Reliability and Construct Validity of the Needle Sharing Inventory

Abstract

The Needle Sharing Inventory (NSI) is a 59-item test developed to specify and assess behavior patterns associated with drug use and needle sharing. In order to determine its reliability and construct validity, the NSI was administered to 80 intravenous drug users (IVDUs) recruited from a methadone maintenance program in New York City. Patients were included in the study if they reported using intravenous drugs during the previous month. Factor analysis was performed indicating that 31 of the items loaded onto 6 factors similar to those hypothesized: four dealing with the social context of needle sharing — indiscriminate sharing, social sharing, intimate sharing, and use of shooting galleries; and two dealing with the emotional context of intravenous drug use — negative affect states and positive affect states. These variables accounted for 71% of the total variance, suggesting internal consistency of these items. Factor scores significantly correlated to subjects' self- reported estimates of time using nonsterile needles and sharing needles. These data suggest that the NSI is both a reliable and a valid measure which may be used in future studies of intravenous drug use and needle sharing behavior patterns. The NSI may prove useful for the purpose of developing and evaluating interventions aimed at preventing or reducing the spread of HIV through needle sharing.