Health Technology Assessment (Jul 2024)
Emollient application from birth to prevent eczema in high-risk children: the BEEP RCT
Abstract
Background Atopic eczema is a common childhood skin problem linked with asthma, food allergy and allergic rhinitis that impairs quality of life. Objectives To determine whether advising parents to apply daily emollients in the first year can prevent eczema and/or other atopic diseases in high-risk children. Design A United Kingdom, multicentre, pragmatic, two-arm, parallel-group randomised controlled prevention trial with follow-up to 5 years. Setting Twelve secondary and four primary care centres. Participants Healthy infants (at least 37 weeks’ gestation) at high risk of developing eczema, screened and consented during the third trimester or post delivery. Interventions Infants were randomised (1 : 1) within 21 days of birth to apply emollient (Doublebase Gel®; Dermal Laboratories Ltd, Hitchin, UK or Diprobase Cream®) daily to the whole body (excluding scalp) for the first year, plus standard skin-care advice (emollient group) or standard skin-care advice only (control group). Families were not blinded to allocation. Main outcome measures Primary outcome was eczema diagnosis in the last year at age 2 years, as defined by the UK Working Party refinement of the Hanifin and Rajka diagnostic criteria, assessed by research nurses blinded to allocation. Secondary outcomes up to age 2 years included other eczema definitions, time to onset and severity of eczema, allergic rhinitis, wheezing, allergic sensitisation, food allergy, safety (skin infections and slippages) and cost-effectiveness. Results One thousand three hundred and ninety-four newborns were randomised between November 2014 and November 2016; 693 emollient and 701 control. Adherence in the emollient group was 88% (466/532), 82% (427/519) and 74% (375/506) at 3, 6 and 12 months. At 2 years, eczema was present in 139/598 (23%) in the emollient group and 150/612 (25%) in controls (adjusted relative risk 0.95, 95% confidence interval 0.78 to 1.16; p = 0.61 and adjusted risk difference −1.2%, 95% confidence interval −5.9% to 3.6%). Other eczema definitions supported the primary analysis. Food allergy (milk, egg, peanut) was present in 41/547 (7.5%) in the emollient group versus 29/568 (5.1%) in controls (adjusted relative risk 1.47, 95% confidence interval 0.93 to 2.33). Mean number of skin infections per child in the first year was 0.23 (standard deviation 0.68) in the emollient group versus 0.15 (standard deviation 0.46) in controls; adjusted incidence rate ratio 1.55, 95% confidence interval 1.15 to 2.09. The adjusted incremental cost per percentage decrease in risk of eczema at 2 years was £5337 (£7281 unadjusted). No difference between the groups in eczema or other atopic diseases was observed during follow-up to age 5 years via parental questionnaires. Limitations Two emollient types were used which could have had different effects. The median time for starting emollients was 11 days after birth. Some contamination occurred in the control group ( 2). Research nurses conducting outcome assessments were masked to participant treatment allocation. Families were not masked to the allocated interventions and were reminded not to reveal allocation to research nurses. The trial was powered to detect a relative reduction of 30% in the primary outcome at the 5% significance level (two-sided) with 90% power assuming that 30% of children in the control group would have eczema and 20% attrition, resulting in a sample size of 1282. The target sample size was reached faster than anticipated at which point the Trial Steering Committee permitted that all pregnant mothers who had already consented to the trial could be randomised on the birth of the baby giving a maximum possible sample size of 1400. We analysed participants as randomised regardless of adherence with allocation using available data (i.e. without imputation for missing data) with sensitivity analyses for missing data. The adjusted relative risk (RR) and risk difference for the primary outcome were estimated using generalised estimating equations with the binomial family and log/identity link respectively, with an exchangeable correlation matrix to account for randomisation stratification by centre and number of immediate family members with atopic disease (one, two, or more than two) included as a covariate. A number of planned subgroup analyses for the primary outcome were conducted including according to FLG genotype, to test the hypothesis that FLG null genotype affects response to intensive emollient use from birth. Results One thousand three hundred and ninety-four newborns were randomised between 19 November 2014 and 18 November 2016; 693 to the emollient group and 701 to the control group. Primary outcome data at 2 years were collected for 1210 infants (87%). Unblinding of research nurses prior to skin examination occurred for 12 infants in the intervention group and 6 in the control group. Adherence in the emollient group was 88% (466/532) at 3 months, 82% (427/519) at 