Letters6 September 2016Opioid Prescribing After Nonfatal Overdose and Association With Repeated OverdoseMarc R. Larochelle, MD, MPH, Jane M. Liebschutz, MD, MPH, Fang Zhang, PhD, Dennis Ross-Degnan, ScD, and J. Frank Wharam, MB, BCh, BAO, MPHMarc R. Larochelle, MD, MPHFrom Boston University School of Medicine and Boston Medical Center, and Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts.Search for more papers by this author, Jane M. Liebschutz, MD, MPHFrom Boston University School of Medicine and Boston Medical Center, and Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts.Search for more papers by this author, Fang Zhang, PhDFrom Boston University School of Medicine and Boston Medical Center, and Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts.Search for more papers by this author, Dennis Ross-Degnan, ScDFrom Boston University School of Medicine and Boston Medical Center, and Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts.Search for more papers by this author, and J. Frank Wharam, MB, BCh, BAO, MPHFrom Boston University School of Medicine and Boston Medical Center, and Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts.Search for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/L16-0168 SectionsAboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail IN RESPONSE:We chose to use the extended Kaplan–Meier approach to provide a descriptive summary, both graphical and numerical, of the association between the category of daily opioid dosage after an opioid overdose and risk for repeated overdose. Traditional Kaplan–Meier approaches require time-invariant covariates. Snapinn and colleagues (1) summarize well the flaws of past approaches that have chosen a single time point (that is, baseline, intermediate, or end) for time-varying covariates and compare those with their suggested extended Kaplan–Meier approach that we used. Opioid prescriptions are typically dispensed monthly and may be adjusted frequently; thus, dosages may vary greatly over ...