During the November 2005 – April 2006 timeframe, there were a total of 127,031 link outs to resources. Of the 127,031 total link outs, 24,015 were to free resources. This is 19% of the total link outs. When the guest users are removed from the analysis, there were a total of 107,602 link outs to resources by registered ADL members. Of those link outs, 15,712 were to free resources. This indicates that 15% of the link outs by the registered users are to free resources. It is important to note that since guests only have access to free resources, 100% of resource use by guests as measured by link outs is for free resources. Despite the fact that a slim majority of resources are free, the vast majority of resource use through the ADL is to licensed resources. This confirms data gathered from a user survey in 2004 where users placed primary value on the ADL as a source for licensed resources. It seems clear that while the free resources are used, that they are not the primary resources accessed by ADL licensed users.
There are 2056 free resource URLs in the ADL, to which 1351 were linked out, meaning there was at least one link out to 65% of the free resources. The single most popular free resource was PubMed with 4803 link outs or nearly 20% of the total link outs to free resources. PubMed's popularity as the most accessed free resource can be seen in the fact that nearly 20% of the total link outs to free resources are to PubMed. The second most popular resource, MedlinePlus, only has approximately 3% of the total link outs to free resources. PubMed also ranks highly among all resources, free and licensed together – accounting for 3% of the total link outs. Other than the University of North Carolina at Chapel Hill (UNC) e-journals listing, PubMed is the only free resource in the top 10 most frequently linked to URLs in the ADL.
The breakdown of free resource use by different user groups indicates that the highest percentage of use of free resources was by guests followed by institutional affiliates and AHEC Faculty/Staff. The next 3 highest user groups are: paid members, preceptors, and residents. The final 3 groups registered less than 3% of the total use of free resources. These groups are: community faculty, other, and trial accounts. The breakdown of free resource use by different user groups is illustrated in figure . Due to the way that Excel rounded the numbers underlying the table, the figure indicates that the final 3 groups add up to 0% and give 100% of use to the Guests, Institutional Affiliates, AHEC Faculty, Paid Members, Preceptors, and Residents.
Free Resource Use by Account Type.
Not surprisingly the guests make up the largest group accessing free resources. The most likely reason for this is that guests only have access to the free resources. Although guests only make up 2% of total user link outs from the ADL, they make up 33% of the access to the free resources. While information on registered ADL members can be tracked, very little is known about the guest users.
It is also useful to look at free resource use without guest usage. When guests are removed from the equation, institutional users are the highest user group accessing free resources. Institutional affiliates are the largest active user group with 30% of total link outs during the period studied. The hypothesis that the largest free resource user groups will emerge from the largest overall user groups when excluding guests from the free resource analysis, gets mixed validation when examining actual ADL link outs as illustrated in Figure . When comparing overall link outs to link outs to free resources, 6 user groups align. The top 2 groups: Institutional Affiliates and AHEC faculty, and the 4th highest link out group, the preceptors. The bottom 3 groups also aligned between their overall resource use and their use of free resources. There were 2 groups with some discrepancy between overall link outs and the link outs to free resources. The paid members are the 5th highest overall link out group, but the 3rd highest user group accessing free resources. Despite the difference in ranking, they have a similar use percentage with 12% of the overall resource use and a 16% use of the free resources use. The group with the largest discrepancy is the medical residents. They are the 3rd highest overall link out group but only the 5th highest group using free resources. The discrepancies with the medical residents are best highlighted in link out percentages: the overall link out compared to the link outs to free resources. The medical residents had 18% of the overall resource usage but only 7% of the use of free resources. Despite these 2 groups evincing discrepancies between overall resource usage and free resource usage, the overall usage patterns support the hypothesis that the largest free resource user groups will emerge from the largest overall user groups when excluding guests from the examination of the free resources.
Total Link Outs to All Resources by Account Type.
In addition to examining overall free resource use by user group, we also examined the specific free resources accessed by each different user group. Tables , , , , illustrate the top ten most frequently used resources overall and by user group. The tables provide the names of the resources and the total number of link outs during the November 2005 – April 2006 timeframe. Some highlights of those results include the fact that of the ten most frequently accessed free resources, five were to patient education resources. Of the five patient education resources accessed by institutional affiliates, three of the titles: Diseases, Conditions & Injuries; the MEDEM Library of Patient Education Information; and [MedlinePlus] Online Interactive Health Tutorials, account for more 50% of the total link outs for each title. For guests, 3 of the top 10 resources accessed most frequently were for nursing resources. They are the only group with any link outs to nursing resources in the top 10 most frequently accessed resources. AHEC Faculty/Staff accessed the EBM Center of Excellence for 40% of the link outs to that title. Another interesting note is that individual paid members accessed Dermatology resources at a much higher rate than any of the other groups.
The top ten most frequently used free resources by all user groups: (resource name/link outs)
Top ten most frequently used free resources by Guests.
Top ten most frequently used free resources by Institutional Affiliate Members.
Top ten most frequently used free resources by AHEC Faculty/Staff members.
Top ten most frequently used free resources by Paid Individual Members.