title: Late response to patient-reported outcome questionnaires after surgery was associated with worse outcome.
abstract: OBJECTIVE
  Nonresponse to patient-reported outcome (PRO) questionnaires after surgery might bias the results. Our aim was to gauge the potential impact of nonresponse bias by comparing the outcomes of early and late responders.
  
  
  METHODS
  This study compares 59,565 early and 20,735 late responders who underwent a hip or knee replacement, hernia repair, or varicose vein (VV) surgery. The association between timeliness of response and three outcomes (the mean postoperative disease-specific PRO and generic PRO scores and the proportion reporting a fair or poor result) was examined by regression analysis.
  
  
  RESULTS
  Late responders were slightly more likely to be young, nonwhite, deprived, and have a more severe preoperative condition with poorer quality of life. Late response was associated with a slightly poorer outcome in all four procedures although not statistically significant (P < 0.05) for VV surgery. Adjusting for preoperative characteristics reduced the strength of the associations, but they remained statistically significant.
  
  
  CONCLUSIONS
  As nonresponse to PRO questionnaires introduces slight bias, differences in response rates between hospitals should be taken into account when making comparisons so as to avoid overestimating the performance of those with lower response rates and failing to detect poor performing hospitals.
authors.affiliation: Department of Health Services Research & Policy, London School of Hygiene & Tropical Medicine, 15-17 Tavistock Place, London WC1H 9SH, United Kingdom.
authors.forename: Andrew
authors.initials: A
authors.lastname: Hutchings
authors.forename: Kirstin
authors.initials: K
authors.lastname: Grosse Frie
authors.forename: Jenny
authors.initials: J
authors.lastname: Neuburger
authors.forename: Jan
authors.initials: J
authors.lastname: van der Meulen
authors.forename: Nick
authors.initials: N
authors.lastname: Black
mesh_terms: D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000379:methods; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects / Q000379:methods; D015982:Bias; D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D017558:Elective Surgical Procedures / Q000009:adverse effects / Q000379:methods*; D005260:Female; D059685:Herniorrhaphy / Q000009:adverse effects / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010349:Patient Compliance / Q000706:statistics & numerical data*; D011183:Postoperative Complications / Q000453:epidemiology*; D011788:Quality of Life; D012647:Self-Assessment; D011795:Surveys and Questionnaires; D013997:Time Factors; D016896:Treatment Outcome; D014648:Varicose Veins / Q000601:surgery