Trial characteristics and treatment effect estimates in randomized controlled trials of Chinese herbal medicine: A meta-epidemiological study

BACKGROUND

Previously published meta-epidemiological studies focused on Western medicine have identified some trial characteristics that impact the treatment effect of randomized controlled trials (RCTs). Nevertheless, it remains unclear if similar associations exist in RCTs on Chinese herbal medicine (CHM). Further, Chinese medicine-related characteristics have not been explored yet.

OBJECTIVE

To investigate trial characteristics related to treatment effect estimates on CHM RCTs.

SEARCH STRATEGY

This meta-epidemiological study searched 5 databases for systematic reviews on CHM treatment published between January 2011 and July 2021.

INCLUSION CRITERIA

An eligible systematic review should only include RCTs of CHM and conduct at least one meta-analysis.

DATA EXTRACTION AND ANALYSIS

Two reviewers independently conducted data extraction on general characteristics of systematic reviews, meta-analyses and included RCTs. They also assessed the risk of bias of RCTs using the Cochrane risk of bias tool. A two-step approach was used for data analyses. The ratio of odds ratios (ROR) and difference in standardized mean differences (dSMD) with 95% confidence interval (CI) were applied to present the difference in effect estimates for binary and continuous outcomes, respectively.

RESULTS

Ninety-one systematic reviews, comprising 1338 RCTs were identified. For binary outcomes, RCTs incorporated with syndrome differentiation (ROR: 1.23; 95 % CI: [1.07, 1.39]), adopting Chinese medicine formula (ROR: 1.19; 95% CI: [1.03, 1.34]), with low risk of bias on incomplete outcome data (ROR: 1.29; 95% CI: [1.06, 1.52]) and selective outcome reporting (ROR: 1.12; 95% CI: [1.01, 1.24]), as well as a trial size ≥ 100 (ROR: 1.23; 95% CI: [1.04, 1.42]) preferred to show larger effect estimates. As for continuous outcomes, RCTs with Chinese medicine diagnostic criteria (dSMD: 0.23; 95% CI: [0.06, 0.41]), judged as high/unclear risk of bias on allocation concealment (dSMD: -0.70; 95% CI: [-0.99, -0.42]), with low risk of bias on incomplete outcome data (dSMD: 0.30; 95% CI: [0.18, 0.43]), conducted at a single center (dSMD: -0.33; 95% CI: [-0.61, -0.05]), not using intention-to-treat analysis (dSMD: -0.75; 95% CI: [-1.43, -0.07]), and without funding support (dSMD: -0.22; 95% CI: [-0.41, -0.02]) tended to show larger effect estimates.

CONCLUSION

This study provides empirical evidence for the development of a specific critical appraisal tool for risk of bias assessments on CHM RCTs. Please cite this article as: Wang BH, Lin YL, Gao YY, Song JL, Qin L, Li LQ, Liu WQ, Zhong CCW, Jiang MY, Mao C, Yang XB, Chung VCH, Wu IXY. Trial characteristics and treatment effect estimates in randomized controlled trials of Chinese herbal medicine: A meta-epidemiological study. J Integr Med. 2024; 22(3): 223-234.

Characteristics, level of evidence, and impact of clinical studies on peri-implantitis: 2017 to 2021

BACKGROUND

The level of evidence (LOE) is an important tool in current evidence-based practice and clinical research. However, in clinical studies on peri-implantitis, the present status of the LOE and its association with research impact remains to be determined. The present study aimed to gather the characteristics and LOE of clinical studies on peri-implantitis conducted from 2017 to 2021 and assess the association of the LOE with social and scientific impact.

METHODS

The PubMed database was searched to retrieve clinical studies that evaluated peri-implantitis-related healthcare interventions and were published between 2017 and 2021. A 4-level modified Oxford 2011 LOE tool was used to determine the LOE of these studies. Citation count and Altmetric Attention Scores (AAS) were derived from the Web of Science and Altmetric Explorer, respectively. Multivariate generalized estimation equation (GEE) analysis was conducted to explore relationships between the LOE and citation count, and between the LOE and AAS; the publication year was considered the grouping factor for adjusting for potential clustering effects.

