The Characteristics and Level of Evidence of Clinical Studies Published in 5 Leading Orthodontic Journals

Abstract

Objectives: To assess the characteristics and level of evidence (LOE) of clinical studies recently published in leading orthodontic journals, and explore the association between LOE and potentially related factors. Methods: The official online archives of five leading orthodontic journals were handsearched to identify clinical research articles published during 2015 to 2017. The LOE of all included studies was assessed using a modified LOE classification system developed based on the Oxford LOE and GRADE (Grading of Recommendations Assessment, Development and Evaluation). Univariable and multivariable logistic regression analyses were performed to identify the association between the LOE of each article (high LOE vs. low LOE) and 7 factors. Results: A total of 637 studies were included and assessed. Of these, 8 (1.3%) were level-1 studies, 160 (25.1%) were level-2, 326 (51.2%) were level-3, and 143 (22.4%) were level-4. According to multivariable logistic regression analyses, journal of publication (P<0.001), funding status (P=0.003), and the geographic origin of the first author (P=0.006) were significantly associated with LOE. Conclusions: The number of high LOE studies in leading orthodontic journals was limited. There is still need for further improvement in the overall LOE of clinical studies in orthodontics.

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

“…Similar to previous studies (Chen et al, 2019;Kulkarni, Busse, & Shams, 2007;Livas & Delli, 2018), we extracted the following information from each article: (1) article title; (2) journal title; (3) publication year; (4) multiple affiliations; (5) geographical origin (as defined by the first author), that is North America, Europe, Asia, South America, Africa and Oceania; (6) type of institution (as defined by the first author), that is university, public health service, private practice and others; (7) funding status, that is funded by industry, funded by other sources, unfunded or unreported; 8open-access status; (9) research topic; (10) study type; (11) citation count; and (12) AAS.…”

“…Moreover, the explosion of clinical studies published, heavy workload and a lack of time make it necessary for clinicians to have a quick overview of study quality, which can be provided by the LOE assessment (Luksanapruksa & Millhouse, 2016). Practices of several journals (Obremskey, Pappas, Attallah-Wasif, Tornetta, & Bhandari, 2005;Swiontkowski, Heckman, & Wright, 2003) and recently published studies (Chen et al, 2019;Joyce, Joyce, Kelly, Kelly, & Carroll, 2015;Judy et al, 2018;Sandhu, 2012;Shafiei & Shahravan, 2013) indicate that LOE in clinical studies is receiving increasing attention.…”

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

“…Although the overall LOE of studies in oral implantology was higher than that in orthodontics (Chen et al, 2019), the majority of studies were with low LOE (67.2%…”

“…A modified LOE classification system was used, based on Oxford 2009 LOE, Oxford 2011 LOE, and the GRADE guidelines according to a previous study regarding the LOE of clinical studies in orthodontics (Chen et al., 2019). Additionally, for ease of description, level‐1 and level‐2 were defined as high level while level‐3 and level‐4 as low level.…”

“…The modified level of evidence assessment tool used in this study (Chen et al, 2019) † When the primary outcome of a study was categorical and the risk ratio (RR) was >5 (or <0.2), the effect size was recognized as dramatic effect. If the sample size and odd ratio (OR) were provided, the RR was calculated and it was decided whether to level up or not of the confounders was removed even if the association was nonsignificant.…”