Factors associated with non-response in routine use of patient reported outcome measures after elective surgery in England

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. CONCLUSION: 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.