Table 4.
Results of (a) un-adjusted Cox proportional hazards models to test univariate associations between patient characteristics and time to end (days) of post-intervention (PI) patency loss of PI cumulative patency loss, (b) adjusted Cox proportional hazards model controlling for all patient characteristics, and (c) stepwise estimation, for patients with one lesion only (N = 80).
| Patient characteristics; potential predictors of the outcome(s) | (a) Un-adjusted Cox proportional
hazards models HR (95% CI) |
(b) Adjusted Cox proportional hazards
model HR (95% CI) |
(c) Stepwise selection Sig. or NS |
|||
|---|---|---|---|---|---|---|
| PI primary patency loss | PI cumulative patency loss | PI primary patency loss | PI cumulative patency loss | PI primary patency loss | PI cumulative patency loss | |
| Age | ||||||
| <65 (ref) | – | – | – | – | ||
| ⩾65 | 0.79 (0.43, 1.47) | 1.34 (0.55, 3.28) | 0.75 (0.29, 1.89) | 1.15 (0.27, 4.83) | NS | NS |
| Sex | ||||||
| Female (ref) | – | – | – | – | ||
| Male | 1.19 (0.64, 2.22) | 1.28 (0.53, 3.10) | 1.84 (0.83, 4.06) | 2.76 (0.70, 10.89) | NS | NS |
| Ethnicity | ||||||
| Non-white (ref) | – | – | – | – | ||
| White | 0.73 (0.39, 1.37) | 0.82 (0.34, 1.97) | 0.60 (0.26, 1.39) | 1.29 (0.35, 4.65) | NS | NS |
| Age of fistula (log days) | 0.84 (0.66, 1.09) | 0.74 (0.52, 1.06) | *0.65 (0.44, 0.97) | *0.48 (0.23, 0.99) | NS | NS |
| Statins | ||||||
| None (ref) | – | – | – | – | ||
| Any | 1.59 (0.84, 2.99) | *3.10 (1.13, 8.54) | 2.34 (0.99, 5.53) | 3.47 (0.73, 16.49) | NS | *Sig. |
| CAD | ||||||
| No (ref) | – | – | – | – | ||
| Yes | 0.59 (0.23, 1.51) | 1.25 (0.42, 3.75) | 0.76 (0.22, 2.66) | 5.49 (0.92, 32.64) | NS | NS |
| PVD | ||||||
| No (ref) | – | – | – | – | ||
| Yes | 1.19 (0.47, 3.05) | 1.45 (0.42, 4.97) | 0.62 (0.12, 3.07) | 0.67 (0.06, 7.91) | NS | NS |
| Anticoagulation | ||||||
| No (ref) | – | – | – | – | ||
| Yes | 1.45 (0.35, 6.06) | 1.46 (0.20, 11.00) | 4.87 (0.31, 76.75) | NA | NS | NS |
| Diabetes | ||||||
| No (ref) | – | – | – | – | ||
| Yes | 1.04 (0.54, 2.02) | 1.80 (0.74, 4.36) | 1.29 (0.51, 3.26) | 2.12 (0.45, 10.10) | NS | NS |
| Type of access | ||||||
| Brachiobasilic (ref) | – | – | – | – | ||
| Brachiocephalic | 0.72 (0.37, 1.39) | 0.66 (0.26, 1.67) | 0.79 (0.32, 1.97) | 0.49 (0.12, 1.92) | ||
| Radiocephalic | 0.92 (0.31, 2.75) | 0.73 (0.16, 3.37) | 1.15 (0.28, 4.70) | 0.89 (0.09, 8.64) | NS | NS |
| Lesion length (mm) | 1.06 (0.90, 1.24) | *1.21 (1.02, 1.43) | 1.06 (0.81, 1.39) | *1.89 (1.26, 2.84) | NS | *Sig. |
| Lesion site | ||||||
| Anastomotic (ref) | – | – | – | – | ||
| Perianast | 1.01 (0.23, 4.55) | 0.32 (0.03, 3.50) | 3.37(0.43, 26.63) | 0.29 (0.01, 8.21) | ||
| Mid-limb | 1.50 (0.43, 5.18 | 0.89 (0.19, 4.31) | 3.22 (0.54, 19.08) | 0.34 (0.02, 4.71) | ||
| Swing point | 1.42 (0.41, 4.97) | 1.25 (0.27, 5.79) | 3.85 (0.74, 20.08) | 2.36 (0.25, 22.36) | ||
| Central stenosis | 1.82 (0.37, 9.11) | 0.91 (0.08, 10.03) | 10.44 (1.18, 92.51) | 4.78 (0.18, 125.04) | ||
| Arterial | 0.69 (0.07, 6.80) | NA | NA | NA | NS | NS |
| Thrombosis | ||||||
| No (ref) | – | – | – | – | ||
| Yes | 1.96 (0.77, 5.03) | 2.42 (0.71, 8.27) | 2.32 (0.64, 8.42) | 3.54 (0.55, 22.93) | NS | NS |
| Previous intervention | ||||||
| 0 (ref) | – | – | – | – | ||
| 1+ | 1.06 (0.55, 2.05) | −0.81 (0.31, 2.10) | 1.29 (0.46, 3.61) | 0.35 (0.06, 1.94) | NS | NS |
HR: hazard ratio; CI: confidence interval; ref: reference category; Sig.: significant (p < 0.05) in stepwise regression; NS: not significant in stepwise regression and therefore removed from model; NA: not applicable due to small n; CAD: coronary artery disease; PVD: peripheral vascular disease.
Statistically significant at the p < 0.05 level; **statistically significant at the p < 0.001 level.