Table 5.
IRR between the two abstractors, and validity against the “gold standard” for select variables, (N=30)
|
Categorical variables |
Dichotomous variables |
IRR = Kappa (95% LCL)a |
Abstractor 1 vs. “gold standard” |
Abstractor 2 vs. “gold standard” |
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| N | Abstractor 1 vs. Abstractor 2 | Bias Index | N | Agreement (%) | Sensitivity (%) | Specificity (%) | Bias Index | N | Agreement (%) | Sensitivity (%) | Specificity (%) | Bias Index | |||
|
Stroke type |
Infarct |
30 |
1.00 |
0 |
|
30 |
100 |
100 |
100 |
0 |
30 |
100 |
100 |
100 |
0 |
| ICH |
30 |
1.00 |
0 |
|
30 |
100 |
100 |
100 |
0 |
30 |
100 |
100 |
100 |
0 |
|
| TIA |
30 |
0.65 (0.02) |
−0.03 |
|
30 |
100 |
100 |
100 |
0 |
30 |
96.7 |
100 |
96.6 |
0.03 |
|
|
tPA therapy |
Yes |
30 |
1.00 |
0 |
|
30 |
100 |
100 |
100 |
0 |
30 |
100 |
100 |
100 |
0 |
|
Symptomatic hemorrhage |
Yes |
30 |
1.00 |
0 |
|
30 |
100 |
100 |
100 |
0 |
30 |
100 |
100 |
100 |
0 |
|
Disposition |
Death |
30 |
1.00 |
0 |
|
30 |
100 |
100 |
100 |
0 |
30 |
100 |
100 |
100 |
0 |
| Home |
30 |
1.00 |
0 |
|
30 |
93.3 |
100 |
91.3 |
0.07 |
30 |
93.3 |
100 |
91.3 |
0.07 |
|
| Inpatient rehabilitation |
30 |
1.00 |
0 |
|
30 |
100 |
100 |
100 |
0 |
30 |
100 |
100 |
100 |
0 |
|
| Skilled nursing facility |
30 |
1.00 |
0 |
|
30 |
96.7 |
100 |
96.6 |
0.03 |
30 |
96.7 |
100 |
96.6 |
0.03 |
|
|
Initial presentation |
MHH |
30 |
0.92 (0.76) |
0.03 |
|
30 |
100 |
100 |
100 |
0 |
30 |
96.7 |
95.4 |
100 |
−0.03 |
|
Continuous variables |
|
IRR = ICCd(95%LCL)a |
Abstractor 1 vs. “gold standard” |
Abstractor 2 vs. “gold standard” |
|||||||||||
| |
N |
Abstractor 1 vs. Abstractor 2 |
MDc(95%CI)b |
N |
Agreement (%) |
Correlation (95%CI)b |
MDc(95%CI)b |
N |
Agreement (%) |
Correlation (95%CI)b |
MDc(95%CI)b |
||||
|
Age (years) |
30 |
1.00 |
0 (0, 0) |
30 |
96.7 |
0.83 (0.65, 0.91) |
1.4 (−1.5, 4.4) |
30 |
96.7 |
0.83 (0.65, 0.91) |
1.4 (−1.5, 4.4) |
||||
|
Onset time (minutes) |
16 |
1.00 |
4.7 (−14.5, 5.3) |
16 |
93.8 |
1.00 |
9.4 (−10.6, -29.4) |
16 |
87.5 |
1.00 |
14.1 (−7.7, 35.8) |
||||
|
Arrival time (minutes) |
29 |
1.00 |
0 (0, 0) |
30 |
86.7 |
1.00 |
−0.2 (−1.9, 1.5) |
29 |
89.7 |
1.00 |
−0.2 (−2.1, 1.6) |
||||
|
tPA time (minutes) |
7 |
−0.48 (−0.89) |
NR |
7 |
100 |
1.00 |
0 (0, 0) |
7 |
57.1 |
−0.49 (−0.90, 0.45) |
NR |
||||
|
INR |
25 |
0.98 (0.96) |
0.02 (−0.02, 0.06) |
25 |
80 |
0.98 (0.97, 0.99) |
−0.01 (−0.04, 0.02) |
26 |
73.1 |
0.39 (−0.00, 0.67) |
0.1 (−0.2, 0.4) |
||||
| mRS on discharge | 23 | 1.00 | 0 (0, 0) | 23 | 95.6 | 0.98 (0.96, 0.99) | −0.04 (−0.13, 0.05) | 26 | 96.2 | 0.98 (0.96, 0.99) | −0.04 (−0.12, 0.04) | ||||
a 95% LCL = 95% Lower Confidence Limit; b 95% CI = 95% Confidence Interval; cMD = Mean difference for reliability study is calculated based on abstractor #1 minus abstractor #2; for validity study the difference is based on abstractor #1 or abstractor #2 minus the “gold standard”; dICC = Intra-class correlation; NR = Not reported because calculations were misleading due to an error in re-abstraction by abstractor #2 who reported 3 wrong dates (i.e., a wrong day, month or year) out of 7 dates for patients who received tPA therapy, which resulted in a misleading mean difference.