INSTITUTIONS WITH INSTITUTIONAL REVIEW BOARD ORGANIZATION(S): STRUCTURE AND NUMBER
The number of Institutional Review Board Organizations (managing organizations) in the United States is somewhat in flux. From the 2004 Office for Human Research Protections listings, we found that approximately 4.1% no longer functioned as of 2005–2006 because the institution no longer existed or was closed (for example, due to a natural disaster or no longer maintaining an IRB). Fewer Tier One institutions (top 100 funded institutions) had closed down (0.8%) compared to Tier Two institutions (4.7%). Although most institutions in the United States have only one management organization, approximately 5.4% have multiple managing organizations. Among high-volume (Tier One) institutions, approximately 15% have multiple management organizations (<1% of Tier Two have multiple managing organizations) (see ). These institutions are primarily universities with major medical research centers and/or schools of public health. Among institutions with multiple managing organizations, those with two or three management organizations represent the typical structure, and only a rare few have four or more management organizations.
Number of IRB Management Offices (IMOs) per Institution by Institutional Strata.
We computed the number of U.S. institutions with managing organizations using unweighted within-stratum data. The within-stratum data were generalized to all managing organizations in the United States to produce stratum-specific population-level estimates. These estimates were then aggregated across strata to give total population-level results. By working back from the number of managing organizations (2,070) to the number of institutions, we estimate that there were approximately 2,031 institutions with managing organizations (i.e., Institutional Review Board Organizations, see Research Note 1) in the United States for the time period represented.
ESTIMATING THE NUMBER OF IRB COMMITTEES IN THE U.S.
We identified 400 IRBs among the 244 managing organizations in our sample. We estimate that nationally there were 2,728 IRBs among the 2,070 managing organizations identified in the Office for Human Research Protections 2004 listings. Approximately 85% (weighted) of the sampled organizations contained a single IRB. The distribution of IRBs per managing organization is relatively narrow, although one administrator reported managing 10 IRBs. Only 4% of the managing organizations reported four or more IRBs, 4% reported three IRBS, and 7% reported two IRBs. provides the distribution of IRBs (single vs. multiple) by institutional strata. Multiple IRB institutions are more frequent among Tier One institutions (73%) and universities (33%).
Number of IRBs by Institutional Strata (N = 244 IMOs).
CHANGES IN IORGS AND IRBS 2004–2008
The Office for Human Research Protections has recently made available online data on Institutional Review Board Organization(s) and IRBs. These data are presented for each state and the U.S. Territories. The number of IRBs and their managing organizations [Institutional Review Board Organization(s)] are provided on-site in addition to information on location and assurance numbers. It is unclear if IRBs that have been deactivated are included in these counts, but this would have only a small impact on the overall count. The 2008 data indicate that for the 50 states and the District of Columbia, the geographic base for the 2004 data, the number of managing organizations has grown to approximately 3,103, an increase of 1,033 organizations, with an associated increase of 1,125 IRBs (41% increase).
INSTITUTIONAL AND NON-INSTITUTIONAL IRB MEMBERS
In the United States, IRBs are composed chiefly of members derived from the parent institution, typically faculty, one of whom is the IRB Chair. In addition, IRBs are required to include membership from outside the institution that in some manner represents the broader community of research participants. Further, IRBs may recruit scientific expertise from outside the institution to supplement key areas. We examined details of IRB composition among the 400 IRBs enumerated by the sample of management organization administrators (see ). In general, the vast majority of IRBs reach outside the institution for additional, albeit few, members. We identified <1% of IRBs (N = 3) who had not included non-institutional members (science and community) and only 8% (N = 32) who had not included external community membership without scientific training.
Mean Number of IRB Members by Institutional Strata.
We computed the average number of total and non-institutional IRB members by institutional strata (). Tier Two (and “Other”) institutions have significantly smaller total IRB memberships, reflecting perhaps lighter workloads and/or smaller institutional populations from which to draw members. In this regard, Tier Two (and non-university health/“other”) IRBs have significantly more non-institutional members. Thus, smaller/lower volume institutional strata rely to a greater extent on individuals outside the institution to fill IRB membership.
Given a smaller corpus of institutional scientists to draw from, we might expect that smaller research institutions would draw on external sources to recruit ad hoc or regular scientific members. Our data suggest this is the case. First, Tier Two IRBs have more non-institutional members overall than Tier One IRBs. Among the non-institutional IRB membership, Tier Two IRBs and Tier One IRBs are similar in their representation of non-institutional community representatives without scientific training. Therefore, Tier Two IRBs must be drawing on more external (non-institutional) scientific expertise than Tier One IRBs. The “other” institutional IRBs have a pattern similar to Tier Two IRBs, suggesting that they also recruit more external scientific expertise to fill committee seats. Non-university health-related institutions (for example, free-standing healthcare corporations) have IRBs with a slightly different pattern. They have more non-institutional members overall and more non-institutional community members without scientific training than their counterparts on IRBs for universities. That is, they are recruiting more community representatives than scientists from outside the institution.
WORKLOAD VOLUME IN THE U.S. (RESEARCH APPLICATIONS REVIEWED)
We computed the total number of research applications processed by the sampled managing organizations at each institution in the past year with breakdowns by the number of new applications and new applications requiring full committee review (Tables -). As noted previously, we assessed the number of applications received as categorical frequencies. The category boundaries can be understood to represent low- and high-end estimates of the actual frequencies. Midpoints of the categories are used in all computations unless indicated otherwise.
