2 population aged 18 years or older. The survey is designed and conducted annually by the CDC in collaboration with the state health departments to monitor health-related behaviors and risk factors in the US population. The survey selects state-speciﬁc probability samples of households using a mul- tistage cluster design to produce a nationally representative sample. The BRFSS uses random-digit dialing within blocks of telephone numbers to identify a probability sample of households with telephones in each state. In each household, one adult is randomly identiﬁed and interviewed. All 50 states, in addition to the District of Columbia, and the three US territories participated in the 2008 BRFSS. Detailed description of the BRFSS survey sample selection and study methodology are available online [12]. In 2008, the median cooperation rate was 75.0% and the median overall response rate was 53.3% [12]. All participants provided informed consent and this study was approved by the West Virginia University Institutional Review Board. To examine the association between insuﬃcient rest/sleep and SRH, out of the 408,068 BRFSS participants who were aged ≥18 years and not pregnant, we further ex- cluded subjects with missing information on variables in- cluded in the multivariable model, including insuﬃcient rest/sleep, SRH, body mass index, smoking, education, em- ployment, physical activity, or physician-diagnosed cardio- vascular disease. This resulted in 377,160 subjects with com- plete covariate data for the current analysis. 2.2. Main Outcome of Interest: SRH. In 2008, BRFSS included a new question on self-rated health, which asks, “Would you say that in general your health is excellent, very good, good, fair, poor, or do not know/not sure?” SRH is also termed “general health” because it refers to an individual’s perception of his or her own health. The SRH continuum has been shown to be a reliable indicator of a person’s objective or true health status [13]. A negative association between SRH and all-cause mortality has also been established [14]. 2.3. Exposure Measurements. The 2008 BRFSS survey includ- ed the question, “During the past 30 days, for about how many days have you felt you did not get enough rest or sleep?” Data from all sites were aggregated, and the numbers of days of perceived insuﬃcient rest or sleep were categorized into six groups as zero days, 1–6 days, 7–13 days, 14–20 days, 21–29 days, and 30 days. This question was previously tested and validated in the 2006 BRFSS survey in four states (Delaware, Hawaii, New York, and Rhode Island) [15]. Also, national estimates of insuﬃcient rest or sleep according to these categories have been recently published by the CDC [16]. Age, gender, race/ethnicity, smoking status, alcohol intake, level of education, employment status, income, and physical activity were assessed using a standardized ques- tionnaire. Individuals who had not smoked ≥100 cigarettes in their lifetimes were classiﬁed as never smokers; those who had smoked ≥100 cigarettes in their lifetimes were classiﬁed as former smokers or current smokers based on their response to the question on current smoking. Heavy Journal of Environmental and Public Health alcohol drinking was deﬁned as men who reported having more than 2 drinks per day, or more than 1 drink per day for women. Education was categorized into below high school, high school, or above high school education. Employment status was categorized as employed, unemployed, retired, unable to work, homemaker, or student. Body mass index (BMI) was categorized into <25, 25–29, ≥30 kg/m2. Subjects were classiﬁed as having no regular exercise if they reported not to be participating in any physical activities such as running, calisthenics, golf, gardening, or walking for exercise during the previous month. People married at the time of the survey were classiﬁed as married, while widows and divorcees were coded as unmarried. The annual household income variable was reported in quintiles as follows: less than $15,000, $15,000–$24,999, $25,000–$34,999, $35,000– $49,999, $50,000 or more. Depression (description used in BRFSS questionnaire: depression, major depression, dysthymia, or minor depression) and anxiety (description used in BRFSS questionnaire: acute stress disorder, anxiety, generalized anxiety disorder, obsessive-compulsive disorder, panic disorder, phobia, posttraumatic stress disorder, or social anxiety disorder) were categorized into dichotomous, yes/no variables. 2.4. Statistical Analysis. We examined the characteristics of the study sample by calculating variable frequencies. Perceived insuﬃcient rest/sleep was categorized into six groups as zero days, 1–6 days, 7–13 days, 14–20 days, 21–29 days, and 30 days. Our single outcome of interest was SRH. We used logistic regression models to calculate odds ratio ((OR) (95% conﬁdence interval (CI)) of the outcome of interest associated with increasing categories of insuﬃcient rest/sleep, taking zero days of insuﬃcient rest/sleep as the referent category. We used two logistic regression models: the unadjusted model and the multivariable model, adjusting for sex (men, women), age (years), race-ethnicity (non-Hispanic white, non-Hispanic black, Hispanic, other), education cate- gories (<high school, high school, >high school), (employed, unemployed, retired, unable to work, homemaker, student), income category (quintiles), marital status (no, yes), smoker (never, former, current), heavy drinker (no, yes), no regular exercise (yes, no), BMI (<25, 25–29, ≥30 kg/m2), CVD (no, yes), depression (no, yes), and anxiety (no, yes). Trends in the OR of the outcome across increasing insuﬃcient rest/sleep category were determined by modeling these categories as an ordinal variable. Appropriate BRFSS survey weights that account for unequal probabilities of selection, oversampling, and nonresponse were applied for all analyses using SUDAAN (version 8.0; Research Triangle Institute, Research Triangle Park, NC) and SAS (version 9.2; SAS Institute, Cary, NC) software; SEs were estimated using the Taylor series linearization method. 3. Results Table 1 presents characteristics of the study population. Nearly half of the study population were women, and about 17% were 65 years of age or older. Blacks comprised 9.7%