Results
During the first evaluation period (04 September 2017–22 December 2017), 37,247 imaging examinations (radiography, CT, MRI) were reported by the decentralized/modality-based radiology system during standard working hours. This was compared to 38,754 reports which were acquired during the second evaluation period (03 December 2018–21 December 2018) by the centralized/subspecialized system (3.9% increase). The number of reports with two signatures decreased from 16,632 to 15,967 (4.0% decrease) between the first and second evaluation periods.
Overall turnaround time
The median RTAT for the first signature was 32 min for both evaluation periods. The 80th percentile RTAT, however, decreased (
p < 0.001,
r = 0.02) from 82 to 77 min (Table
1), and the median RTAT for the second signature also decreased (
p < 0.001,
r = 0.06), from 119 to 107 min, between the two periods. The corresponding 80th percentile RTAT decreased from 295 to 238 min.
Table 1
Overall radiology report turnaround time of all hospitals —04 September 2017–22 December 2017 vs. 03 September 2018–21 December 2018
1st signature | 37,247 | 38,754 | 32 | 32 | 82 | 77 | < .001* (r = 0.02) |
2nd signature | 16,632 | 15,967 | 119 | 107 | 295 | 238 | < .001* (r = 0.06) |
Turnaround time for imaging modalities
Subgroup analyses demonstrate a significant difference (
p < 0.001) of the RTAT between the two evaluation periods for all evaluated imaging modalities (Table
2).
Table 2
Comparison of radiology report turnaround time by modalities (all hospitals) —04 September 2017–22 December 2017 vs. 03 September 2018–21 December 2018
MRI |
1st signature | 8122 | 8839 | 45 | 55 | 124 | 112 | < .001* (r = 0.09) |
2nd signature | 3837 | 4581 | 206 | 163 | 1051 | 401 | < .001* (r = 0.09) |
CT |
1st signature | 9058 | 9758 | 35 | 41 | 78 | 90 | < .001* (r = 0.09) |
2nd signature | 4547 | 4688 | 87 | 110 | 168 | 214 | < .001* (r = 0.15) |
Conventional radiographs |
1st signature | 20,067 | 20,157 | 27 | 20 | 71 | 51 | < .001* (r = 0.14) |
2nd signature | 8248 | 6698 | 117 | 77 | 278 | 171 | < .001* (r = 0.21) |
For both first and second signatures, the median RTAT (2017, 27 and 117 min; 2018, 20 and 77 min) and 80th percentile RTAT (2017, 71 and 278 min; 2018, 51 and 171 min) decreased (p < 0.001, r = 0.14 and 0.21, respectively) for conventional radiographs.
Between the two periods, the median RTAT increased (p < 0.001, r = 0.09) for the first signature on MRI reports; by contrast, the 80th percentile RTAT for the first signature on MRI reports decreased from 124 to 112 min. Both the median and 80th percentile RTAT for the second signature on MRI reports decreased (p < 0.001, r = 0.09; median 206 to 163 min; 80th percentile, 1051 to 401 min), while the median RTAT and 80th percentile RTAT for both signatures on CT reports increased (p < 0.001, r = 0.09 and 0.15, respectively).
Report turnaround time for subspecialization reporting
Subgroup analyses demonstrate a difference (
p < 0.001) of the RTAT between the two evaluation periods for all evaluated subspecializations (Table
3).
Table 3
Comparison of radiology report turnaround time by subspecializations (all hospitals) —04 September 2017–22 December 2017 vs. 03 September 2018–21 December 2018
Body radiology |
1st signature | 14,259 | 14,211 | 35 | 33 | 86 | 89 | < .001* (r = 0.04) |
2nd signature | 6969 | 5428 | 113 | 128 | 252 | 267 | < .001* (r = 0.05) |
Musculoskeletal radiology |
1st signature | 16,392 | 17,718 | 30 | 26 | 80 | 64 | < .001* (r = 0.06) |
2nd signature | 6419 | 6898 | 123 | 81 | 300 | 170 | < .001* (r = 0.21) |
Neuroradiology |
1st signature | 6596 | 6825 | 31 | 44 | 79 | 85 | < .001* (r = 0.15) |
2nd signature | 3244 | 3641 | 128 | 139 | 409 | 346 | < .001* (r = 0.05) |
The median and 80th percentile RTAT, for both signatures on body radiology reports, increased (p < 0.001, r = 0.04 and 0.05, respectively).
For first and second signatures on musculoskeletal radiology reports, the median RTAT (2017, 30 and 123 min; 2018, 26 and 81 min) and 80th percentile RTAT (2017, 80 and 300 min; 2018, 64 and 170 min) decreased (p < 0.001, r = 0.06 and 0.21, respectively).
