Adherence in the Treatment of Inflammatory Bowel Disease With Particular Focus on the Importance of the Clinical Pharmacist: A Systematic Review

ABSTRACT

Background

The prevalence of inflammatory bowel disease (IBD) is increasing. While several studies have shown that incorporating a clinical pharmacist into patient care can improve quality of life, evidence specifically addressing their role in IBD management remains limited.

Objectives

This study aimed to systematically review the evidence on treatment adherence in IBD, with a focus on the potential role of clinical pharmacist counselling to improve medication adherence.

Methods

Three databases (PubMed, MEDLINE and Embase) were searched to identify relevant literature, using keywords derived from the PICO model.

Results

Seven full‐text articles met the inclusion criteria. Three of these reported that pharmacist involvement had a positive effect on treatment adherence in patients with IBD. Furthermore, two studies reported that pharmacist involvement in treatment improved disease activity. Patients' perceptions of pharmacist involvement were generally positive, particularly after receiving information about pharmacist services and education. Finally, studies also indicate that pharmacists require greater knowledge of IBD to provide optimal care.

Conclusion

Although the available literature is limited, it indicates that involving clinical pharmacists in IBD treatment may have a positive impact—improving medication adherence and enhancing disease control.

Plain Language Summary

Inflammatory bowel disease (IBD) is becoming increasingly common. Clinical pharmacists may help improve patients' quality of life, but there is limited research on their role in IBD care. This study reviewed the existing literature to investigate how pharmacists might support IBD patients in adhering to their treatment. Results showed that pharmacist involvement improved patients' medication adherence and reduced disease activity. Patients valued the support provided by pharmacists, but pharmacists reported a need for more training in IBD to offer optimal care. Although research is limited, the findings suggest that including pharmacists in IBD treatment has positive effects on patient outcomes and overall health.

1. Introduction

Inflammatory bowel disease (IBD) encompasses chronic inflammatory disorders of the gastrointestinal tract, primarily ulcerative colitis (UC) and Crohn's disease (CD). UC involves continuous mucosal inflammation of the colon, starting in the rectum and potentially extending proximally, whereas CD is marked by segmental, transmural granulomatous inflammation that can affect any part of the gastrointestinal tract, most often the ileocecal region. Both conditions typically follow a relapsing–remitting course. UC often presents with bloody diarrhoea and rectal discharge, while CD more commonly causes diarrhoea and abdominal pain [1].

The precise aetiology of IBD remains unclear, but it is thought to result from a complex interplay of genetic susceptibility, environmental triggers, immune dysregulation and gut microbiota disturbances, leading to chronic inflammation and impaired intestinal barrier function [1]. Treatment aims to control inflammation, relieve symptoms and prevent complications, most often through long‐term or lifelong pharmacotherapy with anti‐inflammatory agents, immunosuppressants and biologics [2].

Despite advances in therapy, optimal disease control is often hindered by poor medication adherence. Nonadherence—common in IBD—can result in disease flare‐ups, complications and reduced quality of life [3, 4]. Reasons for nonadherence include the unpredictable disease course, the disconnect between symptoms and inflammatory activity, complex treatment regimens, side effects and misperceptions such as discontinuing medication during asymptomatic periods. These challenges underscore the need for disease‐specific strategies to promote adherence.

Clinical pharmacists have emerged as valuable contributors to chronic disease management, offering patient education, medication counselling and therapy monitoring. Although several studies in other chronic conditions show that pharmacist involvement can improve adherence and clinical outcomes, evidence specific to IBD is limited.

Therefore, this review aims to systematically evaluate the existing evidence on medication adherence in IBD, assess its impact on disease control and examine the potential role of clinical pharmacist‐led interventions in improving adherence and patient outcomes.

2. Methods

A systematic review was conducted using the electronic databases MEDLINE, Embase and PubMed, following the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) guidelines [5]. A PRISMA flow diagram and checklist are provided in the supplementary materials.

2.1. Search Strategy

The review focused on the role of pharmacist support in medical gastroenterology, specifically in the management of IBD. Interventions of interest included patient education by pharmacists, pharmacist‐led medication reviews and pharmacist–specialist collaboration to optimize treatment. Particular emphasis was placed on evaluating the potential benefits of clinical pharmacist involvement on treatment adherence and patient outcomes in IBD.

