Contribution to authorship
DS Sahota 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. LC Poon and DS Sahota designed the study. P Chaemsaithong, YM Wah, SY Hui, YH Ting, KM Lam, TY Leung were responsible for data collection and confirmation. DS Sahota analyzed the data. WT Sin and DS Sahota were in charge of data interpretation and writing the manuscript raft. WT Sin, LC Poon and DS Sahota made substantial revisions to the manuscript.