RESULTS

Two hundred and thirty-five studies were considered eligible. The percentages by level from Level-1 to Level-4 were 9.8%, 35.7%, 28.9%, and 25.5%. Multivariable GEE analyses revealed that studies with higher LOE ratings had significantly greater citation counts (p = 0.008). However, no significant association (p = 0.872) was observed between the LOE and AAS.

CONCLUSIONS

From 2017 to 2021, more than 40% of studies published on peri-implantitis each year had high-LOE ratings. High-LOE studies showed a tendency to have greater scientific impact.

Reporting of flow diagrams in randomised controlled trials published in periodontology and implantology: a survey

BACKGROUND

Item 13 of the CONSORT guidelines recommends documentation of the participant flow in randomised clinical trials (RCTs) using a diagram. In the medical literature, the reporting of the flow of participants in RCTs has been assessed to be inadequate. The quality of reporting flow diagrams in periodontology and implantology remains unknown. The aim of this study was to assess the reporting of flow diagrams in RCTs published in periodontology and implantology journals.

MATERIALS AND METHODS

RCTs published between 15^th January 2018 and 15^th January 2022 in twelve high-ranked periodontology and implantology journals were identified. Trial characteristics at the RCT level were extracted. The flow diagram included in each RCT was assessed for completeness of reporting in relation to published criteria and the CONSORT flow diagram template.

RESULTS

From the 544 eligible articles, 85% were single-centre, 82% of parallel-group design and 79% investigated surgical interventions. Three-hundred and fifteen (58%) articles were published in CONSORT endorsing journals. A flow diagram was reported in 317 (58%) trials and reporting was more common in periodontology (73.1%). Overall, 56% of publications with a flow diagram reported a complete CONSORT flow diagram, while in 44% of flow diagrams, at least one point from the CONSORT reporting template was missing. Reasons for loss to follow-up (69.7%) and exclusions from the RCT analysis (86.4%) were poorly reported.

CONCLUSION

The reporting of flow diagrams in periodontology and implantology RCTs was sub-optimal. Greater awareness of the importance of fully completing the participant CONSORT flow diagram is required.

Equine assisted services impact on social skills in autism spectrum disorder: A meta-analysis

Many studies focus on the impact of equine assisted services (EAS) on social skills in autism spectrum disorder (ASD) but existing data are not consensual and the only available meta-analysis included only three studies and did not consider the social responsiveness scale (SRS). This meta-analysis aims to measure the impact of EAS on social skills in ASD. Using Pubmed, Embase, Web of Science and the Cochrane Library, the means and standard deviations of every available SRS post-intervention scores in each participant group were collected from the five selected randomised controlled trials with 240 participants. An EAS significant beneficial impact was found for the total SRS score, social communication and social cognition. A tendency to a significant impact was found for social awareness and social motivation. No significant difference was shown for autistic mannerisms. This meta-analysis shows a significant beneficial impact of EAS for several social skills in ASD. Further randomised controlled trials are required to complement these results and expand the knowledge on the field of possibilities of this care in ASD.

Level of evidence and characteristics of clinical studies published in leading prosthodontics journals

STATEMENT OF PROBLEM

Data on the level of evidence and the characteristics of studies published in peer-reviewed prosthodontic journals are lacking.

PURPOSE

The purpose of this study was to investigate the characteristics and level of evidence (LOE) scores of studies published in 3 leading peer-reviewed prosthodontic journals.

