title: Research design and statistical methods in Pakistan Journal of Medical Sciences (PJMS).
abstract: OBJECTIVE
  This article compares the study design and statistical methods used in 2005, 2010 and 2015 of Pakistan Journal of Medical Sciences (PJMS).
  
  
  METHODS
  Only original articles of PJMS were considered for the analysis. The articles were carefully reviewed for statistical methods and designs, and then recorded accordingly. The frequency of each statistical method and research design was estimated and compared with previous years.
  
  
  RESULTS
  A total of 429 articles were evaluated (n=74 in 2005, n=179 in 2010, n=176 in 2015) in which 171 (40%) were cross-sectional and 116 (27%) were prospective study designs. A verity of statistical methods were found in the analysis. The most frequent methods include: descriptive statistics (n=315, 73.4%), chi-square/Fisher's exact tests (n=205, 47.8%) and student t-test (n=186, 43.4%). There was a significant increase in the use of statistical methods over time period: t-test, chi-square/Fisher's exact test, logistic regression, epidemiological statistics, and non-parametric tests.
  
  
  CONCLUSIONS
  This study shows that a diverse variety of statistical methods have been used in the research articles of PJMS and frequency improved from 2005 to 2015. However, descriptive statistics was the most frequent method of statistical analysis in the published articles while cross-sectional study design was common study design.
authors.affiliation: Dr. Sohail Akhtar, PhD (UK), Department of Statistics, University of Malakand, Lower Dir, KPK, Pakistan.
authors.forename: Sohail
authors.initials: S
authors.lastname: Akhtar
authors.affiliation: Syed Wadood Ali Shah (PhD Candidate), Department of Pharmacy, University of Malakand, Lower Dir, KPK, Pakistan.
authors.forename: Syed Wadood Ali
authors.initials: SW
authors.lastname: Shah
authors.affiliation: M. Rafiq (M.Phil), Department of Statistics, University of Malakand, Lower Dir, KPK, Pakistan.
authors.forename: M
authors.initials: M
authors.lastname: Rafiq
authors.affiliation: Ajmal Khan, Department of Zoology, University of Malakand, Lower Dir, KPK, Pakistan.
authors.forename: Ajmal
authors.initials: A
authors.lastname: Khan
keywords: Bibliometric analysis; Biostatistics; Statistical analysis; Statistical methods; Study design