Clinical Trials

Clinical Trials: A Practical Guide ■❚❙❘Table 3. Insonated venous segments [5].Superficial venous systemSaphenofemoral junctionLong saphenous vein (above knee)Long saphenous vein (below knee)Saphenopopliteal junctionShort saphenous veinCalf-perforating veinsDeep venous systemCommon or superficial femoral veinPopliteal vein (above knee)Popliteal vein (below knee)Reproduced with permission from Elsevier (Lancet 2004;363:1854–9).‘Venous reflux’ was identified as either:• superficial (arising in any superficial segment)• mixed superficial and segmental deep (one or two of the threeinsonated deep segments)• mixed superficial and total deep (all three deep segments)This defines the main subgroups that will be used in the analysis of this trial.However, this might not be considered a good use of a table in a journalmanuscript where the number of tables is restricted; in this situation, tables shouldbe used for detailed results of the study.Reasons to include a figure in addition to, or instead of, a tableIf there is one main outcome measurement for all patients included in the trialthen it might be more helpful to show the results for this outcome in detailthrough a figure, rather than a table. For instance, the authors might include a dotplot or survival curve, according to the nature of the data collected. The IMAGES(Intravenous Magnesium Efficacy in Stroke) study (from which Table 1 andFigure 1 were extracted) reported the main outcome measure on all trial patientsby including the following sentence: “When analyzed as time to event, the hazardratio for death during the study was 1.18 (95% CI 0.97, 1.42, P = 0.098)”; theypresented the corresponding survival curve shown in Figure 2 [3].Inclusion of this figure gives appropriate emphasis on the main outcome for allpatients, as well as allowing extra detail to be observed (such as cumulativeproportions of death at any time point and any changes in pattern by lengthof follow-up).397