Introduction

Ulcerative colitis (UC) is a global disease, the incidence and prevalence of which have increased in several regions of the world [1, 2]. As an immune-mediated chronic inflammatory bowel disease, UC is characterized by continuous and superficial inflammation of the colon. However, its etiology and pathogenesis have not yet been determined and are generally considered to be influenced by genetic, environmental, and microbial factors [3]. The treatment goal of UC is to achieve symptomatic relief, endoscopic healing, normalization of serum and fecal markers, absence of disability, restoration of quality of life, and normal growth in children [4].

Conventional treatments control symptoms through pharmacotherapy, including aminosalicylates, corticosteroids, immunomodulators, and biologics, with other general measures or surgical resection if necessary [5]. Aminosalicylates are known to be the first-line treatment option for mild to moderate UC [6], but they may cause gastrointestinal discomfort such as nausea, abdominal pain, and diarrhea [7, 8]. Corticosteroids are a kind of treatment selection for UC patients who have inadequate response to mesalazine, however, their long-term treatment is not recommended due to significant adverse effects such as an increased risk of mortality, infection, diabetes mellitus, hypertension, and osteoporosis [7, 9]. Immunomodulators and biologics are beneficial to patients with moderate to severe disease activity, corticosteroid dependence, or those at high risk of colectomy, but up to 74% of UC patients may lose response over time [10]. Limitations such as inadequate response, side effects, dependence, and drug resistance to Western medicine (WM) remain to be solved [11, 12].

Chinese medicine (CM), a medical system based on distinctive Chinese cultural theories and practices, has been increasingly introduced into the treatment of UC, especially in Asia [13]. CM treatment mainly includes Chinese herbal formula (oral or rectal), acupuncture, and moxibustion. Due to its multi-targeted mode of action, CM has unique advantages for treating inflammatory bowel diseases, including maintaining intestinal integrity, reducing inflammation, and decreasing oxidative stress, with minor side effects [14]. With the extensive studies on UC in recent years, it is confirmed that both CM and WM have unique advantages in UC management.

In China, most patients of UC preferred Integrated Chinese and Western medicine (ICWM) therapy over CM or WM alone. Several reviews supported the promising effect and few side effects of ICWM for UC [15, 16], but most of the included trials had a high risk of bias and major methodological deficiencies, including an insufficient description of the randomization process, lacking appropriate therapeutic endpoints, and missing power calculations. Although the quality of reporting in RCTs in medical sciences has been discussed, the quality of reporting in RCTs on the treatment of UC with ICWM has not yet been assessed after the publication of the CONSORT (Consolidated Standards of Reporting Trials) 2010 Statement. Furthermore, it is unclear whether the details of ICWM interventions, such as selection rationale, indications and timing of interventions, implement design and potential interactions, were adequately reported in current randomized clinical trials (RCTs). Therefore, this review aimed to assess the quality of reporting in RCTs of ICWM for UC, based on the checklists of CONSORT 2010 [17] and a self-designed ICWM-specific checklist.

Materials and methods

Eligibility criteria

This study included ICWM interventional RCTs of UC published in English or Chinese from the date of inception for each database up to 16 June 2023. We included studies on subjects given the diagnosis of UC defined by clear diagnostic criteria or references, regardless of age, gender, course of disease, and severity. The ICWM intervention is defined as the combination of CM therapies and WM treatments. Specifically, we included a wide range of CM interventions, such as herbal medicines, acupuncture, and moxibustion, while only pharmacological therapy of WM was in the intervention group. There were no limitations in the types of control groups and the assessed outcomes. Repeat publications, non-randomized or non-controlled trials, quasi-randomized controlled trials, non-ICWM interventional trials, study protocols, reviews, observational studies, case reports, abstracts, full-text reports not found, and non-human studies were excluded. Table 1 provides details on the inclusion and exclusion criteria of PCC used in this review. The conduction of this review is referred to the Chapter 11-Scoping Reviews of Joanna Briggs Institute Reviewer's Manual for Evidence Synthesis [17, 18], also with some modifications in terms of format as this review focused on the quality assessment.

