CLiREN-LMS
Data Cleaning and Preparation in R

Handling Missing Data in Cleaning Workflows

Table 1

30-45 minutes Applied Step 6 of 11
Table

Table 1

6 / 11
Table

Table 1

Missingness typeExampleData management interpretationPossible action
Not yet dueDay 28 outcome missing on day 10Expected missingnessDo not query yet; monitor due date
Not applicablePregnancy test for male participantStructurally missingConfirm skip logic and coding
PendingLaboratory culture not yet releasedTemporarily missingReconcile with laboratory log
UnknownParticipant cannot recall symptom onset dateKnown unknownCode according to CRF guidance
Accidental omissionConsent date blank despite completed consentData entry issueQuery site
Export problemVariable absent from exportStructural/export issueReview export settings