Best evidence topic reports (BETs) summarise the evidence pertaining to particular clinical questions. They are not systematic reviews, but rather contain the best (highest level) evidence that can be practically obtained by busy practising clinicians. The search strategies used to find the best evidence are reported in detail in order to allow clinicians to update searches whenever necessary. Each BET is based on a clinical scenario and ends with a clinical bottom line, which indicates, in the light of the evidence found, what the reporting clinician would do if faced with the same scenario again. The BETs published below were first reported at the Critical Appraisal Journal Club at the Manchester Royal Infirmary¹ or placed on the BestBETs website. Each BET has been constructed in the four stages that have been described elsewhere.² The BETs shown here together with those published previously and those currently under construction can be seen at http://www.bestbets.org.³ Four BETs are included in this issue of the journal.

• Diagnostic utility of electrocardiogram for diagnosing pulmonary embolism.

• Lignocaine as a pretreatment to rapid sequence intubation in patients with status asthmaticus.

• Steroids in sudden sensorineural hearing loss.

• Differential diagnosis of narrow complex tachycardias by increasing electrocardiograph speed.