A comprehensive search of all three databases was performed from database inception to 30 May 2024. Search terms were derived from the PICO model, incorporating combinations of keywords relating to IBD, clinical pharmacy, adherence and quality of life. The heterogeneity of study designs and outcome measures was anticipated to preclude a formal meta‐analysis, and therefore, results were synthesized narratively. The full search strategy is available in Appendix A.

2.2. Eligibility Criteria

Studies were eligible for inclusion if they met the following PICO‐based criteria:

• Population (P): Patients diagnosed with ulcerative colitis (UC) or Crohn's disease (CD);

• Intervention (I): Clinical pharmacist services, including but not limited to patient education, medication counselling, therapeutic monitoring or collaboration with medical specialists;

• Comparison (C): Standard care without explicit pharmacist involvement, or no intervention;

• Outcome (O):

  • Primary: Medication adherence;
  • Secondary: Quality of life, clinical outcomes (e.g., disease activity) and patient satisfaction with treatment and healthcare providers.

No restrictions were placed on the type of medication. Studies involving patients with other inflammatory conditions were excluded. The search was performed without language or time limits, but only studies available in full text and in English were ultimately included.

2.3. Study Selection

All identified records were imported into Covidence Systematic Review Software (Covidence, Melbourne, Australia) for screening. Titles and abstracts were independently screened by FS according to the predefined eligibility criteria. Potentially eligible studies underwent full‐text review, during which study aims, methods and main findings were extracted. Articles not meeting the inclusion criteria were excluded.

In cases of uncertainty regarding study eligibility, a second reviewer (MA) was consulted. Although this process carries a potential risk of bias, this was minimized through the use of predefined inclusion criteria, structured screening procedures and documentation of all decisions.

2.4. Outcomes

The primary outcome of interest was medication adherence among patients with IBD.

Secondary outcomes included as follows:

• Health‐related quality of life;

• Clinical endpoints such as disease activity;

• Patient satisfaction with treatment and healthcare providers.

These outcomes were chosen to align with the review's objectives of assessing how clinical pharmacist interventions impact adherence, patient experience, and disease management.

3. Results

3.1. Study Selection

A total of 2357 articles were identified using the search strategy. After removing 496 duplicates with Covidence software, 1861 unique records remained. Titles and abstracts were screened, resulting in 105 potentially relevant articles. Sixty articles were excluded based on abstract screening. Full‐text screening excluded 14 articles due to wrong interventions, eight due to inappropriate patient populations and five for irrelevant outcomes. Additionally, 11 abstracts from conferences were excluded because full texts were unavailable. Ultimately, seven articles were included as the most representative of clinical pharmacist involvement in IBD treatment. The selection process is detailed in the PRISMA flow diagram (Figure 1). Table 1 includes an overview of the seven full‐text articles with characteristics of each study including aim, method, population, intervention, comparison, measured outcome and main findings.

FIGURE 1.

Study selection (PRISMA diagram).

TABLE 1.

Characteristics of the studies included in the systematic review.

