Table 3

Methodologic Assessment of Studies Concerning Therapy for Deep Venous Thrombosis (DVT) (12)

QuestionConsiderations
Was the assignment of patients to treatment randomized?Are there any studies with randomization?
Were all patients who entered the trial properly accounted for and attributed at the conclusion?Was follow-up complete? Were patients analyzed in the groups to which they were randomized?
Were patients, their clinicians and study personnel blind to treatment?
Were the groups similar at the start of the trial?If the studies were not randomized, is there evidence that the study groups were similar enough with respect to outcome variables that any differences might confidently be attributable to treatment effects alone?
Aside from the experimental intervention, were the groups treated equally?Did all patients receive the same diagnostic scrutiny for the development of DVT and pulmonary embolism? Were there any other interventions that might affect outcome that differed among the study groups?
How large was the treatment effect?Was the treatment effect both clinically and statistically relevant? Did the use of heparin reduce the outcome of interest enough to justify clinical interest?
How precise was the estimate of treatment effect?Were confidence intervals sufficiently narrow to support confidence in any positive findings of the study?
Can the results be applied to the care of my patient?Were the patients being treated for DVT prophylaxis similar to those of the patient being studied? Were the injuries and treatment settings sufficiently similar that the results might be generalized to the patient in question?
Were all clinically important outcomes considered?Did the studies address complications of intervention as well as reduction in adverse outcomes such as DVT, pulmonary embolism and death?