Date	Event	Description
8 November 2012	New search has been performed	A new review author joined the team to update this review. We updated the searches in November 2012. Two new trials were identified for the review of antibiotics against placebo (Hoberman 2011; Tähtinen 2011). These studies included children < 35 months of age and provided data on pain (Tähtinen 2011), contralateral otitis, late recurrences (Hoberman 2011), perforation and adverse events (Hoberman 2011; Tähtinen 2011). The Laxdal 1970 trial has been removed from the review of antibiotics against placebo and added to the review of immediate antibiotics versus expectant observation. No new trials were identified for the review of immediate antibiotics compared with expectant observation. Furthermore, we did not identify ongoing trials. In this updated review, we now provide outcome data for pain at 24 hours, two to three days and four to seven days (in earlier versions outcome data for pain were presented at 24 hours and two to seven days).
8 November 2012	New search has been performed	The general conclusions and recommendations regarding the effectiveness of antibiotics on pain and adverse events remained unchanged. Antibiotic treatment led to a statistically significant reduction of children with AOM experiencing pain at two to seven days compared with placebo, but since most children (82%) settle spontaneously, about 20 children must be treated to prevent one suffering from ear pain at two to three and four to seven days. (In the previous version the number needed to treat to benefit (NNTB) was 16). However, in this updated review antibiotic treatment appeared to have a statistically significant beneficial effect on the number of tympanic membrane perforations (risk ratio (RR) 0.37, 95% confidence interval (CI) 0.18 to 0.76; NNTB 33) and contralateral acute otitis media (AOM) episodes (RR 0.49, 95% CI 0.25 to 0.95; NNTB 11) compared with placebo. For every 14 children treated with antibiotics one child experienced an adverse event (such as vomiting, diarrhoea or rash) that would not have been occurred if antibiotics were withheld. (In the previous version the number needed to treat to harm (NNTH) was 24). Antibiotics are most useful in children under two years of age with bilateral AOM, or with both AOM and otorrhoea. For most other children with mild disease, an expectant observational approach seems justified. We have no data on populations with higher risks of complications.
19 June 2012	Feedback has been incorporated	Feedback added to review.
2 September 2009	Amended	95% confidence intervals corrected for the outcome pain at two to seven days and adverse events stated in the abstract and body of the review.
2 July 2008	New search has been performed	The search was updated in July 2008. Four new trials were identified and included in the review (Le Saux 2005; McCormick 2005; Neumark 2007; Spiro 2006). One of these trials compared antibiotics with placebo (Le Saux 2005). For the outcome pain at 24 hours and two to seven days, inclusion of this trial did not alter the overall conclusions of the primary analysis. The three other new trials compared immediate antibiotics with various observational approaches (McCormick 2005; Neumark 2007; Spiro 2006). One of the new trials compared immediate antibiotics with delayed prescribing (Spiro 2006). The other trials compared immediate antibiotics with 'watchful waiting', in which no prescription was supplied but advice on when to seek treatment was provided (McCormick 2005; Neumark 2007). Outcome data on pain at three to seven days from these trials were analysed with data from another trial of immediate versus delayed prescription (Little 2001). In earlier versions of the review data from the Little trial had been included in a sensitivity analysis (Little 2001). In this update, data from the four trials comparing immediate versus observational management strategies have been included in the main analysis. Information on subgroups of children who are most likely to benefit from treatment with antibiotics, obtained from a meta‐analysis of individual patient data, has been included in this review (Rovers 2006). Methods of the IPD meta‐analysis, conducted by two authors on this review (and others) are also included. Survival curves from the IPD meta‐analysis showing the pattern of recovery from acute otitis media over time has been included as an extra figure. Two ongoing trials comparing antibiotics with placebo in children < 35 months have been identified.
17 January 2008	Amended	Converted to new review format.
4 September 2007	Feedback has been incorporated	Feedback added.
18 February 2005	Feedback has been incorporated	Feedback and reply added.
24 March 2003	New search has been performed	Searches conducted.
24 August 2002	Feedback has been incorporated	Feedback added.
17 February 2002	Feedback has been incorporated	Feedback added.
20 November 2000	Feedback has been incorporated	Feedback comments and replies added.
3 February 2000	New search has been performed	Searches conducted.
3 February 2000	New citation required and conclusions have changed	Conclusions changed.
30 December 1998	New search has been performed	Searches conducted.
30 July 1994	New search has been performed	Searches conducted.