Author, publication year, country	Aim of the study	No. of patients	Age	Population	Methods	Intervention	Comparison	Outcomes	Main findings
Alrashed et al. 2022, Kuwait [6]	Evaluate IBD patients and doctors' satisfaction regarding clinical pharmaceutical interventions in outpatients and in patient settings.	108 patients with IBD and 20 physicians. CD(70) UC(38)	18 + years	Patients diagnosed with IBD for a minimum of 8 weeks since recruitment	A study conduted at a single IBD centre. Two types of questionnaires are used, and given to patients and physicians. It is a single‐centre, uncontrolled, prospective intervention study.	Clinical pharmacist	None	Patient satisfaction with pharmacist intervention	Majority of patients expressed high levels of satisfaction with the services provided by clinical pharmacist. Few patients were uncertain about the time spent with clinical pharmacist
Chellangi et al. 2015, India [7]	Demonstrate the importance of a pharmacist and investigates if the clinical pharmacist will improve patient outcome.	1	35 years	1 female patient diagnosed with UC	Case study	Pharmacist	None	Not applicable	Clinical pharmacists' play a crucial role, benefitting patients and healthcare organizations. They can help reduce drug‐related issues.
Prasad et al. 2020, Australia [8]	The study investigates pharmacists' confidence in managing IBD patients and which potentiel barriers they meet.	125 participants who attended an IBD educational session	—	Pharmacists	Survey based study. A single‐centre, uncontrolled, prospective intervention study.	Clinical pharmacist	None	Pharmacists perceived level of confidence	Majority of participants reported having a moderate to low level of confidence in managing IBD. Pharmacist who attended the session did not feel entirely safe in their knowledge about IBD. Therefore they need education within pharmacy profession in order to support IBD patients.
Tiao et al. 2017, Australia [9]	Aim is to demonstrate how pharmaceutical conuselling can improve medication adherence among patients with CD and UC.	114 patietns	18–70 years	Patients with CD and UC diagnosed for at least 6 months, conformined by standard test and the use of maintenance IBD medications such as 5‐aminosalicylates, immunomodulators or biological agents.	It is a multicentre prospective longitudinal parallel interventional study. IBD subjects were either medication ‘baseline nonadherers’ or ‘baseline adherers’. Baseline nonadherers got the IBD pharmacist Adherence Counselling intervention, and baseline adherers were controls. Both groups were followed longitudinally for 2 years.	Clinical pharmacist	Standard care	Medication adherence, risk of disease relapse	Nonadherence was seen in 45% of patients with IBD. This led to higher disease relapse and utilization of healthcare services. The study focused on intentional nonadherence and how that successfully can be managed with help from clinical pharmacist. The patients who had most use of clinical pharmacist were the patients with lowest adherence.
Butler et al. 2023, [10]	Investigate patient view on the involvement of pharmacist in the care of patient with CVD and IBD.	27 patients 18 with CVD and 9 with IBD	25 + years	Patients with CVD and IBD recruited trough PERC programme.	15 min prework survey to evaluate their interaction with pharmacist. Subsequent five live virtual focus group sessions were held. Patients gave feedback on patient–pharmacist interaction. A single, uncontrolled, prospective intervention study.	Clinical pharmacist	None	Feedback on pharmacist–patient interactions, the pharmacists' role in patient care and recommendations for improvement	Patients perceived pharmacists’ as having greater expertise than other healthcare providers regarding medication side effects, interactions and having more knowledge about the prescribed medications. Patients showed increased interest after learning about the pharmacist qualifications and want pharmacists’ to work with their primary caretaker.
Kim et al. 2021, South Korea [11]	In the study, they investigated the impact of pharmacist interventions on medication adherence and clinical outcomes among patients with UC with low medication adherence, compared with a control group of similar patients who did not receive intervention.	99 patient with UC, 33 and 66 included in the intervention and control group	19 + years	Patients with UC diagnosed for at least 6 months and receiving outpatient treatment with a specific gastroenterologist.	Retrospective longitudinal study. Data were extracted from the electronic medical records. UC patients who had low medication adherence were split into two groups. One group got pharmacist intervention, and the other were controls. Then their medication possession ratio and nonadherence rate were investigated for 6 months before and after baseline.	Clinical pharmacist	Standard care	Medication adherence, clinical outcomes	Pharmacist interventions improved patient outcomes by increasing medication adherence when educating patients with IBD trough clinical pharmacist. The intervention group showed improvement in medication adherence, disease activity and flare up incidence were reduced.
Ashok et al. 2017, India [12]	Investigate clinical pharmacists’ interventions role on medication adherence of patients with IBD.	110 patients with IBD	18 + years	Patients clinically diagnosed with IBD and who are taking at least one medication as part of their treatment.	A prospective interventional follow‐up study. Clinical pharmacist had counselling sessions with the patients. They talked about the disease, drugs, importance of compliance etc.	Clinical pharmacist	None	Medication adherence	Medication adherence was observed to be lacking in IBD patients. There was enhanced drug adherence and increased knowledge among the patients with the help from clinical pharmacist.

3.2. Clinical Pharmacists' Role in Adherence

The primary outcome of this review was medication adherence. Several studies demonstrated that clinical pharmacist interventions positively influence adherence in patients with IBD.

• Tiao et al. [9] performed a 2‐year prospective study dividing patients into baseline adherers and nonadherers. Nonadherers received pharmacist counselling, resulting in significantly improved medication acceptance. This intervention was a personalized single counselling session addressing medication concerns, which effectively improved both unintentional (e.g., forgetfulness) and intentional nonadherence (based on beliefs about medication necessity or side effects). Limitations include challenges in assessing adherence due to lack of a perfect measurement method and potential follow‐up losses.

• Kim et al. [11] retrospectively analysed 99 UC patients with low adherence, comparing 33 patients receiving pharmacist intervention to 66 controls. The intervention group showed significant reductions in nonadherence rates over 6 months. Limitations included small sample size, retrospective design and unaccounted confounding factors such as socioeconomic status.

