Table 1. Patient demographics.
| All patients (N = 707,842) | After match 1:4 (N = 51,915) | |||||
|---|---|---|---|---|---|---|
| Non-appendectomy (N = 697,459) | Appendectomy (N = 10,383) | p-value | Controls (N = 41,532) | Appendectomy (N = 10,383) | p-value | |
| Demographics | ||||||
| Gender, male | 334,344 (47.94%) | 5,253 (50.59%) | <0.0001 | 21,249 (51.16%) | 5,253 (50.59%) | 0.2982 |
| Age | 43.53 ± 16.67 | 41.71 ± 16.38 | <0.0001 | 41.48 ± 16.39 | 41.71 ± 16.38 | 0.2044 |
| Monthly income (NTD) | 18,436.6 ± 15,974.1 | 17,975.8 ± 15,225.0 | 0.0022 | 17,886.9 ± 15,479.9 | 17,975.8 ± 15,225.0 | 0.5957 |
| Clinic visit frequency | 16.01 ± 14.30 | 17.04 ± 14.26 | <0.0001 | 17.02 ± 15.45 | 17.04 ± 14.26 | 0.8784 |
| Comorbidities disease at baseline | ||||||
| Hypertension | 114,369 (16.40%) | 1,551 (14.94%) | <0.0001 | 6,124 (14.75%) | 1,551 (14.94%) | 0.6209 |
| Diabetes mellitus | 47,722 (6.84%) | 647 (6.23%) | 0.0143 | 2,602 (6.27%) | 647 (6.23%) | 0.8991 |
| Hyperlipidemia | 69,706 (9.99%) | 923 (8.89%) | 0.0002 | 3,710 (8.93%) | 923 (8.89%) | 0.8898 |
| CAD | 44,464 (6.38%) | 642 (6.18%) | 0.4267 | 2,540 (6.12%) | 642 (6.18%) | 0.7978 |
| CHF | 9,419 (1.35%) | 134 (1.29%) | 0.5995 | 9,419 (1.35%) | 134 (1.29%) | 0.5995 |
| Arrhythmia | 25,794 (3.70%) | 425 (4.09%) | 0.0344 | 1,685 (4.06%) | 425 (4.09%) | 0.8676 |
| Stroke | 28,713 (4.12%) | 368 (3.54%) | 0.0035 | 1,458 (3.51%) | 368 (3.54%) | 0.8675 |
| PAOD | 5,265 (0.75%) | 64 (0.62%) | 0.1051 | 257 (0.62%) | 64 (0.62%) | 0.9777 |
| Gout | 36,749 (5.27%) | 525 (5.06%) | 0.3356 | 2,074 (4.99%) | 525 (5.06%) | 0.7936 |
| COPD | 70,848 (10.16%) | 1,046 (10.07%) | 0.7789 | 4,105 (9.88%) | 1,046 (10.07%) | 0.5620 |
| CCI score | 0.65 ± 1.33 | 0.88 ± 1.76 | <0.0001 | 0.86 ± 1.80 | 0.88 ± 1.76 | 0.2601 |
| Long term medication use | ||||||
| Anti-diabetic agents | 32,681 (4.69%) | 411 (3.96%) | 0.0005 | 1,595 (3.84%) | 411 (3.96%) | 0.5769 |
| Antihypertensive drug | 110,224 (15.80%) | 1,492 (14.37%) | <0.0001 | 5,924 (14.26%) | 1,492 (14.37%) | 0.7826 |
| Diuretics | 27,619 (3.96%) | 368 (3.54%) | 0.0310 | 1,557 (3.75%) | 368 (3.54%) | 0.3236 |
| ACEIs/ARBs | 51,323 (7.36%) | 617 (5.94%) | <0.0001 | 2,693 (6.48%) | 617 (5.94%) | 0.0433 |
| Beta-blockers | 54,829 (7.86%) | 724 (6.97%) | 0.0008 | 2,940 (7.08%) | 724 (6.97%) | 0.7062 |
| NSAIDs | 41,546 (5.96%) | 667 (6.42%) | 0.0460 | 2,593 (6.24%) | 667 (6.42%) | 0.4975 |
| Analgesic drugs other than NSAIDs | 23,206 (3.33%) | 441 (4.25%) | <0.0001 | 1,697 (4.09%) | 441 (4.25%) | 0.4594 |
| Statins | 24,292 (3.48%) | 279 (2.69%) | <0.0001 | 1,125 (2.71%) | 279 (2.69%) | 0.9031 |
| Propensity score | 0.015 ± 0.005 | 0.016 ± 0.008 | <0.0001 | 0.016 ± 0.008 | 0.016 ± 0.008 | 0.9999 |
| Outcome | ||||||
| CKD | 26,298 (3.77%) | 451 (4.34%) | 0.0024 | 1,430 (3.44%) | 451 (4.34%) | <0.0001 |
| ESRD | 1,544 (0.22%) | 35 (0.34%) | 0.0131 | 75 (0.18%) | 35 (0.34%) | 0.0019 |
| Death | 86,965 (12.47%) | 1,129 (10.87%) | <0.0001 | 5,300 (12.76%) | 1,129 (10.87%) | <0.0001 |
| Subsequent death after ESRD or CKD | 9,640 (1.38%) | 145 (1.40%) | 0.9346 | 533 (1.28%) | 145 (1.39%) | 0.3897 |
| Death without CKD or ESRD | 77,325 (11.09%) | 984 (9.48%) | <0.0001 | 4767 (11.48%) | 984 (9.47%) | <0.0001 |
Notes.
Abbreviations
- NTD
- new Taiwan dollars
- ACEI
- Angiotensin-converting-enzyme inhibitor
- ARB
- Angiotensin II receptor blocker
- CAD
- coronary artery disease
- CHF
- congestive heart failure
- CCI
- Charlson’s comorbidity index
- CKD
- chronic kidney disease
- ESRD
- end-stage renal disease
- NSAIDs
- Non-steroidal anti-inflammatory drugs
- PAOD
- peripheral artery occlusive disease
- COPD
- chronic obstructive pulmonary disease