Table 1 Inclusion and exclusion criteria based on the Population, Concept, and Context (PCC) framework
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Search strategy

A systematic search was conducted on 17 June 2023 for the following databases: MEDLINE < 1946 to 16 June 2023 > , Embase < 1974 to 16 June 2023 > , CENTRAL (Cochrane Central Register of Controlled Trials) < May 2023 > , Web of Science < 1900 to 16 June 2023 > , CINAHL < 1937 to 16 June 2023 > , AMED (Allied and Complementary Medicine Database) < 1985 to May 2023 > , CNKI (China National Knowledge Infrastructure) < 1979 to 16 June 2023 > , Wanfang < 1979 to 16 June 2023 > , VIP (Chinese Science and Technology Periodical Database) < 1989 to 16 June 2023 > , CBM (Chinese Biomedical Literature Database) < 1978 to 16 June 2023 > . The search terms were “ulcerative colitis”, “inflammatory bowel disease”, “randomized controlled trial”, “random”, “Chinese medicine”, “herbal”, and “drug”. The detailed search strategy is presented in Additional file 1: Appendix 1.

Study selection

Endnote 20 (Clarivate, Philadelphia, PA 19130) was used for de-duplication, title and abstract screening. After de-duplication, four review authors (JLZ, NNW, FL, and PJC) independently screened titles and abstracts of the retrieved records based on the inclusion and exclusion criteria, and another two review authors (JSD and JW) conducted a second check. Full text of potentially relevant papers were reviewed (JLZ, NNW, FL, and PJC) and double-checked (JSD and JW) for further assessment of eligibility. Differences of opinion were settled by consensus.

Data extraction

We developed a data extraction Microsoft Excel form to extract data on general characteristics of included records, including study title, publication year and language, information of corresponding author(s), types of journals, types of study design (e.g., assignment, randomization, blinding, sample size and participating centers), features of interventions, types of participant(s) and control(s), period of treatment and follow-up (if any), as well as the categories of diagnosis criteria, outcome(s) and study conclusions. We piloted the extraction form on a random sample of ten included articles and achieved consistency in data item interpretations. Then, four trained authors (JLZ, FL, NNW, and JSD) independently extracted the data, and another two review authors (XZ and JW) conducted a second check. Disagreements were resolved by discussion.

Reporting quality assessment

The reporting quality of included studies was evaluated according to a standard checklist of the CONSORT 2010 statement, of which the checklist of the CONSORT for Abstract was extracted for independent evaluation. For rating the CONSORT items, the assessment rules were referred to the CONSORT 2010 statement (including the CONSORT for Abstract) with its explanation and elaboration document which provides the definitions and rationale for each checklist item and examples of good reporting (e.g., scored as 2 points) [19, 20]. The total score of the CONSORT checklist and CONSORT for the abstract checklist was 72 and 34, respectively.

A specially designed checklist comprised of 27 items related to specific characteristics of ICWM trials (Table 2) was developed by five researchers (XZ, JL, PW, FH, and ZXB) based on an internal discussion. This list focused on the identification of critical issues in the procedure of ICWM design, implementation, and assessment, particularly in the selection rationale, details of therapy combination, and the efficacy assessment. Each item/question was scored in terms of three possibilities: “2” for “fully reported”, “1” for “partially reported”, and “0” for “not reported” or “not applicable”. The total score of the ICWM-specific checklist was 54. For rating the ICWM items, the details of scoring rules are presented in Additional file 1: Appendix 2 which includes the explanations for each question and examples of eligible reporting. The quality assessment was independently conducted by one review author and verified by another review author. A total of four authors (YHW, JSD, NNW, and WTC) participated in the quality assessment. Possible disagreements were resolved with the consultation of the third senior review authors (XZ or ZXB).

Table 2 Questions for assessing the reporting of ICWM-specific items
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Data analysis

As this review is focused on reporting characteristics and quality evaluation, we thereby applied frequency and percentage to present categorical variables, and mean (standard deviation) or median (interquartile range, IQR) to present continuous variables in the section of “Results”. For individual item of reporting quality, the compliance rate was calculated with the number of items acquired “2” based on the total number of included reports, which was further categorized as three levels: excellent compliance (> 90%), good compliance (between 65 and 90%), and poor compliance (< 65%). The total scores of the CONSORT, CONSORT for Abstract, and ICWM-specific checklists of RCTs published before and after 2010 were compared with Student’s t test or Mann–Whitney U test. Statistics analyses were performed using SPSS software (version 28.0). Statistical significance was defined as two-sided P value < 0.05.

Results

Literature search

The flowchart of the selection and screening process is shown in Fig. 1. Briefly, the electronic search yielded 9332 records, after removing duplicates and screening titles and abstracts, a total of 1773 reports were identified for the full-text assessment. Finally, we included 1458 eligible RCTs for analysis, of which 1385 articles with abstracts and 73 without abstracts.

