Early recovery trajectories after fast-track primary total hip arthroplasty: the role of patient characteristics

Figures & data

Table 1. Pre- and postoperative characteristics of patients according to class membership

	Class 1:	Class 2:	Class 3:
	Fast	Average	Slow	Total
	recovery (n = 17)	recovery (n = 53)	recovery (n = 24)	recovery (n = 94)
Preoperative or pre-discharge characteristics
Female sex, n	8	29	19^a	56
Age, mean (SD)	59 (8.6)^a	65 (8.3)	69 (7.3)^a	65 (8.7)
BMI, mean (SD)	27 (5.3)	27 (3.5)	28 (4.2)	27 (4.1)
ASA score, n
1	9	18	7	34
2	8	32	15	55
3	0	3	2	5
Charlson comorbidity index, n
0	11	28	9	48
1	5	15	7	27
≥ 2	1	10	8	19
Kellgren–Lawrence classification >3, n	12	41	16	69
Outpatient surgery, n	13^a	25	4^a	42
Length of stay in nights, median (IQR)	0.0 (0.5)^a	1.0 (1.0)	1.0 (1.0)^b	1.0 (1.0)
Operated side, left, n	12^a	20	12	44
Discharged to home, n	17	52	22	91
Living alone, n	1	6	5	12
Additional prostheses, n	3	6	9^a	18
No surgical complications, n	17	51	22	90
Oxford Hip Score, mean (SD)	24 (7.5)	24 (8.5)	23 (9.4)	24 (8.5)
EQ–5D, median (IQR)
mobility (1–5)	2.0 (0.0)	2.0 (0.0)	2.0 (0.0)	2.0 (0.0)
self-care (1–5)	1.0 (1.0)	1.0 (1.0)	1.0 (1.0)	1.0 (1.0)
usual activities (1–5)	2.0 (1.0)	2.0 (0.0)	2.0 (0.0)	2.0 (0.0)
pain/discomfort (1–5)	2.0 (0.0)	2.0 (1.0)	2.0 (1.0)	2.0 (1.0)
mental health (1–5))	1.0 (0.0)	1.0 (0.0)	1.0 (0.0)	1.0 (0.0)
VAS (0–100), mean (SD)	70 (18)	71 (17)	61 (26)^a	69 (20)
NRS pain in rest (0–10), mean (SD)	4.4 (2.6)	4.6 (2.4)	6.0 (2.5)^a	4.9 (2.5)
NRS pain movement-evoked (0–10), mean (SD)	6.5 (2.0)	7.0 (1.9)	7.2 (1.9)	7.0 (1.9)
Healthcare utilization and assistance during recovery
Number of weeks, median (IQR)
with attended physical therapy sessions	5.0 (1.0)	6.0 (1.0)	6.0 (1.0)	6.0 (1.0)
with a doctor’s visit	0	0	0	0
with pain medication usage	3.0 (2.0)^b	5.0 (3.0)	6.0 (1.0)^a	5.0 (3.0)
with personal hygiene assistance	2.0 (2.0)^a	3.0 (4.0)	6.0 (2.8)^a	3.5 (4.0)
with housekeeping assistance	5.0 (3.0)	6.0 (1.0)	6.0 (1.0)	6.0 (1.0)
when walking aids were required inside	3.0 (2.5)^b	5.0 (2.0)	6.0 (1.0)	5.0 (3.0)
when walking aids were required outside	2.0 (2.5)^b	4.0 (2.0)	5.0 (1.0)^a	4.0 (2.0)
Postoperative PREMs^c
Satisfaction, median (IQR)
with result THA (0–10)	10 (0.0)	10 (1.0)	8.0 (3.0)^b	10 (2.0)
with general result THA (1–5)	5.0 (0.5)	5.0 (1.0)	4.0 (0.0)^b	5.0 (1.0)
with current pain (1–5)	5.0 (0.5)	4.0 (1.0)	4.0 (2.0)^b	4.0 (1.0)
with activities of daily living (1–5)	5.0 (1.0)	4.0 (0.0)	4.0 (1.0)^b	4.0 (1.0)
with quality of life (1–5)	5.0 (1.0)	4.0 (1.0)	3.5 (1.0)^b	4.0 (1.0)
Would have THA again if needed, n	17	50	20	87
Would recommend to others, n	17	50	21	88
Positive attitude fast-track THA, n	15	47	18	80
Positive attitude assistance during recovery, n	16	48	18^a	82
Positive attitude provided information, n	9	40	17	66

a p < 0.05, compared with the average recovery class 2.

b p < 0.01, compared with the average recovery class 2.

c PREMs: Patient reported experience measures

Table 2. Piecewise latent class growth model results

Number of classes Intercept^a (SE) Slopes^b (SE) free parameters		BIC^c		BLRT^d		Number of Entropy^e Patients per class
1-class	Class 1	24 (0.76)	5.41 (0.47)	10	4291.627	–	–	94
2-class	Class 1	22 (1.2)	3.94 (0.61)	21	4024.293	p < 0.001	0.92	49/45
	Class 2	25 (1.0)	7.09 (0.74)
3-class	Class 1	25 (1.9)	9.52 (0.91)	32	3912.545	p < 0.001	0.96	24/17/53	0.90 (0.12)
	Class 2	24 (0.89)	5.30 (0.46)	2.03 (0.15)
	Class 3	22 (1.6)	2.68 (0.89)	1.73 (0.39)
4-class	Class 1	25 (0.96)	5.84 (0.51)	43	3867.885	p < 0.001	0.94	26/33/18/17	1.93 (0.20)
	Class 2	24 (1.3)	4.54 (0.75)	1.86 (0.21)
	Class 3	20 (1.7)	2.57 (0.84)	1.92 (0.52)
	Class 4	25 (1.9)	9.56 (0.94)	0.89 (0.13)

a Estimated average OHS at preoperative baseline.

b The first number refers to the estimated weekly growth rate in the first 2 weeks of the 6-week recovery period; the second number refers to the estimated weekly growth rate in the last 4 weeks of the 6-week recovery period.

c Bayesian Information Criterion, a lower value indicates better model fit.

d Bootstrapped Likelihood Ratio Test, tests whether a significant improvement in model fit occurred with the addition of an extra class.

e Entropy index (0–1), higher values indicate better overall accuracy of class separation.

Trajectories of 6-week recovery after THA in a 3-class model (mean OHS [95% CI]).