Article:

Brix, N., Ernst, A., Lauridsen, L. L. B., Parner, E. T., Arah, O. A., Olsen, J., Henriksen, T. B., Ramlau, H. C. H., & Ramlau-Hansen, C. H. (2020). Risk of selection bias due to non-participation in a cohort study on pubertal timing. Paediatric & Perinatal Epidemiology, 34(6), 668-677. https://doi.org/10.1111/ppe.12679

1. Identify and describe the data sources and sampling techniques used in the article above.
2. Describe any imprecision or measurement error you see in the article.
3. Explain possible sources of selection bias and/or information bias in the article.
4. Explain any attempts by the researchers to mitigate the effects of these biases.
5. Support or challenge the researchers' approach. Include an explanation of changes you would propose, if any, to the study design. Justify your position.