Table 2.
Risk factors for delirium
| Delirium outcomes | No delirium | Delirium | Total | P-value | (uni) Odds ratio (CI 95%) | Adjusted odds ratio (CI 95%) |
|---|---|---|---|---|---|---|
|
| ||||||
| (N=370) (65.4%) | (N=196) (34.6%) | N=566 | ||||
| Preoperative delirium | 0 (0) | 46 (23.5) | 46 | |||
| Duration of delirium (days), Median (IQR) | 0 (0) | 4 (4) | 4 (4) | |||
| Delirium at discharge | 0 (0) | 100 (51) | 100 | |||
| Died while delirious | 0 (0) | 8 (4) | 8 | |||
| Risk factors | ||||||
| Sex | 1.05 (0.71–1.60) | |||||
| Female (ref) | 279 (75.4) | 146 (74.5) | 425 | |||
| Male | 91 (24.6) | 50 (25.5) | 141 | 0.811 | ||
| Age | 2.65 (1.71–4.10) | |||||
| 70–79 | 126 (34.0) | 32 (16.3) | 158 | |||
| 80+ (ref) | 244 (66.0) | 164 (83.7) | 408 | <0.001 | ||
| Median (IQR) | 83 (10) | 85.5 (8) | <0.001^ | 1.07 (1.04–1.10) | ||
| Burden of comorbidity | ||||||
| CCI, Median (IQR) | 5.0 (3) | 6.0 (2) | <0.001^ | 1.17 (1.06–1.30) | 1.09 (0.98–1.21) | |
| ASA | ||||||
| 1–2 | 132 (35.7) | 36 (18.4) | 168 | |||
| 3–4 (ref) | 238 (64.3) | 160 (81.6) | 398 | <0.001 | 2.47 (1.62–3.75) | 0.45 (0.30–0.70)c |
| Medical history | ||||||
| Contralat hip fracture | 28 (7.6) | 17 (8.7) | 45 | 0.644 | 1.16 (0.62–2.20) | |
| Cardial | 164 (44.3) | 85 (43.4) | 248 | 0.827 | 0.96 (0.68–1.36) | |
| Pulmonal (COPD) | 68 (18.4) | 39 (20.0) | 107 | 0.660 | 1.10 (0.71–1.71) | |
| Neurologicala | 127 (34.3) | 76 (38.7) | 203 | 0.293 | 1.21 (0.85–1.74) | |
| Renal insufficiency | 49 (13.2) | 33 (16.8) | 82 | 0.248 | 1.33 (0.82–2.14) | |
| Dementia | 71 (19.2) | 97 (49.5) | 168 | <0.001 | 0.25 (0.16–0.35) | 0.26 (0.18–0.38)c |
| Previous delirium | 61 (16.5) | 78 (40.0) | 139 | <0.001 | 0.29 (0.20–0.44) | 0.31 (0.21–0.46)c |
| Missing data (%) | 6 (1.1) | |||||
| Diabetes | 82 (22.2) | 51 (26.0) | 133 | 0.303 | 1.24 (0.83–1.85) | |
| Osteoporosis | 70 (18.9) | 25 (12.7) | 95 | 0.062 | 0.63 (0.38–1.03) | |
| BMI, Median (IQR) | 23.6 (4.8) | 23.5 (5.8) | 0.561^ | 0.99 (0.95–1.04) | ||
| SNAQ <3 | 317 (85.7) | 160 (81.6) | 479 | |||
| SNAQ ≥3 (ref) | 36 (10.1) | 25 (12.7) | 61 | 0.240 | 1.39 (0.80–2.34) | |
| Daily alcohol use | 79 (21.3) | 37 (18.9) | 116 | 0.503 | 0.86 (0.56–1.33) | |
| Visual impairment | 203 (55) | 116 (59.2) | 319 | 0.325 | 1.20 (0.84–1.70) | |
| Hearing impairment | 137 (37) | 86 (43.9) | 223 | 0.113 | 1.33 (0.93–1.90) | |
| Functional dependency | ||||||
| Katz ≤ score 5 | 156 (42.1) | 146 (75.0) | 302 | <0.001 | 0.23 (0.16–0.34) | 0.26 (0.18–0.40)c |
| Katz ≤ score 2 | 55 (14.9) | 83 (42.3) | 138 | <0.001 | 0.23 (0.15–0.34) | 0.24 (0.16–0.40)c |
| Missing data (%) | 8 (1.4) | |||||
| AO classification | ||||||
| 31a1 (ref) | 54 (14.6) | 35 (17.9) | 89 | 0.666 | ||
| 31a2 | 62 (16.8) | 33 (16.8) | 95 | 0.8 (0.5–1.5) | ||
| 31a3 | 30 (8.1) | 19 (10.0) | 49 | 0.9 (0.4–1.8) | ||
