Table 1.

Characteristics of included studies*

Author and year	Institution or guideline program (country)	Objective	Design	Sample	Health topic	Time to update
Shekelle 2001[3]	AHRQ (USA)	Evaluating if out of date	One strategy	17 CPGs	Several topics	4-8 years
Bosquet 2003[9]‡	FNCLCC (France)	Evaluating if out of date	One strategy	1 CPG	PET scanning in cancer	NS
Gartlehner 2004[7]	RTI-UNC EPC, USPSTF, AHRQ (USA)	Evaluating if out of date	Two strategies	6 topics	Prevention topics	6 years
Nunes 2009[15]‡§	NCGC, NICE (UK)	Evaluating if out of date	One strategy	1 CPG	Obesity	3 years
Eccles 2002[10]	North of England Evidence Based Guideline Development Programme (UK)	Updating	Two strategies (development vs updating)	2 CPGs	Angina and asthma in adults	4-5 years
Newton 2006[14]‡§	AHTA (Australia)	Updating (updating by adapting)	One strategy	1 CPG	Posttraumatic stress disorder	1-3 years
Parmelli 2010[16]	ERHCA (Italy)	Updating	Two strategies (development vs updating)	15 recommendations	Anticancer drugs for breast, colorectal and lung cancer	3 years
Johnston 2003[8]	CCOPGI (Canada)	Continuously monitoring and updating	One strategy	20 CPGs	Cancer	NS

*Ordered by type of strategy and chronology; ‡Only abstract available; §Information provided by the author.

Abbreviations: AHRQ: Agency for Healthcare Research and Quality; AHTA: Adelaide Health Technology Assessment; CCOPGI: Cancer Care Ontario Practice Guidelines Initative; CPG: Clinical practice guideline; ERHCA: Emilia-Romagna Health Care Agency; FNCLCC: Fédération Nationale des Centres de Lutte Contre le Cancer; NCGC: National Clinical Guidelines Centre for Acute and Chronic Conditions; NICE: National Institute for Health and Clinical Excellence; NS: Not stated; PET: Positron Emission Tomography; RTI-UNC EPC: RTI International–University of North Carolina Evidence-based Practice Center; UK: United Kindom; USA: United States of America; USPSTF: US Preventive Services Task Force; vs: Versus.