Table 1.
Baseline characteristics of study subjects (before and after propensity score matching)
| Before matching | After matchinga | ||||||
|---|---|---|---|---|---|---|---|
| TKR cohort (n = 43,670) |
Control cohort (n = 2,073,676) |
Standardized difference | TKR cohort (n = 43,670) |
Control cohort (n=43,670) |
Standardized difference | ||
| Age at index | |||||||
| Mean±SD | 64.3 ± 10.4 | 60.6 ± 14.6 | 0.29 | 64.3 ± 10.4 | 64.3 ± 10.8 | 0.01 | |
| Sex | |||||||
| Male | 16851 (38.6) | 805087 (38.8) | 0.00 | 16851 (38.6) | 16914 (38.7) | 0.00 | |
| Female | 26723 (61.2) | 1213427 (58.5) | 0.05 | 26723 (61.2) | 26662 (61.1) | 0.00 | |
| Race, n (%) | |||||||
| White | 31364 (71.8) | 1404380 (67.7) | 0.09 | 31364 (71.8) | 31389 (71.9) | 0.00 | |
| Black or African American | 4741 (10.9) | 259381 (12.5) | 0.05 | 4741 (10.9) | 4719 (10.8) | 0.00 | |
| Asian | 1267 (2.9) | 45289 (2.2) | 0.05 | 1267 (2.9) | 1267 (2.9) | 0.00 | |
| Native Hawaiian or other Pacific Islander | 388 (0.9) | 7665 (0.4) | 0.07 | 388 (0.9) | 404 (0.9) | 0.00 | |
| Lifestyle | |||||||
| Alcohol dependence, smoking and substance use | 2392 (5.5) | 128739 (6.2) | 0.03 | 2392 (5.5) | 2179 (5.0) | 0.02 | |
| Comorbidities | |||||||
| Hypertension | 12263 (28.1) | 456075 (22.0) | 0.14 | 12263 (28.1) | 12052 (27.6) | 0.01 | |
| Diabetes mellitus | 4506 (10.3) | 197939 (9.5) | 0.03 | 4506 (10.3) | 4406 (10.1) | 0.01 | |
| Hyperlipidemia | 7098 (16.3) | 267686 (12.9) | 0.09 | 7098 (16.3) | 6908 (15.8) | 0.01 | |
| Ischemic heart diseases | 3104 (7.1) | 122550 (5.9) | 0.05 | 3104 (7.1) | 2901 (6.6) | 0.02 | |
| Chronic kidney disease | 1120 (2.6) | 54785 (2.6) | 0.00 | 1120 (2.6) | 923 (2.1) | 0.03 | |
| Chronic obstructive pulmonary disease | 1163 (2.7) | 56763 (2.7) | 0.00 | 1163 (2.7) | 991 (2.3) | 0.03 | |
| Ankylosing spondylitis | 52 (0.1) | 2191 (0.1) | 0.00 | 52 (0.1) | 27 (0.1) | 0.02 | |
| Systemic lupus erythematosus | 158 (0.4) | 9752 (0.5) | 0.02 | 158 (0.4) | 92 (0.2) | 0.03 | |
| Sjögren syndrome | 133 (0.3) | 6284 (0.3) | 0.00 | 133 (0.3) | 86 (0.2) | 0.02 | |
| Psoriasis | 302 (0.7) | 14742 (0.7) | 0.00 | 302 (0.7) | 218 (0.5) | 0.03 | |
| Socioeconomic Status | |||||||
| Health hazards related to socioeconomic and psychosocial circumstances |
214 (0.5) | 14202 (0.7) | 0.03 | 214 (0.5) | 147 (0.3) | 0.02 | |
| Medical Utilization Status | |||||||
| Ambulatory visit | 27839 (63.7) | 1128558 (54.4) | 0.19 | 27839 (63.7) | 27711 (63.5) | 0.01 | |
| Inpatient visit | 10930 (25.0) | 288753 (13.9) | 0.28 | 10930 (25.0) | 10778 (24.7) | 0.01 | |
| Vaccination Status | |||||||
| Encounter for herpes zoster vaccination | 3884 (8.9) | 169650 (8.2) | 0.03 | 3884 (8.9) | 3831 (8.8) | 0.00 | |
| Laboratory data | |||||||
| BMI, n (%) | |||||||
| ≥ 25 (kg/m2) | 8572 (19.6) | 259197 (12.5) | 0.20 | 8572 (19.6) | 8576 (19.6) | 0.00 | |
| C reactive protein, n (%) | |||||||
| ≥ 3 (mg/L) | 3434 (7.9) | 73956 (3.6) | 0.19 | 3434 (7.9) | 3169 (7.3) | 0.02 | |
| Procalcitonin, n (%) | |||||||
| ≥ 10 (ng/ml) | 10 (0.0) | 146 (0.0) | 0.01 | 10 (0.0) | 10 (0.0) | 0.00 | |
Bold font represents a standardized difference was more than 0.1; In order to protect privacy of individuals, in the TriNetX research network, if the patient amount is less or equal to 10, results show the count as 10
a Propensity score matching was performed on age at index, sex, race, body mass index, lab data, status of comorbidities, lifestyle, socioeconomic issues, medical utilization status, vaccination for herpes zoster status.