title: Factors associated with non-response in routine use of patient reported outcome measures after elective surgery in England.
abstract: BACKGROUND
  Patient-reported outcome measures are increasingly being used to compare providers. We studied whether non-response rates to post-operative questionnaires are associated with patients' characteristics and organisational features of providers.
  
  
  METHODS
  131,447 patients who underwent a hip or knee replacement, hernia repair or varicose vein surgery in 2009-10 in England. Multivariable logistic regression to calculate adjusted odds ratios of non-response for characteristics of the patients and organisational characteristics of providers. Multiple imputation was used for missing patient characteristics. Providers were included as random effects.
  
  
  RESULTS
  Response rates to the post-operative questionnaire were 85.1% for hip replacement (n = 37 961), 85.3% for knee replacements (n = 44 422), 72.9% for hernia repair (n = 34 964), and 64.8% for varicose vein surgery (n = 14 100). Across the four procedures, there were higher levels of non-response in men (odds ratios 1.03 [95% CI 0.95-1.11] - 1.35 [1.25-1.46]), younger patients (those under 55 years 3.01 [2.72-3.32] - 6.05 [5.49-6.67]), non-white patients (1.24 [1.11-1.38] - 2.08 [1.89-2.31]), patients in the most deprived quintile of socio-economic status (1.47 [1.34-1,62] - 1.86 [1.71-2.03]), those who lived alone (1.11 [0.99-1.23] - 1.27 [1.18-1.36]) and those who had been assisted when completing their pre-operative questionnaire (1.26 [1.10-1.46] -1.67 [1.56-1.79]). Non-response rates were also higher in patients who had poorer pre-operative health (three or more comorbidities: 1.14 [0.96-1.35] - 1.45 [1.30-1.63]). Providers' patient recruitment rates before surgery and the timing of pre-operative questionnaire administration did not affect the rates of response to post-operative questionnaires.
  
  
  CONCLUSIONS
  If non-response can be shown to be associated with outcome, then rates of non-response to post-operative questionnaires would need to be taken into account when these measures are being used to compare the performance of providers or to evaluate surgical procedures.
authors.affiliation: Department of Health Services Research & Policy, London School of Hygiene & Tropical Medicine, UK. Andrew.hutchings@lshtm.ac.uk
authors.forename: Andrew
authors.initials: A
authors.lastname: Hutchings
authors.forename: Jenny
authors.initials: J
authors.lastname: Neuburger
authors.forename: Kirstin
authors.initials: K
authors.lastname: Grosse Frie
authors.forename: Nick
authors.initials: N
authors.lastname: Black
authors.forename: Jan
authors.initials: J
authors.lastname: van der Meulen
mesh_terms: D000368:Aged; D019644:Arthroplasty, Replacement, Hip; D019645:Arthroplasty, Replacement, Knee; D015897:Comorbidity; D017558:Elective Surgical Procedures / Q000592:standards*; D004739:England; D005260:Female; D059685:Herniorrhaphy / Q000592:standards; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D010817:Physician-Patient Relations; D011182:Postoperative Care / Q000523:psychology; D011300:Preoperative Care / Q000523:psychology; D011788:Quality of Life / Q000523:psychology; D017678:Sex Distribution; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D014648:Varicose Veins / Q000601:surgery