Author Contributions: Drs Subramanian and Ackerson 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: Subramanian, Ackerson, Davey Smith, John.
Acquisition of data: Subramanian.
Analysis and interpretation of data: Subramanian, Ackerson.
Drafting of the manuscript: Subramanian, Ackerson, John.
Critical revision of the manuscript for important intellectual content: Subramanian, Ackerson, Davey Smith.
Statistical analysis: Subramanian, Ackerson.
Administrative, technical, or material support: John.
Study supervision: Subramanian, Davey Smith.
Financial Disclosures: None reported.
Funding/Support: Dr Subramanian is supported by a National Institutes of Health Career Development Award (NHLBI K25 HL081275).
Role of the Sponsor: The National Institutes of Health and Macro International Inc 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 acknowledge the support of Macro International Inc (Washington, DC) for providing access to the 2005-2006 Indian National Family Health Survey 3 data.