[Influence of impact factor on reporting sample size calculations in publications on studies exemplified by AMD treatment : Cross-sectional investigation on the presence of sample size calculations in publications of RCTs on AMD treatment in journals with low and high impact factors]

BACKGROUND

For scientific and ethical reasons randomized controlled clinical trials (RCTs) should be based on a sample size calculation. The CONSORT statement, an established publication guideline for transparent study reporting, requires a sample size calculation in every study publication.

OBJECTIVE

The availability of sample size calculations in RCT publications on treatment of age-related macular degeneration (AMD) was investigated. The primary hypothesis of this investigation compared the prevalence of reported sample size calculations between journals with higher (≥5) versus lower (<5) impact factors (IF).

MATERIAL AND METHODS

It was examined whether information on sample size calculation was available in a series of 97 publications of RTCs on AMD treatment published between 2004 and 2014.

RESULTS

Only 46 out of 97 (47%) study publications provided information on the reason for the number of patients enrolled. The comparison of publications from journals with an IF ≥ 5 (63%, 30) and from journals with an IF < 5 (40%, 67) showed a statistically significant difference of 23% in the frequencies of available sample size calculations (95% confidence interval, CI 2%; 44%). Of the publications published before 2010, 43% reported a sample size calculation versus 51% of the publications afterwards.

CONCLUSION

Publications in journals with higher IF more frequently reported a sample size calculation. More than 50% of the publications did not report any sample size calculation. Authors and reviewers of publications should pay more attention to the explicit reporting of sample size calculations.

Does personalized goal setting and study planning improve academic performance and perception of learning experience in a developing setting?

Objective

The learning process for pharmacists must enable the skillful harnessing of metacognition, critical thinking, and effective application of specialized skills. This study assessed the impact of self-developed academic goals and study plans on pharmacy students' academic performance and perception of learning experience in a developing setting.

Methods

A prospective cohort study was conducted at the College of Clinical Pharmacy, King Faisal University, KSA, in a compulsory 4th year course (Pharmacy management). The study group was exposed to goal setting and study planning while the control group had only routine teaching and learning activities planned for the course. Academic performance was determined with quizzes, midterm, and final exams, and the percentage achievement for the course objectives. An end-of-course evaluation, with a pre-tested questionnaire, was used to assess the perception of learning experience.

Results

The study group constituted 41.4% (29), while 58.6% (41) were in the control group, with a mean ± SD age of 22.9 (SD = 3.2) and 21.6 (SD = 6.1) years, respectively. The mean ± SD scores for quizzes (8.4 (SD = 2.2), mid-term (21.9 (SD = 3.7), and final exams (42.8 (SD = 5.3), and the percentage achievement for the course objectives A (77%) and B (78%) were significantly higher in the study group (P < 0.001). The end-of-course feedbacks showed key differences in the perception of learning experience between the study and control groups.

Conclusion

Personalized goal setting and study planning appeared to significantly improve continuous engagement with learning, focus on academic goals, and academic performance.

A plea to provide best evidence in trials under sample-size restrictions: the example of pioglitazone to resolve leukoplakia and erythroplakia in Fanconi anemia patients

In planning a clinical trial for demonstrating the efficacy of pioglitazone to resolve leukoplakia and erythroplakia in Fanconi anemia patients we had to discuss the need for a randomized controlled trial particularly under sample-size restrictions as very promising results were available from a single-arm clinical trial. Unfortunately, at a later stage, we had to suffer from the fact that single-arm clinical trials may sometimes mislead. When revisiting our planning at a later stage of a grant application, results of a randomized controlled trial had become available which were less impressive, but may still be of clinical interest. However, these results were perceived as disappointing in the light of previously raised hopes based on the results of the single-arm trial. We highlight some major problems when research is based on single-arm trials compared to randomized controlled trials. After debunking common arguments for the conduct of single-arm trials in rare disease we conclude that particularly in rare disease research should be based on randomized building blocks simply because more robust evidence is generated. The plea for single-arm trials should be substituted by a plea for cooperation of all stakeholders to provide best evidence for decision making under sample-size restrictions.

Randomized controlled trials vs. observational studies: why not just live together?

Randomized controlled trials (RCTs) are considered the gold standard for clinical research, thus having a high impact on clinical guidelines and our daily patients’ care. However, various treatment strategies which we consider “evidence based” have never been subject to a prospective RCT, as we would rate it unethical to withheld an established treatment to individuals in an placebo controlled trial.

In a recent BMC Anesthesiology publication, Trentino et al. analyzed the usefulness of observational studies in assessing benefit and risk of different transfusion strategies. The authors nicely reviewed and summarized similarities and differences, advantages and limitations, between different study types frequently used in transfusion medicine. In this interesting article, the authors conclude, that ‘when comparing the results of observational studies with RCTs assessing transfusion outcomes, it is important that one consider not only the study method, but also the key elements of the study design’. Thus, in this commentary we now discuss the pro’s and con’s of different study types, even irrespective of transfusion medicine.