Quality of reporting of descriptive and inferential statistics in negative studies published in Indian medical journals

Abstract

Aims and Objectives: It is observed that negative studies published in medical journals
are underpowered to detect the actual difference between the groups, but no data are
available on the quality of the statistics reported in these studies. Therefore, this study
was carried out with aim of evaluating negative studies published in Indian medical
journals for adequacy of reporting of descriptive and inferential statistics. Materials
and Methods: All the original articles published in 14 Pubmed-indexed Indian medical
journals were analyzed to determine whether the study was negative or positive. All the
negative studies were analyzed for correctness of the descriptive statistics and inferential
statistics. The types of data and statistical methods were also noted down. Descriptive
statistics was used and values were expressed as frequency, percentages and confidence
interval. Results: Incorrect descriptive statistics was mentioned in 15 (28.8%, 95%
CI 18.3–42.2%) studies. Information related to assumptions of statistical tests were
mentioned in only two (3.8%, 95% CI 1.0–12.9%) articles. Inappropriate/incorrect
statistical tests was used in 22 (42.3%, 95% CI 29.8–55.8%) studies. The most common
reason for inappropriate reporting of descriptive statistics was use of mean and SD
for description of ordinal data. The most common reason for incorrect statistical test
was use of parametric test for ordinal data. The most common statistical test was the
t-test. Conclusion: Negative studies published in prominent Indian medical journals
are statistically weak, and readers critically analyze these studies before making any
opinion based on them..