Phase I: quantitative study Facility selection Because we were interested primarily in facility-level differences in alert management practices, we used a three-step process to select facilities from which to recruit participants. Step 1: Calculating perceived vulnerability. We conducted Temsirolimus FDA a cross-sectional, web-based survey of all VA PCPs (N=5290) from June 2010 through November 2010. The survey content was guided by our eight-dimensional

sociotechnical model16 and assessed PCPs’ perceptions of multiple facets of EHR-based test-result notifications. The survey was developed by a multidisciplinary team who wrote and refined items using input from subject-matter experts and then pilot testing the survey for readability, clarity and ease of completion. Details of the survey development are published elsewhere.17 We classified facilities on the basis of PCPs’ responses to two items in this survey17: “I missed alerts that led to delayed care” and “The alert system

makes it possible for providers to miss alerts.” Both survey items were rated on a five-point Likert scale from ‘strongly agree’ to ‘strongly disagree’. Responses to these two questions were positively correlated13 with responses pertaining to information overload,11 22 23 which itself is related to safety, system performance,24 and organisational and communication practices.25 We calculated the mean of the two question scores to create an aggregate score of perceived

vulnerability to missed test results. We sorted facilities by perceived vulnerability score and designated those with a score in the top 30% (3.315 or above on a five-point scale) and bottom 30% (2.947 or lower) as low and high perceived risk, respectively. Step 2: Adjusting for site characteristics. We controlled for facility-level structural characteristics using the ‘nearest neighbour’ methodology for creating peer groups for healthcare facilities.26 Our criteria for peer grouping by facility complexity included patient volume, academic affiliation, disease burden and patient reliance on VA for healthcare, care delivery structures, medical centre infrastructure and community Brefeldin_A environment.26 Step 3: Prioritizing facility pairs. We generated a list of potential pairs of high and low perceived risk facilities with otherwise relatively similar structures (ie, for each facility pair, the structural difference score was small), attempting to maximise contrasts between structural similarity and differences in perceived vulnerability. We contacted 48 facilities for participation in this order of prioritisation. Participants We separately interviewed one patient safety manager (PSM, n=40) and one IT/EHR staff member (designated in the VA as clinical application coordinator (CAC, n=40)) at each facility.