Abstract
OBJECTIVE: Evaluators must develop methods to characterize the use of the rapidly proliferating electronic networks that link patients with health services. In this article the 4-S framework is proposed for characterizing the use of health services delivered via computer networks. The utility of the 4-S framework is illustrated using data derived from a completed, randomized field experiment in which 47 caregivers of persons who had Alzheimer's disease accessed ComputerLink, a special computer network providing information, communication, and decision support to homebound caregivers of persons who have Alzheimer's disease. DESIGN: Human-computer interaction theories characterize the use of health services delivered via computer networks in behavioral terms. The 4-S framework incorporates perspectives based on user (subject) behavior: access to and use of the total system, use of specific services, behavior within single sessions, and enduring behavioral characteristics. The 4-S framework was tested in a secondary analysis of data from over 3,800 uses of ComputerLink. MEASUREMENT: The 4-S framework was instantiated using data obtained from the ComputerLink evaluation. Three types of secondary data were obtained. A passive monitor of access to the computer network provided quantitative information, such as time of day when access occurred, duration of access, and sequence of services used. Full-text messages were available from the public message postings. Subjective appraisal of use was obtained from self-reporting by users at the end of the experiment. RESULTS: The components of the 4-S framework were suitable to characterize operational aspects of ComputerLink use by Alzheimer's disease caregivers. Through application of the 4-S framework, an understanding of both quantitative use and qualitative use emerged (e.g., insight was gained into the differential use of specific services). CONCLUSIONS: The 4-S framework provided a mechanism for combining various measures of use into a coherent whole. The framework promotes a precise characterization of use and thereby facilitates evaluation of health services delivered via computer networks. It is suitable for evaluation of user satisfaction, measurement of needs resolution, and ascertainment of selected clinical outcomes.