title: Antibiotic Use in Cold and Flu Season and Prescribing Quality: A Retrospective Cohort Study.
abstract: BACKGROUND
  Excessive antibiotic use in cold and flu season is costly and contributes to antibiotic resistance. The study objective was to develop an index of excessive antibiotic use in cold and flu season and determine its correlation with other indicators of prescribing quality.
  
  
  RESULTS
  We included Medicare beneficiaries in the 40% random sample denominator file continuously enrolled in fee-for-service benefits for 2010 or 2011 (7,961,201 person-years) and extracted data on prescription fills for oral antibiotics that treat respiratory pathogens. We collapsed the data to the state level so they could be merged with monthly flu activity data from the Centers for Disease Control and Prevention. Linear regression, adjusted for state-specific mean antibiotic use and demographic characteristics, was used to estimate how antibiotic prescribing responded to state-specific flu activity. Flu-activity associated antibiotic use varied substantially across states-lowest in Vermont and Connecticut, highest in Mississippi and Florida. There was a robust positive correlation between flu-activity associated prescribing and use of medications that often cause adverse events in the elderly (0.755; P<0.001), whereas there was a strong negative correlation with beta-blocker use after a myocardial infarction (-0.413; P=0.003).
  
  
  CONCLUSIONS
  Adjusted flu-activity associated antibiotic use was positively correlated with prescribing high-risk medications to the elderly and negatively correlated with beta-blocker use after myocardial infarction. These findings suggest that excessive antibiotic use reflects low-quality prescribing. They imply that practice and policy solutions should go beyond narrow, antibiotic specific, approaches to encourage evidence-based prescribing for the elderly Medicare population.
authors.affiliation: *Center for Health Policy and the Center for Primary Care and Outcomes Research, Stanford University, Stanford, CA †National Bureau of Economic Research, Cambridge, MA ‡Dartmouth Institute for Health Policy and Clinical Practice, Lebanon, NH §Department of Community and Family Medicine, Geisel School of Medicine at Dartmouth, Hanover, NH ∥Vancouver School of Economics, University of British Columbia, Vancouver, BC, Canada ¶Department of Economics, Dartmouth College, Hanover, NH.
authors.forename: Marcella
authors.initials: M
authors.lastname: Alsan
authors.forename: Nancy E
authors.initials: NE
authors.lastname: Morden
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Gottlieb
authors.forename: Weiping
authors.initials: W
authors.lastname: Zhou
authors.forename: Jonathan
authors.initials: J
authors.lastname: Skinner
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D004363:Drug Utilization / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007251:Influenza, Human / Q000188:drug therapy*; D016014:Linear Models; D008297:Male; D006278:Medicare / Q000706:statistics & numerical data; D009203:Myocardial Infarction / Q000188:drug therapy; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D012621:Seasons; D012737:Sex Factors; D012959:Socioeconomic Factors; D014481:United States
chemical_list: D000319:Adrenergic beta-Antagonists; D000900:Anti-Bacterial Agents