Travel and venous thrombosis: an exercise in thinking about bias.
Vandenbroucke
Jan P
JP
Cannegieter
Suzanne C
SC
Rosendaal
Frits R
FR
D006801:Humans; D012107:Research Design / Q000592:standards*; D018570:Risk Assessment; D015983:Selection Bias; D013997:Time Factors; D014195:Travel; D054556:Venous Thromboembolism / Q000209:etiology*