After the subjects are recruited into the trial, strategies
aimed to conduct an adequate follow-up must be considered. This is a
critical point, especially in long-term studies, or in trials where the
outcome(s) of interest take some time to develop after recruitment.
Primary and secondary endpoints must be systematically recorded, as
well as any adverse event. Follow-up also includes a monitoring of
compliance, protocol deviations, contamination, and co-interventions if
appropriate, according to the trial design and objectives, as well as a
documentation of losses and dropouts. This information in a randomized
controlled trial is important, as the interpretation of the trial
results must consider treatment acceptability and the level of
non-adherence to therapy. Furthermore, in pragmatic trials the level of
compliance must be seen as one aspect of the assessment of treatment,
as it reflects behavior in clinical practice outside the trial setting.
Whatever the purpose of the trial, data collection is only possible if
the staff remain actively involved throughout the duration of the trial
and if the subjects are willing to maintain their participation in the
study.
In order to ensure continuing commitment to a trial investigators must
develop retention strategies such as newsletters, posters and
merchandise. These will often have resource implications and
should be budgeted for.
Many recommendations exist for managing follow-up. However,
many have not been formally evaluated. Researchers should
balance the potential benefits of each component of the plan with the
main objectives of the trial on one hand, with the resources and
logistics required for its execution, on the other.
Illustrative example - Scottish Bell's Palsy Study (video) |
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In a double-blind,
placebo-controlled, randomized, factorial trial
involving patients with Bell's palsy who were recruited
within 72 hours after the onset of symptoms. Patients were
randomly assigned to receive 10 days of treatment with prednisolone,
acyclovir, both agents, or placebo. Follow up was at 3 and 9 months.
Keeping patient's interested in the study was of prime
importance. Of 551 patient's who were randomised, 496 were assessed at
both time points. Dr Fergus Daly, University of Dundee, UK, and
the study coordinator,
describes
how patient interest was maintained (MP4, 21 seconds). Can't see
video controller? Play
it in your media player. |