Table 1.

Summary of studies by primary care intervention (n = 34)

StudyYearCountryStudy typeSIGN quality rating
Telephone triage (n= 11)
Bunn et al22004VariousMeta-analysis/systematic review2++
Dunt et al132005AustraliaBefore–after/interrupted time series3
Graber et al142003New ZealandCross-sectional study3
Lattimer et al152005UKBefore–after /interrupted time series3
Munro et al162001UKNon-comparative (case series/study)3
Munro et al172005UKBefore–after /interrupted time series3
Shekelle and Roland 181999VariousNon-comparative (case series/study)3
Stacey et al192003VariousMeta-analysis/systematic review2++
Stewart et al202006UKCohort study2+
South Wiltshire Out of Hours Project211997UKNon-comparative (case series/study)3
Vedsted and Olesen221999DenmarkBefore–after /interrupted time series3
Walk in clinics (n= 2)
Chalder et al242003UKCross-sectional study3
Salisbury et al252007UKBefore–after /interrupted time series3
Community health centres (n= 2)
Choudhry et al292006USNon-comparative (case series/study)3
Rust et al302009USCross sectional study3
GP out of hours/GP cooperatives (n= 11)
Bury et al312006IrelandCross-sectional study3
Moll van Charante et al322007The NetherlandsCross-sectional study3
O’Keeffe et al332008IrelandBefore–after /interrupted time series3
O’Kelly et al342001IrelandBefore–after /interrupted time series3
Pickin et al362004UKBefore–after /interrupted time series3
Philips et al352010BelgiumNon-randomised controlled trial1–
Salisbury et al251997UKCross-sectional study3
Van Uden and Crebolder382004The NetherlandsBefore–after /interrupted time series3
van Uden et al392005The NetherlandsBefore–after /interrupted time series3
van Uden et al372006The NetherlandsCross-sectional study3
Vedsted and Christensen402001DenmarkBefore–after /interrupted time series3
Emergency nurse practitioner (n= 1)
Codde et al412010AustraliaBefore–after /interrupted time series3
Various (n= 7)
Arendts et al422010AustraliaNon-comparative (case series/study)3
Bickerton et al282011UKBefore–after /interrupted time series3
Coleman et al272001UKNon-comparative (case series/study)3
Cooke et al42004VariousMeta-analysis/systematic review2++
Health Services Utilization and Research Committee21997CanadaMeta-analysis/systematic review2++
Liebowitz et al232003VariousMeta-analysis/systematic review2++
Murphy71998VariousMeta-analysis/systematic review2++