An investigation into nonresponse bias in a postal survey on urinary symptoms

Abstract

Overall, for people aged >or= 40 years there was no evidence of a nonresponse bias in the reporting of urinary symptoms, providing confidence in such prevalence rates. However, poorer general health and greater reporting of some urinary symptoms by the older nonresponders (>or= 70 years) suggests prevalence rates in this age group may be underestimated.