Network support for drinking and for abstinence was measured using the Important People and Activities Instrument (IPA; Clifford & Longabaugh, 1991). The IPA is a structured interview that asks patients to identify those people with whom they spent the most time in the previous 12 months. For each person identified, the patient specifies the nature of the relationship (e.g., spouse, friend, co-worker), duration of the relationship, frequency of contact, the drinking behavior of each person (frequency and quantity), and the person's behavior with respect to the patient's drinking (neutral, supportive of drinking, supportive of abstinence). The IPA was chosen because of the ability of its subscales to predict alcohol-related outcomes (e.g., Zywiak, Longabaugh, & Wirtz, 2002). Five subscales developed for use in Project MATCH (Project MATCH Research Group, 1993) were used in the present study: Social Support for Drinking, Behavioral Support for Drinking, Attitudinal Support for Drinking, Behavioral Support for Abstinence, and Attitudinal Support for Abstinence.
