.001
Energy	3.61 ± 3.29	2.39 ± 2.76	5.11 ± 3.28	<0.001
Emotions	2.11 ± 2.68	1.14 ± 1.86	3.31 ± 3.04	<0.001
Body image	1.24 ± 2.26	0.84 ± 1.78	1.72 ± 2.69	0.141
Sexual functions	0.38 ± 1.69	0.23 ± 0.89	0.56 ± 2.32	0.818
Overall IBD-disk score	20.70 ± 18.69	11.23 ± 9.93	32.28 ± 20.40	<0.001

Using a total score of more than 40 as a threshold for disability indicator, the prevalence of IBD-related disability was 18.8% (15/80). The prevalence of disability in active disease was much higher at 38.9% (14/36) compared to inactive disease at 2.2% (1/44). Likewise, the prevalence of IBD-related disability varied based on gender, surgery, duration of IBD, the type of IBD, and medications [Figure 1].

Figure 1.

Prevalence of IBD related disability

Factors associated with disability

The type of IBD (CD or UC) did not significantly influence the total IBD-disk scores. Although females, older patients, and those with EIM had a trend toward worse scores, this however was not statistically significant. Use of biologics or having surgery did not result in better IBD-disk scores. Disease activity was strongly associated with worsening scores. Having a clinically active disease based on global physician assessment worsened the IBD-disk scores. Similarly, high CRP and high calprotectin were strongly associated with higher disk scores [Table 3]. In addition, we looked at the proportion of patients with and without IBD disk >40 score and its association with the above clinical features [Supplementary Table]. Having inactive disease and a low calprotectin level were strongly associated with IBD-disk scores of ≤40. Disease duration of ≤2 years, absence of EIM, and normal CRP showed a trend toward having IBD-disk scores of ≤40 that did not reach statistical significance.

Table 3.

Association of clinical factors with IBD-disk score

	All IBD	P	CD	P	UC	P
Type of disease
UC	22.3 ± 18.95	0.45
CD	19.1 ± 18.5
Age, years
<25	23.25 ± 22.53	0.43	22 ± 24.76	0.50	24.73 ± 20.66	0.62
≥25	19.61 ± 16.89		17.7 ± 15.01		21.38 ± 18.56
Gender
Men	23.24 ± 15.95	0.23	21.16 ± 21.76	0.51	25.87 ± 22.43	0.36
Women	18.83 ± 21.85		17.24 ± 15.34		20.16 ± 16.65
Disease duration (years)
≤2 years	15.5 ± 14.10	0.21	19.54 ± 18.37	0.74	11.46 ± 6.41	0.19
2-8	23.85 ± 21.04		25.46 ± 20.88		22.85 ± 21.59
>8	22.68 ± 19.43		22.77 ± 19.06		22.5 ± 22.06
Disease activity
Inactive	11.23 ± 9.93	0.0000	10.31 ± 22.55	0.00001	10.31 ± 6.40	0.00001
Active	32.28 ± 20.40	1	35.43 ± 6.40		35.43 ± 22.55
CRP
High	26.91 ± 20.68	0.014	23 ± 22.32	0.20	32.62	0.015
Normal	16.56 ± 16.16		15.57 ± 13.89		17.33
Calprotectin
High	36.12 ± 19.82	0.0000	39.67 ± 21.53	0.00001	34 ± 18.97	0.00001
Low	10.42 ± 7.61	1	10.29 ± 6.16		10.6 ± 9.43
CD location
L1/L2	16.87 ± 17.40	0.38	16.87 ± 17.40	0.38
L3	22.12 ± 20.08		22.12 ± 20.08
UC location
E1/E2	20.68 ± 18.67	0.56			20.68 ± 18.67	0.56
E3	24.28 ± 19.64				24.28 ± 19.64
CD behavior
B1			15.47 ± 17.53	0.62
B2			20.53 ± 20.04
B3			22.4 ± 18.61
EIM
Yes	28.27 ± 24.88	0.15	37.8 ± 31.32	0.06	20.33 ± 16.95	0.79
No	19.49 ± 17.43		19.1 ± 14.81		22.65 ± 19.49
Biologics			N/A
Yes	19.18 ± 18.41	0.38			20.79 ± 19.92	0.54
No	24 ± 18.03				24.56 ± 18.55
Surgery
Yes	19.27 ± 19.15	0.68	17.45 ± 17.12	0.55	N/A
No	21.24 ± 18.65		21.4 ± 21.39

Supplementary Table.

