Placebo works in abdominal pain

In April 2017, Lucina commented on the high placebo response rate seen in studies comparing migraine headache treatments (doi.org/10.1136/archdischild-2017–3 12 882). Now a review paper has looked specifically at placebo effects reported in studies of abdominal pain-related functional gastrointestinal disorders (AP-FGIDs) in children (HoekmanJ et al. J Pediatr 2017. doi.org10.1016/j.jpeds.2016.12.022). They found 21 randomised placebo-controlled trials, which used a variety of pain-rating scales. Looking only at the placebo groups, they found that the proportion of children ending up with no pain was 17% (95% CI 8% to 32%), and reporting an improvement in pain was 41% (95% CI 34% to 49%). As the studies varied considerably in their designs, they were able to look at factors that seemed to create a significantly greater placebo response: these included, as expected, longer durations of treatment and higher drop-out rates, and more surprisingly, once-daily versus twice-daily dosing regimes—perhaps because every dose given reminds the child that there is supposed to be something wrong with them. Some earlier studies have suggested that placebo response rates are generally higher in children compared with adults, but this review found rates for AP-FGIDs that are comparable to similar studies in adults, around 36% to 42%.

This is good …