Prediction of 90-day mortality in older patients after discharge from an emergency department: a retrospective follow-up study

Table 1 Baseline characteristics of study population

ED Characteristics	All unique patients^a (N = 3291)
Demographics
Age, median (IQR)	78.3 (74.0–83.6)
Female, N (%)	1748 (53.1)
Time of ED visit, N (%)
Day 08.00 h-15.59 h	1677 (51.0)
Evening 16.00 h-23.59 h	1254 (38.1)
Night 00.00 h-07.59 h	360 (10.9)
Way of arrival, N (%)
Self-referral	654 (19.9)
Brought in by ambulance	1159 (35.2)
General practitioner	1108 (33.7)
LUMC internal	338 (10.3)
Other hospital	28 (0.9)
Unknown	4 (0.1)
Presentation, N (%)
Limb problems	608 (18.5)
Unwell	598 (18.2)
Chest pain	346 (10.5)
Shortness of breath	304 (9.2)
Abdominal pain	214 (6.5)
Collapsed	168 (5.1)
Falls	122 (3.7)
Wounds	108 (3.3)
Palpitations	101 (3.1)
Other	722 (21.9)
Consulting medical specialty, N (%)
Surgical	1371 (41.7)
Non-surgical	1920 (58.3)
Vital signs^b
Systolic BP (mmHg), mean (sd)	146.5 (28.3)
Heart rate (beats/min), mean (sd)	83.7 (21.0)
Oxygen saturation (%), median (IQR)	98 (3)
Respiration rate (breaths/min), mean (sd)	18.7 (5.5)
Temperature (°C), mean (sd)	36.9 (1.0)
Pain score (NRS)^b, median (IQR)	3 (1–5)
Laboratory results ^b,c
Haemoglobin (mmol/L), mean (sd)	8.1 (1.2)
Thrombocytes (10⁹/L), mean (sd)*	229 (94)
Leukocytes (10⁹/L), median (IQR)*	8.75 (6.80–11.41)
C-reactive protein (mg/L), median (IQR)	6.0 (0.0–30.0)
Sodium (mmol/L), mean (sd)	139 (4)
Potassium (mmol/L), mean (sd)	4.3 (0.6)
Creatinine (μmol/L), median (IQR)	84 (67–109)
Urea (mmol/L), median (IQR)	7.6 (5.9–10.2)
Troponin T (μg/L), median (IQR)	0.014 (0.007–0.028)
Non fasted glucose (mmol/L), mean (sd)	7.9 (3.3)

Abbreviations: ED emergency department, N number, sd standard deviation, IQR interquartile range, h hours, BP blood pressure, °C degrees celcius, NRS numeric rating scale
^aA unique patient was defined as the first presentation of a patient to our ED in 2012
^bMissing data (%): Systolic BP 768 (23.3), Heart rate 719 (21.8), Respiratory rate 1482 (45.0), Temperature 1077 (32.7), Pain score 173 (5.3), Haemoglobin 831 (25.3), Thrombocytes 1576 (47.9), Leukocytes 831 (25.3), C-reactive protein 945 (28.7), Sodium 873 (26.5), Potassium 1021 (31.0), Creatinine 873 (26.5), Urea 878 (26.7), Troponin T 1539 (46.8), Glucose 908 (27.6)
^cReference ranges for laboratory results: Haemoglobin male 8.5-11.0 mmol/L; female 7.5-10.0 mmol/l, Thrombocytes 150-400*10⁹/L, Leukocytes 4.00-10.00*10⁹/L, C-reactive protein 0.0-5.0 mg/L, Sodium 136-144 mmol/L, Potassium 3.6-4.8 mmol/L, Creatinine 64-104 μmol/L, Urea 2.5-7.5 mmol/L, Troponin T 0.000-0.050 μg/L, Non-fasted glucose 3.1-11.0 mmol/L