ABSTRACT
BACKGROUND: Statistical type II error has seemed to be ignored commonly by medical researchers. To control and present a power value could be helpful to reduce this type of error and to improve a quality of scientific decision making. We performed the post-hoc survey of the power of the negative results in Korean Journal of Anesthesiology (KJA). METHODS: One Hundred nineteen articles with negative results published in KJA during a year of 1997 were selected. We collected the numbers of the sample size and calculated the power of the given negative result only when applicable. And each author's attitude to negative results was taken by arbitrary criteria. RESULTS: Median sample size of these negative results was 16 12 (median interquartile range). We can calculate the power only in 43 articles of 119 negative results. Median power is 18.0% (interquartile range 26.0). In thirty six articles (83.8% of 43) the powers are proved to be under 80.0%. And 22 articles (51.2% of 43) have the powers even under 20.0%. We couldn't find any author who included either power or effect size in the article, and there was only one article in which its authors considered their inadequate number of sample size. CONCLUSIONS: We conclude that authors of KJA tend to ignore statistical type II error. In 119 negative results published in KJA during 1997, the calculated powers were very low and were not reported in the text.
Subject(s)
Anesthesiology , Decision Making , Sample SizeABSTRACT
BACKGROUND: The purpose of this study is to investigate the frequency of and errors in citation of references in articles from the Korean Journal of Anesthesiology (KJA) from the first application of the present contribution rules (1996) to 1998 and to suggest a clue to improve the quality of our journal. METHODS: All references cited from KJA were reviewed using a computerized searching system. If any differences are found during the review, we compare it with the original article. Errors on the contribution rules were examined according to the instructions for the authors revised in 1995. RESULTS: Overall 74% of the articles had more than one reference cited from KJA. The average number of the references cited from KJA per article was 1.73. In such references, citation errors were found in 48% of articles published in 1996, 44% in 1997, and 43% in 1998. The percentages of general errors and errors involving the contribution rules were 62% and 38%, respectively. Common general errors were found in titles (164 cases), pages (102 cases), and name (60 cases). Those involving the contribution rules found in the notation of name (120 cases), pages (54 cases), and inadequate notation of the number of issue (49 cases). CONCLUSIONS: Despite numerous efforts, the incidence of citation errors was still high when the articles of KJA were cited as references. Improvement in the quality of our journal will be possible only by rigid adherence to contribution rules, thorough review of the articles, and a lucid explanation of contribution rules.