Table 3.
Sensitivity analysis evaluating effect of misclassification across key metrics related to treatment and outcomes among 524 patients with breast cancer with confirmed bone metastases by ICD-9 classification
| Bone metastasis confirmed in unstructured EHR ± ICD-9 198.5 | ICD-9 198.5 either in the structured EHR or claims | No ICD-9 code | |
|---|---|---|---|
| N | 524 | 435 | 89 |
| Key metrics | |||
| BTA treated (ever) | 77% | 89% | 15% |
| BTA within 30 days of diagnosis | 30% | 52% | 7% |
| Median time to BTA start (days) | 43 | 43 | 86 |
| Median follow-up (months) | 21.1 | 23.4 | 9.2 |
| Number of SREs | |||
| None | 50% | 45% | 71% |
| 1 SRE | 26% | 28% | 17% |
| 2 SREs | 11% | 12% | 9% |
| 3 SREs | 6% | 15% | 3% |
Abbreviations: ICD-9, International Classification of Diseases, ninth revision; EHR, electronic health records; BTA, bone-targeting agent; SREs, skeletal-related events.