Converting from face-to-face to postal follow-up and its effects on participant retention, response rates and errors: lessons from the EQUAL study in the UK

Table 3 Categories of errors made in the EFU questionnaire

Category of Error	Number of errors	Percentage of all errors made (%)
Blank	144	44.7
Duplication: “no” along with a quantifier	74	23.0
Skipped whole page	65	20.2
Corrected error	23	7.1
Duplication: Ticked “no” and “yes”	4	1.2
Duplication: ticked 2+ quantifiers	4	1.2
Uncorrected error	4	1.2
Responded “N/A” regarding sexual health	4	1.2
Total	322	100

Labels regarding “Duplication” are related to the Dialysis Symptom Index, whereby some patients ticked “no” for whether they have a particular symptom but also ticked how much the symptom bothers them (“quantifier”), or answered both “no” and “yes” for whether they experience the symptom, or answered ≥ 2 quantifiers for how much the symptom bothers them

ISSN: 1471-2288