Total Applications Submitted to IRB Management Offices in Past Year.
New Applications Submitted to IRB Management Offices Receiving Full-Committee Review in Past Year.
At the national level, we estimated that a total of 269,740 IRB applications were processed by all managing organizations in the past year. Among these, approximately 181,669 applications were new and 95,702 received a full IRB committee review. This latter figure represents over a third (35%) of the total workload. Tier One institutions (and universities) carry larger workloads (see Tables -). For example, at the national level, Tier One institutions, which represent 4.9% of federally assured managing organizations in the United States, reviewed approximately 20% of all applications (54,394/269,740) and 40% (38,604/95,702) of all new applications.
Inspection of Tables - indicates that the average number of applications received by Tier One institutions is nearly three times that of Tier Two institutions. Further, Tier One managing organizations, compared to Tier Two organizations, receive nearly four times the average number of new applications and approximately six times the average number of new full-committee review applications. Since Tier One institutions have more IRBs per institution, we adjusted the workload estimates accordingly. Adjusting for the number of IRBs, Tier One averages 101 total applications/IRB/year vs. 103 applications/IRB/year for Tier Two (applications/IRB: Tier One 21,101/209; Tier Two 19,592/191). Thus, overall, Tier One and Tier Two look similar at the level of total average applications per IRB. However, there are substantial differences in the more labor-intensive new applications, particularly those requiring full IRB committee review. Tier One averages 91 new applications/IRB/year vs. 63 new applications/IRB/year for Tier Two (applications/IRB: Tier One 19,003/209; Tier Two 11,981/191), and, respectively, 63 vs. 29 new full-committee review applications/IRB/year (applications/IRB: Tier One 13,209/209; Tier Two 5,529/191). Similar relative differences were found in comparing universities to other types of research institutions.
The disproportionate workload between Tier One and Tier Two institutions (or universities and other institutions) may be a function of Tier One institutions receiving more protocols dealing with sensitive issues or vulnerable populations, particularly medical and mental health-related research protocols (see accompanying article). That is, proportionately more protocols may proceed to full-committee review in Tier One institutions.
As an overall assessment of workload and IRB structure, we computed correlations between the number of IRBs within managing organizations and the number of applications processed (total, new, full committee review). The results indicate moderate associations between workload and the number of IRBs (total applications r = .41, new applications r = .51, and full committee review applications r = .69, all p-values < .0001). That is, a strong relationship between workload and committee number would be evidenced by correlations of .90 and larger. Stated differently, as in the case of new applications, only 26% of the variation in total workload is accounted for by the number of IRB committees devoted to the task.
WORKLOAD COMPARISONS TO 1995
We examined change by comparing our findings to those of Bell et al. (1998)
There are many differences between the two studies (see discussion), but there are also points of comparison. We determined how many applications were “new rather than modifications or renewals,” which encompasses the definition in Bell et al. of “initial” reviews. Both studies also determined the number of applications that required full committee reviews.
In terms of new and full committee reviews, the universe of federally assured IRBs in 1995 received approximately 105,000 new applications and conducted an estimated 60,900 full-committee reviews (58% of new applications). By 2005, we estimate that, nationally, IRBs received 181,669 new applications and conducted 95,702 full committee reviews (53% of new applications). Thus federally assured IRBs in 2005 reviewed more new and full review applications in total volume than IRBs in 1995, but the relative percentage of new applications needing full review was similar over time.
Changes in total workload may be a function of there being a larger universe of federally assured IRBs in 2005 as compared to 1995. Changes in the size and composition of the base population over time present barriers to trends analyses unless one can adjust for these differences. A typical solution of computing the average workload per IRB is flawed in this case because the 491 federally assured IRBs in 1995 are over-represented by universities and top National Institute of Health–funded institutions (among the first entities developing federally assured administrations). We had insufficient information to adjust differences between studies at this level. Making comparisons without these adjustments would result in artificially divergent findings. For instance, in Bell et al., the 491 IRBs averaged 214 new applications/IRB, while in the present study the average number of new applications is approximately 88/IRB. This difference between studies in average work volume is likely due to differences in research volume between sample frames. Indeed, university IRBs in our study average 230 new applications/year, a value similar to the Bell et al. average for their total sample frame. Adjusting for diverging population and definitional differences between studies and, consequently, the observed differences in workload is necessary, but beyond the scope of the current project.
Despite limitations, Bell et al. provided data that may be combined with current estimates to generate more detailed workload indices. In particular, Bell et al. provided data on the number of hours spent reviewing applications outside formal committee meetings. On average, they found that IRB members reviewing new applications spent approximately 11.0 hours/review outside the IRB meetings. Assuming that time spent per review outside the IRB has remained approximately the same over time (as noted previously it has changed within the IRB), we can estimate this portion of current workload in hours (see Research Note 2). The average number of new applications per IRB in our study is estimated at 87.8/IRB with an average committee size of 13.9 members. Assuming the workload is distributed evenly, we estimate that each member is spending a total of 69.5 hours/year outside IRB meetings on new applications alone. For Tier One IRBs, this figure is substantially higher at 274.5 hours/year spent reviewing new applications outside the committee proper by each member, while for Tier Two IRBs, the figure is lower at 39.5 hours/year.