Finally, Andrew Balas, M.D., Ph.D., University of Missouri-Columbia, convened experts in medical informatics for a telephone conference to assist the study staff in formulating questions about the role of information technologies in these micro-systems.

The first task of the steering group was to develop a clear conceptual and operational definition of the micro-system that would be easily conveyed to the interview sites. Some questions the group addressed were: What size group is too big or too small to be a micro-system? How can we identify micro-systems? That is, what definition would include perhaps 80 percent of the groups that we were to talk with but not be too restrictive? The group did not establish a priori a minimal or maximum size for a micro-system. Generally, a micro-system must be large enough to accomplish its clinical purpose, but small enough to allow knowledge of the individual parts and to manage the interactions among its parts. The group identified several ways that micro-systems might recognize themselves as groups, including

• the members recognize themselves as having a common aim, service line, or clinical purpose such as care of patients with a specific clinical condition, a panel of patients, or care of a defined population; there is a self-conciousness about working together for a defined purpose; or

• units that have a direct service relationship to patients; that is, they speak to or touch the patient or are “one step away” from doing so;

• the members recognize themselves as part of a team that consciously organizes its work processes;

• the people who share an intimacy of working relationship; and

• the people who cross-cover for one another, share call rotation, define the content and process of care for their patients and formulate clinical guidelines.

The Steering Group developed the following working definition of a micro-system, choosing a general and inclusive definition so that it might learn from the respondents how they describe their own micro-systems. A micro-system is a small, organized patient care unit with a specific clinical purpose, set of patients, technologies and practitioners who work directly with these patients.

During the second stage of the study we developed and finalized the protocol, selected the micro-system sites, drafted, pilot tested, and revised the interview instruments, conducted tests of interrater reliability, conducted the interviews, and transcribed notes.

During late spring and summer 1999—we developed the methodology and structured interview content. The Steering Group reviewed several drafts of the interview protocol and instruments. The methodology used was a structured one and a half-hour interview with each micro-system leader preceded by a mailed two-page pre-interview survey