Rationale: Electronic knowledge resources are routinely searched by physicians for clinical information in practice. With respect to searching, no studies have systematically assessed the relevance of clinical information, its cognitive impact, the use of information for specific patients and information-related patient health benefits. In our companion paper (Part 1) we critically reviewed the literature and proposed a model of the value of clinical information for health professionals, which includes types of information use and subsequent patient health benefits. Aims and objectives: The purpose of the present paper (Part 2) is to systematically examine patient health benefits associated with physicians’ use of information retrieved from one electronic knowledge resource in routine clinical practice. Methods: Longitudinal mixed methods study. Cases were 84 critical searches for information for patients conducted by 16 family medicine residents over two months. Using the Information Assessment Method (IAM), each ‘opened’ information object was linked to a questionnaire (n = 309). IAM permitted residents to systematically document the cognitive impact of information. Guided by reports of quantitative data, residents were interviewed to explore the search context, the cognitive impact, the use of information and information-related patient health benefits. Results and conclusion: Our results suggest patterns of information use and show that 14.3% of residents’ searches were associated with health benefits. This suggests a new concept we refer to as the Number Needed to Benefit from Information (NNBI). In this study, the number of patients for whom information was retrieved to observe health benefits for one patient, was seven.