Author Contributions: Dr Hung 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: Hung, Cocks, and Graham. Acquisition of data: Cocks and Ong. Analysis and interpretation of data: Hung, Chan, Cocks, Rainer, and Graham. Drafting of the manuscript: Hung and Cocks. Critical revision of the manuscript for important intellectual content: Hung, Chan, Cocks, Ong, Rainer, and Graham. Statistical analysis: Hung, Chan, and Graham. Obtained funding: Hung and Graham. Administrative, technical, and material support: Rainer and Graham. Study supervision: Chan, Cocks, and Graham.