Protocol of a multicentric prospective cohort study for the VALIDation of the IBD-disk instrument for assessing disability in inflammatory bowel diseases: the VALIDate study

Inflammatory Bowel Diseases (IBD), comprising Crohn’s Disease (CD) and Ulcerative Colitis (UC), are chronic gastrointestinal disorders leading to a progressive and cumulative digestive tract damage [1‐3]. They often are responsible for many digestive and extra-intestinal symptoms (diarrhoea, abdominal pain, rectal bleeding, joint pain) but can also affect psychological, family, social and professional dimensions of patients’ life, leading to decrements of function or disability [4‐13], without taking into account the high societal costs directly or indirectly linked to this disease-related burden [14].

Over the past decade, due to an increasing attention to the patient’s voice in all aspects of health care, the concept of “Patient-Reported Outcomes” (PROs) has been developed, defined as any report that comes directly from a patient about a health condition or its treatment, without interpretation of the patient’s response by a clinician or anyone else [15]. PROs have become an integral part of the endpoints evaluated in IBD clinical trials [16‐18], strongly recommended by the United States Food and Drug Administration (FDA) [19], as PROs are now considered as real therapeutic targets [20, 21]. Indeed PRO bring benefit for both patients and health care professionals improving physician-patient communication and patient’s quality of life. PROs foster patient-centered care; patients feel better able to communicate their experience to the team, it improves communication and shared decision-making, and facilitates multidisciplinary team care [22].

Several disease-specific and generic tools have been developed to assess PROs in IBD patients: some are devoted to quality of life like the Inflammatory Bowel Disease Questionnaire (IBDQ) and its short version (SIBDQ) [23‐25], while others permit to assess fatigue (Functional Assessment Chronic Illness Therapy–Fatigue FACIT-F) [26], work productivity [27‐29], as well as depression and anxiety [30‐34]. More recently, an IBD Distress Scale has been constructed to evaluate IBD-specific distress [35].

A French cohort of 1185 IBD patients has shown that half of the patients reported poor quality of life with a SIBDQ< 45 (53.3%), severe fatigue with a FACIT-F < 30 (47.4%) and/or depression (HAD-D > 7: 49.4%). Around one third of the patients reported anxiety (HAD-A > 7: 30.3%) and/or moderate (22.4%) or severe (11.9%) disability [36].

Health-related quality of life has been explored since the 1970s in IBD,[37] but this concept is subjective. Furthermore, none of the existing tools measuring quality of life in IBD was developed according to the FDA guidance [19]. Conversely, according to the World Health Organization (WHO), disability is an objective umbrella term for impairments, activity limitations and participation restrictions, which is essential to quantify because physicians frequently underestimate disease-related disability in IBD patients [38‐40]. However, before 2015, when compared to quality of life, there was no specific tool dedicated to disability in the field of IBD, in contrast to other chronic diseases especially inflammatory diseases, like psoriasis [41, 42], rheumatoid arthritis [43, 44] or multiple sclerosis [45, 46].

Yet, several surveys have shown disparities between patients’ and gastroenterologists’ perceptions of the impact of IBD on patients’ lives [38‐40, 47]: indeed, physicians often under-estimate disease burden while disabled patients prefer to accommodate their lives to their disease rather than act to optimize therapy [48]. Thus, there is a need for reliable tools to assess disability in IBD patients, in order to improve communication between patients and gastroenterologists, thereby enhancing treatment adherence [49‐52].

In 2015, a new index has been developed, based on the World Health Organization’s International Classification of Functioning, Disability and Health (ICF) [53], and specifically devoted to the assessment of disability in IBD patients [54]. This index, called Inflammatory Bowel Diseases Disability Index (IBD-DI), comprises 14 questions and ranges from 0 to 100. The IBD-DI has been validated in a French population based-cohort for use in clinical trials and epidemiological studies, and showed high internal consistency, interobserver reliability and construct validity, and a moderate intra-observer reliability [55]. Despite its robustness, this index requires to be filled in attendance of a health care professional and seems to be difficult to apply in daily practice.