Association of clinical factors with IBD-Disk cut-off score of 40

	Proportional of patients with IBD-Disk score ≤40 (n)	Proportional of patients with IBD-Disk score >40 (n)	P
Type of disease
UC	80% (32)	20% (8)	0.77
CD	83% (33)	17% (7)
Age Years
<25	75% (18)	25% (6)	0.46
≥25	82% (56)	18% (10)
Gender
Men	76% (26)	24% (8)	0.35
Women	85% (39)	15% (7)
Disease duration (years)
≤2 years	96% (25)	4% (1)	0.06
2-8	74% (25)	26% (9)
>8	74% (14)	26% (5)
Disease Activity
Inactive	98% (43)	2% (1)	0.0000
Active	58% (21)	42% (15)	1
CRP
High	72% (23)	28% (9)	0.08
Normal	86% (42)	14% (6)
Calprotectin
High	57% (20)	43% (15)	0.0000
Low	97% (44)	3% (1)	1
CD location
L1/L2	87% (20)	13% (3)	0.39
L3	76% (13)	24% (4)
UC location
E1/E2	81% (18)	19% (4)	0.75
E3	78% (14)	22% (4)
CD behavior
B1	87% (13)	13% (2)	0.87
B2	80% (12)	20% (3)
B3	80% (8)	20% (2)
EIM
Yes	64% (7)	36% (4)	0.08
No	86% (59)	14% (10)
Biologics
Yes	82% (51)	18% (11)	0.67
No	78% (14)	32% (4)
Surgery
Yes	82% (18)	18% (4)	0.94
No	81% (47)	19% (11)

Looking at the specific IBD type, patients with CD had a mean age of 30 years, with 47% males and a mean disease duration of more than 6 years. Most had the disease in the ileocolonic location, with 22% having perianal disease. Only about 12% had EIM, with a quarter of them having had surgery. Almost all were on biologic therapy, apart from two who were on an immunomodulatory and antibiotic treatment. Thirty five percent had an active disease [Table 4]. The location or behavior did not correlate with disk scores and neither did gender or age. Patients who had EIM with CD had higher disk scores, although not statistically significant from those who did not have EIM with CD. Apart from two, all patients with CD were on biologics making it difficult to compare the scores with those not on biologics. Patients who had clinically active disease and high calprotectin scored notably higher on the disk compared with those who did not. Although patients with higher CRP had worse scores, this did not reach statistical significance [Table 3].

Table 4.

Demographics and clinical characteristics of CD and UC patients

Characteristic	CD, n=40	UC, n=40
Age, years	30.3 ± 9.99	34.8 ± 13.27
Male gender	19 (47)	15 (38)
BMI, kg/m2	23.47 ± 6.93	25.24 ± 7.7
Duration of IBD, years	6.4 ± 4.3	5.0 ± 3.4
Age at diagnosis (%)
A1: ≤16 years	8 (20)	N/A
A2: 17-40 years	29 (72)
A3: >40 years	3 (8)
Disease location CD
L1	22 (55)	N/A
L2	1 (2)
L3	17 (43)
Disease behavior CD
B1	15 (38)	N/A
B2	15 (38)
B3	10 (24)
Perianal disease	9 (22)
Disease location UC
E1		8 (20)
E2		14 (35)
E3		18 (44)
History of intestinal resection	20 (25)	2 (4)
EIM	5 (12)	6 (15)
Current treatment
Antibiotics	1 (2)	0 (0)
5-ASA	0 (0)	13 (33)
Immunomodulator alone	1 (2)	3 (8)
Corticosteroids	1 (2)	3 (8)
Infliximab	17 (42)	6 (15)
Adalimumab	6 (15)	7 (18)
Vedolizumab	6 (15)	8 (20)
Ustekinumab	9 (22)	3 (8)
Combination	18 (44)	10 (24)
CRP
High	19 (48)	13 (33)
Low	21 (52)	27 (67)
Calprotectin
High	12 (30)	20 (50)
Low	28 (70)	20 (50)
Physician Global Assessment
Active disease	14 (35)	18 (44)
Inactive disease	26 (65)	22 (55)

Data presented as mean ± standard deviation, or n (%) as appropriate

In patients with UC, the mean age was around 35 years, with 62% females. The majority had proctitis or a left-sided colitis and the mean duration of disease was 5 years. Only around 4% had surgery with 15% manifesting extraintestinal disease. Nearly 60% were on a biologics and the rest were on either 5ASA or immunomodulatory. Forty four percent had a clinically active disease, 33% had high CRP, and 50% had high calprotectin [Table 4]. Patients with UC had a similar association with disk scores as with the overall patients with IBD. Gender, age, duration of disease, location of disease, EIM, or the use of biologics did not affect the disk scores significantly. Only two patients with UC had surgery, and hence not feasible to make a meaningful comparison with those who did not. However, UC was strongly associated with disease activity both clinically and biochemically (CRP/calprotectin) [Table 3].

