Exposure to general anaesthesia in childhood and the subsequent risk of attention-deficit hyperactivity disorder: A meta-analysis of cohort studies.

ABSTRACT

BACKGROUND: The evidence for a relationship between general anaesthesia induced in childhood and the risk of attention-deficit hyperactivity disorder (ADHD) in later life is inconsistent. We systematically assessed whether such an association existed. METHODS: We searched the PubMed and EMBASE databases for relevant cohort studies. Relative risks (RRs) and 95 % confidence intervals (CIs) were calculated to determine the relationship between induction of childhood general anaesthesia and the risk of ADHD in later life. RESULTS: Seven studies (eight publications) on developmental outcomes after the induction of childhood general anaesthesia met our inclusion criteria but not our exclusion criteria. Repeat childhood general anaesthesia (RR = 1.84, 95 CI% 1.14-2.97; P < 0.001; I2 = 74.8 %), but not one-off general anaesthesia (RR = 1.09, 95 CI% 0.93-1.27; P = 0.301; I2 = 0%), was associated with an increased risk of ADHD in later life. The association was evident only when the total general anaesthesia exposure exceeded 90 min. CONCLUSIONS: Our meta-analysis indicated that the effect of general anaesthesia on the risk of ADHD is dose- or duration-dependent.