Table 1
Author, date, and countryPatient groupStudy type (level of evidence)OutcomesKey resultsStudy weaknesses
Hodge et al, 1985, USA192 children attending an emergency department with a history of coin ingestion. 25 oesophageal coinsRetrospective surveyProportion of oesophageal coins that were asymptomatic11 of 25 (44%) asymptomatic
Caravati et al, 1989, USA266 children attending for chest x ray with a history of coin ingestion. 11 oesophageal coinsProspective surveyProportion of oesophageal coins that were asymptomatic2 of 11 (18%) asymptomatic
Schunk et al, 1989, USA352 children attending an emergency department with a history of coin ingestion. 30 oesophageal coinsProspective surveyProportion of oesophageal coins that were asymptomatic9 of 30 (32%) asymptomatic
Suita et al, 1989, Japan4141 children attending an emergency department with a history of ingested foreign body. 11 oesophageal coinsRetrospective surveyProportion of oesophageal coins that were asymptomatic7 of 11 (64%) asymptomatic
Stringer et al, 1991, UK550 children with a history of coin ingestion. 15 oesophageal coinsRetrospective surveyProportion of oesophageal coins that were asymptomatic9 of 15 (60%) asymptomatic
Conners et al, 1995, USA673 children with oesophageal coinsRetrospective surveyProportion of oesophageal coins that were asymptomatic5 of 73 (7%) asymptomatic
Macpherson et al, 1996, USA7118 children with 123 episodes of retained oesophageal foreign bodies. 85 oesophageal coinsRetrospective surveyProportion of oesophageal foreign bodies that were asymptomatic20% asymptomaticNot only coins studied and results for coins alone not clear