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

Abstract

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.

Do sample size calculations in longitudinal orthodontic trials use the advantages of this study design?

“…The greatest number of trials was published in 2019 (33.3%) and in orthodontic specialty journals (61.9 %). The median number of time points was four (range, [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. Approximately 90% of the studies reported a 1:1 treatment arm allocation ratio.…”

“…[2][3][4] The importance of trials having an appropriate sample size is further highlighted by the fact that overestimation of the calculated required sample size can lead to additional study costs, resource waste, and potentially result in participants being exposed to ineffective/harmful treatments. 5,6 Alternatively, underestimation of the sample size can result in small trials that are considered less reliable and likely to report equivocal results attributed to a lack of study power to detect differences between intervention groups. 7,8 To understand the effect of interventions over time within the same individual, longitudinal orthodontic trials involving the repeated measurement of outcomes over several time points are commonly conducted.…”

“…15 It has been reported that recommendations facilitate both the accurate assessment of the quality of the study and the correct interpretation of the results. 6 Despite this, concerns regarding the optimal reporting of sample size calculations within the literature have been raised. Within both dental and orthodontic RCTs, the completeness of sample size calculations has been reported at 29.3% 16 and 29.5%, 12 respectively, and appears to be influenced by certain trial characteristics.…”

Methodological Gaps in Studying the Oral-Systemic Disease Connection

“…Various approaches have been used to study this relationship, which range from in vitro experiments to animal, epidemiological, and clinical studies. A recent study prompted our interest in highlighting some of the methodological gaps of epidemiological studies that investigate the relationship between oral and systemic diseases (Pandis et al 2020). For example, the authors of many reviews in this area conclude that studies are of poor quality (Simpson et al 2015; Liu et al 2019; Manohar et al 2020), yet there are no articles that attempt to address the common concerns raised in these studies.…”

“…This is often due to an overreliance on an arbitrary 0.05 threshold or use of statistical methods that produce “statistically significant” results (Greenland et al 2016). Reporting, focusing, and highlighting P values is an endemic practice across medical and dental fields (Greenland et al 2016; Pandis et al 2020). For instance, a review on obesity and periodontal disease reported 15 single P values without corresponding estimates on effect size in a single paragraph (Martens et al 2017).…”