Table 1 Descriptive analysis: stratified by income status and patterns of quality of care

Hospital-level

Accreditation status, n (%)

0.6392^†

<0.0001^†

Medical center

6955(67.39)

6869(67.37)

86(69.35)

6395(69.95)

560(47.54)

Not medical center

3365(32.61)

3327(32.63)

38(30.65)

2747(30.05)

618(52.46)

Ownership, n (%)

0.5134^‡

0.4790^‡

Public hospital

3706(35.91)

3658 (35.88)

48 (38.71)

3272(35.79)

434(36.84)

Not public hospital

6614(64.09)

6538 (64.12)

76 (61.29)

5870(64.21)

744(63.16)

Hospital service volume, mean (S.D.)

147.56(92.45)

147.83(92.53)

124.90(82.40)

0.0060^‡

151.12(90.68)

119.89(101.03)

0.0001^‡

Hospital risk-adjusted infection rate (%), mean (S.D.)

1.31(1.83)

1.31(1.82)

1.43(2.13)

0.5238^‡

1.40(1.86)

0.57(1.25)

0.0001^‡

Hospital risk-adjusted mortality rate (%), mean (S.D.)

5.41%(5.53)

5.39(5.40)

7.48(12.10)

0.0504^‡

5.79(5.61)

2.45(3.68)

0.0001^‡

Surgeon-level

Surgeon´s gender, n (%)

0.1783^‡

0.0003^‡

Female

287(2.78)

286(2.81)

1 (0.81)

235(2.57)

52(4.41)

Male

10027(97.22)

9904(97.19)

123 (99.19)

8901(97.43)

1126(95.59)

Surgeon´s age, mean (S.D.)

44.46(7.65)

44.48(7.65)

42.77(6.82)

0.0134^‡

44.48(7.63)

44.29(7.79)

0.4244^‡

Surgeon service volume, mean (S.D.)

50.38(34.65)

50.46(34.66)

44.40(32.94)

0.0439^‡

50.12(33.46)

52.46(42.70)

0.0285^‡

Surgeon risk-adjusted infection rate (%), mean (S.D.)

1.28(3.18)

1.28(3.18)

1.27(2.76)

0.9568^‡

1.39(3.31)

0.50(1.63)

0.0001^‡

Surgeon risk-adjusted mortality rate (%), mean (S.D.)

4.89(7.31)

4.88 (7.24)

6.40(11.71)

0.0236^‡

5.29(7.53)

1.86(4.30)

0.0001^‡

Patient-level

Age, mean (S.D.)

65.35(10.95)

65.40(10.93)

61.38(11.74)

0.0001^‡

65.44(10.96)

64.65(10.84)

0.0187^‡

Gender, n (%)

0.1289^‡

0.1504^‡

Female

2424(23.49)

2402(23.56)

22(17.74)

2167(23.70)

257(21.82)

Male

7896(76.51)

7794(76.44)

102(82.26)

6975(76.30)

921(78.18)

CCI, n (%)

0.0001^‡

0.6394^‡

<=1

5453(52.84)

5412(53.08)

41(33.06)

4823(52.76)

630(53.48)

2+

4867(47.16)

4784(46.92)

83(66.94)

4319(47.24)

548(46.52)

Number of vessels obstructed, n (%)

0.5094^‡

0.0001^‡

1

4278(41.45)

4223(41.42)

55(44.35)

3634(39.75)

644(54.67)

2+

6042(58.55)

5973(58.58)

69(55.65)

5508(60.25)

534(45.33)

Patterns of quality of care

Not excellent, n (%)

9142(88.59)

9025(88.52)

117(94.35)

0.0421^‡

Excellent, n (%)

1178(11.41)

1171(11.48)

7(5.65)

Inpatient mortality, n (%)

550(5.33)

535 (5.25)

15(12.10)

0.0007^‡

519(5.68)

31(2.63)

0.0001^‡