Author Contributions: Dr Williamson had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Williamson, Little.
Acquisition of data: Williamson, Rumsby, Benge, Moore, Cross.
Analysis and interpretation of data: Williamson, Rumsby, Benge, Moore, Smith, Little.
Drafting of the manuscript: Williamson, Benge, Smith, Little.
Critical revision of the manuscript for important intellectual content: Williamson, Rumsby, Benge, Moore, Cross, Little.
Statistical analysis: Williamson, Rumsby, Benge, Smith, Little.
Obtained funding: Williamson, Little.
Administrative, technical, or material support: Rumsby, Benge, Moore, Cross.
Study supervision: Williamson.
Financial Disclosures: Dr Little reported receiving consultancy fees for 2 half days from Abbott Pharmaceuticals regarding complications of respiratory tract infections. No other authors reported financial disclosures.
Funding/Support: This study was supported by the UK Department of Health.
Role of the Sponsor: The UK Department of Health did not participate in the design and conduct of the study, in the collection, analysis, and interpretation of the data, or in the preparation, review, or approval of the manuscript.
Additional Contributions: We thank the funders at the UK Department of Health, the patients who participated, and the recruiting physicians and practices.