A systematic review to ascertain whether the standard needle is more effective than a longer or wider needle in reducing the incidence of local reaction in children receiving primary immunization.

CONTEXT

Millions of doses of vaccines are given to children within the United Kingdom (UK) each year, yet there is conflicting national guidance on the length of needle to use. Prefilled syringes come supplied with 25 Gauge 16 millimetres long needles.

OBJECTIVES

A systematic review was completed to answer the clinical question of whether the standard needle is more effective than a longer and/or wider needle in reducing local reactions in children receiving primary immunizations.

DATA SOURCES

A comprehensive search strategy, including searching of electronic databases, hand searching, reference/citation searching, contacting researchers in the field and searching for unpublished literature.

STUDY SELECTION

Selection of studies was guided by the clinical question, the inclusion and exclusion criteria being applied by two people independently. Study quality assessment: An established quality checklist was used. Critical analysis of the quality of the components of the studies is included in the discussion.

DATA EXTRACTION

Two people independently applied a data extraction form, designed for the study.

RESULTS

(1). Rev Man (a Windows-based software package used by the Cochrane Collaboration) was used to perform a meta-analysis on the binary results of two small studies using Relative Risk as the summary statistic 16 mm vs. 25 mm needle. (2). The pooled Relative Risk for redness was 2.52 [95% confidence interval (CI) fixed 1.70-3.72] P < 0.00001. (3). The pooled Relative Risk for swelling was 2.31 (95% CI fixed 1.55-3.43) P < 0.00003.

CONCLUSION

(1). The results are statistically very highly significant and favour the use of the 25 millimetre long needle. (2). No studies were identified to separate the effect of the gauge of the needle used, but the discussion shows that needle length is the most important variable. (3). The results should be incorporated into any future guidelines on vaccine administration in the UK.