Table 4. Baseline characteristics before and after propensity score matching.
| Risk factors | Before matching (n=64,982) | After matching (n=21,248) | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Regular user (n=53,991) | Non-user (n=10,991) | SD | p | Regular user (n=10,624) | Non-user (n=10,624) | SD | p | ||
| Followed duration (month) | 24.33 (21.43–24.33) | 24.33 (18.03–24.33) | 0.14 | - | 24.33 (21.53–24.33) | 24.33 (18.07–24.33) | 0.11 | - | |
| Age (year) | 60 (51–69) | 62 (52–71) | −0.15 | - | 62 (52–71) | 61 (52–71) | −0.01 | - | |
| Male | 41,426 (76.73) | 8,243 (75.00) | 0.03 | <0.0001 | 7,988 (75.19) | 7,991 (75.22) | 0.00 | <0.0001 | |
| Study enrollment | <0.0001 | 0.8109 | |||||||
| 2005–2008 | 17,629 (32.65) | 5,138 (46.75) | −0.24 | 4,886 (45.99) | 4,930 (46.40) | −0.01 | |||
| 2009–2011 | 16,477 (30.52) | 2,639 (24.01) | 0.12 | 2,589 (24.37) | 2,557 (24.07) | 0.01 | |||
| 2012–2014 | 19,885 (36.83) | 3,214 (29.24) | 0.13 | 3,149 (29.64) | 3,137 (29.53) | 0.00 | |||
| Underlying medical condition | |||||||||
| Hypertension | 26,685 (49.42) | 5,135 (46.72) | 0.04 | <0.0001 | 5,058 (47.61) | 4,989 (46.96) | 0.01 | <0.0001 | |
| DM | 14,656 (27.15) | 3,090 (28.11) | −0.02 | 0.0377 | 2,993 (28.17) | 2,975 (28.00) | 0.00 | <0.0001 | |
| Dyslipidemia | 14,653 (27.14) | 3,094 (28.15) | −0.02 | 0.0302 | 3,041 (28.62) | 3,006 (28.29) | 0.01 | <0.0001 | |
| Previous stroke, all type | 3,968 (7.35) | 1,024 (9.32) | −0.06 | <0.0001 | 993 (9.35) | 969 (9.12) | 0.02 | <0.0001 | |
| CHF | 1,728 (3.20) | 526 (4.79) | −0.07 | <0.0001 | 505 (4.75) | 493 (4.64) | 0.02 | <0.0001 | |
| ESRD | 2,340 (4.33) | 563 (5.12) | −0.03 | 0.0003 | 532 (5.01) | 538 (5.06) | −0.01 | <0.0001 | |
| History of malignancy | 1,363 (2.52) | 317 (2.88) | −0.02 | 0.0303 | 312 (2.94) | 304 (2.86) | 0.02 | <0.0001 | |
| Charlson comorbidity score | 1 (0–2) | 1 (0–2) | −0.04 | - | 1 (0–2) | 1 (0–2) | 0.01 | - | |
| ≤1 | 36,729 (68.03) | 7,287 (66.3) | 0.03 | 0.0005 | 7,006 (65.95) | 7,054 (66.40) | −0.01 | 0.8917 | |
| 2–3 | 10,364 (19.20) | 2,149 (19.55) | −0.01 | 2,091 (19.68) | 2,078 (19.56) | 0.00 | |||
| 4–5 | 4,821 (8.93) | 1,082 (9.84) | −0.03 | 1,068 (10.05) | 1,041 (9.80) | 0.01 | |||
| ≥6 | 2,077 (3.85) | 473 (4.30) | −0.02 | 459 (4.32) | 451 (4.25) | 0.00 | |||
| Type of stent | <0.0001 | 0.1590 | |||||||
| BMS | 2,262 (4.19) | 592 (5.39) | −0.05 | 514 (4.84) | 573 (5.39) | −0.02 | |||
| 1st generation DES | 14,902 (27.60) | 4,044 (36.79) | −0.16 | 3,948 (37.16) | 3,887 (36.59) | 0.01 | |||
| 2nd generation DES | 36,827 (68.21) | 6,355 (57.82) | 0.18 | 6,162 (58.00) | 6,164 (58.02) | 0.00 | |||
| Number of stents | 0.7611 | 0.4762 | |||||||
| 1 | 44,670 (82.74) | 9,088 (82.69) | 0.00 | 8,736 (82.23) | 8,786 (82.70) | −0.01 | |||
| 2 | 6,096 (11.29) | 1,228 (11.17) | 0.00 | 1,196 (11.26) | 1,188 (11.18) | 0.00 | |||
| ≥3 | 3,225 (5.97) | 675 (6.14) | −0.01 | 692 (6.51) | 650 (6.12) | 0.01 | |||
| Followed medication | |||||||||
| Dual antiplatelet agent | 31,584 (58.50) | 6,745 (61.37) | −0.05 | <0.0001 | 6,686 (62.93) | 6,725 (63.30) | −0.01 | 0.0001 | |
| Aspirin users | 15,556 (28.81) | 2,693 (24.50) | 0.08 | 2,653 (24.97) | 2,690 (25.32) | −0.01 | |||
| Clopidogrel users | 6,363 (11.79) | 1,008 (9.17) | 0.07 | 983 (9.25) | 1,007 (9.48) | −0.01 | |||
| No antiplatelet agents | 488 (0.90) | 545 (4.96) | −0.23 | 302 (2.84) | 202 (1.90) | 0.05 | |||
| RAAS blocker | 39,369 (72.92) | 6,089 (55.40) | 0.31 | <0.0001 | 6,163 (58.01) | 6,082 (57.25) | 0.01 | <0.0001 | |
| CCB | 4,192 (7.76) | 1,026 (9.33) | −0.05 | <0.0001 | 1,024 (9.64) | 1,015 (9.55) | 0.01 | <0.0001 | |
| Statin | 46,501 (86.13) | 7,991 (72.70) | 0.29 | <0.0001 | 8,061 (75.88) | 7,979 (75.10) | 0.01 | <0.0001 | |
| High intensity statin | 11,962 (22.16) | 1,541 (14.02) | 0.17 | <0.0001 | 1,505 (14.17) | 1,521 (14.32) | −0.01 | <0.0001 | |
| Thiazide | 2,580 (4.78) | 569 (5.18) | −0.02 | 0.0762 | 598 (5.63) | 561 (5.28) | 0.05 | <0.0001 | |
| Loop diuretics | 5,535 (10.25) | 1,195 (10.87) | −0.02 | 0.0515 | 1,232 (11.60) | 1,184 (11.14) | 0.03 | <0.0001 | |
| Spironolactone | 3,014 (5.58) | 612 (5.57) | 0.00 | 0.9528 | 609 (5.73) | 604 (5.69) | 0.01 | <0.0001 | |
| Vasodilators | 18,320 (33.93) | 4,088 (37.19) | −0.06 | <0.0001 | 4,069 (38.30) | 4,035 (37.98) | 0.01 | <0.0001 | |
Values are expressed as median (interquartile range) or number (%).
BMS = bare metal stent; CCB = calcium channel blocker; CHF = congestive heart failure; DES = drug-eluting stent; DM = diabetes mellitus; ESRD = end-stage renal disease; RAAS = Renin-angiotensin-aldosterone system; SD = standard deviation.