Both the median and 80th percentile RTAT for the first signature on neuroradiology reports increased (p < 0.001, r = 0.15). The median RTAT increased for the second signature on neuroradiology reports; by contrast, the 80th percentile RTAT for the second signature decreased from 409 to 346 min (p < 0.001, r = 0.05).
Comparison of major versus minor hospitals
The outpatient medical center did not fulfill the criteria for neither major nor minor hospitals. Thus, the imaging examinations were excluded from the comparison of major versus minor hospitals.
Overall turnaround time of major versus minor hospitals
Table
4 shows both the median and 80th percentile RTAT for the first signature at the major hospitals increased (
p < 0.001,
r = 0.02). By contrast, both the median and 80th percentile RTAT for the first signature at the minor hospitals decreased (
p < 0.001,
r = 0.12; median 32 to 24 min, 80th percentile 92 to 62 min). At both major and minor hospitals, for the second signature, both the median and 80th percentile RTAT decreased (
p < 0.001,
r = 0.03 and 0.15, respectively). The 80th percentile RTAT decreased at major hospitals from 288 to 245 min and decreased at minor hospitals from 300 to 198 min.
Table 4
Comparison of major vs. minor hospitals’ radiology report turnaround time by modalities —04 September 2017–22 December 2017 vs. 03 September 2018–21 December 2018
Period | 2017 | 2018 | 2017 | 2018 | 2017 | 2018 | | 2017 | 2018 | 2017 | 2018 | 2017 | 2018 | |
All modalities |
1st signature | 26,524 | 27,356 | 32 | 34 | 78 | 81 | < .001* (r = 0.02) | 9906 | 10,446 | 32 | 24 | 92 | 62 | < .001* (r = 0.12) |
2nd signature | 13,195 | 11,868 | 117 | 110 | 288 | 245 | < .001* (r = 0.03) | 3270 | 3663 | 125 | 91 | 300 | 198 | < .001* (r = 0.15) |
CT |
1st signature | 6897 | 7274 | 33 | 42 | 71 | 92 | < .001* (r = 0.14) | 2150 | 2459 | 40 | 38 | 108 | 83 | .01* (r = 0.04) |
2nd signature | 3799 | 3677 | 86 | 109 | 162 | 212 | < .001* (r = 0.16) | 746 | 997 | 93 | 111 | 204 | 224 | < .001* (r = 0.09) |
Conventional radiographs |
1st signature | 12,311 | 12,170 | 26 | 19 | 63 | 49 | < .001* (r = 0.13) | 7756 | 7987 | 30 | 20 | 88 | 54 | < .001* (r = 0.16) |
2nd signature | 5724 | 4032 | 110 | 73 | 248 | 156 | < .001* (r = 0.21) | 2524 | 2666 | 137 | 83 | 331 | 189 | < .001* (r = 0.23) |
Turnaround time for imaging modalities of major versus minor hospitals
Subgroup analyses show a difference for the RTAT of the evaluated imaging modalities at major and minor hospitals between the first and second evaluation periods (Table
4).
Most interestingly, the 80th percentile RTAT of the second signature on conventional radiographs decreased at major hospitals from 248 to 156 min, while it decreased from 331 to 189 min at minor hospitals (p < 0.001, r = 0.21 and 0.23, respectively).
Turnaround time for subspecialization reporting of major versus minor hospitals
Subgroup analyses demonstrate a difference between the RTAT of the evaluated subspecializations at major and minor hospitals between the first and second evaluation periods (Table
5).
Table 5
Comparison of major vs. minor hospitals’ radiology report turnaround time by subspecializations —04 September 2017–22 December 2017 vs. 03 September 2018–21 December 2018
Period | 2017 | 2018 | 2017 | 2018 | 2017 | 2018 | | 2017 | 2018 | 2017 | 2018 | 2017 | 2018 | |
Body radiology |
1st signature | 10,722 | 10,591 | 35 | 36 | 83 | 94 | .46 (r = 0.01) | 3368 | 3342 | 34 | 25 | 93 | 66 | < .001* (r = 0.15) |
2nd signature | 5821 | 4295 | 115 | 131 | 256 | 277 | < .001* (r = 0.06) | 1114 | 1001 | 105 | 107 | 231 | 217 | .61 (r = 0.01) |
Musculoskeletal radiology |
1st signature | 10,042 | 10,915 | 29 | 27 | 74 | 66 | < .001* (r = 0.02) | 6096 | 6553 | 31 | 23 | 94 | 59 | < .001* (r = 0.12) |
2nd signature | 4374 | 4343 | 114 | 79 | 269 | 157 | < .001* (r = 0.20) | 1997 | 2464 | 145 | 84 | 344 | 192 | < .001* (r = 0.24) |
Neuroradiology |
1st signature | 5760 | 5850 | 30 | 44 | 77 | 86 | < .001* (r = 0.16) | 442 | 551 | 26 | 31 | 78 | 65,6 | .22 (r = 0.04) |
2nd signature | 3000 | 3230 | 131 | 141 | 423 | 346 | < .001* (r = 0.05) | 159 | 198 | 73 | 106 | 147 | 185 | .004 (r = 0.15) |
Most interestingly, the median and 80th percentile RTAT for musculoskeletal radiology reports decreased for both signatures at major (p < 0.001, r = 0.02 and 0.20, respectively) and minor (p < 0.001, r = 0.12 and 0.24, respectively) hospitals (80th percentile: major hospitals from 269 to 157 min, minor hospitals from 344 to 192 min).
