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. 2021 Feb 5;2021(2):CD013534. doi: 10.1002/14651858.CD013534.pub2

Risk of bias for analysis 1.2 Sensitivity analysis: Eczema by 1‐3 years including aggregate trial data.

Study Bias
Randomisation process Deviations from intended interventions Missing outcome data Measurement of the outcome Selection of the reported results Overall
Authors' judgement Support for judgement Authors' judgement Support for judgement Authors' judgement Support for judgement Authors' judgement Support for judgement Authors' judgement Support for judgement Authors' judgement Support for judgement
Chalmers 2020 Low risk of bias Quote: "The randomisation schedule was created by the CTU using computer‐generated pseudo‐random code with permuted blocks of randomly varying size. The sequence was known only to the programmer until database lock." Baseline variables by treatment group do not suggest a problem with randomisation, characteristics well balanced (IPD available) Low risk of bias Not possible to blind participants’ carers, but there is no evidence that deviations arised because of the trial context. The control group rates of skin care application were consistent with other trials and observational studies (e.g. up to 75 % in Rendell 2011). Quote: “Of families in the emollient group with complete questionnaire data on adherence at each time point, 466 (88%) of 532 had satisfactory adherence at 3 months, 427 (82%) of 519 at 6 months, and 375 (74%) of 506 at 12 months.” “No emollient was supplied to the control group, but self‐directed use of emollients at least three times per week to most of the body (contamination) occurred in 18% (82 of 457) at 3 months, 17% (62 of 372) at 6 months, and 15% (49 of 324) at 12 months” Low risk of bias 1210/1394 = 87% have outcome. Sensitivity analysis using the IPD reveals conclusions do not change significantly if everyone missing is assumed to not have eczema, RR=0.93, 95% 0.76 to 1.15,  or if all assumed to have eczema, RR=0.99, 95% CI 0.86 to 1.15. Low risk of bias UK working party criteria and blinded assessor used. Quote: "Research nurses doing skin examinations, skin prick testing, food challenges, or making food allergy decisions, and the statistician, were masked to treatment allocation during the study." Low risk of bias Full trial data set provided by investigators and IPD meta‐analysis SAP followed. Low risk of bias Low risk of bias in all 5 domains.
Dissanayake 2019 Low risk of bias Randomisation performed using minimization at a central location. Baseline variables by treatment group do not suggest a problem with randomisation, characteristics well balanced (IPD available). Low risk of bias Not possible to blind participants’ carers, but there is no evidence that deviations arised because of the trial context. Quote: “we did not prohibit the application of moisturizers in the no‐intervention group. As this could mask the effect of the moisturizer used as an intervention, we looked at the effect of any emollient (irrespective of the formal intervention assigned) on the development of AD. We did not observe any difference in incidence between children who received any type of emollient vs. those who did not (data not shown).” “Approximately 80% of the parents/guardians in the emollient groups reported that they applied the emollient at least twice a day. Adjusting for emollient application rate did not lead to a significant difference in the rate of AD development among the groups. The effect of emollient application was also investigated in all babies who received emollient (groups 1 and 3) versus those who did not (groups 2 and 4), but this too did not show any difference in the incidence of AD.” Low risk of bias 455/549=83% have outcome. Sensitivity analysis using the IPD shows conclusions do not change significantly if all individuals missing eczema outcome are assumed to not have eczema (RR 1.24 95% CI[0.84, 1.83]) or they do have eczema (RR 1.00 95% CI[0.79, 1.27]). Low risk of bias UK working party criteria and blinded assessor used. Quote: "AD diagnosis was further confirmed blindly." Low risk of bias Full trial dataset provided by investigators and IPD meta‐analysis SAP followed. Low risk of bias Low risk of bias in all 5 domains.
Lowe 2018a Low risk of bias Quote from trial protocol: "A computer generated random allocation list in blocks of variable length (4‐12) will be used. This list will be held by The RCH Pharmacy Department, which will be independent from the participant recruitment or testing. At all times, the allocation list will be concealed from the study coordinator and the other study investigators, who will manage participant recruitment." Baseline variables by treatment group do not suggest a problem with randomisation, characteristics well balanced (IPD available). Low risk of bias Not possible to blind participants’ carers, but there is no evidence that deviations arised because of the trial context. The control group rates of skin care application were consistent with other trials and observational studies e.g. up to 75 % in Rendell et al. 2011. The IPD shows regular use of emollient (≥ 3 days a week) by 11/36 (31%) control participants and 30/38 (79%) with eczema outcome recorded). Low risk of bias 74/80 = 93% have outcome. Sensitivity analysis using the IPD reveals conclusions do not change significantly if everyone missing is assumed to not have eczema, RR=0.61 [0.26 to 1.40] or if all assumed to have eczema, RR=0.67 [0.34 to 1.33]. Low risk of bias UK working party criteria and blinded assessor used. Low risk of bias Full trial dataset provided by investigators and IPD meta‐analysis SAP followed. Low risk of bias Low risk of bias for all 5 domains.
