Screening, Rescreening and Baseline

Part of Sub-Investigator (SUBI) Training: Eligibility and the Protocol.

About 2 minutes. Free, in your language, no account needed.

Screening is where most eligibility errors are made

Multiple results, several clinicians, a window running, and a participant who wants to start.

Slowing down here is the cheapest quality control in the study.

Every criterion needs a dated source

Not a recollection, not a summary letter without a date. A source value with a date you can point to.

Where the source is elsewhere, obtain the record rather than accepting a report of it.

Screen failures are recorded, not deleted

A participant who consents and does not enroll is a screen failure with a documented reason. That number is part of the trial's account of itself.

Their data does not simply disappear because they did not enroll.

Rescreening follows the protocol's rule

Some protocols permit it, some limit the number of attempts, and some require a new consent and a new participant number.

A participant rescreened without following that rule can end up with two identities in the dataset, which is difficult to unpick later.

Baseline is a measurement, not a formality

Baseline assessments are the comparator for everything that follows. A baseline done carelessly weakens every subsequent timepoint for that participant.

Symptoms present at baseline also determine what counts as an adverse event later.

Record pre-existing conditions properly

A condition present before the first dose is medical history. The same condition worsening afterward is an adverse event.

If baseline is vague, that distinction cannot be made, and it is one of the most common sources of unusable safety data.

Do not start before eligibility is confirmed

A first dose given while a result is outstanding is an enrollment outside criteria if the result does not qualify. The pressure to start is real and the rule is not negotiable.