Author Contributions: Drs Tiwari, Humphreys, and Bullock had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Tiwari, Fong, Yuen, Yuk, Pang, Humphreys, Bullock.
Acquisition of data: Tiwari, Yuen, Yuk, Pang.
Analysis and interpretation of data: Tiwari, Fong, Humphreys, Bullock.
Drafting of the manuscript: Tiwari, Fong.
Critical revision of the manuscript for important intellectual content: Tiwari, Fong, Yuen, Yuk, Pang, Humphreys, Bullock.
Statistical analysis: Fong.
Obtained funding: Tiwari, Fong, Yuen, Yuk, Pang.
Administrative, technical, or material support: Tiwari, Yuen, Yuk, Pang, Humphreys, Bullock.
Study supervision: Tiwari, Fong, Yuen, Yuk, Pang.
Financial Disclosures: None reported.
Funding/Support: This study was supported by the Health and Health Services Research Fund awarded by the Food and Health Bureau of the Hong Kong SAR Government (project 04060741).
Role of the Sponsor: The funding organizations had no role in the design and conduct of the study; the collection, management, analysis, and interpretation of the data; or the preparation, review, or approval of the manuscript.
Trial Registration: This study was first registered with the Hong Kong Clinical Trial Register (http://www.hkclinicaltrials.com) (trial number HKCTR-866) on February 9, 2007, and was subsequently registered with ClinicalTrials.gov.
Additional Contribution: We thank Janet Wong, MNurs, School of Nursing, The University of Hong Kong, for contributing to the analysis of the data. Ms Wong received no compensation for her contributions.