Attention is frequently focused on patient records in hospitals rather than in outpatient settings. (An inpatient record is used by many different individuals during an episode of illness, so its weaknesses can appear quite pronounced.) Yet outpatient records are greater in number, are scattered among individual physician offices, and may exhibit even greater variance in quality than inpatient records. There are no established standards or review organizations for outpatient records as there are for inpatient records. As a result, outpatient records often serve as files for ''correspondence and reports rather than as a well organized chronology of health care" (Pories, 1990:49).
Ambulatory care records frequently contain poorly organized data, lack documentation of key aspects of care, and exhibit inaccurate diagnostic coding (IOM, 1990c). Health care researchers and clinicians who conduct retrospective studies using such records are likely to identify at least four weaknesses: lack of standardization in content and format, inaccessibility (except in some hospitals or large health plans), incompleteness, and inaccuracies (Davies, 1990).
Providing high-quality health care services is an information-dependent process. Indeed, the practice of medicine has been described as being "dominated" by how well information is processed or reprocessed, retrieved, and communicated (Barnett, 1990). An estimated 35 to 39 percent of total hospital operating costs have been associated with patient and professional communication activities (Richart, 1970). Physicians spend an estimated 38 percent (Mamlin and Baker, 1973) and nurses an estimated 50 percent (Korpman and Lincoln, 1988) of their time writing up patient charts.
Information-processing activities associated with providing health services to patients are extremely varied. Clinicians obtain and record information about patients, consult with colleagues, read scientific literature, select diagnostic procedures, interpret results of laboratory studies, devise strategies for patient care, instruct allied health professionals, discuss care plans with patients and families, and document the progress of patients. In addition, health care practitioners must distill knowledge, interpret data, apply knowledge, and manage the complexities of medical decision making (Haynes et al., 1989; Greenes and Shortliffe, 1990). Thus, health care professionals routinely need access to appropriate compilations of thorough, up-to-date knowledge and advice to make prompt, informed decisions regarding