Diagnostic assessment
Diagnosis of past-year dependence on alcohol or drugs was based on the Alcohol Use Disorder and Associated Disabilities Interview Schedule—DSM-IV Version (AUDADIS-IV). The AUDADIS-IV includes an extensive list of symptom questions that separately operationalize DSM-IV criteria for abuse of and dependence on alcohol and ten classes of illicit or prescription drugs (referred to as "medicines" in the interview). Consistent with the DSM-IV, AUDADIS-IV past-year dependence diagnoses require at least three of the seven DSM-IV criteria for dependence to be met during the past year.
The AUDADIS-IV was also used to generate diagnoses of past-year mood disorders, including major depression, dysthymia, mania, and hypomania; past-year anxiety disorders, including panic disorder with and without agoraphobia, social phobia, specific phobia, and generalized anxiety disorder; and personality disorders, including schizoid, paranoid, avoidant, dependent, obsessive-compulsive, histrionic, and antisocial. Mood and anxiety diagnoses in NESARC are consistent with
DSM-IV criteria for primary or independent diagnosis, meaning that mental disorders that are substance induced, a result of a general medical condition, or entirely accounted for by bereavement were excluded (
14 ). Numerous studies conducted with clinical and general population samples have demonstrated good to excellent reliability and validity of the AUDADIS-IV diagnoses (
13,
14,
15,
16 ).
Variables
Dependent variable. Respondents were asked, "Have you ever gone anywhere or seen anyone for a reason that was related in any way to your drinking or use of medicine or drugs?" Responses included Alcoholics Anonymous or any other type of 12-step meeting; family services or another social service agency; alcohol or drug detoxification program; inpatient ward of a psychiatric or general hospital or community mental health program; outpatient clinic, including outreach programs and day or partial hospital programs; alcohol or drug rehabilitation program, including methadone maintenance; emergency service; halfway house or therapeutic community; crisis center; employee assistance program; clergyman, priest, rabbi, or any type of religious counselor; private physician, psychiatrist, psychologist, social worker, or any other medical or social services professional or agency.
Respondents who indicated that they had sought help from any of the options within the past 12 months were coded as 1, for having received help, on the dependent variable. Those who indicated they had not received help were asked, "Was there ever a time when you thought you should see a doctor, counselor, or other health professional or seek any other help for your drinking or medicine or drug use?" Respondents who indicated yes with reference to the past 12 months were coded as 2, for perceived a need for help but did not receive it. All others were coded as 3, for no perceived need for help and no help received in the past year.
Predictor variables. These variables were selected on the basis of the conceptual model of health services utilization and organized into three groups, as described below.
Predisposing variables referred to fixed characteristics of the individual and included gender, ethnicity (dichotomized into nonwhite and white because of small cell sizes for some of the categories), age, and educational status (categorized into less than high school, high school graduate, and some college or higher).
Enabling variables represented factors that may facilitate or impede help-seeking behavior. These were marital status (categorized into married or living with someone; widowed, separated, or divorced; and never married), household income, place of residence (urban or rural), U.S. region of residence (Northeast, Midwest, South, or West), and health insurance status (yes or no).
Need-related variables pertained to the type, history, and severity of substance dependence and associated problems. These included whether the individual had ever sought help for an alcohol or drug problem prior to the past year and the type of substance dependence (alcohol only, drug only, or alcohol and drug). The average number of years since the onset of dependence was calculated on the basis of earliest age of onset of alcohol or any drug dependence for cases in which there was dependence on more than one type of substance. Mean imputation was used for 56 cases with missing values, with imputation based on both age category and type of substance. A square-root transformation was performed on this variable because of data skewness. Past-year mood or anxiety disorder or lifetime personality disorder were coded as separate dichotomous variables. Having a family member with alcohol or drug problems comprised "natural or blood relatives," including parents, siblings, children, aunts or uncles, or grandparents who had physical, emotional, legal, familial, work, or health problems related to their use of alcohol or drugs.
Problems related to substance use were determined by asking respondents whether they had had problems in the past year stemming from their use of alcohol or drugs with regard to job or school, driving, risk of getting hurt, trouble with family or friends, physical fights, taking care of home or family, or legal issues. Positive responses to each item (responses taken separately for alcohol and drugs) that had occurred in the past year were coded as 1 and summed for an aggregate measure that ranged from 0 to 14 and was entered as a continuous variable in the multivariate models. Current health status was assessed by an item that asked respondents to classify their health as poor, fair, good, very good, or excellent; this variable was dichotomized as good to excellent, coded 1, or fair to poor, coded 0.