6 months and 74% (375/506) at 12 months. In the control group, contamination due to self-directed use of emollients was reported for 18% (82/457), 17% (62/372) and 15% (49/324) at 3, 6 and 12 months, respectively, for infants who did not have a parental report of a doctor diagnosis of eczema. At age 2 years, eczema was present in 139 (23%) of 598 infants in the emollient group and in 150 (25%) of 612 infants in the control group [adjusted RR 0.95, 95% confidence interval (CI) 0.78 to 1.16; p = 0.61; adjusted risk difference −1.2%, 95% CI −5.9% to 3.6%]. All sensitivity analyses conducted, including using multiple imputation for missing primary outcome data, were consistent with the primary analysis. There was no evidence of an interaction effect with allocated group for the primary eczema outcome in any of the subgroup analyses (including FLG genotype). Other eczema definitions supported the results of the primary analysis. Eczema severity and time to onset of eczema were also similar in the two groups. Mean number of skin infections per child in year 1 was 0.23 [standard deviation (SD) 0.68] in the emollient group versus 0.15 (SD 0.46) in the control group; adjusted incidence rate ratio 1.55 (95% CI 1.15 to 2.09). Infant slippage incidents were reported for 15/584 (2.6%) in the emollient group and 11/584 (1.9%) in the control group. Food allergies to milk, egg or peanut at 2 years were confirmed in 41/547 (7.5%) infants in the emollient group and 29/568 (5.1%) in the control group (adjusted RR 1.47, 95% CI 0.93 to 2.33). The largest difference was in the proportion of infants with confirmed food allergy to egg, with an adjusted RR of 1.56 (95% CI 0.92 to 2.65). Results of other measures of food allergy and food sensitisation were similar. The proportion of infants with allergic rhinitis, wheezing and allergic sensitisation to cat dander, grass pollen and dust mite was similar between groups at 2 years. The differences in quality of life (using CHU-9D for the child and EuroQol-5 Dimensions, five-level version for the main carer) between the two groups were very small. Although the emollient intervention period was the first year of life, parents in the emollient group continued to report more frequent moisturiser application through to 5 years than in the control group. By 5 years, 188/608 (31%) parents in the emollient group had reported a clinical diagnosis of eczema in their child since 12 months, compared with 178/631 (28%) in the control group (adjusted RR 1.10, 95% CI 0.93 to 1.30). A diagnosis of food allergy by 5 years was reported for 92/609 (15%) allocated to emollients and 87/632 (14%) allocated to control (adjusted RR 1.11, 95% CI 0.84 to 1.45). Similarly, the percentage of parents reporting that their child had a clinical diagnosis of asthma or allergic rhinitis by 5 years were similar in the two groups. In the complete-case CEA mean cost was £398.23 (SD 1408.39) per child in the emollient group (n = 598) and £312.16 (SD 1105.04) in the control group (n = 610). When intervention use was combined with other health resource use, the adjusted incremental cost was £87.45 (95% CI −54.31 to 229.27). The adjusted difference in the proportion of children without eczema at 2 years was 0.0164 (95% CI −0.0329 to 0.0656) higher in the emollient group compared to the control group. The adjusted incremental cost per percentage decrease in risk of eczema was £5337 at 2 years. Adjusted QALYs for children were very slightly improved (i.e. higher) in the emollient group at 2 years. Conclusions We found no evidence of a useful preventive effect of emollients for eczema at our primary outcome time of 2 years. The failure to show a reduction in eczema was consistent regardless of how eczema was assessed. Some evidence of an increase in skin infections during the intervention period and a possible increase in food allergy at age 2 years was observed. No benefit was observed for time to onset of eczema or eczema severity, and no benefits were observed for eczema, asthma, hay fever or food allergy in longer-term follow-up to 5 years. Emollient use is unlikely to be considered cost effective in this context. Inclusion of individual patient data from all similar eczema prevention studies in further meta-analysis may provide a clearer assessment of whether emollients can prevent eczema and related diseases and provide more certainty about potential harms. Implications for health care The study does not support the use of emollients to prevent eczema and has found a small signal of possible harms, so this intervention cannot be recommended for health care or public health use. As the study relates to prevention of eczema, emollients should continue to be used as part of standard treatment for eczema. Trial registration This trial is registered as ISRCTN21528841. Funding This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 12/67/12) and is published in full in Health Technology Assessment; Vol. 28, No. 29. See the NIHR Funding and Awards website for further award information.
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