Table 1

 Population studies of the prevalence of gastro-oesophageal reflux disease (defined as at least weekly heartburn and/or acid regurgitation or diagnosed by a physician) included in the analysis

Reference (first author)CountryPopulationAge
>group (y)		Method of data
>collection		Sample
>size		Response
>rate (%)		Recall
>period		Prevalence
>of heartburn
>(%)		Prevalence
>of acid
>regurgitation
>(%)		Prevalence of heartburn and/or acid regurgitation (%)
*Calculated from raw data.
Locke (1997)4USAOlmsted County25–74Postal questionnaire2073731 year17.86.319.8
Locke (1999)5USAOlmsted County25–74Postal questionnaire2118721 year17.4*6.6*20
Talley (1992)6USAOlmsted County30–64Postal questionnaire1021821 year13.26.5
El-Serag (2004)7USAEmployees18–75Postal questionnaire915571 yearBlacks: 27,
>Whites: 23		Blacks: 16,
>Whites: 15		Blacks: 29,
>Whites: 28
Mohammed (2003)8UKTwin Registry19–81Postal questionnaire8960561 year––18
Thompson (1982)9UKEmployees and elderly residents17–91Physician interview315*95.61 year10.3–
Isolauri (1995)10FinlandNational population>20Postal questionnaire2500681 week1515–
Terry (2000)11SwedenNational population(Median 68)Face to face interview1123*
>controls in
>case control
>study		731 year––16.7
Valle (1999)12ItalyEmployees21–68Physician interview768911 year7.76.6–
Diaz-Rubio (2004)13SpainNational population40–79Telephone interview868671.21 year––9.8
Hu (2002)14ChinaNational population>18Telephone interview2640621 year––4.8
Wong (2003)15ChinaEthnic population>18Telephone interview360561.31 year––2.5
Pan (2000)16ChinaPopulation of 2 regions18–70Assisted self
>completed
>questionnaire		500099.81 year3.1–