Low concentration atropine eye drops and progression of myopia in children: multicentre placebo controlled, double masked, randomised trial in the UK (CHAMP-UK).

The introduction cites prior epidemiological trends, a Cochrane review highlighting uncertainties, and gaps in evidence for Western populations. The rationale directly follows: atropine is used worldwide but not available in the UK NHS, and existing trials have variable results. Limitations of prior research (e.g., small samples in European studies, lack of objective adherence monitoring) are explicitly discussed and addressed in the study design.

Randomisation was computer-generated using a minimisation algorithm (2:1), with allocation concealed from recruitment staff. Unit is individual participant. Double-masking is described explicitly (participants, investigators, monitors all masked). A power analysis with sample size justification is present (90% power to detect 40% reduction, accounting for 15% dropout). Inclusion/exclusion criteria are pre-specified and detailed. Outlier handling is addressed via sensitivity analyses with extreme value imputation and complete-case primary analysis. Controls (placebo) and independent replication (comparison with other trials) are not applicable for a human RCT; replicate distinction is also n/a. Blinding levels are adequate.

Sex, age, weight, height, ethnicity, parental myopia, and baseline myopia severity are reported in Table 1. Health status is addressed through exclusion criteria. For a human RCT, species/strain and housing are not applicable.

The paper explicitly states ethics approval by the Office for Research Ethics Committees Northern Ireland (reference 18/NI/0164). Parental consent is mentioned: 'After parental consent had been obtained, children were screened and, if eligible, enrolled and randomised.' Regulatory compliance is stated with the European Clinical Trials Directive 2001/20/EC. All applicable criteria (irb_ethics_statement, informed_consent, regulatory_compliance) are reported adequately.

The atropine formulation is described: 'preserved atropine sulfate 0.01% eye drops' with preservative benzalkonium chloride 0.01% w/v. The placebo is identical. The manufacturer of the drug is stated: Stockport Pharmaceuticals. The MEMS device is identified (AARDEX Group, Switzerland). The autorefractor models are listed. Statistical software is identified (Stata version 15.1). The clinical trial database is identified (MACRO release 4.9.1). All these are reported_and_adequate. Reagents_identified applies to the investigational product.

Tests named include GEE, independent t-test, ANCOVA, χ² tests, repeated measures mixed models. Exact p-values reported (e.g., P<0.001, P=0.003). Effect sizes and 95% CIs are reported for all primary and secondary outcomes. Statistical software is identified (Stata 15.1). Data presentation: Table 2 provides per-group n, means, SDs, and CIs. Individual data points are not shown but this is a clinical trial, so the CONSORT-type presentation is adequate. Assumptions_verified is adequate for a human trial using standard methods (GEE, mixed models). Mathematical_plausibility: no demonstrable arithmetic errors were detected in the reported data (e.g., baseline means and SDs plausible, percentages sum appropriately within rounding).

The data availability statement states: 'The data underlying the findings in this paper are openly and publicly available and can be found here: https://doi.org/10.25934/PR00013003 .' This is a concrete route with a DOI. The code used to analyse the data is stated to be in the supplemental files. Repository_deposit is adequate (DOI). Accession_numbers are n/a (no sequencing data). Code_sharing is reported_and_adequate: 'The code used to analyse the data in the paper can be found in the supplemental files.' The DOI link and supplemental code are explicit.

Methods are detailed enough for replication (dosing, timing, measurements, statistical methods). The trial is registered with two registries (ISRCTN99883695, NCT03690089). No explicit reporting checklist (CONSORT) is referenced in the methods, but the paper follows CONSORT-like structure and includes a flow diagram (Fig 1). All outcomes listed in the Methods are reported in the Results. Limitations are discussed in a dedicated section (Strengths and limitations), including adherence, generalisability, subgroup power, the COVID-19 pandemic, and unvalidated tolerability questionnaire. Conclusions are appropriately cautious: 'should be considered as an alternative to manage myopia progression' — not overclaiming causation. Funding (NIHR EME) and competing interests are comprehensively disclosed.