Fig. 1
figure 1

Flow chart of the literature screening and selection

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Characteristics of included trials

A total of 1458 RCTs of ICWM for UC were included between January 1998 to June 2023. The number of these studies increased gradually during the first 10 years and then presented a rapid increase starting from 2009 (Fig. 2). The most common design of included studies was a single-center (97.94%), two parallel arms (94.10%), a sample size of 51–100 (70.30%), Chinese herbal formula (90.53%) as CM treatment, and intervention period within 30 days (48.49%). There were 575 (39.44%) studies that applied CM diagnosis when recruited UC participants, while only 349 (23.94%) adopted CM-related outcomes to assess the efficacy of treatments. Around 98.63% (1438) trials concluded a confirmed efficacy of ICWM for UC. However, the missing reporting is common for several critical aspects, such as 97.94% of trials did not whether to adopt blinding or not, and 71.88% of trials did not specify the studied phase(s) of UC (e.g., active, remission, or both). Details are shown in Table 3.

Fig. 2
figure 2

The number of ICWM interventional RCTs of UC publications between Jan 1998 to June 2023

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Table 3 Characteristics of included articles (n = 1458)
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Reporting completeness and features

The results of adherence to the CONSORT, the CONSORT for Abstract, and ICWM-specific checklist items are presented in Tables 4, 5, and 6. For the completeness of the CONSORT checklist, the median (IQR) reporting score was 21 (18–25). Specifically, the reporting quality was excellent (> 90%) in 4 items (2a, 6b 15, and 22); good (65–90%) in 5 items (4b, 5, 11b, 13a, and 16); and poor (< 65%) in 27 items (1a, 2b, 3a, 3b, 4a, 6a, 7a, 7b, 8a, 8b, 9, 10, 11a, 12a, 12b,13b, 14a, 14b,17a, 17b, 18,19, 20, 21, 23, 24, and 25). For the CONSORT for Abstract, the reporting score was 13 (12–15). The quality of reporting was excellent (> 90%) in 3 items (3, 6, and 15); good (65–90%) in 1 item (10); and poor (< 65%) in 13 items (1, 2, 4, 5, 7, 8, 9, 11, 12, 13, 14, 16, and 17).

Table 4 Reporting assessment of included studies based on the CONSORT items (n = 1458)
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Table 5 Reporting assessment of included studies based on the CONSORT for Abstract checklist (n = 1385)
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Table 6 Reporting assessment of included studies based on ICWM-specific items (n = 1458)
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The reporting score of the ICWM-specific items was 18 (15–21). Four items were “excellent” (Q13, Q15, Q16, Q17, Q23), and “good” reporting in 5 items (Q1, Q5, Q6, Q14). The remaining 18 items were reported poorly (Q2, Q3, Q4, Q7, Q8, Q9, Q10, Q11, Q12, Q18, Q19, Q20, Q21, Q22, Q24, Q25, Q26, Q27), of which 16 items showed extremely low (< 33%), particular in the rationale for ICWM design with definite objectives or hypotheses, specific timepoint/stage of integrative therapy for UC, CM-related diagnosis criteria and outcome(s), discussion about the internal and external validity of ICWM results and value of ICWM design were insufficient or not articulated in most studies. The total scores of the CONSORT, the CONSORT for Abstract, and ICWM-specific checklist items were significantly improved after 2010 (all P < 0.01; Table 7).

Table 7 Overall reporting quality scores for included studies, by subgroup
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Discussion

ICWM has been widely applied for UC in China [16]. There have been a large number of ICWM RCTs of UC published in Chinese and English literature. This study provides a scoping review of the reporting quality of the RCTs of ICWM for UC publications between January 1998 to June 2023. Unfortunately, the reporting quality we reviewed was suboptimal and substantial improvement could be required to meet the recommendations of reporting guidelines. Based on the CONSORT checklist, the items with good reporting in the included articles cover scientific background and rationale; settings and locations where the data were collected, intervention details; baseline demographic and clinical characteristics; and interpretation consistent with results. Although subgroup analysis showed better reporting quality after the CONSORT checklist was updated in 2010, this review demonstrated that there is much room for improvement with respect to ICWM RCTs reporting.