• Ashok et al. [12] conducted a prospective interventional study of 110 IBD patients assessing the impact of clinical pharmacist intervention on medication adherence. After pharmacist‐led counselling, use of pill cards and provision of information leaflets, the proportion of patients with high medication adherence rose from 30.9% to 78.2% (MMAS‐8). Main barriers to adherence were being busy and forgetfulness. Limitations include use of self‐reported adherence, a single‐centre design among literate patients, lack of a control group and short follow‐up. Nonetheless, the study demonstrates that targeted pharmacist interventions can sharply improve medication adherence in IBD.

3.3. Secondary Outcomes

Other outcomes reported were the following.

3.3.1. Health‐Related Quality of Life

• The previously described study by Ashok et al. [12] suggests that pharmacist‐led improvements in medication adherence may enhance quality of life, but disease‐specific quality of life was not measured. Their study assessed adherence, knowledge and patient satisfaction; any impact on quality of life remains speculative and was not directly documented.

3.3.2. Clinical Endpoints

• The previously described study of Tiao et al. [9] investigating the effect of pharmacist intervention on medication adherence also compared disease relapse rates in adherers and nonadherers who received pharmacist counselling and found no statistically significant difference. Unfortunately, relapse rates in nonadherers before pharmacist counselling were not reported.

• Likewise, the previously described study by Kim et al. [11] investigating the effect of pharmacist intervention on medication adherence also studied the effect of this intervention on disease activity. Patients receiving pharmacist intervention had significant improvement in disease activity and a reduction in the incidence of flare‐ups.

3.3.3. Patient Satisfaction

• Alrashed et al. [6] conducted a patient and physician satisfaction survey using 5‐point Likert scales after counselling sessions by clinical pharmacists. Among 108 patients, most agreed or strongly agreed they were satisfied with pharmacist counselling, particularly appreciating communication on medication use and side effects. Physicians also reported high satisfaction, noting reduced medication errors and improved quality of care. This study did not include a control group and was limited to a single hospital.

• Butler et al. [10] explored patients' perspectives on pharmacist involvement via surveys and focus groups across IBD and cardiovascular disease cohorts. IBD patients reported infrequent pharmacist contact and desired more personalized interaction and empathy. Education on the pharmacist's role enhanced patient trust and interest. Small sample size and study design limited generalizability.

• The previously mentioned study by Ashok et al. [12] investigated patient knowledge about their disease before and after pharmacist intervention. Patient knowledge about their disease (as evaluated by a questionnaire) generally improved following the intervention by the pharmacist.

3.4. Exploratory Outcomes

The studies included in this review also addressed a number of endpoints not predefined in the review protocol. These included the following.

3.4.1. Pharmacist Knowledge and Education

• Prasad et al. [8] surveyed pharmacists' confidence in IBD management before and after an educational session. Confidence increased notably posttraining. Time constraints and limited resources were barriers to learning. The study was limited by potential participation bias and single‐site recruitment.

3.4.2. Supporting Physicians in IBD Management

• Several studies [6, 10, 12] emphasized how pharmacists can alleviate specialist physicians' workload by managing medication‐related issues, thereby improving comprehensive drug management and potentially patient outcomes.

3.4.3. Financial Consequences

• While not a predefined outcome of this review, some included studies discussed economic implications related to adherence and pharmacist interventions. For example, Alrashed et al. [6] noted the growing global cost burden of IBD treatments, Kim et al. [11] linked poor adherence to increased disease activity and healthcare costs, and Chellangi et al. [7] provided a case where pharmacist intervention corrected unnecessary or suboptimal medications, reducing patient costs. However, financial outcomes were incidental findings and not systematically assessed.

4. Discussion

The present review of the available evidence indicates that integrating clinical pharmacists into the IBD care team consistently led to significantly improved medication adherence, as demonstrated across all included studies. Pharmacist interventions—including tailored counselling, medication education and adherence support—were effective in addressing both intentional and unintentional nonadherence, resulting in a higher proportion of patients maintaining their prescribed treatment regimens. In addition to improved adherence, evidence suggests that pharmacist intervention reduced rates of disease flare‐ups and suggested a favourable perception of pharmacist involvement among patients and physicians.

