title: Factors affecting response rates to mailed preoperative surveys among arthroplasty patients.
abstract: OBJECTIVE
  To identify factors that affect patient response rates to preoperative functional surveys in hip and knee arthroplasty patients.
  
  
  METHODS
  From May 2008 to March 2009, 247 patients were scheduled more than 4 wk in advance for hip or knee arthroplasty by one of two participating surgeons at our center. A personalized questionnaire comprised of the Short Form 12 (SF-12) and Western Ontario and McMaster Universities (WOMAC) Index was mailed to patients at random time points ranging from 7 to 101 d prior to surgery. Nine independent factors were documented prospectively, including age, gender, ethnicity, marital status, type of surgery, surgeon, days prior to surgery (DPS) of survey mailing, WOMAC score and SF-12 score. The date of the completed survey receipt was also documented. For non-responders, the surveys were completed with the research team at the hospital upon admission. Multivariate regression and χ(2) analysis were performed with Statistical Analysis Software software.
  
  
  RESULTS
  DPS was the only factor that affected patient response. Mailing surveys 26 d to 31 d prior to surgery dates led to a peak response rate of 80% that was significantly higher (P < 0.023) than response rates for patients who were mailed their surveys ≤ 16 d (62.5%), 17 d to 25 d (70%) or ≥ 32 d prior to surgery (55%). No other factors, including preoperative WOMAC and SF-12 scores, significantly influenced response behavior.
  
  
  CONCLUSIONS
  The DPS was independently the most significant predictor of response rates for pre-operative functional data among patients scheduled for hip and knee arthroplasty.
authors.affiliation: Wenbao Wang, Jeffrey A Geller, Abraham Kim, Todd A Morrison, Jung Keun Choi, William Macaulay, Center for Hip and Knee Replacement, Department of Orthopaedic Surgery, New York-Presbyterian Hospital at Columbia, New York, NY 10032, United States.
authors.forename: Wenbao
authors.initials: W
authors.lastname: Wang
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Geller
authors.forename: Abraham
authors.initials: A
authors.lastname: Kim
authors.forename: Todd A
authors.initials: TA
authors.lastname: Morrison
authors.forename: Jung Keun
authors.initials: JK
authors.lastname: Choi
authors.forename: William
authors.initials: W
authors.lastname: Macaulay