In this context, in 2017, Ghosh et al. have developed the IBD Disk, a shortened, self-administered and visual tool, adapted from the validated IBD-DI, in order to give immediate representation of patient-reported IBD-related disability [56]. The IBD Disk is largely inspired by the PsoDisk, a visual instrument developed in 2012 by the dermatologists to assess disability in patients suffering from psoriasis [57], which has been validated since in an Italian cohort of 320 patients [58]. The IBD Disk was developed using a consensus-based process to select items from the IBD-DI that are most likely to be important in assessing patient’s disease burden and are relevant to both patient and physician.

This new tool should allow the gastroenterologist to rapidly assess the patient’s disability at a given time, but could also be used to follow changes in disease burden over time, thereby monitoring treatment efficacy with a more global picture of the patient’s health.

However, the IBD Disk has not been validated yet in national clinical practice. In 3 hospitals located in the West region of France (Nantes, Angers and Rennes), we begin to use it, as a physician help. But it was crucial to know if this questionnaire was reproducible and if it could correlate with what physicians see and what the patient describes.

After a comprehensive description of the study sample which will allow to better describe French IBD-patients’ characteristics, the primary objective of the VALIDate study will be to validate the IBD Disk and to evaluate its consistency with the already validated IBD-Disability Index.

Other investigations will allow to assess the reliability of the tool, its variability over time, and its correlation with the clinico-biological activity of the disease, and with the assessment of the disease activity by the patient and the physician.

The VALIDate study is a prospective multicentric cohort study with the aim of validating the IBD Disk in a large population of IBD patients and to compare it to the already validated IBD-Disability Index (IBD-DI).

This reflects the growing consideration for patients’ well-being for about 10 years in the IBD field. Besides, Patient-Reported Outcomes (PROs) and among them disability, have been included in the STRIDE consensus [20] initiated by the International Organization for the Study of Inflammatory Bowel Diseases (IOIBD) in order to determine therapeutic goals in IBD in the context of “treat-to-target” strategies that could be used in clinical practice [64]. However, up to now, the IBD-DI was the only tool validated for the assessment of disability in IBD patients, however it is not appropriate for use in routine due to its complexity. The IBD-Disk was then developed, based on the IBD-DI, but has not been validated yet.

The strengths of the VALIDate study will rely on its rigorous, prospective and multicentric design, with a large sample of IBD patients, allowing us to foresee a good statistical power for required analyzes. Apart from the aims of this study, all the socio-demographic and clinical information collected will constitute a valuable database, including data about regimen, sporting activity, medication use (symptomatic and anxiolytic/antidepressant treatments), professional and family status. Moreover, this study will provide interesting comparisons between Physician Global Assessment (PGA) and Patient Global Assessment (PtGA) in a large French cohort of IBD patients (CD and UC), while most of the few studies which analyzed the gaps between physicians’ and patients’ perspectives until now were not conducted specifically in French patients [38‐40, 47].

The main practical issue of the study will be patients’ follow-up. Indeed, in order to assess the variability of the IBD Disk over time, patients will be asked to complete again the questionnaires between 3 and 12 months after baseline, during a routine follow-up visit. This will require an efficient “tracking” of included patients, in order to minimize the number of lost to follow-up patients. For that purpose, the person who will manage the electronic dataset (CLB) will also collect the date of the follow-up visit for each patient. However, it seems inevitable that some patients will change the date and others will miss their appointment. To reduce this attrition bias, we chose to increase the sample size at a minimum of 400 patients, while a formula based on feasibility criteria suggested a sample of 100 patients [59]. The same problem will exist for the test-retest reliability: a sub-sample of 70 patients will be asked to complete again the IBD Disk 7 days after baseline visit and to send it by post. In the same way, it is expected that a high proportion of this sub-sample forget to send the questionnaire again. In order to minimize this risk, a phone contact may be made to the patient at the end of the 7-day period.

To conclude, the VALIDate study should be the first study to validate the IBD Disk in a large cohort of French IBD patients. If this instrument proves to be valid, reliable, and reproducible, its use should probably be extended all across France and to other countries, as part of PROs’ assessment in daily practice. Successful dissemination of this tool to other countries will nonetheless require a cultural adaptation and translation process in other languages [60].