Effect on response rates of stamps vs a pre-printed business reply envelope in a mailed follow-up survey among middle-aged Danish men.
Osler
Merete
M
Juhl
Mette
M
Lund
Rikke
R
Andersen
Anne-Marie Nybo
AM
Kriegbaum
Margit
M
Christensen
Ulla
U
D003299:Cooperative Behavior; D003718:Denmark; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D011177:Postal Service; D011795:Surveys and Questionnaires