| 31b1 | 53 (14.3) | 21 (10.7) | 74 | 0.6 (0.3–1.2) | ||
| 31b2 | 81 (22.0) | 37 (19.0) | 118 | 0.7 (0.4–1.3) | ||
| 31b3 | 90 (24.3) | 51 (26.0) | 141 | 0.8 (0.5–1.5) | ||
| Preoperative anticoagulants | 201 (54.3) | 105 (53.6) | 306 | 0.864 | 0.97 (0.69–1.40) | |
| Kind of anesthesia | 0.393 | 0.82 (0.53–1.28) | ||||
| General (ref) | 292 (78.9) | 161 (82.1) | 453 | |||
| Epidural | 77 (20.8) | 35 (17.8) | 112 | |||
| Duration of surgery minutes, Median (IQR) | 77 (24) | 69 (23) | 0.455^ | 1.00 | ||
| Blood loss cc, Median (IQR) | 200 (200) | 200 (150) | 0.564^ | 1.00 (0.99–1.00) | ||
| Duration of admission until surgery | ||||||
| <24 hours (ref) | 130 (35.1) | 62 (31.6) | 192 | 0.696 | 1.16 (0.801.70) | |
| 24–48 hours | 202 (54.6) | 112 (57.1) | 314 | |||
| >48 hours | 38 (10.3) | 22 (11.1) | 60 | |||
| Operation description | 0.738 | 0.94 (0.66–1.33) | ||||
| Osteosynthesis (ref) | 172 (46.5) | 94 (35.3) | 266 | |||
| Arthroplasty | 198 (53.5) | 102 (34.0) | 300 | |||
| Hemoglobin level (mmol/L) | ||||||
| Preoperative Hb level, Median (IQR) | 7.8 (1.3) | 7.6 (1.3) | 0.051^ | 0.86 (0.73–1.02) | ||
| Postoperative Hb level, Median (IQR) | 6.6 (1.5) | 6.2 (1.6) | 0.002^ | 0.77 (0.66–0.92) | 0.83 (0.70–0.98)c | |
| Missing data (%) | 10 (1.7) | |||||
| Blood transfused | 99 (26.8) | 66 (33.7) | 165 | 0.085 | 1.40 (0.95–2.02) | |
| Amount, Median (IQR) | 0 (1) | 0 (1) | 0.041^ | 1.23 (1.06–1.43) | 1.20 (1.03–1.40)c | |
| Home care prior to admission | ||||||
| Care prior to admission | 154 (41.6) | 149 (76.0) | 303 | <0.001 | 0.23 (0.15–0.33) | 0.26 (0.17–0.38)c |
| Nursing home | 78 (21.1) | 96 (48.5) | 174 | <0.001 | 0.28 (0.10–0.41) | 0.31 (0.21–0.45)c |
| Care at home | 76 (20.8) | 53 (27.0) | 129 | 0.079 | 0.71 (0.47–1.06) | |
| Medication useb | ||||||
| No medication (ref) | 303 (82.0) | 22 (11.2) | 325 | <0.001 | ||
| Prophylactic | 62 (16.7) | 71 (36.2) | 133 | 0.06 (0.04–0.11) | ||
| Therapeutic | 5 (1.3) | 103 (52.6) | 108 | 18.00 (6.88–47.0) | ||
Notes: Log regression for univariate measurements; CI 95%; adjusted OR for age. Katz ≤ score 5 physical impairment, Katz ≤ score 2 severe physical impairment.
a
Excluding dementia and delirium.
b
Haloperidol, seroquel, lorazepam.
c
Significant association with delirium when adjusted for age; Pearson chi-square test;
^
Mann–Whitney U-test; IQR: Interquartile range (of the median), missing data described in case of missing data and significant outcome.
Abbreviations: ASA, American Society of Anesthesiology; BMI, body mass index; cc, cubic centimeter; CI, confidence interval; CCI, Charlson comorbidity score; COPD, chronic obstructive pulmonary disease; Hb, hemoglobin; IQR, interquartile range; Katz, Katz Index of Independence; OR, odds ratio; SNAQ, Short Nutritional Assessment Questionnaire; uni, univariate odds ratio.