title: Using health outcomes to validate access quality measures.
abstract: BACKGROUND
  Medicare payment reforms will reimburse accountable care organizations (ACOs) for providing high-quality healthcare. Quality measures that reliably predict health outcomes are required.
  
  
  OBJECTIVE
  To compare the ability of alternative wait time measures to predict glycated hemoglobin (A1C) levels among diabetes patients.
  
  
  METHODS
  This retrospective observational study relied on Veterans Health Administration utilization data and Medicare claims data from 2005 to 2010.
  
  
  METHODS
  Outcomes included an average A1C level and uncontrolled A1C. Heckman selection models simultaneously predicted the presence of an A1C value and its level. Models were risk adjusted for prior individual health status. The main explanatory variables of interest were facility-level primary care wait times measured in days. Several measures were tested, including capacity measures and retrospective and prospective time stamp measures. The time stamp measures used either the date the appointment was created in the scheduling system (create date) or the date the patient or provider desired the appointment (desired date) as the start date for wait time computation. All measures were calculated separately for new and returning patients.
  
  
  RESULTS
  New patient capacity and create date measures significantly predicted outcomes, but desired date measures did not. The returning patient retrospective create date and desired date wait time measures significantly predicted higher and uncontrolled A1C, but capacity and prospective create date measures did not.
  
  
  CONCLUSIONS
  Different administrative wait times predict A1C for new and returning patients. To properly measure quality, ACOs should use wait time measures that demonstrate relationships with outcomes for subpopulations of patients.
authors: Health Care Financing and Economics, VA Boston Health Care System, 150 South Huntington Ave, Mail Stop 152H, Boston, MA 02130. E-mails: jprentic@bu.edu.
authors: Julie C
authors: JC
authors: Prentice
authors: Sydney
authors: S
authors: Dy
authors: Michael L
authors: ML
authors: Davies
authors: Steven D
authors: SD
authors: Pizer
mesh_terms: D060866:Accountable Care Organizations; D000368:Aged; D001071:Appointments and Schedules; D003920:Diabetes Mellitus / Q000097:blood*; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D008297:Male; D006278:Medicare; D017063:Outcome Assessment, Health Care / Q000592:standards; D019984:Quality Indicators, Health Care; D011787:Quality of Health Care; D012189:Retrospective Studies; D013997:Time Factors; D014481:United States; D014493:United States Department of Veterans Affairs
chemical_list: D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human