From: A randomized trial of mailed questionnaires versus telephone interviews: Response patterns in a survey
Theme
Number of questions
Range of missing* (%)
Telephone
Mail
Medicine
3
0
1.58 – 3.63
Smoking habits
1
0.73
Self-esteem
9
0 – 0.51
1.85 – 6.00
Well-being
11
0 – 0.13
0.92 – 6.00
Depression
7
2.04 – 4.88
Stress
15
2.04 – 4.75