Table 2.
Accuracy of Stage Inferred from Medicare Claims to Identify Stage Reported in the SEER Data (Gold Standard)
SEER Historic Stage | Stage Inferred from Metastasis Codes in Medicare Claims | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
N | % | Sensitivity | Specificity | PPV | NPV | |||||
Cancer site | Local | Regional | Distant | Any metastases* | ||||||
Breast | Local | 18,310 | 98.6 | 0.9 | 0.5 | 1.4 | 98.6 | 43.9 | 78.5 | 93.8 |
Regional | 7,191 | 60.0 | 35.3 | 4.7 | 40.0 | 35.3 | 98.4 | 88.8 | 80.8 | |
Distant | 1,642 | 39.3 | 9.7 | 51.0 | 60.7 | 51.0 | 98.3 | 65.8 | 96.9 | |
Any metastases* | 8,833 | 56.1 | 30.5 | 13.3 | 43.9 | 43.9 | 98.6 | 93.8 | 78.5 | |
Colorectal | Local | 11,213 | 96.8 | 1.0 | 2.2 | 3.2 | 96.8 | 55.0 | 65.0 | 95.2 |
Regional | 9,213 | 55.0 | 34.0 | 11.0 | 45.0 | 34.0 | 97.6 | 89.7 | 70.6 | |
Distant | 3,790 | 20.6 | 6.6 | 72.8 | 79.4 | 72.8 | 93.8 | 68.5 | 94.9 | |
Any metastases* | 13,003 | 45.0 | 26.0 | 29.0 | 55.0 | 55.0 | 96.8 | 95.2 | 65.0 | |
Lung | Local | 6,850 | 94.2 | 3.2 | 2.6 | 5.8 | 94.3 | 45.0 | 34.9 | 96.1 |
Regional | 8,249 | 75.0 | 17.6 | 7.4 | 25.0 | 17.6 | 89.3 | 40.0 | 72.9 | |
Distant | 13,594 | 42.9 | 14.4 | 42.7 | 57.1 | 42.7 | 94.8 | 88.1 | 64.7 | |
Any metastases* | 21,843 | 55.0 | 15.6 | 29.3 | 45.0 | 45.0 | 94.3 | 96.1 | 34.9 |
Note: PPV = positive predictive value, NPV = negative predictive value;
Any metastases combines regional and distant stage.