Table 2

Result of logistic regression analysis evaluating the association between centre feature and likelihood of having surgery (n=95 818)

No. of patients (%)No. of patients with surgery (%)Unadjusted OR (95% CI)Adjusted OR (95% CI)*χ2 p value log-likelihood ratio test
Surgical centre annual catchment population
 <4007566 (8)1122 (15)11 
 400–70015 581 (16)1929 (12)0.81 (0.74 to 0.87)0.87 (0.78 to 0.97) 
 700–110033 009 (34)4464 (14)0.89 (0.83 to 0.96)0.87 (0.79 to 0.95) 
 >110039 662 (41)5244 (13)0.87 (0.81 to 0.93)0.88 (0.80 to 0.96)0.06
No. of cardiothoracic surgeons on-site 
 ≤3 surgeons26 493 (28)3517 (13)11 
 >3–≤5 surgeons51 579 (64)8095 (13)0.98 (0.94 to 1.03)0.99 (0.93 to 1.05) 
 >5 surgeons7746 (8)1147 (15)1.13 (1.05 to 1.22)0.99 (0.90 to 1.09)0.88
  • *Adjusted for patient features only.