Ten studies were included in the review. Six studies assessed complication rates only, one assessed test accuracy only and three assessed both. For the nine studies that assessed complication rate, the median STROBE score was 14 (range 13 to 19). QUADAS assessment of the four studies that reported test accuracy data showed that nine of the 14 criteria were met by all studies. No study interpreted the reference standard blind to the results of the index test and that the delay between the index test and the reference standard was unclear in three out of four studies.
Test accuracy (714 biopsies in 639 patients):
The pooled estimate of sensitivity was 87.0% (95% CI 80.7 to 91.4%), Ι²=47.6% (moderate heterogeneity), and the pooled estimate of specificity was 96.4% (95% CI 81.4 to 99.4%), Ι²=73.6% (substantial heterogeneity). Results were similar when core-needle and fine-needle aspiration biopsy were analysed separately. For these subgroup analyses there was no evidence for between-study heterogeneity in most estimates; however, the very small numbers of studies involved meant that this assessment was unlikely to have been reliable.
A total of 859 biopsies were performed in 741 patients (370 core-needle and 489 fine-needle aspiration). Complications were reported in 46 biopsies (10 major and 36 minor). Of the 10 major complications, nine were related to haemorrhage and one was pneumothorax. Of the 36 minor complications, 29 were related to pain, six were related to haemorrhage, and one was a vasovagal episode. Four of the major, and 16 or the minor complications occurred in 33 biopsies that were performed with needles larger than 18-gauge.
The pooled overall (major and minor) complication rates were 4.2% (95% CI 1.0 to 15.5%) for all biopsies, 4.3% (95% CI 2.7 to 6.7%) for fine-needle aspiration biopsy (six studies), and 5.8% (95% CI 1.1 to 26%) for core-needle biopsy (seven studies). The sensitivity analysis (33 biopsies performed with needles larger than 18-gauge excluded) gave an overall complication rate of 3.9% (95% CI 2.7 to 5.6%) for all biopsies and 3.6% (95% CI 2.0 to 6.4%) for core-needle biopsies. Separate data were also reported for major and minor complications. There was no evidence of publication bias.