Turnaround time for residents versus board-certified radiologists
Interestingly, subgroup analyses demonstrate a difference between the RTAT of reports written by board-certified radiologists between the first and second evaluation periods (Table
6). For the first signature, the median RTAT decreased from 29 to 27 min and the 80th percentile RTAT decreased from 80 to 69 min (
p < 0.001,
r = 0.05) between the two periods. For the second signature, the median RTAT decreased from 119 to 107 min, while the corresponding 80th percentile RTAT decreased from 296 to 238 min (
p < 0.001,
r = 0.06).
Table 6
Comparison of radiology report turnaround time residents versus board-certified radiologists—04 September 2017–22 December 2017 vs. 03 September 2018–21 December 2018
Residents |
1st signature | 17,037 | 18,109 | 36 | 37 | 85 | 86 | .013 (r = 0.01) |
Board-certified radiologists |
1st signature | 20,132 | 20,584 | 29 | 27 | 80 | 69 | < .001* (r = 0.05) |
2nd signature | 16,551 | 15,862 | 119 | 107 | 296 | 238 | < .001* (r = 0.06) |
By contrast, there was no significant difference between the median and 80th percentile RTAT of reports written by residents (p < 0.013, r = 0.01) between the two evaluation periods.
Discussion
The most important finding of this study is that changing the reporting system from decentralized/modality-based radiology to centralized/subspecialized radiology resulted in a significant decrease of the RTAT. Overall, the RTAT decreased from 82 to 77 min (80th percentile) for the first signature (p < 0.001), while it decreased from 119 to 107 min (median) and from 295 to 238 min (80th percentile) for the second signature (p < 0.001). Subgroup analyses demonstrated a significant decrease of the RTAT for MRI reports (e.g., second signature, 80th percentile RTAT, 1051 to 401 min; p < 0.001) and conventional radiographs (e. g., second signature, 80th percentile RTAT, 278 to 171 min; p < 0.001).
It has to be noted that the effect size analyses correspond to small effects. Notably, minor hospitals benefited most from the change to centralized/subspecialized radiology, as the RTAT decreased overall from 300 to 198 min (second signature, 80th percentile; p < 0.001), while the corresponding RTAT of major hospitals decreased, less remarkably, from 288 to 245 min (p < 0.001).
Similarly, to other recently published surveys, the present study demonstrated an annual increase of 3.9% in the number of radiology reports and imaging examinations during the evaluation period in 2018 compared to 2017 (Table
1) [
3,
12,
13]. Interestingly, there was an increase from 37,247 to 38,754 reports but a decrease in reports with a second signature from 16,632 to 15,967 reports (Table
1). During the period of decentralized/modality-based radiology, radiologists occasionally forwarded difficult reports to specialists for a second opinion and a second signature, respectively. One may speculate that centralized/subspecialized radiology increases the experience and confidence of radiologists in their dedicated tasks. Thus, centralized/subspecialized radiology may decrease the necessity for requesting a second opinion for challenging radiology reports. The increasing number of radiology reports of 3.9% between the evaluation periods 2017 and 2018 can be considered as the normal annual growth rate of our radiology department.
Thus, as hypothesized, it appears that the RTAT decreased in spite of the increased workload. One may assume that the experience gained by residents and board-certified radiologists may also have improved the RTAT values. Nonetheless, new residents were hired and residents got board-certified as part of the real-life setting. Nonetheless, there was an unchanged number of residents and board-certified radiologists for both evaluation periods. Interestingly, after changing the reporting system from decentralized/modality-based radiology to centralized/subspecialized radiology, the RTAT for reports written by board-certified radiologists decreased significantly, while there was no significant difference of the RTAT for reports written by residents (Table
6). As board-certified radiologists unlike residents focus on one of the four subspecializations, it may also indicate an improvement between the two investigated systems of radiological reporting.
