Who used the exchange?
summarizes, for each month, the total number of visits across participating sites and the rate of HIE access. As sites were added, the total visit number increased with time. The HIE access rate was also increasing during the study period in general, except for one major healthcare organization which changed its HIE usage policy in June 2008 resulting in a sharp decline in HIE use. After approximately 24 months, overall rates of access steadily increased from 4% to 6.5% of patient encounters across all participating sites. As summarized in , using data from the last month of the study, HIE access rates varied among sites, ranging from <1% to 16%. HIE access averaged 14.6% for return visits to the ED (defined as a second visit within 30 days) and 18.7% for return visits to the clinics (p<0.001).
Figure 3 Health information exchange (HIE) access overview. This figure depicts monthly emergency department visits at participating sites, percent of visits for which HIE data were accessed, and the number of participating sites. Total visits increased as more (more ...)
Figure 4 Health information exchange (HIE) access rate by site. The figure shows rates of HIE access with 95% CIs for new and return visits, and associated logon activity for each site. Physician and nurse/clerk logon activity are shown separately. For each site, (more ...)
HIE access rates were highest at sites serving the underserved (ED A, ED K, ED N, ED B, ED H) and lowest at sites with specialized patient populations (ED G, ED I). HIE access rates differed significantly between ED sites and clinic sites (6.9% vs 5.8%; p<0.001). HIE access was higher for all return visits within 30 days. In primary care clinics, return visits were associated with HIE access more often than return visits in ED sites (18.7% vs 14.6%; p<0.001). HIE access was significantly higher for patients with high levels of comorbidity (28% access with one or more comorbidities vs 24% access with no comorbidities; mean Charlson score of 0.47 vs 0.375; p<0.001). Sites with no nurse or clerk access to HIE had very low levels of access, while sites with nurses, clerks, and physicians accessing the system had the highest levels of access.
Visits typically fell into one of four categories, as shown in . HIE access was lowest for visits where there was no chance of data being present in the exchange, and highest for visits where data were present from another site of care.
Health information exchange (HIE) access rates according to number and type of visits to exchange sites
System usage varied by site and was related to the roles of people with HIE access and site policies governing use. Interviews disclosed a strong association between HIE access and the involvement of nursing and registration staff. For example, one of the two primary care groups printed a summary record whenever a patient was being seen for follow-up or had not been seen in over a year. This site had nearly twice the rate of access as the other primary care group. As seen in , there also was a large decrease in overall usage in June 2008, related to a policy change at site ED K. This site initially permitted registrars to search for each patient in the exchange and to print out a summary sheet if any records were available from other sites. Nurses, nurse practitioners, and physicians could then choose to check the exchange based on this information. As more functionality became available, clinical security team members judged that removing access from registrars and nurses would reduce the risk of privacy breaches. Use subsequently shifted to nurse practitioners and physicians, radically decreasing HIE access rates at this site.
Usage at one pediatric tertiary care site approached 0%, despite high levels of available data in the system for their patient population. At the time the system became available at this site, very little data from external sites were available, thus providing marginal benefit for HIE use. Users initially consulted the system at a high rate, but once the limited amount of available data became clear, usage dropped precipitously. Although more data from external sites became available over time and users at the pediatric site were repeatedly notified of the additional available data, usage remained low. Users across multiple sites reported lack of awareness regarding available data and when additional data were made available.
Which data were accessed?
Most HIE access began from the Recent Registration screen, which displayed the patients currently checked into the registration system at the local site. Because this screen listed whether or not each patient had data in the exchange from other sites, accessing this page may have been sufficient to impact further usage. In the small number of sites where the Recent Registration screen was not available, users searched for patient data using patient information such as medical record number, social security number, or a combination of demographic information including name, gender, and date of birth.
summarizes the frequency and types of data accessed. For the purposes of this analysis, we considered a data type accessed each time a screen of that data type was displayed for a particular patient by a specific provider. The most common usage pattern involved starting from the Overview screen. This screen provides access to all other patient-specific data in MSeHA including information on encounter date, service, and all related data. The Overview screen also lists each screen available and the percent of MSeHA use for each screen. From the Overview screen, users were able (, top) to review reports, patient demographic information, aggregated laboratory data, medication history data for one insurance provider, discharge summaries, or all data collected during a specific visit. Because multiple reports could be viewed from the report view, this page was accessed more than once for some visits. Also, two screens (Aggregated Laboratory Results and Medication List) were modified extensively after their initial roll out, based on user needs. Despite these modifications, use of these screens remained consistently low.
Frequency of data types accessed.
Percent of access is based on the total number of times the corresponding tab is selected, divided by the total number of HIE accesses during the study period. Note that both survey and observational data disclosed that users lacked clarity about the exact scope of HIE participation, the types of data contributed from different organizations, and the timing of data availability. These concerns were voiced frequently by experienced users, especially when sites took over the task of ongoing system training and education about enhancement updates.
Reasons for and consequences of use
User feedback gathered through interviews disclosed multiple themes about factors that prompted providers to access the exchange, including issues with patient–provider communication, patient-disclosed visits to other sites, concerns about patient willingness to share information, following up on referrals, medication reconciliation, and identifying the preferred site of care. provides specific provider feedback from users at the point of care regarding reasons why the exchange was accessed, as well as consequences of HIE access.
Primary user-reported consequences of health information exchange use
Patient opt-out rates
Patients whose records were included from various sites had the option of opting out so that either all records or records from one site were not available. Throughout the implementation of the exchange, the opt-out rate remained constant at 1%–3%.