title: Utilization of Preoperative Electrodiagnostic Studies for Carpal Tunnel Syndrome: An Analysis of National Practice Patterns.
abstract: OBJECTIVE
  Given the lack of a reference standard diagnostic tool for carpal tunnel syndrome (CTS), we conducted a population-level analysis of patients undergoing carpal tunnel release to characterize the utilization of preoperative electrodiagnostic studies (EDS). Secondarily, we sought to determine the impact of EDS utilization on timeliness of surgery, number of preoperative physician visits, and costs.
  
  
  METHODS
  The 2009-2013 Truven MarketScan databases were used to identify a national cohort of adult patients undergoing carpal tunnel release. Three multivariable regression models were designed to evaluate the relationship between preoperative EDS use and timing of surgical release, the number of preoperative physician visits, and total costs for CTS-related visits, while controlling for sociodemographic variables, insurance type, comorbid conditions, and treatment characteristics.
  
  
  RESULTS
  The final study cohort included 62,894 patients who underwent carpal tunnel release, of whom 58% had preoperative EDS. Patients undergoing EDS waited 36% longer for surgical release than patients without EDS. The mean time between diagnosis and surgery was predicted to be 183 days for patients who underwent preoperative EDS and 135 days for patients who did not. Patients having EDS experienced 1 additional visit, $996 greater total costs, and $112 additional out-of-pocket costs on average. Occupational therapy consultation and steroid injection were also associated with increased time to surgery, but with one-fourth and one-third the added cost of EDS, respectively.
  
  
  CONCLUSIONS
  On the basis of national practice trends, providers do not consistently agree with the practice of performing EDS before carpal tunnel release. Given the uncertain utility of routine EDS before carpal tunnel release and its association with delays to surgery and increased costs, further evaluation of EDS in relation to patient preferences and value of care is warranted.
  
  
  METHODS
  Prognostic II.
authors.affiliation: Department of Surgery, Section of Plastic Surgery, University of Michigan Health System, Ann Arbor, MI; VA Center for Clinical Management Research, VA Ann Arbor Healthcare System, Ann Arbor, MI. Electronic address: endavis@med.umich.edu.
authors.forename: Erika D
authors.initials: ED
authors.lastname: Sears
authors.affiliation: University of Michigan Medical School, Ann Arbor, MI.
authors.forename: Peter R
authors.initials: PR
authors.lastname: Swiatek
authors.affiliation: University of Michigan Health System, Ann Arbor, MI.
authors.forename: Hechuan
authors.initials: H
authors.lastname: Hou
authors.affiliation: Department of Surgery, Section of Plastic Surgery, Ann Arbor, MI; University of Michigan Medical School, Ann Arbor, MI.
authors.forename: Kevin C
authors.initials: KC
authors.lastname: Chung
mesh_terms: D000368:Aged; D002349:Carpal Tunnel Syndrome / Q000175:diagnosis* / Q000601:surgery*; D015331:Cohort Studies; D016208:Databases, Factual; D019299:Decompression, Surgical / Q000379:methods*; D004568:Electrodiagnosis / Q000706:statistics & numerical data*; D004576:Electromyography / Q000706:statistics & numerical data; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008475:Median Nerve / Q000503:physiopathology; D008875:Middle Aged; D010818:Practice Patterns, Physicians' / Q000592:standards / Q000639:trends*; D011300:Preoperative Care / Q000379:methods; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D016896:Treatment Outcome; D014481:United States
keywords: Carpal tunnel release; carpal tunnel syndrome; electrodiagnostic studies; practice guidelines; practice patterns