Recent literature revealed conflicting data regarding the RTAT: Change of reporting system from decentralized/modality-based radiology to centralized/subspecialized radiology demonstrated both a decrease of the RTAT, as shown by the results of Stern et al. [
14], and, conversely, an increase of the RTAT, as shown by the results of Meyl et al. [
3]. In the present study, the change to a centralized/subspecialized system of radiological reporting leads overall to a significant decrease of the RTAT (Tables
1 and
4). The RTAT for MRI reports and conventional radiographs decreased most significantly (Tables
2 and
4), which other studies confirm [
14]. In some important and critical areas, significant increases of the RTAT were noted, e.g., for the median of the first signature of MR reports (Table
2), for both signatures of body radiology (Table
3), for the first signature of neuroradiology (Table
3), and for the first signature of major hospitals (Table
4). This may be explained by redistributive effects. Not all areas of this heterogeneous survey benefited from the system change to centralized/subspecialized radiological reporting.
Before the change management from decentralized/modality-based radiology to centralized/subspecialized radiology, the radiology network showed a very low RTAT (Table
1) compared with peer-valued studies [
14], which could be improved even further after the change (Table
1). Interestingly, there was an increase for both signatures of the RTAT for CT reports (Table
2) which may be explained because of its very complex or time-consuming cases, by a work redistribution in favor of MRI reports and by general redistribution effects from the management. Time-critical CT reports (e.g., stroke, trauma) were given higher priority than MR reports or reports for conventional radiographs in both evaluated systems of radiological reporting. In addition, a senior staff radiologist was in duty to identify time-sensitive examinations and, if necessary, to distribute them along the radiologists to provide fast reports for emergency and urgent cases. However, this study did not differentiate between emergency and routine CT examinations.
In contrast to the results of Meyl et al. [
3], the current study showed particularly that the RTAT for medium-challenging/time-consuming reports, represented by the 80th percentile RTAT, decreased significantly; this is especially true of the RTAT for the subspecialization of musculoskeletal radiology. In the other subspecializations, however, the trend tended towards increased RTATs (Tables
3 and
5), which was also observed by other recent studies [
3].
Furthermore, as suspected, there was a connection between the size of hospitals and change of reporting system. Notably, minor hospitals noted a general improvement of the RTAT overall, as well as a significant improvement of the RTAT for conventional radiographs and CT scans (Table
4). Furthermore, minor hospitals benefited from a decreased RTAT for the body and musculoskeletal subspecializations (Table
5). The decreased RTAT may demonstrate a better distribution of workload among all radiologists through the use of teleradiology, in spite of the more centralized and subspecialized multi-center radiology network [
15‐
17].
The findings of this study differ from the other cited surveys, as it provides RTATs not only for single academic or public hospitals but for a multi-center radiology network consisting of eleven radiology sites—which represent public hospitals of various sizes (Fig.
1)—as well as a fully integrated diagnostic neuroradiology department, which is an unusual setup compared to most larger European radiology departments [
2].
The limitations of this statistical evaluation were many confounding variables including the experience of radiologists, case complexity, and case volume. Furthermore, as part of the real-life setting, the number of studies included by modality was not equitable as the number of conventional radiographs exceeds the number of CT and MRI reports. Although RTAT may not be considered as the best measure to determine efficiency of a radiology department, it is a frequently used scale for the evaluation of the workflow of many radiology institutions [
18‐
21] as well as the 80th percentile RTAT [
14,
22,
23]. Outlier (= very complex or time-consuming cases) such as cardiovascular CT or MR examinations were difficult to define. However, these examinations occurred in both systems of radiological reporting and are part of everyday clinical practice in large institutions. Regarding distortion caused by outliers, the median serves as a robust measurement [
24]. According to Cohen’s guidelines, most results of the study show a small effect size. However, there are indications to consider these normative guidelines and to use correlations of 0.10, 0.20, and 0.30 to represent relatively small, typical, and relatively large effects [
25].
A study comparing the quality of radiology reports between decentralized/modality-based radiology and centralized/subspecialized radiology was conducted and will be published as a separate study.
In conclusion, changing the reporting system from decentralized/modality-based radiology to a centralized/subspecialized radiology was associated with a significant decrease of the RTAT overall and a significant decrease of the RTAT for MRI reports and conventional radiographs. A significant decrease of the RTAT at minor hospitals, organized in a multi-center radiology network, was also noted—a significant improvement between the two evaluation periods. The effect size corresponds to small effects.
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