Triggered or routine site monitoring visits for randomised controlled trials: results of TEMPER, a prospective, matched-pair study

Background/Aims
In multi-site clinical trials, where trial data and conduct are scrutinised centrally with pre-specified triggers for visits to sites, targeted monitoring may be an efficient way to prioritise on-site monitoring. This approach is widely used in academic trials, but has never been formally evaluated.

Methods
TEMPER assessed the ability of targeted monitoring, as used in three ongoing phase III randomised multi-site oncology trials, to distinguish sites at which higher and lower rates of protocol and/or Good Clinical Practice violations would be found during site visits.  Using a prospective, matched pair design, sites that had been prioritised for visits after having activated “triggers” were matched with a control (“untriggered”) site, which would not usually have been visited at that time.  The paired sites were visited within four weeks of each other, and visit findings recorded and categorised according to the seriousness of the deviation. The primary outcome measure was the proportion of sites with ≥1 “Major” or “Critical” finding not previously identified centrally. The study was powered to detect an absolute difference of ≥30% between triggered and untriggered visits. A sensitivity analysis, recommended by the study’s blinded endpoint review committee, excluded findings related to re-consent. Additional analyses assessed the prognostic value of individual triggers and data from pre-visit questionnaires completed by site and trials unit staff. 

Results
42 matched pairs of visits took place between 2013 and 2016. In the primary analysis, 88.1% of triggered visits had ≥ 1 new Major/Critical finding, compared to 81.0% of untriggered visits, an absolute difference of 7.1% (95% CI -8.3%, +22.5%; p=0.365). When re-consent findings were excluded, these figures reduced to 85.7% vs 59.5%, (difference = 26.2%, 95% CI 8.0%, 44.4%; p=0.007).  Individual triggers had modest prognostic value but knowledge of site staff trial-related activities may be useful.  

Conclusions
Triggered monitoring approaches, as used in these trials, were not sufficiently discriminatory. The rate of Major and Critical findings was higher than anticipated, but the majority related to consent and re-consent with no indication of systemic problems that would impact trial-wide safety issues or integrity of the results in any of the three trials. Sensitivity analyses suggest triggered monitoring may be of potential use, but needs improvement and investigation of further central monitoring triggers is warranted.  TEMPER highlights the need to question and evaluate methods in trial conduct, and should inform further developments in this area.