| Characteristic | History of Ostomy | p-value2 | |
|---|---|---|---|
| Ostomy Prior to THA, N = 4631 | No Ostomy Prior to THA, N = 125,9511 | ||
| Indication | <0.001 | ||
| OA | 217 (46.9%) | 66,191 (52.6%) | |
| AVN | 56 (12.1%) | 7,343 (5.8%) | |
| Inflammatory arthritis | 17 (3.7%) | 3,591 (2.9%) | |
| Unspecified | 173 (37.4%) | 48,826 (38.8%) | |
| Age (years) | 67.6 +/- 11.2 | 64.9 +/- 11.5 | <0.001 |
| Sex | 0.742 | ||
| Female | 263 (56.8%) | 70,588 (56.0%) | |
| Male | 200 (43.2%) | 55,363 (44.0%) | |
| Race | 0.142 | ||
| White | 394 (85.1%) | 103,250 (82.0%) | |
| Black | 34 (7.3%) | 9,718 (7.7%) | |
| Hispanic | 19 (4.1%) | 5,761 (4.6%) | |
| Asian | 4 (0.9%) | 696 (0.6%) | |
| Native American | 0 (0.0%) | 202 (0.2%) | |
| Other or Unknown | 12 (2.6%) | 6,324 (5.0%) | |
| Elixhauser score | 2.0 +/- 5.4 | 0.8 +/- 4.2 | <0.001 |
| Insurance | <0.001 | ||
| Private | 171 (36.9%) | 62,155 (49.3%) | |
| Medicare | 269 (58.1%) | 57,359 (45.5%) | |
| Medicaid | 10 (2.2%) | 3,433 (2.7%) | |
| Worker's Compensation | 10 (2.2%) | 1,642 (1.3%) | |
| Other | 3 (0.6%) | 1,360 (1.1%) | |
| Follow-up duration (years) | 4.8 +/- 2.1 | 5.4 +/- 2.3 | <0.001 |
| 1 n (%); Mean +/- SD | |||
| 2 Pearson’s Chi-squared test; Welch Two Sample t-test; Fisher’s Exact Test for Count Data with simulated p-value (based on 2000 replicates) | |||
Ostomy Prior to THA Increases Risk of PJI
Tidy data
Load packages
Load data
Clean data
Methods
Summary of included patients
Initial data query yielded a total of 332,638 cases in 281,988 patients. Revision cases where the corresponding primary case was not found in the database (e.g., because the primary occurred prior to the study period or outside of New York state) were excluded (15,444 cases in 12,763 patients). Additional cases with illogical or inconsistent data, likely to be the result of medical coding errors, were removed as necessary (e.g., patients greater than 2 primary cases or more than 1 primary case of the same laterality). For the purposes of this analysis hemiarthroplasty cases were excluded (46,782 cases) and patients who underwent THA for hip fracture were excluded (18,384 cases). Patients with less than 2 years of postoperative follow up were also excluded. The final cohort consisted of 126,414 cases in 111,550 patients.
Results
Demographics
Outcomes
| Characteristic | History of Ostomy | p-value2 | |
|---|---|---|---|
| Ostomy Prior to THA, N = 4631 | No Ostomy Prior to THA, N = 125,9511 | ||
| Length of hospital stay (days) | 4.0 +/- 4.5 | 3.1 +/- 1.8 | <0.001 |
| Discharge disposition | 0.012 | ||
| Home | 256 (55.3%) | 78,360 (62.2%) | |
| Skilled Nursing Facility | 154 (33.3%) | 33,823 (26.9%) | |
| Inpatient Rehabilitation | 50 (10.8%) | 13,075 (10.4%) | |
| Transfer | 2 (0.4%) | 558 (0.4%) | |
| Against Medical Advice | 1 (0.2%) | 32 (0.0%) | |
| Discharged to Court | 0 (0.0%) | 95 (0.1%) | |
| Hospice | 0 (0.0%) | 8 (0.0%) | |
| Expired | 0 (0.0%) | 0 (0.0%) | |
| ED presentation within 3 months | 77 (16.6%) | 13,257 (10.5%) | <0.001 |
| Readmission within 3 months | 79 (17.1%) | 8,900 (7.1%) | <0.001 |
| Readmission within 12 months | 129 (27.9%) | 15,013 (11.9%) | <0.001 |
| All-cause revision | 19 (4.1%) | 3,551 (2.8%) | 0.096 |
| Revision for PJI | 9 (1.9%) | 1,108 (0.9%) | 0.023 |
| Time to first revision (years) | 2.8 +/- 2.7 | 3.0 +/- 2.7 | 0.739 |
| Reoperation within 3 months of primary | 6 (1.3%) | 736 (0.6%) | 0.057 |
| Reoperation within 12 months of primary | 7 (1.5%) | 1,179 (0.9%) | 0.216 |
| 1 Mean +/- SD; n (%) | |||
| 2 Welch Two Sample t-test; Fisher’s Exact Test for Count Data with simulated p-value (based on 2000 replicates); Pearson’s Chi-squared test; Fisher’s exact test | |||
GLM for risk of revision
| Characteristic | OR1 | 95% CI1 | p-value |
|---|---|---|---|
| Ostomy Prior to THA | |||
| No | — | — | |
| Yes | 2.19 | 1.04, 4.00 | 0.021 |
| Ostomy After THA | |||
| No | — | — | |
| Yes | 0.52 | 0.13, 1.35 | 0.256 |
| Age (years) | 0.98 | 0.98, 0.99 | <0.001 |
| Sex | |||
| Female | — | — | |
| Male | 1.22 | 1.08, 1.38 | 0.001 |
| Elixhauser score | 1.02 | 1.00, 1.03 | 0.038 |
| Operative indication | |||
| OA | — | — | |
| Inflammatory arthritis | 2.01 | 1.51, 2.61 | <0.001 |
| AVN | 1.59 | 1.28, 1.96 | <0.001 |
| Unspecified | 0.98 | 0.86, 1.12 | 0.797 |
| Obesity | |||
| No | — | — | |
| Yes | 1.68 | 1.46, 1.92 | <0.001 |
| DM | |||
| No | — | — | |
| Yes | 1.21 | 1.03, 1.43 | 0.022 |
| History of smoking | |||
| No | — | — | |
| Yes | 1.22 | 1.01, 1.46 | 0.034 |
| 1 OR = Odds Ratio, CI = Confidence Interval | |||
Table: Logistic regression model demonstrating the odds of revision for PJI for patients undergoing THA with at least 2 years of follow-up. Patients with a history of an ostomy prior to undergoing THA demonstrated an increased risk of infection-related revision when controlling for the effects of age, gender, Elixhauser score, operative indication, obesity, DM, and smoking history. Patients who underwent ostomy after THA did not demonstrate an increased risk of infection-related revision.
