LACHS is a random-digit-dialed telephone survey of the noninstitutionalized population in Los Angeles County.4 The adult (persons aged ≥18 years) component of the survey was conducted during September-December 1999. Of 15,301 adults eligible for participation, 8354 (54.6%) completed the survey. Interviews were offered in English, Spanish, Cantonese, Mandarin, Korean, and Vietnamese. All respondents were asked (1) "Would you say that in general your health is excellent, very good, good, fair, or poor?"; (2) "Now thinking about your physical health, which includes physical illness and injury, for how many days during the past 30 days was your physical health not good?"; (3) "Now thinking about your mental health, which includes stress, depression, and problems with emotions, for how many days during the past 30 days was your mental health not good?"; and (4) "During the past 30 days, for about how many days did poor physical or mental health keep you from doing your usual activities, such as self-care, work, or recreation?"