Risk Factors for 30-Days Mortality After Proximal Femoral Fracture Surgery, a Cohort Study

Figures & data

Figure 1 Flow chart of included patients.

Figure 2 Kaplan–Meier curve of the 30-day mortality rates after Hip fracture surgery. Blue line: survivors’ function, with 95% CI.

Table 1 Univariable Analyses of Risk and Prognostic Baseline Factors

Variable	All Patients (n=3523)	Deceased <30 days (n=302)	Not Deceased <30 days (n=3221)	Odds Ratio	P-value
	n (%)	n (%)	n (%)	(95% CI)
Age
– <60 (ref.)	215 / 3523 (6)	2 / 302 (0.7)	213 / 3221 (6)	–	–
– 61–70	369 / 3523 (10)	13 / 302 (4)	356 / 3221 (11)	3.89 (0.87–17.40)	0.076
– 71–80	905 / 3523 (26)	49 / 302 (16)	856 / 3221 (26)	6.10 (1.47–25.27)	0.013
– 81–90	1540 / 3523 (44)	163 / 302 (54)	1377 / 3221 (43)	12.61 (3.10–51.22)	<0.001
– 91–100	485 / 3523 (14)	73 / 302 (24)	412 / 3221 (13)	18.87 (4.59–77.64)	<0.001
– >100	9 / 3523 (0.2)	2 / 302 (0.7)	7 / 3221 (0.2)	30.43 (3.73–248.38)	0.001
Male Gender	1172 / 3523 (33)	154 / 302 (51)	1018 / 3221 (32)	2.25 (1.78–2.86)	<0.001
ASA score
– 1 and 2 (ref.)	1275 / 3523 (36)	34 / 302 (11)	1241 / 3221 (39)	–	–
– 3 and 4	2248 / 3523 (64)	268 / 302 (89)	1980 / 3221 (61)	4.94 (3.43–7.11)	<0.001
CCI (mean ±SD)	4.7 ± 1.8	5.5 ± 1.4	4.6 ± 1.8	1.31 (1.23–1.40)	<0.001
NHFS (mean ±SD)	4.5 ± 1.7	5.7 ± 1.7	4.4 ± 1.7	1.86 (1.70–2.04)	<0.001
Missing	66 (2)	4 (1)	62 (2)	–	–
Medical history
– Atrial fibrillation	659 / 3523 (19)	67 / 302 (22)	592 / 3221 (18)	1.27 (0.95–1.68)	0.106
– Cardiac valve disease	246 / 3523 (7)	28 / 302 (9)	218 / 3221 (7)	1.41 (0.93–2.13)	0.104
– Cerebrovascular accident	407 / 3523 (12)	42 / 302 (14)	365 / 3221 (11)	1.26 (0.90–1.78)	0.182
– COPD	416 / 3523 (12)	48 / 302 (16)	368 / 3221 (11)	1.47 (1.06–2.03)	0.022
– Decompensation cordis	242 / 3523 (7)	34 / 302 (11)	208 / 3221 (6)	1.84 (1.25–2.70)	0.002
– Dementia	804 / 3523 (23)	137 / 302 (45)	667 / 3221 (21)	3.18 (2.50–4.05)	<0.001
– Diabetes Mellitus	664 / 3523 (19)	71 / 302 (24)	573 / 3221 (18)	1.42 (1.07–1.88)	0.014
– Malignancy in < 20 years	524 / 2736 (19)	44 / 224 (20)	480 / 2512 (19)	1.03 (0.73–1.46)	0.846
– Myocardial infarction	320 / 3523 (9)	37 / 302 (12)	283 / 3221 (9)	1.45 (1.01–2.09)	0.046
