title: Methods in pharmacoepidemiology: a review of statistical analyses and data reporting in pediatric drug utilization studies.
abstract: OBJECTIVE
  To evaluate the quality of data reporting and statistical methods performed in drug utilization studies in the pediatric population.
  
  
  METHODS
  Drug utilization studies evaluating all drug prescriptions to children and adolescents published between January 1994 and December 2011 were retrieved and analyzed. For each study, information on measures of exposure/consumption, the covariates considered, descriptive and inferential analyses, statistical tests, and methods of data reporting was extracted. An overall quality score was created for each study using a 12-item checklist that took into account the presence of outcome measures, covariates of measures, descriptive measures, statistical tests, and graphical representation.
  
  
  RESULTS
  A total of 22 studies were reviewed and analyzed. Of these, 20 studies reported at least one descriptive measure. The mean was the most commonly used measure (18 studies), but only five of these also reported the standard deviation. Statistical analyses were performed in 12 studies, with the chi-square test being the most commonly performed test. Graphs were presented in 14 papers. Sixteen papers reported the number of drug prescriptions and/or packages, and ten reported the prevalence of the drug prescription. The mean quality score was 8 (median 9). Only seven of the 22 studies received a score of ≥10, while four studies received a score of <6.
  
  
  CONCLUSIONS
  Our findings document that only a few of the studies reviewed applied statistical methods and reported data in a satisfactory manner. We therefore conclude that the methodology of drug utilization studies needs to be improved.
authors: Laboratory for Mother and Child Health, Department of Public Health, Mario Negri Institute for Pharmacological Research, via G. La Masa 19, 20156 Milan, Italy. marco.sequi@marionegri.it
authors: Marco
authors: M
authors: Sequi
authors: Rita
authors: R
authors: Campi
authors: Antonio
authors: A
authors: Clavenna
authors: Maurizio
authors: M
authors: Bonati
mesh_terms: D000293:Adolescent; D000367:Age Factors; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D003627:Data Interpretation, Statistical; D011307:Drug Prescriptions / Q000706:statistics & numerical data; D004363:Drug Utilization; D017723:Drug Utilization Review / Q000379:methods / Q000592:standards / Q000706:statistics & numerical data*; D017408:Guidelines as Topic; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D015233:Models, Statistical; D017891:Pharmacoepidemiology / Q000379:methods / Q000592:standards / Q000706:statistics & numerical data*; D012107:Research Design / Q000592:standards / Q000706:statistics & numerical data*; D055815:Young Adult