Which of the following is a limitation of FAEMS reporting?

• A. Causation
• B. Verified
• C. Occurrence
• D. Duplicate; Incomplete

Answer: (D)

Spontaneous reporting systems rely on voluntary submissions, so data quality is a core limitation. Duplicate reports for the same event can inflate counts and mislead signal evaluation unless careful deduplication is done. Incomplete reports—missing essential details like exposure dose, timing, patient demographics, concomitant medications, and outcomes—hamper the ability to assess causality, seriousness, and the need for follow-up. These data-quality problems directly affect how reliably FAEMS data reflect true associations, making duplicates and incomplete information the most salient limitation. While causation cannot be inferred from spontaneous reports and other issues exist, the specific limitation highlighted here is the presence of duplicates and missing data.