Objective: The aim of the study was to perform a systematic review of research articles related to cholangiocarcinoma (CCA), the bile duct cancer in Southeast Asian (SEA) countries published during 2010-2015 including analysis of inappropriate use/misuse of statistics.
Methods: Research articles were retrieved from the PubMed database using different 'keywords' for seven research disciplines/categories in biomedical sciences (medicine/physiology, epidemiology, immunology, pharmacology and toxicology, diagnosis/diagnostics, drug resistance, and biochemistry).
Results: A total of 353 articles were finally included in the analysis based on the pre-defined eligibility criteria. Most were articles of which the studies were conducted in Thailand (335 articles, 94.90%). Disease diagnosis/diagnostics (n=266, 75.35%), biochemistry (n =223, 63.17%), and pharmacology and toxicology (n =218, 61.76%) were the three main research disciplines/categories for CAA conducted in SEA countries during 2010-2015. Thailand was the country which most published CCA-related research articles in all disciplines/categories. Drug resistance was the research category that most applied both descriptive and inferential statistics (100%). The student's t-test was the most applied test (35.13%). Inappropriate use/misuse of statistics in all types was highest in diagnosis/diagnostics (73.59%) and pharmacology and toxicology (73.06%) research disciplines/categories and was lowest in medicine/pathophysiology (0.26%). Inappropriate use/misuse in almost all types (seven types) was found in the diagnosis/diagnostics category.
Conclusion: Results of the systematic analysis of CCA-related research articles published from the ten SEA countries during 2010-2015 reveal high rates of inappropriate use/misuse of statistics. The readers should be aware of the reliability of the articles and the possibility of wrong interpretation and conclusion of these articles.
Keywords: Statistical misuse; Systematic review; cholangiocarcinoma; statistics.