Table 3.
Over-interpretation, under-interpretation, and misclassification rates associated with three second opinion strategies based on case volume of interpreting pathologist
| Strategy | Single interpretation rate (%) | Overall (95% CI) | Second opinion strategy rate (%) | Overall (95% CI) | P value* | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Reference consensus diagnosis | Reference consensus diagnosis | ||||||||||||
| Benign | Atypia | DCIS | Invasive | Benign | Atypia | DCIS | Invasive | ||||||
| Strategy 10: | Low volume pathologist | Second opinion from low volume pathologist, third opinion from high volume pathologist | |||||||||||
| Over-interpretation | 14.4 | 17.9 | 2.8 | – | 10.5 (9.4 to 11.7) | 8.4 | 11.2 | 0.7 | – | 6.1 (4.7 to 6.7) | |||
| Under-interpretation | – | 36.9 | 14.5 | 4.4 | 15.9 (14.5 to 17.4) | – | 30.0 | 9.4 | 3.6 | 12.2 (10.1 to 14.3) | |||
| Misclassification | 14.4 | 54.8 | 17.2 | 4.4 | 26.4 (25.1 to 27.8) | 8.4 | 41.2 | 10.1 | 3.6 | 18.3 (16.2 to 20.1) | P<0.001 | ||
| Strategy 11: | Low volume pathologist | Second opinion from high volume pathologist, third opinion from high volume pathologist | |||||||||||
| Over-interpretation | 14.4 | 17.9 | 2.8 | – | 10.5 (9.4 to 11.7) | 7.3 | 11.0 | 0.4 | – | 5.6 (4.1 to 7.6) | |||
| Under-interpretation | – | 36.9 | 14.5 | 4.4 | 15.9 (14.5 to 17.4) | – | 26.8 | 7.9 | 3.1 | 10.7 (8.5 to 13.0) | |||
| Misclassification | 14.4 | 54.8 | 17.2 | 4.4 | 26.4 (25.1 to 27.8) | 7.3 | 37.8 | 8.2 | 3.1 | 16.3 (13.9 to 18.7) | P<0.001 | ||
| Strategy 12: | High volume pathologist | Second opinion from high volume pathologist, third opinion from high volume pathologist | |||||||||||
| Over-interpretation | 10.1 | 16.5 | 2.2 | – | 8.7 (7.1 to 10.1) | 6.1 | 10.4 | 0.2 | – | 5.0 (3.0 to 8.2) | |||
| Under-interpretation | – | 30.7 | 11.1 | 3.0 | 12.9 (11.3 to 14.3) | – | 23.7 | 6.4 | 2.5 | 9.3 (6.1 to 12.8) | |||
| Misclassification | 10.1 | 47.2 | 13.3 | 3.0 | 21.5 (19.5 to 23.4) | 6.1 | 34.1 | 6.6 | 2.5 | 14.3 (10.9 to 18.0) | P<0.001 | ||
High volume pathologists defined as those who report interpreting an average of 10 or more breast biopsy specimens per week. A lower volume pathologist reports 9 or fewer breast biopsy specimens per week. Study sample comprised 75 lower volume pathologists and 40 high volume pathologists.
*Based on Wald test for difference in overall misclassification rates between second opinion strategy and single pathologist interpretation. Test statistic uses bootstrap standard error of difference in rates