The review concluded that probably one in five patients with airway stent was affected by stent-associated respiratory tract infection. In light of the limited search for studies and the lack of a study quality assessment, the authors' conclusions should be interpreted with caution.

To evaluate the evidence regarding infections associated with airway stenting.

PubMed was searched to December 2007 for studies in English and French; search terms were reported. Bibliographies of retrieved papers were handsearched.

Studies that reported at least one patient with a clinical infection related to airway stenting (or reported no infectious complications following stent insertion) were eligible for inclusion. Studies that reported only colonisation were excluded.

Just over half of the included patients had a benign disorder and just under half had malignant disease; some studies examined mixed populations. Around a quarter of the patients with benign disease underwent lung or heart/lung transplants. Polymeric, metallic or hybrid stents were used.

Two reviewers independently selected studies for inclusion; disagreements were resolved by consensus.

The authors did not state that they assessed study quality.

Two reviewers independently extracted data; disagreements were resolved by consensus.

The studies were combined in a narrative synthesis with tabulated study details.

Twenty-three studies (n=501) were included in the review (12 retrospective cohorts, three prospective cohorts, four retrospective case series, and four case reports).

Nineteen per cent of all patients experienced a stent-associated respiratory tract infection (16% in patients with malignant disease, 19% in patients with benign disease; 21% for metallic stents, 20% for polymeric stents and 23% for hybrid stents). Complications (reported in 19 studies, n=93) included pneumonia (47%), bronchial infection (24%), cavitary pneumonia/lung abscess (2%) and intraluminal fungus ball (2%).

Twenty-six out of the 38 patients with stent-associated respiratory tract infection, for whom outcome data was available, died (76% for patients with malignant disease, 88% for transplant patients and 42% for non-transplant benign patients). Stent removal or replacement was required for treatment of six patients with bronchial infection and one patient with recurrent pneumonia associated with tumour overgrowth. Five different types of pathogen were found Only three cases of antimicrobial treatment were reported (results were provided).

Probably one in five patients with airway stent was affected by stent-associated respiratory tract infection. There was an urgent need for establishing a consensus definition and diagnostic criteria for stent-associated respiratory tract infection.

The review addressed a clear question supported by broad inclusion criteria. Only one database was searched and no search was undertaken for unpublished studies, so some relevant studies may have been missed. The restriction to including only studies in English and French exacerbated the risk of missed studies. Suitable methods were used when selecting studies and extracting data to minimise the risk of reviewer error and bias. No formal assessment of study quality was made, which made it difficult to assess the strength of the evidence presented (although the authors discussed the limitations of studies generally). The decision to synthesise the studies narratively appeared appropriate. The lack of comparison data (for patients who did not receive stenting) made it difficult to place the review results in context. In light of the limited search for studies and the lack of a study quality assessment, the authors' conclusions should be interpreted with caution.

Practice: The authors stated that different patterns of stent-associated respiratory tract infection presentation may have implications on prevention and management strategies.

Research: The authors stated that prospective studies were needed to identify risk factors for stent-associated respiratory tract infection and determine optimal prevention and management strategies.

Not stated.

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.