– Parkinson	169 / 3523 (5)	18 / 302 (6)	151 / 3221 (5)	1.29 (0.78–2.13)	0.324
– Previous hip fracture surgery	353 / 3523 (10)	32 / 302 (11)	321 / 3221 (10)	1.07 (0.73–1.57)	0.727
– TIA	314 / 3523 (9)	31 / 302 (10)	283 / 3221 (9)	1.19 (0.80–1.76)	0.389
Anticoagulation use
– No anticoagulation use (ref.)	1782 / 3523 (50)	124 / 302 (41)	1658 / 3221 (51)	–	–
– PAI	977 / 3523 (28)	92 / 302 (31)	885 / 3221 (28)	1.39 (1.05–1.84)	0.022
– VKA / DOAC	660 / 3523 (19)	76 / 302 (25)	584 / 3221 (18)	1.74 (1.29–2.35)	<0.001
– Combination	104 / 3523 (3)	10 / 302 (3)	94 / 3221 (3)	1.42 (0.72–2.80)	0.308
Polypharmacy (>4 medications)	1942 / 3523 (55)	202 / 302 (67)	1740 / 3221 (54)	1.72 (1.34–2.21)	<0.001
Immunosuppression	233 / 3523 (7)	16 / 302 (5)	217 / 3221 (7)	0.77 (0.46–1.31)	0.337
Albumin on admission (g/L) (median (IQR))	38 (34–41)	35.5 (32–39)	38 (34–41)	0.95 (0.93–0.98)	<0.001
Missing	1631 (46)	134 (44)	1497 (46)	–	–
GFR on admission (median (IQR))	70 (51–85)	56 (39–76)	71 (53–85)	0.98 (0.97–0.98)	<0.001
Missing	21 (1)	0 (0)	21 (1)	–	–
Hb on admission (median (IQR))	8 (7.2–8.6)	7.6 (6.8–8.3)	8 (7.3–8.6)	0.70 (0.63–0.79)	<0.001
Missing	11 (1)	0 (0)	11 (1)
Residential status
– Home (reference)	2433 / 3464 (70)	127 / 293 (44)	2306 / 3171 (73)	–	–
– Semi-independent nursing home	262 / 3464 (8)	30 / 293 (10)	232 / 3171 (7)	2.35 (1.54–3.57)	<0.001
– Nursing home	769 / 3464 (22)	136 / 293 (46)	633 / 3171 (20)	3.90 (3.02–5.05)	<0.001
Walking aids
– None (reference)	2002 / 3275 (61)	102 / 265 (39)	1900 / 3010 (63)	–	–
– Rollator	1158 / 3275 (35)	144 / 265 (54)	1014 / 3010 (34)	2.65 (2.03–3.45)	<0.001
– Wheelchair / mobility scooter / No functional mobility	115 / 3275 (4)	19 / 265 (7)	96 / 3010 (3)	3.69 (2.17–6.27)	<0.001
KATZ-ADL (mean ±SD)	1.86 ± 2.19	3.00 ± 2.3	1.76 ± 2.1	1.27 (1.19–1.34)	<0.001
Missing	657 (19)	64 (21)	593 (18)	–	–
SNAQ
– 0 (reference)	2355 / 3183 (74)	178 / 274 (65)	2177 / 2909 (75)	–	–
– 1–2	401 / 3183 (13)	41 / 274 (15)	360 / 2909 (12)	1.39 (0.97–1.99)	0.069
– ≥3	427 / 3183 (13)	55 / 274 (20)	372 / 2909 (13)	1.81 (1.31–2.49)	<0.001
Underweight (BMI<18,5)	187 / 2491 (8)	22 / 191 (12)	165 / 2300 (7)	1.68 (1.05–2.70)	0.030

