This work was supported by VA Health Services Research and Development IIR grant 18-231-2 from the US Department of Veterans Affairs Health Services. Support for US Department of Veterans Affairs (VA) and Centers for Medicare & Medicaid Services data was provided by the VA, VA Health Services Research and Development Service, and VA Information Resource Center (project numbers SDR 02-237 and 98-004). In addition, NN is supported by the California Tobacco-Related Disease Research Program (grant number T32KT5071), the NIH/National Institute on Drug Abuse (K01DA056693), and the Hellman Fellowship. The content is solely the responsibility of the authors and does not necessarily represent the official views of the funding agencies. The views expressed in this article are those of the authors and do not necessarily represent the views of the Department of Veterans Affairs and the funding agencies.