Response to Letters to the Editors: 1. More details on the database used by the study should be provided. 2. Mediclaim Hospital Discharge System and income levels of cohort

Affiliations

• ¹ Duke-NUS Graduate Medical School Singapore, Singapore; Department of Rheumatology and Immunology, Singapore General Hospital, Singapore. Electronic address: [email protected].
• ² Epidemiology & Disease Control Division, Ministry of Health, Singapore.
• ³ Duke-NUS Graduate Medical School Singapore, Singapore.
• ⁴ Division of Cancer Control and Population Sciences, University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA.
• ⁵ Division of Cancer Control and Population Sciences, University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA; Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA.
• ⁶ Duke-NUS Graduate Medical School Singapore, Singapore; Saw Swee Hock School of Public Health, National University of Singapore, Singapore. Electronic address: [email protected].