MATERIAL AND METHODS

Clinical studies published in the Journal of Prosthetic Dentistry (JPD), the Journal of Prosthodontics (JP), and the International Journal of Prosthodontics (IJP) in 2013 and 2020 were included in the analysis. Abstracts, letters to the editor, book reviews, and animal and laboratory studies were excluded from the investigation. For each study, design, type and LOE scores (Levels 1 to 5), publication year, impact factor (IF) of the journals, geographic origins of the first and corresponding authors, and funding status were recorded. Level 1 and Level 2 were defined as high evidence (HE), and Level 3, Level 4, and Level 5 were defined as low evidence (LE). Descriptive statistics and logistic regression analysis were performed (α=.05).

RESULTS

Among the 439 studies included in the analysis, the proportion of HE and LE studies was 14.1% and 85.9%, respectively. According to univariate and multivariate analysis results, year of publication (P=.010 and P=.029), geographic origin of the corresponding author (P<.001), and funding status (P<.001 and P=.002) were significantly associated with the LOE of a study. However, the journal IF was not associated with LOE (P=.328).

CONCLUSIONS

Although the number of HE studies in 3 leading prosthodontic journals has increased over time, the total number was still limited compared with LE studies. A further improvement in the overall LOE of clinical studies in prosthodontics is needed.

The reporting and methodological quality of split-mouth trials in oral implantology: A methodological study

OBJECTIVES

The objective of this study is to assess the reporting and methodological quality of split-mouth trials (SMTs) in oral implantology published during the past 10 years, and to investigate whether there was any improvement over time.

MATERIALS AND METHODS

We searched PubMed for SMTs in oral implantology published during 2011-20. We used CONSORT 2010, its extension for within-person trial (WPT), and an SMT-specific methodological checklist to assess trial reporting quality (TRQ), WPT-specific reporting quality (WRQ), and SMT-specific methodological quality (SMQ), respectively. Binary scores were given to each item, and total scores of TRQ (range 0-32), WRQ (0-15), and SMQ (0-3) were calculated for each study. Multivariable regression analyses were performed to compare the quality of SMTs published before (2011-17) and after (2018-20) the release of CONSORT for WPT.

RESULTS

Seventy-nine SMTs were included. The mean TRQ, WRQ, and SMQ were 16.4, 6.7, and 1.3, respectively. Less than one-third (n = 25, 31.6%) reported the rationale for using split-mouth designs. Only 4 (5.1%) trials adequately conducted sample size calculation, and 40 (50.6%) used appropriate statistical methods that considered dependency and clustering of data. In multivariable analyses, compared with 2011-17, studies published in 2018-20 had significantly higher TRQ (p = .044), while WRQ and SMQ did not show improvement.

CONCLUSIONS

The reporting and methodological quality of SMTs in oral implantology need to be improved. Joint efforts are needed to improve the reporting and methodology of SMTs in this field.

The reporting and handling of missing data in longitudinal studies of older adults is suboptimal: a methodological survey of geriatric journals

Background

Missing data are common in longitudinal studies, and more so, in studies of older adults, who are susceptible to health and functional decline that limit completion of assessments. We assessed the extent, current reporting, and handling of missing data in longitudinal studies of older adults.

Methods

Medline and Embase databases were searched from 2015 to 2019 for publications on longitudinal observational studies conducted among persons ≥55 years old. The search was restricted to 10 general geriatric journals published in English. Reporting and handling of missing data were assessed using questions developed from the recommended standards. Data were summarised descriptively as frequencies and proportions.

Results

A total of 165 studies were included in the review from 7032 identified records. In approximately half of the studies 97 (62.5%), there was either no comment on missing data or unclear descriptions. The percentage of missing data varied from 0.1 to 55%, with a 14% average among the studies that reported having missing data. Complete case analysis was the most common method for handling missing data with nearly 75% of the studies (n = 52) excluding individual observations due to missing data, at the initial phase of study inclusion or at the analysis stage. Of the 10 studies where multiple imputation was used, only 1 (10.0%) study followed the guideline for reporting the procedure fully using online supplementary documents.