McClanahan 2019 Low risk of bias Quote: "Randomization was completed via a computer‐generated randomization list issued by a statistician with block sizes of 10 and concealed from the recruitment coordinator until randomization." Baseline variables by treatment group do not suggest a problem with randomisation, characteristics well balanced (IPD available). Low risk of bias Not possible to blind participants’ carers, but there is no evidence that deviations arised because of the trial context. Quote: "At 2, 6 and 12 months, the intervention group had 87%, 72.4% and 66.7% high adherence, respectively, vs. 45.2%, 45.8% and 45.5% in the control group, respectively." The control group rates are high but similar to those reported in another study by the same group (e.g. up to ~75 % in Rendell et al. 2011.). Some concerns Loss to follow‐up was 40% for eczema by 2 years and incident eczema was captured through voluntary contacting of investigators. Sensitivity analysis of IPD reveals conclusions do not change if all missing are assumed to not have eczema:  RR=0.53 [0.20, 1.35], but conclusions do change if all missing were assumed to have eczema RR=0.93 [0.65, 1.34] (point estimate of RR >20% of the complete case estimate). Low risk of bias U.K. Working Party Criteria adapted to identify incident cases, some as young as 2 weeks. Some uncertainty about validity of this tool at this age. Incident cases not followed further after first diagnosis. Low risk of bias as this is our pre‐defined preferred tool. Low risk of bias Full trial dataset provided by investigators and IPD meta‐analysis SAP followed. Some concerns Some concerns due to missing outcome data (results varied in sensitivity analysis), low risk of bias for all other domains.
Migacheva 2018 Some concerns No information given on randomization process.Baseline characteristics (russian language table) do not suggest a problem with with imbalance in a small number of key baseline characteristics, but only limited baseline aggregate data provided. Some concerns Trial not registered so intended intervention unclear and it's not clear whether the patients were analysed as randomised. Some concerns It's unclear how many participants were included in the analysis. No information available on the number of participants with missing data. The circumstances of the trial make it unlikely that missingness depends on outcome. Some concerns Eczema assessed by a trained investigator but no information on blinding status. Some concerns Not a registered trial, therefore unclear if outcomes are reported as initially planned. Some concerns This study was unregistered and reported in an abstract only, not clear regarding blinding of outcomes or missing data and analysis population.
NCT03376243 Low risk of bias Baseline variables by treatment group do not suggest a problem with randomisation, characteristics well balanced (IPD available). Low risk of bias Not possible to blind participants’ carers, but there is no evidence that deviations arised because of the trial context. The control group rates of skin care application were consistent with other trials and observational studies e.g. e.g. up to ~75 % in Rendell et al. 2011. The IPD shows daily use of emollient over intervention period by 7/27 (26%) control and 19/22 (86%) intervention participants with eczema outcomes recorded. Some concerns 49/54=91% have outcome. Sensitivity analysis using the IPD reveals conclusions do not change significantly if everyone missing is assumed to not have eczema, RR=0.73, 95% 0.24 to 2.23 but conclusions do change when all missing are assumed to have eczema RR=1.24, 95% CI 0.55 to 2.78 (point estimate of RR >20% of the complete case estimate). Low risk of bias Quote: "assessor‐blind." UKWP criteria used. Patients were followed up until they had eczema or 12 months or were lost to follow‐up. Low risk of bias Full trial dataset provided by investigators and IPD meta‐analysis SAP followed. Some concerns Some concerns due to missing outcome data (results varied in sensitivity analysis), low risk of bias for all other domains.
Skjerven 2020 Low risk of bias Quote: “we used computer‐generated cluster randomisation based on 92 geographical living area blocks as well as eight 3‐month time blocks. All infants born in the same 3‐month period and belonging to the same postal code or city area were allocated to the same intervention group”. Baseline variables by treatment group do not suggest a problem with randomisation, characteristics well balanced (IPD available). Low risk of bias Not possible to blind participants’ carers, but there is no evidence that deviations arised because of the trial context. The IPD shows regular use of emollient (ceridal cream) (≥ 3 days a week averaged over intervention period) by only 1 control participant and 262/599 = 44% intervention arm. Some concerns Outcome available for 89.8%. Sensitivity analysis using the IPD reveals conclusions do not change significantly if everyone missing is assumed to not have eczema, RR=1.42 [1.00 to 2.02] but conclusions change if all missing are  assumed to have eczema, RR=2.03 [1.56 to 2.63] (point estimate of RR >20% of the complete case estimate). Low risk of bias Used UK Working party criteria and HF at 12 months. Assessors were blinded. Low risk of bias Full trial dataset provided by investigators and IPD meta‐analysis SAP followed. Some concerns Some concerns due to missing outcome data (results varied in sensitivity analysis), low risk of bias for all other domains.
Yonezawa 2018 Low risk of bias Quote: "Randomization was performed individually according to central registration after measuring the skin barrier function at baseline.” Baseline variables by treatment group do not suggest a problem with randomisation, characteristics well balanced (IPD available). Low risk of bias Not possible to blind participant carers, but there is no evidence that deviations arised because of the trial context. The control group rates of skin care application were consistent with other trials and observational studies e.g. up to ~75 % in Rendell et al. 2011. The IPD shows regular use of emollient (≥ 3 days a week) by 63/69 (91%) intervention participants 52/87 (60%) control participants with outcomes recorded). Quote: “The frequency of bathing (mean +/‐ standard deviation [SD], 0.81 +/‐ 0.22 vs 0.99 +/‐ 0.06 times/day, P < 0.001) and soap use was lower (mean +/‐ SD, 0.50 +/‐ 0.09 vs 0.98 +/‐ 0.05 times/ day, P < 0.001), and that of lotion use was higher (1.30 +/‐ 0.67 vs 0.48 +/‐ 0.39 times/day, P < 0.001) in the intervention group than in the control group during the study period.” Some concerns 156/227 = 69% have outcome. Sensitivity analysis of IPD reveals conclusions change if all missing are assumed to not have eczema: RR=0.68 [0.29, 1.61] or if all missing are assumed to have eczema RR=1.40 [0.98, 2.00] (point estimate of RR >20% of the complete case estimate). Some concerns Eczema was collected from parents using a self‐reported questionnaire. Outcome assessors were reporters who were aware of the allocation. Low risk of bias Full trial dataset provided by investigators and IPD meta‐analysis SAP followed. Some concerns Some concerns due to missing outcome data (results varied in sensitivity analysis), low risk of bias for all other domains.