Clinical pharmacists can help identify and address barriers to adherence, optimize pharmacotherapy and ensure continuity of care. Evidence from other chronic disease areas supports their integration into multidisciplinary teams, showing benefits for adherence, patient satisfaction and clinical outcomes, alongside potential reductions in healthcare expenditure [13]. Although the literature specific to IBD remains limited, the available data suggest similar advantages. Editorial and expert panel discussions [14, 15] have recommended incorporating IBD‐specialist pharmacists into multidisciplinary teams, particularly at treatment initiation, to improve adherence, minimize flares and reduce hospitalization and treatment costs. They may also help relieve some of the workload pressures on gastroenterologists.

A number of important limitations should be acknowledged. The number of studies is small and often of modest quality. This limited quantity and quality of evidence—which also led to the consideration that a scoping review might have been a more suitable approach to map the existing literature—restricts the strength of conclusions that can be drawn. Only one study [9] was a prospective controlled study, but patients were not randomly assigned to intervention or control groups, so comparability cannot be assumed. Three prospective intervention studies [6, 8, 12] lacked control groups, limiting attribution of observed improvements solely to pharmacist interventions. One retrospective controlled study [11] was non‐randomized, introducing a risk of bias, and one was a single‐patient case report with very limited generalizability. Follow‐up durations were generally short, sample sizes small, and none of the studies were blinded—although blinding is difficult in counselling interventions.

Additional limitations include heterogeneous definitions and methods used to assess adherence, hindering direct comparisons across studies. Furthermore, clinical pharmacists are not uniformly available across healthcare systems, limiting the generalisability of these findings [7]. Finally, study screening in this review was primarily conducted by a single reviewer, increasing the risk of selection bias despite the use of predefined criteria.

4.1. Future Directions

Several authors [6, 8, 15] suggest that future research should explore both patient and healthcare provider perspectives on the role of IBD clinical pharmacists, alongside assessing specific outcomes such as changes in adherence, achievement of treatment goals and effects on quality of life. Randomized, prospective, multicentre studies using standardized adherence measures are needed to determine the causal impact of pharmacist involvement in IBD care. Educational needs for pharmacists should also be addressed to ensure optimal contribution to clinical outcomes.

In conclusion, this systematic review suggests that the involvement of clinical pharmacists in IBD care may improve medication adherence and help reduce flare‐ups. Although the evidence base is currently limited in both size and methodological quality, the consistent positive trends observed support further well‐designed research to clarify and strengthen the case for pharmacist integration in IBD management.

Conflicts of Interest

F.S. has no conflicts of interest. M.A.A. has served as a consultant for AbbVie, Celltrion, Eli Lilly, Janssen, MSD and Takeda.

Supporting information

Data S1: PRISMA checklist.

Appendix A.

PubMed

((‘Pharmacists’[Mesh]) OR ‘Pharmacy Technicians’[Mesh]) OR ‘clinical pharmacist’ OR ‘pharmacists’ OR ‘pharmaceutical services’)) AND (‘gastroenterology’ OR ‘gastrointestinal’ OR’inflammatory bowel disease’ OR ‘ulcerative colitis’ OR ‘Crohn's disease’ OR ‘Inflammatory Bowel Diseases’[Mesh] OR ‘Crohn Disease’[Mesh] OR ‘Colitis, Ulcerative’[Mesh])).

Embase

1	Pharmacist OR pharmacist
2	Pharmacy technicians OR pharmacy technician
3	Clinical pharmacist OR clinical pharmacist
4	Pharmaceutical services
5	Gastroenterology OR gastroenterology disease
6	Inflammatory bowel disease OR Crohn disease OR ulcerative colitis
7	Crohn's disease OR Crohn disease
8	1 OR 2 OR 3 OR 4
9	5 OR 6 OR 7
10	8 AND 9

Medline

1	Pharmacist OR pharmacist
2	Pharmacy technicians OR pharmacy technician
3	Clinical pharmacist OR clinical pharmacist
4	Pharmaceutical services
5	Gastroenterology
6	Gastroenterology diseases OR gastrointestinal
7	Inflammatory bowel disease OR Inflammatory bowel diseases
8	Ulcerative colitis OR colitis, ulcerative
9	Crohn's disease OR Crohn disease
10	1 OR 2 OR 3 OR 4
11	5 OR 6 OR 7 OR 8 OR 9
12	10 AND 11

Sayed F. and Ainsworth M., “Adherence in the Treatment of Inflammatory Bowel Disease With Particular Focus on the Importance of the Clinical Pharmacist: A Systematic Review,” Basic & Clinical Pharmacology & Toxicology 137, no. 5 (2025): e70125, 10.1111/bcpt.70125.