Aanesthetic Agents for Day Surgery - NIHR Health Technology ...

Aims and objectives of the review
The aim of the literature review was to provide a
comprehensive and critical analysis of the currently
available evidence to place the study in context,
facilitate the use of accepted research methods
and provide additional secondary data for the
economic analysis.
The objectives of the review were to:
• Inform the project of the following aspects of
anaesthesia in adult and paediatric day surgery:
– current practice patterns, variations
and trends
– relative effectiveness, costs, cost-effectiveness
and patient-based outcomes.
• Inform the practice survey.
• Produce a literature review that provides qualityassessed
clinical, economic and patient-based
outcomes data and information on practice
variation for the economic analysis, using
standard quality-assessment indicators.
• Produce a literature report that provides a
comprehensive and critical analysis of the
evidence currently available.
The section below details the search strategy and
quality criteria used, and the following three sections
provide a summary of the current evidence
of the relative effectiveness, the impact on patientbased
outcomes and the costs of the principal anaesthetic
agents and techniques used in day-surgery
general anaesthesia. Standard quality-assessment
indicators are used to indicate the quality of the
literature in each area. The last section gives a
summary of the current level of evidence.
Search strategy
Although not a formal systematic review, the search
strategy used in this study follows the NHS Centre
for Reviews and Dissemination Guidelines 39 in
order to minimise biases and random errors. The
principal components of the search strategy were:
• sources of evidence (databases searched
and keywords used)
• an assessment of the quality of the evidence
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Chapter 2
Literature review
Health Technology Assessment 2002; Vol. 6: No. 30
• the inclusion and exclusion criteria for the
studies (see appendix 1).
Sources of evidence
The range of databases interrogated cover relevant
medical, pharmaceutical, economic, sociological,
organisational and methodological evidence (to
December 2000) (see appendix 1).
In addition to the review of primary studies, goodquality
systematic reviews and meta-analyses were
included if there was evidence of a literature
search strategy, explicit inclusion criteria, a valid
assessment of primary studies and an appropriate
pooling or summary. Relevant systematic reviews
were identified from the NHS Centre for Reviews
and Dissemination database, which reports the
results of reviews from 1994 onwards. Systematic
reviews before this period were identified from
MEDLINE and EMBASE using a recommended
search strategy. 39
Nine meta-analyses were located (see appendix
2). 40–48 These compared the rates of PONV with
different anaesthetic methods. However, eight
included inpatient surgery studies, and so may
be of limited direct relevance to the present study.
One systematic review on postoperative analgesia
and PONV in day surgery was obtained 44 (discussed
on page 15). No systematic reviews were found
that specifically or sufficiently addressed the
impact of different anaesthetic agents on
adult or paediatric patients in day surgery.
Quality assessment of the
literature found
In this study, the quality assessment of literature
had two objectives:
• to generate a statement on the quality of
evidence available in each area reviewed
• to assess the literature for economic
analysis modelling.
Quality assessment was undertaken of all clinical,
patient-based outcomes and economic studies
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