Variability of platelet aggregation in patients with clopidogrel treatment and hip fracture: A retrospective case-control study on 112 patients

Table 1 Cohort characteristics by treatment group n (%)

Variable	None (n = 84)	Responder (n = 20)	Non-responder (n = 8)
Sex
Male	22 (26)	9 (45)	5 (62)
Female	62 (74)	11 (55)	3 (38)
Age	85 (± 7)	82 (± 9)	88 (± 4)
ASA class
1-2	27 (32)	1 (5)	0 (0)
3-4	57 (68)	19 (95)	8 (100)
Fracture type
Femoral neck	23 (27)	8 (40)	0 (0)
Per/subthrochanteric	46 (55)	8 (40)	7 (88)
Periprostethic	15 (18)	4 (20)	1 (12)
Surgery
Hemi/total arthroplasty	23 (27)	8 (40)	0 (0)
Sliding hips screw or intramedullary nail	46 (55)	8 (40)	7 (88)
Locking plate osteosynthesis	6 (7)	1 (5)	1 (12)
Revision of implants	9 (11)	3 (15)	0 (0)

For continuous values the mean together with the standard deviation is used. ASA: American Society of Anesthesiologists.

Table 2 Bleeding, erythrocyte transfusions and adverse events up to 3 mo follow-up

Variable	Control (n = 84)	Responder (n = 20)	Non-responder (n = 8)	P-value
Peroperative bleedning (mean ± SD)	350 (0-1800)	300 (50-1500)	150 (50-550)	0.82
Any erythrocyte transfusion, n (%)	54 (64)	13 (65)	6 (75)
Number of transfusions, median (range)	2 (0-10)	1 (0-6)	2 (0-6)	1.02
Time to surgery (h), mean ± SD	21 (± 12)	45 (± 26)	28 (± 33)	0.0032
Adverse events
Any AE, n (%)	31 (37)	9 (45)	5 (62)	1.03
Type of AE, n1
Deceased, n	14	2	3
Hip related	6	2	0
Cardiovascular	8	1	3
Infection	14	9	4
Other	24	6	3

¹Several patients had more than 1 AE;

²ANOVA;

³χ² test. Bonferroni correction has been applied to all P-values.

Table 3 Anaesthesia and transfusions n (%)

Variable	Control (n = 84)	Responder (n = 20)	Non-responder (n = 8)	P-value
Anaesthesia
Spinal	82 (98)	5 (25)	7 (88)	1
General	2 (2)	15 (75)	1 (12)
Tranexamic acid
No	9 (11)	3 (15)	0 (0)
Yes	75 (89)	17 (85)	8 (100)	0.003
Plasma transfusion transfusion
No	83 (99)	15 (75)	7 (88)
Yes	1 (1)	5 (25)	1 (12)	0.003
Thrombocyte transfusion
No	84 (100)	9 (45)	7 (88)
Yes	0 (0)	11 (55)	1 (12)	0.003

P-value derived from χ² test. Bonferroni correction has been applied to all P-values.