The inadequate reporting domains of reviewed articles include title and abstract, introduction, methods, results, discussion, and other information. With respect to the title and abstract, the reporting percentage for “identification as a randomized trial in the title” of the trials was only 0.89%. Most Chinese articles did not report this item. Indexers may not classify a report as an RCT if the authors do not explicitly report this information, therefore limiting the accessibility [21]. Contact details for the corresponding author were reported in 16.9% of trials. Inadequate contact information would restrict readers from contacting trialists for additional information or clarifications of reported data [22]. Among 1385 (95%) RCTs with abstract, the reporting quality was good in the description of the trial design, objective, number of participants randomized, and results in the section of “Abstract”. However, the overall quality of abstract reporting has been unsatisfactory, presenting the inadequate reporting of participants, interventions, outcomes, randomization, blinding, recruiting objects, outcomes, harms, trial registration, and funding. Regarding introduction, there was only 1/5 studies reported specific objectives or hypotheses. The majority of included trials had poor reporting in methods, including trial design, outcomes, sample size estimation, allocation concealment, implementation, blinding, and statistical methods. In the “Results” section, losses and exclusions after randomization, periods of recruitment and follow-up, precise outcomes, and adverse events were also poorly reported. Limitations, generalizability, registration, protocol, and funding reporting had much room for improvement. There are the major reasons why the total score of the CONSORT checklist was suboptimal. Similar problems were found in the previous study examining systematic reviews of ICWM [23].

Due to the specific characteristics of ICWM interventions, the ICWM-specific checklist was designed to assess the reporting features of ICWM trials, which mainly focused on the rationale, implementation and assessment, details of therapy combination, and efficacy assessment. According to the subgroup analysis, we found that the reporting quality in ICWM-specific items was enhanced after 2010. However, there were several problems in the ICWM reporting. First of all, the rationale or reason for choosing ICWM interventions was reported in less than 20% of studies. Secondly, the diagnostic criteria and outcome assessments of both CM and WM were rarely adopted simultaneously. Additionally, limited trials had reported specific situations (e.g., treatment points, stages of diseases, types of conditions) for the applicable scope of ICWM, settings, and locations where the trials were conducted, the background of treatment providers, measures to improve compliance, reasons for study design, interpretation of ICTM interventions, and conflicts of interests. There was also no study that provided information about participants exposed to ICWM treatment prior to recruitment and external validity of ICWM. Though 98.63% of studies concluded promising efficacy of ICWM for UC, the above problems not only limit the repeatability and reproducibility of the findings, hamper other researchers from identifying gaps that need to be addressed in the design and reporting of future studies, but also mislead healthcare providers in suggesting treatment decisions for patients. Given the deficiencies of reporting identified during this review, strengthening the reporting of the CONSORT are urgently needed. Besides, an extension for ICWM specifics of the CONSORT would be worth considering to improve the current situation.

In this review, we found several problems in the characteristics of included RCTs. Firstly, only 4.95% of articles were published in relatively high-quality journals, such as the Chinese Medical Core Journals and English journals with impact factors. These journals usually provide a peer review process, to assess the validity, quality, and often the originality of articles for publication [24]. Secondly, the most common design was a single center (97.94%) and sample size of 51–100 (70.3%), indicating high-quality ICWM interventional RCTs with multicenter design and larger sample size are needed. Thirdly, the intervention period of no more than 30 days was applied in half of the studies. However, whether such a short intervention period for UC was enough to obtain maximum effectiveness is unknown. Moreover, 82.37% of studies did not report the follow-up period, therefore the long-term effectiveness of ICWM is questionable [25]. Finally, more than two-thirds (71.88%) of the trials did not report the specific stages or phases of UC. TCM treatment strategies for inflammatory bowel diseases are based on disease gradation, stage, and segmentation from multi-dimensional treatment, including etiology, symptoms, syndromes, and internal and external treatment [26]. Chinese medical syndromes of active and remission stages of UC are significantly different [27]. Omit syndrome differentiation in Chinese medicine intervention may lead to unsuccessful treatment [28].

Our review has some limitations. First, this review identified full-text RCTs of UC with ICWM interventions published up to 16 June 2023 in the targeted databases. Any records which had not been included in these databases by that cut-off period, or without available full-text, as well as the grey literature have not been included. In addition, we included only articles in English and Chinese because of language limitations. As such, we may not have captured otherwise eligible trials published in other languages. Second, we rated the items with “not applicable” reporting as “2”, which might overoptimize the total scores. Furthermore, the CONSORT checklist is not intended to construct a “quality score”. Thus, using scores based on the reporting checklists might limit the accuracy of our evaluations and simplify the actual situation. Third, methodology quality (e.g., risk of bias) assessment was not conducted because this review only focused on the reporting quality.

Conclusion

The reporting quality of ICWM RCTs for UC is suboptimal and substantial improvement is required to meet CONSORT guidelines. Consistent with previous studies [29,30,31], this review found improved reporting quality in reviewed RCTs after the CONSORT checklist was updated in 2010. We suggest that authors should adhere to the CONSORT 2010 statement in designing, conducting, and reporting RCTs and that researchers should consider developing a series of standard reporting items specifically relevant to ITCWM design, as an extension to the CONSORT. This might be an effective strategy for achieving the improvement needed [32].