The NHS is under increasing pressure to cut costs while delivering high quality care. At the same time, the demand for healthcare services has grown, driven in part by the increasing number of older people in the population. NHS Trusts are adopting clinical decision support systems (CDSSs) to help decision making at the point of care. CDSSs are said to bring benefits such as improvements in guideline adherence, clinical processes and user performance but evidence of these benefits is not always available and their effectiveness in terms of improving patient outcomes is often open to question. This thesis presents research that was carried out in a large teaching NHS Trust looking at the evaluations of three CDSSs. Semi structured interviews were carried out with key informants who were involved in their adoption, use and evaluations. Documentary analysis and observations were also used to augment the interviews. Most evaluations were carried out informally by the developers and were primarily driven by external regulatory pressures rather than patient outcomes and organisational needs. Evaluation documentation was inadequate or missing, thus making it difficult to systematically assess these evaluations. This thesis contends that evaluations are important to provide decision makers in NHS Trusts with adequate information to make decisions about CDSSs and computerised healthcare information technologies in general. NHS Trusts need to build organisational capacity and readiness to enable them to effectively carry out evaluations that will provide meaningful information to gain better understanding of CDSSs and to inform their successful adoption, implementation, usage and to justify the resource allocation. This research shows that CDSS evaluations investigated took a predominantly narrow view. It thus provides evidence for the need for a more systemic approach to evaluation
