title: Factors Associated With Preventive Pharmacological Therapy Adherence Among Patients With Kidney Stones.
abstract: OBJECTIVE
  To determine adherence patterns for thiazide diuretics, alkali citrate therapy, and allopurinol, collectively referred to as preventive pharmacological therapy (PPT), among patients with kidney stones.
  
  
  METHODS
  Using medical claims data, we identified adults diagnosed with kidney stones between 2002 and 2006. Through National Drug Codes, we determined those with one or more prescription fills for a PPT agent. We measured adherence to PPT (as determined by the proportion of days covered formula) within the first 6 months of starting therapy and performed multivariate analysis to evaluate patient factors associated with PPT adherence.
  
  
  RESULTS
  Among 7980 adults with kidney stones who were prescribed PPT, less than one third (30.2%) were adherent to their regimen (indicated by proportion of days covered  ≥ 80%). Among those on monotherapy, rates of adherence differed by the type of PPT agent prescribed: 42.5% for thiazides, 40.0% for allopurinol, and 13.4% for citrate therapy. Factors that were independently associated with lower odds of PPT adherence included combination therapy receipt, female gender, less generous health insurance, and residence in the South or Northeast. In contrast, older patients and those with salaried employment had a higher probability of PPT adherence.
  
  
  CONCLUSIONS
  Adherence to PPT is low. These findings help providers identify patients where PPT adherence will be problematic. Moreover, they suggest possible targets for quality improvement efforts in the secondary prevention of kidney stones.
authors.affiliation: Divisions of Endourology and Health Services Research, Department of Urology, University of Michigan Medical School, Ann Arbor, MI.
authors.forename: Casey A
authors.initials: CA
authors.lastname: Dauw
authors.affiliation: Divisions of Endourology and Health Services Research, Department of Urology, University of Michigan Medical School, Ann Arbor, MI.
authors.forename: Yooni
authors.initials: Y
authors.lastname: Yi
authors.affiliation: Divisions of Endourology and Health Services Research, Department of Urology, University of Michigan Medical School, Ann Arbor, MI.
authors.forename: Maggie J
authors.initials: MJ
authors.lastname: Bierlein
authors.affiliation: Divisions of Endourology and Health Services Research, Department of Urology, University of Michigan Medical School, Ann Arbor, MI.
authors.forename: Phyllis
authors.initials: P
authors.lastname: Yan
authors.affiliation: Divisions of Endourology and Health Services Research, Department of Urology, University of Michigan Medical School, Ann Arbor, MI.
authors.forename: Abdulrahman F
authors.initials: AF
authors.lastname: Alruwaily
authors.affiliation: Divisions of Endourology and Health Services Research, Department of Urology, University of Michigan Medical School, Ann Arbor, MI.
authors.forename: Khurshid R
authors.initials: KR
authors.lastname: Ghani
authors.affiliation: Divisions of Endourology and Health Services Research, Department of Urology, University of Michigan Medical School, Ann Arbor, MI.
authors.forename: J Stuart
authors.initials: JS
authors.lastname: Wolf
authors.affiliation: Divisions of Endourology and Health Services Research, Department of Urology, University of Michigan Medical School, Ann Arbor, MI.
authors.forename: Brent K
authors.initials: BK
authors.lastname: Hollenbeck
authors.affiliation: Divisions of Endourology and Health Services Research, Department of Urology, University of Michigan Medical School, Ann Arbor, MI. Electronic address: kinks@med.umich.edu.
authors.forename: John M
authors.initials: JM
authors.lastname: Hollingsworth
mesh_terms: D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000188:drug therapy* / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D016903:Drug Monitoring