Hodge et al, 1985, USA1 | 92 children attending an emergency department with a history of coin ingestion. 25 oesophageal coins | Retrospective survey | Proportion of oesophageal coins that were asymptomatic | 11 of 25 (44%) asymptomatic | |
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Caravati et al, 1989, USA2 | 66 children attending for chest x ray with a history of coin ingestion. 11 oesophageal coins | Prospective survey | Proportion of oesophageal coins that were asymptomatic | 2 of 11 (18%) asymptomatic | |
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Schunk et al, 1989, USA3 | 52 children attending an emergency department with a history of coin ingestion. 30 oesophageal coins | Prospective survey | Proportion of oesophageal coins that were asymptomatic | 9 of 30 (32%) asymptomatic | |
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Suita et al, 1989, Japan4 | 141 children attending an emergency department with a history of ingested foreign body. 11 oesophageal coins | Retrospective survey | Proportion of oesophageal coins that were asymptomatic | 7 of 11 (64%) asymptomatic | |
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Stringer et al, 1991, UK5 | 50 children with a history of coin ingestion. 15 oesophageal coins | Retrospective survey | Proportion of oesophageal coins that were asymptomatic | 9 of 15 (60%) asymptomatic | |
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Conners et al, 1995, USA6 | 73 children with oesophageal coins | Retrospective survey | Proportion of oesophageal coins that were asymptomatic | 5 of 73 (7%) asymptomatic | |
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Macpherson et al, 1996, USA7 | 118 children with 123 episodes of retained oesophageal foreign bodies. 85 oesophageal coins | Retrospective survey | Proportion of oesophageal foreign bodies that were asymptomatic | 20% asymptomatic | Not only coins studied and results for coins alone not clear |