Table 2.

Systematic reviews on NPWT: Requirements for primary studies and publications

Systematic review	Interventions	Wound types	Clinical outcomes	Clinical study design	Sample size restrictions	Type of study information considered	Prespecified search for HTAs/SRs	Language restrictions
Samson/AHRQ 2004 [29]	a) NPWT vs. other wound healing interventions b) NPWT + standard care vs. standard wound care alone c) NPWT vs. sham intervention	Chronic wounds: - pressure ulcers - metabolic disorders (e.g., diabetes mellitus) - vascular insufficiency - inflammatory disorders - malignancies - infections - miscellaneous (e.g., burns) Other types of wounds: - acute wounds - traumatic wounds - subacute wounds - dehisced wounds - partial thickness burns - diabetic ulcers - pressure ulcers - flaps - grafts	Primary outcomes: - incidence of complete wound closure - time to complete closure - adverse events Secondary outcomes: - facilitating surgical closure - need for debridement - infections - pain - activities of daily living - quality of life - improved cosmesis - change in wound size* - transcutaneous oxygen tension*	RCT	None	Articles	-	Abstracts published in English; articles without abstracts were reviewed if title indicated that articles met inclusion criteria; non-English articles were reviewed if English abstract indicated that articles met inclusion criteria.
Costa/MUHC TAU 2005 [30]†	NPWT vs. other treatment alternatives	Not prespecified in detail	Not prespecified in detail ("clinical effectiveness")	RCT Non-RCT (clinical comparative studies)	≥ 9 patients in either arm‡	Articles	+	Articles published in English or French
IQWiG 2006 [8]	NPWT vs. a) conventional wound therapy b) another type of NPWT	Acute or chronic wounds	- wound healing time - wound recurrence - revision operations - amputations - mortality - disease-related quality of life - activities of everyday life - pain - time spent in hospital - dressing changes - debridement procedures - adverse events - scar formation - subjective cosmetic results	RCT Non-RCT with a concurrent control group (clinical controlled trials, comparative cohort studies, case control studies)	None	Articles Unpublished data provided by manufacturers§	+	Language restrictions were not specified in the IQWiG review.||
Pham/ASERNI P-S 2006 update [31]¶|	NPWT vs. conventional methods	Particular wound types** - pressure ulcers and leg ulcers - diabetic foot ulcers and wounds - skin grafts - chronic wounds and complex/severe wounds - sternal wounds	Not prespecified in detail ("efficacy and safety outcomes")	RCT Non-RCT (other controlled or comparative studies and case series with consecutive patients)	None	Articles Conference abstracts†† Manufacturer's information††	-	Searches were conducted without language restriction. English abstracts from non-English articles were included if they met the inclusion criteria and included efficacy and safety data.‡‡
OHTAC 2006 (update) [32]§§	NPWT vs. standard care	Wounds, including - Pressure ulcers - diabetic ulcers - sternal wounds - skin grafts	Not prespecified in detail ("Is negative pressure wound therapy effective for healing wounds...?")	RCT	≥ 20 patients	Articles ("peer-reviewed, published")	+	Articles published in English

*"Considered to be of less clinical importance" [29].

^†Costa also considered economic outcomes.

^‡One crossover study involving 7 patients was also included.

^§Unpublished data from primary studies were only to be considered in the review if comprehensive study information (e.g. a clinical study report) was available.

^||Additional information (IQWiG): An English-language title was required. No language restrictions were otherwise posed. If an English-language title or abstract indicated the potential relevance of a foreign-language text, the text was obtained and translated.

^¶Personal communication (C. Perera, ASERNIP-S): "This publication draws from an accelerated systematic review which was published in 2003 and is accessible at http://www.surgeons.org/AM/Template.cfm?Section=ASERNIP_S_Publications&CONTENTID=14159&TEMPLATE=/CM/ContentDisplay.cfm. This review contains the full methodological details, including search strategies and inclusion/exclusion criteria. An accelerated systematic review uses the same methodology as a full systematic review, but may restrict the types of studies considered in order to produce the review in a shorter time period than the full systematic review. For example, accelerated reviews generally only include comparative studies and not case series, unless safety outcomes were inadequately described in the comparative evidence."

**Wound types listed in the results section, not in the methods.

^††"Conference abstracts and manufacturer's information were included if they contained relevant safety and efficacy data." [31]

^‡‡Information according to [31]. Additional information: "Searches for the review were conducted without language restriction in the first instance; however, included studies were limited to those published in English. An exception to this would be if there was a paucity of English language evidence, or if a landmark RCT was published in a non-English language, in which case the studies would then be translated and included." (Personal communication: C. Perera, ASERNIP-S).

^§§OHTAC also considered economic outcomes.

AHRQ: Agency for Healthcare Research and Quality; ASERNIP-S: Australian Safety and Efficacy Register of New Interventional Procedures-Surgical; HTA: health technology assessment; IQWiG: Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen (Institute for Quality and Efficiency in Health Care); MUHC TAU: McGill University Health Centre Technology Assessment Unit; NPWT: negative pressure wound therapy; OHTAC: Ontario Health Technology Advisory Committee; RCT: randomised controlled trial; SR: systematic review.