Strengths and limitations
diarrhoea, illness, vomiting, rash, ill, chest infections
ACUTE INFECTIONS, CHEST INFECTION
This cohort of unwell children provides the best evidence to date of the impact of antibiotics on chest infections in children by nesting trial data (which can be limited by external validity and substantially greater drug compliance compared with observational studiesThe method of controlling for confounding by indication needed to be adapted to improve the balance between groups, and there was evidence of some residual confounding by indication for some of the outcomes — particularly for the progression of illness. It is also likely that residual confounding by indication contributed to the much higher apparent ‘side effects’ seen in the antibiotic group as it is known that diarrhoea, vomiting, and skin rash occur commonly as part of the illness for both children and adults;Some potential confounders may not have been measured, for example, how rapidly a child had become ill — although prior illness duration is a reasonable proxy in acute infections.