Intent to update systematic reviews: results of an internet survey

Updating a systematic review may be necessary when newer evidence is available. Several barriers to conducting updated systematic reviews have been hypothesized.

To conduct an Internet survey to identify the relationship between author and study characteristics and the intent to update a systematic review, to quantify this relationship, and to query authors about perceived barriers to updating.

Manual search of ACP Journal Club (January 2007-December 2008) for featured systematic reviews and/or meta-analyses identified participants. We collected participant demographics and questioned participants on intentions of updating and potential barriers. All variables showing univariate association (P < 0.1) were entered into a backward-stepwise multivariate model.

Upon multivariate logistic regression, those who spend greater than 25% of time dedicated to systematic review were significantly more likely to update their review (adjusted odds ratio, 7.25; 95% confidence interval, 1.45-35.71). Conversely, those whose primary funding was from a government source were significantly less likely to conduct an update (adjusted odds ratio, 0.08; 95% confidence interval, 0.01-0.50).

Authors who spend more time on systematic reviews were more likely to update, whereas those with government funding were less likely to update their systematic reviews. Surveyed authors also identified several perceived barriers to updating. Future efforts may aim to reduce barriers and provide incentives to authors to improve updating practices.