BackgroundAccording to Good Clinical Practice, clinical trials must protect rights and
safety of patients and make sure that the trial results are valid and
interpretable. Monitoring on-site has an important role in achieving these
objectives; it controls trial conduct at trial sites and informs the sponsor
on systematic problems. In the past, extensive on-site monitoring with a
particular focus on formal source data verification often lost sight of
systematic problems in study procedures that endanger Good Clinical Practice
objectives. ADAMON is a prospective, stratified, cluster-randomised,
controlled study comparing extensive on-site monitoring with risk-adapted
monitoring according to a previously published approach.MethodsIn all, 213 sites from 11 academic trials were cluster-randomised between
extensive on-site monitoring (104) and risk-adapted monitoring (109).
Independent post-trial audits using structured manuals were performed to
determine the frequency of major Good Clinical Practice findings at the
patient level. The primary outcome measure is the proportion of audited
patients with at least one major audit finding. Analysis relies on logistic
regression incorporating trial and monitoring arm as fixed effects and site
as random effect. The hypothesis was that risk-adapted monitoring is
non-inferior to extensive on-site monitoring with a non-inferiority margin
of 0.60 (logit scale).ResultsAverage number of monitoring visits and time spent on-site was 2.1 and 2.7
times higher in extensive on-site monitoring than in risk-adapted
monitoring, respectively. A total of 156 (extensive on-site monitoring: 76;
risk-adapted monitoring: 80) sites were audited. In 996 of 1618 audited
patients, a total of 2456 major audit findings were documented. Depending on
the trial, findings were identified in 18%–99% of the audited patients, with
no marked monitoring effect in any of the trials. The estimated monitoring
effect is −0.04 on the logit scale with two-sided 95% confidence interval
(−0.40; 0.33), demonstrating that risk-adapted monitoring is non-inferior to
extensive on-site monitoring. At most, extensive on-site monitoring could
reduce the frequency of major Good Clinical Practice findings by 8.2%
compared with risk-adapted monitoring.ConclusionCompared with risk-adapted monitoring, the potential benefit of extensive
on-site monitoring is small relative to overall finding rates, although
risk-adapted monitoring requires less than 50% of extensive on-site
monitoring resources. Clusters of findings within trials suggest that
complicated, overly specific or not properly justified protocol requirements
contributed to the overall frequency of findings. Risk-adapted monitoring in
only a sample of patients appears sufficient to identify systematic problems
in the conduct of clinical trials. Risk-adapted monitoring has a part to
play in quality control. However, no monitoring strategy can remedy defects
in quality of design. Monitoring should be embedded in a comprehensive
quality management approach covering the entire t...