Table 1

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study weaknesses
Bassett KE et al, 1999, USA¹	176 children attending an emergency department with a known or suspected metallic foreign body. Age range 6 months to 15 years.	Diagnostic	Experienced operators	Sensitivity 100%	Sample size limits power
				Specificity 92.4%
	Hand held metal detector in experienced and inexperienced hands. Radiographic gold standard		Inexperienced operators	Sensitivity 95.75%
				Specificity 81%
				3 false negatives
Seikel K et al, 1999, USA²	91 children with suspected coin ingestion. Age range 9 months to 17 years. Radiographic gold standard	Diagnostic	Inexperienced operators	Sensitivity 100%	Sample size limits power