Question

Patients who remain immobilized for a substantial amount of time can develop deep vein thrombosis (DVT), a blood clot in a leg or pelvis vein. DVT can have serious adverse health effects and can be difficult to diagnose. In a double-blind, multinational study, severely immobilized patients were randomly assigned to receive daily subcutaneous injections of either the drug Fragmin or a placebo for 12 to 14 days and were monitored for 90 days. The results, in number of patients experiencing a complication from DVT (including death!). What kind of study design is this (retrospective, prospective, introspective, extraspective, etc.)

Answer 1