Table 2.
Factors associated with hospitalisation—logistic regression analysisa
| n (%) | Hospitalised n (%) | Crude | Adjusted | |||||
|---|---|---|---|---|---|---|---|---|
| Odds ratio | 95 % CI | p | Odds ratio | 95 % CI | p | |||
| Age | ||||||||
| 26–50 yearsb | 1207 (52) | 245 (20) | ||||||
| ≤ 25 years | 640 (27) | 78 (12) | 0.55 | 0.41–0.72 | <0.001 | 0.75 | 0.53–1.0 | 0.090 |
| > 50 years | 496 (21) | 68 (14) | 0.62 | 0.47–0.84 | 0.002 | 1.2 | 0.83–1.7 | 0.348 |
| Gender | ||||||||
| Malesb | 1600 (68) | 288 (18) | ||||||
| Females | 743 (32) | 103 (14) | 0.73 | 0.57–0.94 | 0.013 | 0.74 | 0.55–1.0 | 0.052 |
| Main toxic agent | ||||||||
| Ethanolb | 1291 (55) | 103 (8) | ||||||
| Opioids | 539 (23) | 102 (19) | 2.7 | 2.0–3.6 | <0.001 | 1.7 | 1.1–2.5 | 0.014 |
| Benzodiazepines | 194 (8) | 65 (34) | 5.8 | 4.1–8.3 | <0.001 | 3.6 | 2.2–5.8 | <0.001 |
| Central stimulants | 132 (6) | 42 (32) | 5.4 | 3.5–8.2 | <0.001 | 2.5 | 1.4–4.5 | 0.001 |
| GHB | 105 (4) | 60 (57) | 15.4 | 9.9–23.8 | <0.001 | 19.0 | 11.3–32.0 | <0.001 |
| Other/Unknown | 82 (3) | 19 (23) | 3.5 | 2.0–6.0 | <0.001 | 2.1 | 1.1–4.2 | 0.026 |
| Number of toxic agents | 1.3 | 1.2–1.5 | <0.001 | 0.89 | 0.75–1.1 | 0.204 | ||
| Suicide attemptc | 139 (6) | 61 (44) | 4.4 | 3.1–6.3 | <0.001 | 6.9 | 4.2–11.4 | <0.001 |
| Treatment with naloxonec | 198 (8) | 48 (24) | 1.7 | 1.2–2.4 | 0.003 | 1.1 | 0.72–1.8 | 0.581 |
| Clinical observationsc | ||||||||
| Respiratory depressiond | 287 (12) | 86 (30) | 2.5 | 1.9–3.3 | <0.001 | 2.4 | 1.7–3.5 | <0.001 |
| Respiratory rate > 20/min | 304 (13) | 61 (20) | 1.3 | 0.96–1.8 | 0.091 | 1.2 | 0.79–1.7 | 0.469 |
| Heart rate ≥ 100/min | 430 (18) | 104 (24) | 1.8 | 1.4–2.3 | <0.001 | 1.7 | 1.2–2.4 | 0.002 |
| Temperature ≥ 39.0 °C | 11 (<1) | 8 (73) | 13.6 | 3.6–51.4 | <0.001 | 1.8 | 0.34–9.3 | 0.503 |
| Glucose ≤ 3.0 mmol/L | 12 (1) | 6 (50) | 5.1 | 1.6–15.8 | 0.005 | 6.5 | 1.8–23.7 | 0.005 |
| Neurological signse | 62 (3) | 22 (35) | 2.9 | 1.7–4.9 | <0.001 | 3.9 | 2.1–7.3 | <0.001 |
| Hallucinations | 59 (3) | 31 (53) | 5.9 | 3.5–10.0 | <0.001 | 9.6 | 5.0–18.5 | <0.001 |
| Chest painc | 24 (1) | 9 (38) | 3.0 | 1.3–7.0 | 0.009 | 5.6 | 2.2–14.6 | <0.001 |
| Head injuryc | 217 (9) | 24 (11) | 0.60 | 0.38–0.92 | 0.021 | 0.97 | 0.59–1.6 | 0.888 |
| Seizuresc | 42 (2) | 17 (40) | 3.5 | 1.9–6.6 | <0.001 | 5.7 | 2.7–12.1 | <0.001 |
| Infectionc | 64 (3) | 31 (48) | 5.0 | 3.0–8.3 | <0.001 | 6.3 | 3.5–11.3 | <0.001 |
| Other complicationsc | 145 (6) | 58 (40) | 3.7 | 2.6–5.3 | <0.001 | 6.5 | 4.2–10.0 | <0.001 |
| Lowest GCS scoref | ||||||||
| 15b | 680 (29) | 85 (13) | ||||||
| 10–14 | 1316 (56) | 208 (16) | 1.3 | 1.0–1.7 | 0.048 | 2.0 | 1.4–2.8 | <0.001 |
| 8–9 | 223 (10) | 49 (22) | 2.0 | 1.3–2.9 | 0.001 | 3.0 | 1.8–4.9 | <0.001 |
| ≤ 7 | 113 (5) | 41 (36) | 4.0 | 2.6–6.2 | <0.001 | 6.5 | 3.7–11.6 | <0.001 |
| Total | 2343 (100) | 391 (17) | ||||||
Adjusted odds ratios for significant associations are shown in bold types
CI confidence interval, GCS Glasgow coma scale, GHB gamma-hydroxybutyrate
a In the univariate analyses, the following variables were not significantly associated with hospitalisation (p ≥ 0.10): systolic blood pressure ≥180 (n = 12, 4 (33 %) admitted); systolic blood pressure ≤ 90 (n = 117, 21 (8 %) admitted); temperature ≤ 34.0 °C (n = 34, 8 (23 %) admitted); glucose ≥ 14.0 mmol/L (n = 19, 5 (26 %) admitted); track marks (n = 375, 60 (16 %) admitted); other injuries (n = 171, 29 (17 %) admitted); and breath analysis alcohol level (analysed in 805 (34 %) patients, median 190 mg/dL in hospitalised patients, 210 mg/dL in discharged patients)
b Reference group
c The reference groups are not suicide attempt/no treatment with naloxone/observation or complication not recorded (reference groups not shown)
d Respiratory rate < 10/min, SpO2 < 90 %, or in need of respiratory support
e Comprises nystagmus, inverted plantar reflex, asymmetric pupil reaction to light or asymmetric movement of limbs
f Eleven cases missing