Structured abstract template
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The recommended structure for research submissions. Copy each heading into the submission form and replace the guidance text.

## Title
- Concise, specific, and free of abbreviations.

## Authors and affiliations
- Presenting author first, marked with an asterisk.
- List each affiliation once and reference it by number.

## Background
- Why the problem matters and what is currently unknown (2-3 sentences).

## Methods
- Study design, setting, data sources and cohort.
- Model or intervention description, including validation approach.

## Results
- Primary outcome with effect size and uncertainty.
- Secondary outcomes and any subgroup findings.

## Conclusion
- What changes for clinicians, patients or health systems.

## Conflict of interest
- Declare funding, employment and commercial relationships, or state 'None'.