title: An appraisal of convergence failures in the application of logistic regression model in published manuscripts.
abstract: BACKGROUND
  Logistic regression model is widely used in health research for description and predictive purposes. Unfortunately, most researchers are sometimes not aware that the underlying principles of the techniques have failed when the algorithm for maximum likelihood does not converge. Young researchers particularly postgraduate students may not know why separation problem whether quasi or complete occurs, how to identify it and how to fix it.
  
  
  OBJECTIVE
  This study was designed to critically evaluate convergence issues in articles that employed logistic regression analysis published in an African Journal of Medicine and medical sciences between 2004 and 2013.
  
  
  METHODS
  Problems of quasi or complete separation were described and were illustrated with the National Demographic and Health Survey dataset. A critical evaluation of articles that employed logistic regression was conducted.
  
  
  RESULTS
  A total of 581 articles was reviewed, of which 40 (6.9%) used binary logistic regression. Twenty-four (60.0%) stated the use of logistic regression model in the methodology while none of the articles assessed model fit. Only 3 (12.5%) properly described the procedures. Of the 40 that used the logistic regression model, the problem of convergence occurred in 6 (15.0%) of the articles.
  
  
  CONCLUSIONS
  Logistic regression tends to be poorly reported in studies published between 2004 and 2013. Our findings showed that the procedure may not be well understood by researchers since very few described the process in their reports and may be totally unaware of the problem of convergence or how to deal with it.
authors.forename: O B
authors.initials: OB
authors.lastname: Yusuf
authors.forename: E A
authors.initials: EA
authors.lastname: Bamgboye
authors.forename: R F
authors.initials: RF
authors.lastname: Afolabi
authors.forename: M A
authors.initials: MA
authors.lastname: Shodimu
mesh_terms: D000349:Africa; D066264:Datasets as Topic; D006306:Health Surveys / Q000706:statistics & numerical data; D006801:Humans; D016013:Likelihood Functions; D016015:Logistic Models; D011643:Publishing / Q000592:standards; D012106:Research / Q000706:statistics & numerical data*