The purpose of this study was to identify essential evidence-based components of first-episode psychosis services.
The study was conducted in two stages. In the first stage a systematic review of both peer-reviewed and gray literature (January 1980 to April 2010) was conducted. Databases searched included MEDLINE, PsycINFO, and EMBASE. In the second stage, a consensus-building technique, the Delphi, was used with an international panel of experts. The panelists were presented the evidence-based components identified in the review, together with the level of supporting evidence for each component. They rated the importance of each component on a 5-point scale. A score of 5 was required to determine that a component was essential.
The review identified 1,020 citations; abstracts were reviewed for relevance. A total of 280 peer-reviewed articles met criteria for relevance. Two researchers independently reviewed these articles and identified 75 unique service components. Each component was assigned a level of supporting evidence. Twenty-seven experts completed the first Delphi round, of whom 23 participated in the second. Consensus was achieved in two rounds, with 32 components rated as essential.
The two-step process yielded a manageable list of 32 evidence-based components of first-episode psychosis services. Given the proliferation of such services and the absence of an evidence-based fidelity scale, this list can form a foundation for developing a fidelity scale for such services. It may also be helpful to funders and providers as a summary of essential services.