Note: Bold: categories.

Abbreviations: ASA, American Society of Anesthesiology; CCI, Charlton Comorbidity Index; NHFS, Nottingham hip fracture score; COPD, chronic obstructive pulmonary disease; TIA, transient ischemic attack; PAI, Platelet aggregation inhibitor; VKA, Vitamin K antagonist; DOAC, direct oral anticoagulants; GFR, glomerular filtration rate in mL/min/1.73m²; Hb, hemoglobin in mmole/L; KATZ-ADL, Katz Index of Independence in Activities of Daily Living; SNAQ, Short Nutritional Assessment Questionnaire; BMI, body mass index.

Table 2 Univariable Analysis of Risk Factors, Prognostic Perioperative Factors

Variable	All Patients (n=3523)	Deceased <30days (n=302)	Not Deceased <30days (n=3221)	Odds Ratio	P-value
	n (%)	n (%)	n (%)	(95% CI)
Fracture
– Femoral neck fracture (ref.)	2491 / 3523 (71)	210 / 302 (70)	2281 / 3221 (71)	–	–
– Trochanter fracture	1032 / 3523 (29)	92 / 302 (30)	940 / 3221 (29)	1.06 (0.82–1.37)	0.640
Surgery
– DHS/FNS (ref.)	237 / 3523 (7)	6 / 302 (2)	231 / 3221 (7)	–	–
– Cannulated screws	78 / 3523 (2)	5 / 302 (2)	73 / 3221 (2)	2.64 (0.78–8.89)	0.118
– Gamma-nail	1035 / 3523 (29)	93 / 302 (31)	942 / 3221 (29)	3.80 (1.64–8.79)	0.002
– Hemiarthroplasty	2052 / 3523 (58)	198 / 302 (65)	1854 / 3221 (58)	4.11 (1.80–9.37)	0.001
– Total hip replacement	121 / 3523 (4)	0 / 302 (0)	121 / 3221 (4)	N/A	N/A
Time to surgery (median (IQR))	19 (13–26)	20 (14–33)	19 (13–25)	1.00 (1.00–1.00)	0.884
Missings	7 (1)	1 (1)	6 (1)	–	–
Moment of the week
– Week days (ref.)	2543 / 3523 (72)	209 / 302 (69)	2334 / 3221 (72)	–	–
– During weekend	980 / 3523 (28)	93 / 302 (31)	887 / 3221 (28)	1.17 (0.91–1.51)	0.228
Moment of the day
– Daytime (8.00–18.00) (ref.)	3087 / 3523 (88)	265 / 302 (88)	2822 / 3221 (88)	–	–
– Night time (18.00–8.00)	436 / 3523 (12)	37 / 302 (12)	399 / 3221 (12)	0.99 (0.69–1.41)	0.945
Anaesthesia
– Spinal (ref.)	3074 / 3510 (88)	266 / 302 (88)	2808 / 3208 (88)
– General	436 / 3510 (12)	36 / 302 (12)	400 / 3208 (12)	0.95 (0.66–1.37)	0.782
Anatomical approach
– Anterolateral (ref.)	1785 / 2157 (83)	172 / 197 (87)	1613 / 1960 (82)	–	–
– MI anterolateral	372 / 2157 (17)	25 / 197 (13)	347 / 1960 (18)	0.68 (0.44–1.04)	0.077
Surgery time (mean ±SD)
– < 45 min	1217 / 3518 (35)	108 / 302 (35)	1109 / 3216 (35)	1.06 (0.83–1.37)	0.629
– 45–90 min (ref.)	2078 / 3518 (59)	174 / 302 (58)	1901 / 3216 (59)	–	–
– > 90 min	226 / 3518 (6)	20 / 302 (7)	206 / 3216 (6)	1.06 (0.65–1.72)	0.812
Hb loss (mmole/l) (mean ±SD)	1.42 ± 0.89	1.45 ± 0.94	1.42 ± 0.89	1.03 (0.91–1.19)	0.604
Missings	93 (3)	15 (5)	78 (2)	–	–
Admission ward
– Trauma / orthopaedic surgery (ref.)	1632 / 3070 (53)	106 / 246 (43)	1526 / 2824 (54)	–	–
– Geriatric trauma unit	1100 / 3070 (36)	116 / 246 (47)	984 / 2824 (35)	1.70 (1.29–2.23)	<0.001
– Other	338 / 3070 (11)	24 / 246 (10)	314 / 2824 (11)	1.10 (0.70–1.74)	0.683
Delirium postoperative	617 / 3523 (18)	95 / 302 (31)	522 / 3221 (16)	2.37 (1.83–3.08)	<0.001
Hematoma postoperative	270 / 3417 (8)	15 / 286 (5)	255 / 3131 (8)	0.62 (0.37–1.07)	0.085
Pneumonia postoperative	310 / 3523 (9)	75 / 302 (25)	235 / 3221 (7)	4.20 (3.13–5.63)	<0.001
Re-operation	110 / 3523 (3)	7 / 302 (2)	103 / 3221 (3)	0.72 (0.33–1.56)	0.403
Urinary tract infection postoperative	257 / 3523 (7)	27 / 302 (9)	230 / 3221 (7)	1.28 (0.84–1.94)	0.251
Wound infection postoperative	134 / 3523 (4)	9 / 302 (3)	125 / 3221 (4)	0.76 (0.38–1.51)	0.435

Abbreviations: DHS, Dynamic hip screw; FNS, Femoral neck system; N/A, not available; MI, minimal invasive; Hb, Hemoglobin.

Table 3 Multivariable Analysis of Factors Associated with 30-Day Mortality After Backward Selection

Factor	OR	95% CI	p – value
Age
– <60 (ref.)	–	–	–
– 61–70	2.10	0.45–9.73	0.341
– 71–80	2.31	0.54–9.93	0.260
– 81–90	3.52	0.83–14.91	0.088
– 91–100	4.62	1.07–19.98	0.041
– >100	11.32	1.28–100.26	0.029
Male gender	2.56	1.97–3.33	<0.001
ASA 3 and 4	2.12	1.44–3.14	<0.001
Dementia	1.72	1.25–2.36	0.001
Albumin on admission	0.94	0.92–0.97	<0.001
GFR on admission	0.98	0.98–0.99	<0.001
Residential status
– Home (reference)	–	–	–
– Semi-independent nursing home	1.46	092–2.31	0.106
– Nursing home	2.03	1.44–2.87	<0.001
KATZ-ADL	1.09	1.01–1.16	0.018
Delirium postoperative	1.29	0.96–1.73	0.087
Pneumonia postoperative	2.41	1.72–3.38	<0.001

Abbreviations: ASA, American Society of Anesthesiology; GFR, glomerular filtration rate in mL/min/1.73m²; KATZ-ADL, Katz Index of Independence in Activities of Daily Living.