DISCUSSION

In our study, the mean overall IBD-disk score was 20.70 ± 18.69. In comparison, the mean score was around 40 in two recent multicenter studies conducted in Europe, that validated the IBD disk.[8,9] In addition, another single-center validation in Portugal reported a similar mean of 42.06 ± 24.50.[14] This may suggest that our population has a lower level of disability, but this has to be addressed taking into consideration the study population size, patient clinical characteristics, and the purpose of the study. The low total mean score in our study was primarily driven by the very low mean subscores in “sexual functions” and “body image” (0.38 ± 1.69 and 1.24 ± 2.26, respectively), whereas the scores in the European study were 3.1 ± 3.4 and 4.1 ± 3.3, respectively.[8] This may suggest the differences in cultural bias in the study population. The only other study that used IBD disk outside the Western world was again from Saudi Arabia in the context of COVID-19, where the researchers used it to evaluate the disability in patients with IBD before and during the pandemic. The mean total score was around 30 with the lowest subscore in the domain of sexual function of 1.63.[15] This is more cognate to our study with patients coming from similar cultural backgrounds. Nevertheless, there was a striking similarity between our study and the European studies with regard to the strong association with clinical activity as judged by the physician and the IBD-disk mean score. As in our study, IBD type, medication, surgery, and disease duration had no correlation with IBD-disk score.[8,9] Two notable risk factors that were at variance were gender and biochemical biomarkers (CRP/calprotectin). The female gender in the European study correlated significantly with high IBD-disk scores, but this was not the case in our study, although females did show a trend toward higher disk scores. Similarly, the biomarkers in our study were associated with notably high scores, which was not so in the European study.[8] This may well be a reflection of the study sample size.

The only other IBD disability tool that has been well validated is the IBD-DI and has been translated into Dutch, Danish, Portuguese, and Chinese languages. The mean scores of IBD-related disability on IBD-DI across the studies varied from 19.23 to 36.55, with the Chinese study population scoring the lowest.[6,16-20] This variation in mean was further demonstrated in a multicenter study performed across continents in Winnipeg, Chicago, Toronto, Hong Kong and Jerusalem, that used IBD-DI as a tool, with mean scores ranging from 24 ± 16 to 37 ± 19 at different centers, suggesting the potential role of culture, health systems, social support, education, and demographics as contributing factors.[21] Similar to IBD disk, IBD disease activity was consistently associated with higher IBD-DI in all the above-mentioned studies.

Disability is a continuum of impairment in functionality that ranges from minor to severe difficulty. To estimate the prevalence of disability in a study population, establishment of a threshold that distinguishes the disabled from those who are not is essential and helps to compare the burden of disability between different health systems and countries and to follow-up on disease impact.[22] The exercise of setting this threshold was performed in a large cohort of patients with IBD from 42 centers across Europe with the IBD disk, and a score of >40 was calculated as optimal for those with a high burden.[9] The prevalence of IBD-related disability, thus in our study for this threshold was 19%, rising to 38% in those with active disease. Similarly, a threshold was set for the IBD-DI tool by two studies. One study determined a cut-off of 35 with a range of 0 (no disability) to 100 (severe disability) and the other -35 with a range of -80 (severe disability) to 22 (no disability), as optimal to discern significant disability.[6,23] In a French national association of patients with IBD study that used the set point of 35 as the tool, the prevalence of disability was 33% (moderate disability: 22% and severe: 12%).[19] A multicenter study from the Netherlands, a single center study from Australia, and a two-center Spanish study that used -35 as a tool for disability reported a prevalence of 7%, 22%, and 12%, respectively, of IBD-related disability.[17,23,24] Evidently, prevalence of IBD disability varies depending on the country, study population size, characteristics, and the measuring tool along with its scoring criteria. Nevertheless, IBD disability prevalence in our study population conforms to the international range of 7% to 33%.

Almost all the studies evaluating IBD-related disability were primarily focused on validation of the measurement tool. Ours is the first study that mainly aimed to estimate the prevalence and the associated risk factors of IBD disability using the IBD disk. However, our study does have several limitations. It is a single, tertiary center study performed in an outpatient setting, with a modest number of participants, leading to selection bias. The limited number of participants included is a major weakness and may not be adequate to detect the correlation of disability with other variables like gender, medication use, and type of IBD, as shown in other studies.[8,14,18,19] More than three-fourth (78%) of our patients were on biologics. This may merely be a reflection of the tertiary referral center bias where the patients treated tend to have more severe disease that requires potent therapy like biologics. Other studies done at tertiary centers similarly had a larger proportion of patients on biologics ranging from 68% to 74%.[8,9] This restricts generalizability and may not be applicable to other healthcare settings.

The cross-sectional design limits the study to single-point measurement failing to assess the change with repeated measurements, over time. A prospective study with a longitudinal follow-up may overcome the possibility of temporary disability measurement. Finally, defining the threshold of disability may be problematic, and if inappropriately set may not reflect the true burden. Nonetheless, the threshold of >40 used in our study was robustly estimated in a large study with pertinently applied statistics and conforms to other studies that validated similar thresholds.[6,9,22]

In conclusion, our study highlights that disability is prevalent in IBD even in our study population and is strongly associated with disease activity. Given that these findings are in keeping with international studies, the IBD disk may be the right clinical tool to measure IBD-related disability beyond the western world. Assessing and quantifying IBD-related disability in different healthcare systems and societies is important to evaluate the burden and set up the right treatment goals and supportive policies. Future multicenter studies with a longitudinal follow-up including a larger cohort of participants may be needed to further validate, investigate responsiveness, and demonstrate its clinical use as a treatment target.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.