Table 2.
Statistically significant (either univariate or multivariable) factors associated with the number of patients recruited per site per month. Data by columns are: 1) number of patients recruited and cumulative number of recruitment months, 2) estimated recruitment rate per month (with 95% CI), 3) relative recruitment rates (with 95% CI), 4) univariate test of differences in recruitment rates, 5) multivariable relative recruitment rates, and 6) multivariable test of differences in recruitment rates. Analysis was also performed for whether the site had affiliates recruitment partners and whether the site was at full staff complement, with neither of these factors being significant (p > 0.1) in either univariate or multivariable analysis (these factors also remain in the multivariable model).
| Factor | Level | Univariate | Multivariable | ||||
|---|---|---|---|---|---|---|---|
| Recruit/Clin Mths | Recruit Rate per Month (95% CI) | Recruitment Ratio (95% CI) | P-Value | Recruitment Ratio (95% CI) | P-Value | ||
| PI Specialty | Interventional Radiology or Neuroradiology | 170 513 |
0.34 (0.24 – 0.47) | 1.01 (0.71 – 1.45) | <0.001 | 1.26 (0.79 – 2.01) | 0.39 |
| Neurology | 36 107 |
0.18 (0.14 – 0.23) | 0.55 (0.42 – 0.72) | 0.001 | 0.84 (0.57 – 1.24) | ||
| Neurosurgery | 73 404 |
0.23 (0.16 – 0.33) | 0.69 (0.46 – 1.04) | 0.92 (0.54 – 1.57) | |||
| Vascular Surgery | 27 118 |
0.23 (0.19 – 0.27) | 0.69 (0.55 – 0.87) | 1.12 (0.78 – 1.61) | |||
| Cardiology | 131 571 |
0.33 (0.29 – 0.39) | 1.00 (ref) | 1.00 (ref) | |||
| Site Type | Private Hospital | 148 482 |
0.31 (0.26 – 0.36) | 1.52 (1.22 – 1.89) | 1.48 (1.08 – 2.03) | <0.001 | |
| Private office | 95 303 |
0.31 (0.26 – 0.38) | 1.55 (1.20 – 1.99) | 1.37 (0.91 – 2.05) | |||
| VA Medical Center | 26 97 |
0.27 (0.18 – 0.40) | 1.33 (0.88 – 2.01) | 3.71 (2.14 – 6.46) | |||
| Academic | 168 831 |
0.20 (0.17 – 0.24) | 1.00 (ref) | 1.00 (ref) | |||
| StrokeNET participation | StrokeNET | 106 608 |
0.17 (0.14 – 0.21) | 0.58 (0.47 – 0.72) | <0.001 | 1.00 (0.73 – 1.36) | 0.98 |
| Non-StrokeNET | 331 1,105 |
0.30 (0.27 – 0.33) | 1.00 (ref) | 1.00 (ref) | |||
| Number of CEA | <10 | 48 133 |
0.36 (0.27 – 0.48) | 1.43 (1.06 – 1.95) | 0.079 | 1.88 (1.24 – 2.85) | 0.020 |
| 10–25 | 22 107 |
0.20 (0.13 – 0.31) | 0.81 (0.53 – 1.25) | 1.51 (0.92 – 2.50) | |||
| 25–50 | 93 388 |
0.24 (0.20 – 0.29) | 0.95 (0.75 – 1.20) | 1.14 (0.88 – 1.49) | |||
| >50 | 274 1,085 |
0.25 (0.22 – 0.28) | 1.00 (ref) | 1.00 (ref) | |||
| Number of CAS | <10 | 65 310 |
0.21 (0.16 – 0.27) | 0.56 (0.42 – 0.76) | <0.001 | 0.57 (0.38 – 0.85) | <0.001 |
| 10–25 | 128 556 |
0.23 (0.19 – 02.7) | 0.62 (0.49 – 0.79) | 0.58 (0.42 – 0.79) | |||
| 25–50 | 103 467 |
0.22 (0.18 – 0.27) | 0.59 (0.46 – 0.77) | 0.42 (0.31 – 0.57) | |||
| >50 | 141 380 |
0.37 (0.31 – 0.44) | 1.00 (ref) | 1.00 (ref) | |||
| Approval by site selection committee | CAS only | 25 72 |
0.35 (0.23 – 0.51) | 1.37 (0.91 – 2.05) | 0.22 | 2.20 (1.20 – 4.04) | 0.04 |
| CEA only | 13 66 |
0.20 (0.12 – 0.34) | 0.78 (0.45 – 1.36) | 1.63 (0.74 – 3.59) | |||
| Both | 399 1,575 |
0.25 (0.23 – 0.28) | 1.00 (ref) | 1.00 (ref) | |||
| Green light authorization for randomization | CAS only | 35 115 |
0.30 (0.22 – 0.42) | 1.01 (0.72 – 1.43) | 0.006 | 0.54 (0.34 – 0.85) | <0.001 |
| CEA only | 56 446 |
0.13 (0.10 – 0.16) | 0.42 (0.32 – 0.55) | 0.28 (0.19 – 0.41) | |||
| Both | 346 1,152 |
0.30 (0.27 – 0.33) | 1.00 (ref) | 1.00 (ref) | |||
| CREST Participation | Top Half | 198 650 |
0.30 (0.27 – 0.35) | 1.40 (1.13 – 1.74) | <0.001 | 1.64 (1.27 – 2.11) | 0.001 |
| Bottom Half | 98 415 |
0.24 (0.19 – 0.29) | 1.08 (0.84 – 1.40) | 1.58 (1.16 – 2.15) | |||
| Not in CREST | 141 648 |
0.22 (0.18 – 0.26) | 1.00 (ref) | 1.00 (ref) | |||