Assessing the feasibility of injectable growth-promoting therapy in Crohn's disease

Despite optimal therapy, many children with Crohn's disease (CD) experience growth retardation. The objectives of the study are to assess the feasibility of a randomised control trial (RCT) of injectable forms of growth-promoting therapy and to survey the attitudes of children with CD and their parents to it.

A feasibility study was carried out to determine study arms, sample size and numbers of eligible patients. A face-to-face questionnaire surveyed willingness to consent to future participation in the RCT. Eligibility to the survey was any child under 18 (with their parent/guardian) with CD whose height standard deviation score (HtSDS) was ≤+1. Of 118 questionnaires, 94 (80%) were returned (48 by children and 46 by parents).

The median age of the patients in the survey was 14.3 years (range 7.0 to 17.7), and 35 (73%) were male. Their median HtSDS was -1.2 (-3.01, 0.23), and it was lower than the median mid-parental HtSDS of -0.6 (-3.1, 1.4). We analysed the willingness of the children whose HtSDS <-1 to take part in the proposed RCT, being those most likely to require treatment. Overall, 18 (47%) children and 17 (46%) parents were willing. This increased to 61% of children who were slightly concerned about their height and 100% (4/4) of those very concerned. A common reason for not taking part in the RCT was fear of injections (44%); 111 children are required for randomisation into three study arms from nine centres.

Almost half of children and parents surveyed would take part in an RCT of growth-promoting therapy. Allaying fears about injections may result in higher recruitment rates.