Clinical Trials

Clinical Trials: A Practical Guide ■❚❙❘Table 1 contd. Checklist of items to include when reporting a randomized trial.PAPER SECTION and topic Item DescriptionAdverse events 19 All important adverse events or side-effects in each intervention group.DISCUSSIONInterpretation 20 Interpretation of the results, taking into account study hypotheses,sources of potential bias or imprecision, and the dangers associatedwith multiplicity of analyses and outcomes.Generalizability 21 Generalizability (external validity) of the trial findings.Overall evidence 22 General interpretation of the results in the context of current evidence.Reproduced from the CONSORT Statement (www.consort-statement.org).Allocated treatmentIn order to avoid bias and preserve the purpose of randomization, analyses shouldbe carried out by allocated treatment and not by received treatment (item 16).In pharmaceutical trials, statistical methods are usually predefined in protocolsbefore the onset of the trial. This ensures that analyses are chosen prior toobtaining data, and not on the basis of significant post-hoc findings after receivingthe data (item 12 and 18).Coherence and clarityResults should correspond to the methods section. Comparison of the flow chartand the methods section will inform the reader of the success of the study designwith respect to enrollment, allocation, and completion. Baseline data are informativewith respect to the success of randomization (item 15), and a table showing adversereactions might explain reasons for dropout (item 19). Results of analyses shouldbe displayed clearly, as outlined in the methods section (items 16–18).If a trial report follows the guidelines outlined in the CONSORT statement thena critical reader should arrive at an interpretation of results similar to that of theauthors (item 20). External validity is more difficult to judge for a reader who is notfamiliar with clinical implications and recent research in the field; however, evenan informed reader will need information on eligibility criteria and interventions(items 3 and 4), the features of randomized patients (item 13 and 15), and timingof recruitment and follow-up (item 14) to judge the applicability of the results topractice. Authors themselves should discuss generalizability and interpret theresults in light of the overall evidence (items 21 and 22).371