Conclusion

The current reporting and handling of missing data in longitudinal observational studies of older adults are inadequate. Journal endorsement and implementation of guidelines may potentially improve the quality of missing data reporting. Further, authors should be encouraged to use online supplementary files to provide additional details on how missing data were addressed, to allow for more transparency and comprehensive appraisal of studies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-022-01605-w.

Increased transparency was required when reporting imputation of primary outcome data in clinical trials

OBJECTIVE

To explore the transparency of reporting primary outcome data within randomised controlled trials (RCTs) in the presence of missing data.

STUDY DESIGN

/ Setting: A cohort examination of RCTs published in the four major medical journals (NEJM, JAMA, BMJ, Lancet) in 2013 and the first quarter of 2018. Data was extracted on reporting quality, the number of randomised participants and the number of participants included within the primary outcome analysis with observed or imputed data.

RESULTS

91/159 (57%) of the studies analysed from 2013 and 19/46 (41%) from 2018 included imputed data within the primary outcome analysis. Of these, only 13/91 (14%) studies from 2013 and 1/19 (5%) studies from 2018 explicitly reported the number of imputed values in the CONSORT diagram. Results tables included levels of imputed data in 12/91 (13%) studies in 2013 and 4/19 (21%) in 2018. Consequently, identification of imputed data was a time-consuming task requiring extensive cross-referencing of all manuscript elements.

CONCLUSION

Imputed primary outcome data is poorly reported. Participant flow diagrams frequently reported participant status which does not necessarily correlate to availability of data. We recommended that the number of imputed values are explicitly reported within CONSORT flow diagrams to increase transparency.

Effect of microthread design on the preservation of marginal bone around immediately placed implants: a 5-years prospective cohort study

Background

This study aimed to evaluate the effect of the microthread design at the implant neck on the preservation of marginal bone around immediately-placed implants in a 5-year follow up.

Methods

Thirty patients received 41 immediately placed implants which were randomly assigned to treatment groups with microthreaded implants (test group, n = 22) or threaded implants (control group, n = 19). Clinical and radiographic analyses were carried out after 1 and5 years. Plaque index, bleeding on probing, suppuration, probing depth and marginal bone loss were subject to evaluations. The results were analyzed with the T-test, Fisher’s exact test and Mann–Whitney U test.

Results

No implants failed; thirty-five implants (in 27 patients); 21 microthreaded and 14 threaded implants; completed the 5 year follow up. The mean values of the marginal bone loss in microthreaded and threaded groups were 1.12 ± 0.95 mm and 0.87 ± 0.78 mm, respectively during an observation period of 70.9 ± 10.4 months; the differences in marginal bone loss and other pre-implant parameters were not significant between groups (P > 0.05).

Conclusion

Both implant designs showed acceptable results in terms of the clinical parameters and marginal bone level. Within the limitation of this study, the results did not demonstrate any superiority of the microthread design compared to threaded one in marginal bone preservation around immediately placed implants over 5 years of loading.

Dental Research Waste in Design, Analysis, and Reporting: A Scoping Review

Research waste is highly prevalent across biomedical investigations. We aimed to assess the evidence on the extent of research waste in dental research. We performed a scoping review of empirical evaluations of dental studies assessing the prevalence and impact of limitations in design, conduct, analysis, and reporting of research. PubMed was searched using specific terms to retrieve studies dealing with design, conduct, analysis, and reporting of studies in dentistry, with no year or language restrictions. Of the 1,807 publications identified from the search and from manual searches, 71 were included in this review. The topic and article selection was based on the expert opinion of the authors. The existing evidence suggests that, although there are improvements over time, substantial deficiencies in all areas (design, conduct, analysis, reporting) were prevalent in dental research publications. Waste in research is a multifaceted problem without a simple solution. However, an appreciation of optimal research design and execution is a prerequisite and should be underpinned by policies that include appropriate training in research methods and properly aligned incentives.

Trends in the level of evidence and impact of clinical studies published in leading oral implantology journals: 2008-2018

OBJECTIVES

To present the characteristics and level of evidence (LOE) of clinical studies published in leading oral implantology journals during 2008-2018 and to explore whether the LOE of a study is associated with its scientific and social impact.

