Factors affecting trial participation at 6 months and 2 years: adjusted analyses.

Notes to table:Variables entered are listed in Tables S1 and S2. Categories were collapsed to avoid low numbers, as necessary. A backwards likelihood ratio criterion was used to select predictor variables. Reports of asthma and eczema were tested separately and together. Models were checked by two of us and found to be robust: removal of outliers made no overall difference. Not all participants responded to all questions. Missing data in some variables reduced the number cases in the analyses. We did not impute values.1Most adverse events related to symptoms typical of common problems in routine clinical practice. None were attributed to the trial intervention by the trial’s data monitoring committee [35].2Not all rashes had been diagnosed by a professional: carer’s report was the variable of interest.3Testing was not offered to 5 infants, who were excluded from this analysis. NS represents ‘not significant’. * denotes reference category.