title: Examining systemic steroid Use in older inflammatory bowel disease patients using hurdle models: a cohort study.
abstract: BACKGROUND
  Interpreting clinical guideline adherence and the appropriateness of medication regimens requires consideration of individual patient and caregiver factors. Factors leading to initiation of a medication may differ from those determining continued use. We believe this is the case for systemic steroid therapy in inflammatory bowel disease (IBD), resulting in a need to apply methods that separately consider factors associated with initiation and duration of therapy. To evaluate the relationship between patient characteristics and the frequency and duration of incident steroid use we apply a 2-part hurdle model to Medicare data. We do so in older patients with tumor necrosis factor antagonist (anti-TNFs) contraindications, as they are of special interest for compliance with Medicare-adopted, quality metrics calling for anti-TNFs and nonbiologic immune therapies to reduce steroid utilization. Many older patients have contraindications to anti-TNFs. However, nonbiologics cause adverse events that are concerning in older adults, limiting their use in this population and increasing reliance on systemic steroids.
  
  
  METHODS
  We used a national Medicare sample for 2006-2009 including patients with 12 months or greater of Parts A and B and 6 months or greater of Part D coverage, IBD confirmed with at least 2 claims for ICD-9CM 555.xx or 556.xx, anti-TNF contraindications and without contraindications to nonbiologic agents. We applied a negative binomial-logit hurdle model to examine patient characteristics associated with systemic steroid utilization.
  
  
  RESULTS
  Among the 1,216 IBD patients without baseline steroid use, 21% used systemic steroids. Odds of receiving systemic steroids were greater in those younger, rural, and those receiving other agents. Available patient characteristics failed to predict longer steroid treatment duration.
  
  
  CONCLUSIONS
  Our study identified differences in predictors of frequency and duration of medication use and suggests the utility of two-part models to examine drug utilization patterns. Applying such a model to Medicare data, we determined that despite medical consensus that systemic steroid use should be minimized, its use was substantial. Findings indicate anticipated difficulties in implementing recently adopted quality measures to avoid systemic steroids.
authors.affiliation: Pharmaceutical Health Services Research Department, University of Maryland School of Pharmacy, 220 Arch Street, 12th Floor, Room 01-218, Baltimore, MD, 21201, USA. sjohnson@rx.umaryland.edu.
authors.forename: Sophia L
authors.initials: SL
authors.lastname: Johnson
authors.affiliation: Department of Population Health Sciences, University of Wisconsin School of Medicine and Public Health, 610 Walnut Street, 53726 608-263-2520, Madison, Wisconsin, USA. mpalta@wisc.edu.|Department of Biostatistics & Medical Informatics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA. mpalta@wisc.edu.
authors.forename: Mari
authors.initials: M
authors.lastname: Palta
authors.affiliation: Department of Medicine, Rheumatology Division, University of Wisconsin School of Medicine and Public Health, 800 Highland Avenue, 608-263-3457, Madison, Wisconsin, USA. Cb4@medicine.wisc.edu.
authors.forename: Christie M
authors.initials: CM
authors.lastname: Bartels
authors.affiliation: Center for Health Equity Research and Promotion, Veterans Affairs Pittsburgh Medical Center, 3501 Terrace Street, 412-624-7794, Pittsburgh, Pennsylvania, USA. ctthorpe@pitt.edu.|Department of Pharmacy and Therapeutics, University of Pittsburgh School of Pharmacy, Pittsburgh, Pennsylvania, USA. ctthorpe@pitt.edu.
authors.forename: Carolyn T
authors.initials: CT
authors.lastname: Thorpe
authors.affiliation: Department of Medicine, Division of Gastroenterology and Hepatology, University of Wisconsin School of Medicine and Public Health, 1685 Highland Avenue, Room 4230, 608-263-1995, Madison, Wisconsin, USA. jmw@medicine.wisc.edu.
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Weiss
authors.affiliation: Department of Biostatistics & Medical Informatics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA. maureensmith@wisc.edu.|Department of Family Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA. maureensmith@wisc.edu.|Department of Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA. maureensmith@wisc.edu.
authors.forename: Maureen A
authors.initials: MA
authors.lastname: Smith
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D004358:Drug Therapy / Q000145:classification / Q000706:statistics & numerical data*; D005260:Female; D005843:Geography; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000188:drug therapy*; D008297:Male; D006278:Medicare / Q000706:statistics & numerical data*; D015999:Multivariate Analysis; D012044:Regression Analysis; D013256:Steroids / Q000627:therapeutic use*; D014481:United States
chemical_list: D013256:Steroids