MATERIALS AND METHODS

Clinical studies with direct relevance to the evaluation of healthcare interventions published in 2008, 2013, and 2018 in six oral implantology journals were identified via hand searches. A modified 4-level Oxford 2011 LOE tool was used to assess the LOE of all eligible studies. The citation count and Altmetric Attention Score (AAS) of each study were extracted from Web of Science and Altmetric Explorer, respectively. Thereafter, multivariable generalized estimation equation analyses were used to investigate the association between LOE, citation counts, and AAS, adjusting for potential confounding factors and clustering effects.

RESULTS

A total of 763 clinical studies were included, among which the proportion of level-1, level-2, level-3, and level-4 studies was 2.4%, 30.4%, 40.2%, and 27.0%, respectively. During 2008-2018, the proportion of high LOE studies (level-1 and level-2) increased substantially from 24.6% to 43.1%, although the number of systematic reviews that only include randomized controlled trials has remained limited. According to multivariable analyses, the citation count (p = .002) and AAS (p = .005) of high LOE studies were both significantly greater than those of low LOE studies.

CONCLUSIONS

During the past decade, the proportion of high LOE studies has increased substantially in the field of oral implantology. Clinical studies with higher LOE tend to have greater scientific and social impact.

Spin in the abstracts of randomized controlled trials in periodontology and oral implantology: A cross-sectional analysis

OBJECTIVES

To investigate the presence and characteristics of spin (a distorted interpretation to make research findings seem favorable) in abstracts of randomized controlled trials (RCTs) in periodontology and oral implantology, and to explore its associated factors and influence on the subsequent literature.

MATERIALS AND METHODS

PubMed was searched to identify recent RCTs in periodontology and oral implantology, whose primary outcome was non-significant. Spin in abstracts was assessed and categorized according to pre-determined spin strategies. The associations between study characteristics and the presence / severity of spin were analyzed using multivariable logistic regressions.

RESULTS

196 abstracts were included, 137 (69.9%) of which had spin. 57 (29.1%) abstracts had spin in the Results Section, 126 (64.3%) had spin in the Conclusion Section. The main spin strategies in the Results and Conclusion Sections were focusing on secondary outcomes (16.3%) and focusing on within-group comparisons (28.6%), respectively. The presence of spin was associated with number of centers (OR=0.28, 95% CI: 0.11-0.73; p=0.009) while its severity was associated with topic (OR=0.24, 95% CI: 0.08-0.70; p=0.009).

CONCLUSIONS

The frequency of spin is relatively high among published RCT abstracts in periodontology and oral implantology. Findings reported in these abstracts need to be interpreted with caution.

The level of evidence, scientific impact and social impact of clinical studies in periodontology: A methodological study

AIMS

To analyse the level of evidence (LOE) of clinical studies in the field of periodontology, and to investigate whether LOE is a predictor of scientific impact and social impact.

MATERIALS AND METHODS

Clinical studies published in five leading periodontal journals during 2015-2019 were identified. The LOE of included studies were assessed with a modified LOE classification system based on Oxford 2009 LOE, Oxford 2011 LOE and GRADE guidelines. Citation counts were harvested from Web of Science and Scopus. Altmetric Attention Scores (AAS) were obtained from Altmetric Explorer. Multivariable generalized estimation equation (GEE) analyses were used to investigate association between LOE and citation count, as well as between LOE and AAS.

RESULTS

Among 768 studies included, the proportion of level-1, level-2, level-3 and level-4 was 10.4%, 44.8%, 13.7% and 31.1%, respectively. In the multivariable GEE analyses, high LOE was a significant predictor of higher average citation count (p = .010) and higher AAS (p < .001).

CONCLUSION

The LOE of clinical studies in the periodontal field is relatively high in general, although it varies significantly in different journals. Studies with high LOE tend to have greater scientific impact and social impact than low LOE studies.