Design Weaknesses and Challenges
The primary weakness of the CAMS design, and other
clinical trials similar to CAMS (e.g., MTA, TADS, and
POTS), is that the CBT and COMB participants were
not blinded. The only double-blinded treatment conditions
were SRT and PBO. CBT participants knew they
were receiving CBT and COMB participants knew they
were receiving both CBT and SRT. This leaves results
from the CAMS trial open to the criticism that participant
and family expectancy effects may potentially bias
outcomes. However, as argued in other similar comparative
treatment trials,[48] the decision not to blind certain
treatment conditions are design choices rather than
necessarily design flaws. In the case of CAMS, the
design chosen represented the best balance between
scientific rigor, potential for public health impact, ecological
validity, feasibility of implementation, and cost.
Moreover, CAMS investigators recognized this limitation
in the design chosen and took deliberate steps to
minimize threats to the internal validity of the trial by
using IEs who were blind to participant’s treatment
assignment to measure outcomes.
The CAMS study experienced challenges, as well as
successes, when it came to monitoring adverse events.
The CAMS Data Safety Monitoring Board (DSMB) initially
approved an adverse event monitoring policy based
on procedures that were used in the TADS study [40].