Summary of Findings
Our study evaluated 165 MPH professional dissertations. Although the overall reporting quality was relatively good, some essential aspects of methods and results were seldom reported, which made difficult for readers to assess the validity and reliability of the observational studies [16]. What’s more, dissertations of superior reporting quality usually contain the following predictive factors: cohort studies, funding support and more published papers during postgraduate period.
Reporting on title and abstract section and introduction section was satisfactory. That may be because each master needs to go through the strictly opening and middle screening stages in the early stage of the dissertation writing. The deficiency of the reporting of MPH dissertations was mainly focused on methods and results. In particular, there was a need for dissertations to improve their reporting of variables definition, statistical methods, and flow diagram.
In actual studies, the outcome, exposure, predictors, potential confounders, and effect modifiers of the study should be clearly defined, but less than half of dissertations fully reported these content. The inadequate reporting of statistical method may not make full use of research results, resulting in a waste of valuable information and varying degrees of bias. However, only a few articles described any methods used to examine subgroups and interactions, explained how missing data were addressed, and described any sensitivity analysis. Only 25 dissertations (15.15%) used the flow diagram, while others did not take advantage of the simple and direct features of flow diagram. In addition, all articles summarised key results with reference to study objectives, but only about a quarter of the articles discussed the generalisability of the study results.
The result of multivariate logistic regression analysis indicated that the funding support was associated with high reporting quality. Funding projects require rigorous research designs, and need to be screened and approved. Therefore, masters are strictly required and trained to learn more knowledge, so that their thesis quality will be higher. Morever, the positive association between more published papers during postgraduate period and high reporting quality were observed. The masters published more papers during postgraduate period have stronger academic ability, are ore familiar with the writing of the articles, and know what should be reported in detail. In addition, the results of univariate logistic regression analyses showed that the number of statistical methods was associated with high reporting quality. Masters who use more statistical methods have a deeper understanding of methodology, are more proficient in using statistical methods, and are more complete in methods reporting in dissertations.
Compared with other studies
A few articles had evaluated the reporting quality of observational studies in other medical disciplines. Several studies have found that the reporting quality of the articles that used STROBE statement to standardize was better than the others [19, 20, 25, 26]. Jacqueline Ramke et al. has used the STROBE statement to evaluated the reporting in the blindness prevalence surveys, and they found that the mean of STROBE score of studies published in the journal requiring STROBE statement was higher than the score for the others [19]. Swords C’s study indicated that STROBE statement had increased the reporting quality of observational Otology and Audiology studies [20]. Hence, we strongly recommend that masters should be familiar with STROBE statement.
On the other hand, many studies have found that reporting of observational studies have defects in methods and results [27-29]. Adams AD et al. discovered that poor reporting was seen in obstetrics observational studies for study size, missing data, and absolutely studies [27]. Karaçam Z have evaluated the reporting quality of observational studies in Turkish nursing journals, and found that the methods sections of the reports were mostly omitted [29]. Our research had yielded similar results.
Education implication
Our study has highlighted the important deficiencies in the reporting of observational studies in MPH’s dissertations. Based on these findings, we believe that if universities adopt the STROBE criteria to guide MPH, it will help improve the reporting quality of MPH’s dissertations. In the course of master's training, it is necessary to strengthen the understanding and flexible application of the statistical methods, and the graduate tutors should pay more attention to the masters who published less papers during postgraduate period.
Strengths and limitations of this study
As a systematic review of MPH’s dissertations, our study has some advantages. First, this study is a comprehensive assessment and used logistic regression analyses to identify factors associated with high-quality reporting. For evaluation of dissertations, we included not only adherence with items but also STROBE score. Second, some of the evaluation items are not applicable to all articles, such as 6b, 14c, and some items are not adequately reported. To minimize biases against systematic review, we identified items as: full reporting, partly reporting, no reporting, not applicable, and assign different scores. Thus, different articles have a more consistent score criterion. Third, since the STROBE statement was published in 2007, no studies has used this guidelines to evaluate the reporting quality of master dissertation. Therefore, our work is innovative and will provide a reference for subsequent similar research. Fourth, the study include the independent assessment of all articles by two authors. All details of our search were transparent and clear, and our search can therefore easily be reproduced.
There are also some limitations in this study. First, scoring of items remains a subjective task, and easily leads to subjective bias. However, two investigators independently used the STROBE statement to evaluate the included studies, and differences were resolved by the group discussion. In this way, we can minimize subjective bias. Second, given that our research was restricted to MPH dissertations published by Chinese master in the past five years, the results can only reflect the integrity and standardization of the reporting of Chinese MPH’s master dissertation to a certain extent. Finally, since there is no literature to be found on the reporting quality of the medical master dissertation with STROBE statement, it is impossible to compare the reporting quality of the dissertation with other profession.