Demographic characteristics of patients undergoing biportal endoscopic lumbar surgery.
| Variable | Statistic | Outpatient | Inpatient | Total | P Valuea |
| (n = 58) | (n = 26) | (N = 84) | |||
| Female | N (%) | 14 (24%) | 11 (42%) | 25 (30%) | 0.15 |
| Age (yrs) | Mean (SD) | 53.9 (15.5) | 73.6 (8.2) | 60.0 (16.4) | < 0.0001 |
| Median (Range) | 57.5 (24–81) | 71.5 (57–89) | 65 (24–89) | ||
| BMI (kg/m2) | Mean (SD) | 27.6 (5.0) | 27.7 (3.6) | 27.6 (4.6) | 0.92 |
| Median (Range) | 26.7 (19.8–38.5) | 27.4 (22.0–36.9) | 27 (19.8–38.5) | ||
| ASA score | N > 2 (%) | 13 (22%) | 19 (73%) | 2.3 (0.6) | < 0.0001 |
| Median (Range) | 2 (1–3) | 3 (2–3) | 2 (1–3) | ||
| Charlson Comorbity Index | Mean (SD) | 1.5 (1.5) | 3.9 (1.7) | 2.2 (1.9) | < 0.0001 |
| Median (Range) | 1.5 (0–6) | 3.5 (1-8) | 2 (0–8) | ||
| Surgery Duration (min) | Mean (SD) | 116 (42) | 146 (51) | 125 (47) | 0.012 |
| Median (Range) | 105 (63-253) | 135 (66-227) | 108 (63-253) | ||
| Length of Stay (days) | Mean (SD) | 0.1±0.3 | 1.6±0.9 | 0.5±0.9 | < 0.0001 |
| Range | 0–1 | 1–4 | 0–4 | ||
| Estimated Blood Loss (mL) | Median (IQR) | 0 (0–0) | 0 (0–8) | 0 (0–0) | 0.21 |
| Median (Range) | 0 (0–35) | 0 (0–30) | 0 (0–35) | ||
| Total Drain Output (mL) | Median (IQR) | 30 (14-51) | 80 (50-134) | 35 (25-80) | < 0.0001 |
| Median (Range) | 30 (0–235) | 80 (30-505) | 35 (0–505) |
Abbreviations: ASA, American Society of Anesthesiologists; IQR, interquartile range.
↵a Adjusted threshold for statistical significance P < 0.0063.