Table 3.
Descriptive statistics of the included AOK cases (2013–2015), presented as a total figure and in accordance with volume categories (I: 1–50, II: 51–75, III: 76–100, IV: 101–125, V: ≥ 126 inguinal hernia repairs per year)
| Total | I | II | III | IV | V | |
|---|---|---|---|---|---|---|
| Caseloads, age and gender | ||||||
| Annual caseload | – | 1–50 | 51–75 | 76–100 | 101–125 | ≥ 126 |
| AOK cases (N) | 133.449 | 4.586 | 12.105 | 17.985 | 20.776 | 77.997 |
| Age (median; IQR) | 59 (47–73) | 60 (49–74) | 61 (48–74) | 60 (48–74) | 60 (48–73) | 59 (47–73) |
| Gender (female, %) | 11.33 | 11.16 | 10.04 | 11.15 | 11.20 | 11.61 |
| Risk factors and surgical technique (%) | ||||||
| Recurrence present on admission | 11.66 | 12.10 | 11.31 | 12.12 | 11.77 | 11.55 |
| Incarceration | 9.42 | 10.64 | 11.93 | 11.10 | 9.86 | 8.45 |
| Gangrene | 0.44 | 0.48 | 0.45 | 0.50 | 0.46 | 0.42 |
| Emergency | 4.08 | 4.62 | 5.15 | 4.96 | 4.36 | 3.60 |
| Bilateral procedure | 15.61 | 9.97 | 11.55 | 12.64 | 14.56 | 17.53 |
| Intestinal procedure | 0.35 | 0.44 | 0.35 | 0.42 | 0.32 | 0.34 |
| Simultaneous repair of umbilical hernia | 5.35 | 3.99 | 4.38 | 4.73 | 4.93 | 5.84 |
| Simultaneous repair of femoral hernia | 0.38 | 0.44 | 0.36 | 0.36 | 0.37 | 0.39 |
| Simultaneous repair of incisional hernia | 0.32 | 0.26 | 0.28 | 0.33 | 0.32 | 0.32 |
| Outpatient repair | 11.21 | 13.06 | 12.43 | 11.08 | 11.79 | 10.79 |
| Open suture procedure | 6.20 | 10.60 | 7.45 | 7.09 | 5.37 | 5.76 |
| Open mesh procedure | 37.92 | 49.30 | 43.89 | 41.03 | 40.85 | 34.82 |
| Minimally invasive mesh procedure | 55.89 | 40.10 | 48.66 | 51.88 | 53.78 | 59.42 |
| Preoperative medication (%) | ||||||
| Immunosuppressants | 0.74 | 0.76 | 0.70 | 0.71 | 0.73 | 0.75 |
| Systemic glucocorticoids | 1.70 | 1.92 | 1.76 | 1.85 | 1.55 | 1.69 |
| Antithrombotics | 13.10 | 14.17 | 14.46 | 13.88 | 13.72 | 12.48 |
| Treatment for chronic inflammatory bowel disease | 0.32 | 0.31 | 0.37 | 0.36 | 0.34 | 0.31 |
| BMI and Elixhauser comorbiditiesa (%) | ||||||
| Obesity grade, unspecified | 0.30 | 0.44 | 0.23 | 0.37 | 0.26 | 0.30 |
| Grade I obesity | 2.79 | 3.47 | 2.73 | 2.66 | 2.81 | 2.79 |
| Grade II obesity | 0.93 | 1.02 | 0.98 | 0.86 | 1.04 | 0.91 |
| Grade III obesity | 0.36 | 0.57 | 0.40 | 0.36 | 0.34 | 0.35 |
| Hypertension, no complications | 31.34 | 34.89 | 34.69 | 33.37 | 32.36 | 29.87 |
| Cardiac arrhythmia | 8.02 | 9.16 | 9.24 | 9.13 | 8.39 | 7.41 |
| Diabetes, no complications | 7.22 | 8.70 | 7.73 | 8.01 | 7.47 | 6.81 |
| Chronic lung disease | 5.38 | 6.13 | 6.39 | 5.67 | 5.35 | 5.12 |
| Hypothyroidism | 4.32 | 4.21 | 4.22 | 4.24 | 4.24 | 4.39 |
| Congestive heart disease | 3.37 | 4.27 | 4.22 | 3.96 | 3.71 | 2.95 |
| Real failure/insufficiency | 3.13 | 3.92 | 3.88 | 3.46 | 3.46 | 2.80 |
| Peripheral occlusive vascular disease | 2.30 | 2.94 | 2.45 | 2.67 | 2.37 | 2.13 |
| Disorders of the water and electrolyte balance as well as of the acid–base balance | 1.97 | 2.25 | 2.19 | 2.16 | 1.94 | 1.88 |
| Other neurologic diseases | 1.92 | 2.35 | 2.00 | 2.17 | 2.04 | 1.78 |
| Heart valve disease | 1.82 | 2.18 | 2.08 | 2.20 | 1.85 | 1.67 |
| Coagulopathy | 1.68 | 1.92 | 1.96 | 1.88 | 1.75 | 1.56 |
| Depression | 1.66 | 2.20 | 1.86 | 1.83 | 1.70 | 1.54 |
| Hypertension, with complications | 1.55 | 1.92 | 1.74 | 1.79 | 1.74 | 1.38 |
aComorbidities with a total incidence of less than 1% are not presented (diabetes with complications, liver disease, alcohol abuse, paralysis, rheumatoid disease, psychosis, pulmonary heart disease and diseases of the pulmonary circulation, weight loss, deficiency anemia, drug abuse, and non-bleeding peptic ulcer)