The NCS-R is a nationally representative survey of 9282 noninstitutionalized participants 18 years and older in the coterminous United States.21- 23 Respondents were selected from a multistage clustered area probability sample of households. Face-to-face interviews were conducted in respondents' homes between February 2001 and April 2003. Individuals residing in nursing homes, assisted living, and independent living facilities were therefore excluded from the sample. Any clustering of respondents by retirement communities was alleviated by the household enumeration procedures used in NCS-R to create a national probability sample. Professional interviewers from the Institute for Social Research at the University of Michigan, Ann Arbor, carried out interviews. The response rate was 70.9%.21