How are those “lost to follow-up” patients really doing? A compliance comparison in arthroplasty patients

Table 1 Active follow-up in the office and non-compliant with office follow-up visits baseline demographics n (%)

Group	OFU	NFU	P value
Number of patients	444	144
Surgeon 1	179 (40.3)	51 (35.4)	0.295
Surgeon 2	265 (59.7)	179 (64.6)
Age at procedure	62.4 ± 12.9	59.6 ± 13.3	0.026a
Length of stay (d)	3.1 ± 1.3	3.4 ± 2.1	0.217
Gender: female	250 (56.3)	67 (46.5)	0.041a
Comorbidities	324 (73.0)	112 (77.8)	0.252
Operative side: right	53.4%	50%	0.542
SF12 physical	30.4 ± 8.2	30.2 ± 7.2	0.778
SF12 mental	49.8 ± 11.4	47.9 ± 11.5	0.080
WOMAC pain score	44.9 ± 26.6	46.6 ± 27.8	0.506
WOMAC stiffness score	42.0 ± 25.1	43.3 ± 23.0	0.581
WOMAC function score	46.0 ± 21.6	48.2 ± 20.9	0.271
BMI (kg/m2)	30.3 ± 7.0	29.9 ± 6.9	0.634
Diagnosis			0.734
Osteoarthritis	347 (78.2)	106 (73.6)
Osteonecrosis	45 (10.1)	18 (12.5)
Rheumatoid arthritis	44 (9.9)	17 (11.8)
Other	8 (2.1)	3 (1.8)
Operative procedure			0.541

^aP < 0.05 vs OFU. WOMAC: Western Ontario and McMaster Universities Osteoarthritis Index; BMI: Body mass index; OFU: Active follow-up in the office; NFU: Non-compliant with office follow-up visits.

Table 2 Comparison of active follow-up in the office and non-compliant with office follow-up visits by operative procedure n (%)

Groups	MOMHR	Primary BKA	Primary THA	Primary TKA	Primary UKA	Revision THA	Revision TKA	Total
OFU	94 (21)	12 (3)	148 (34)	130 (29)	23 (5)	28 (6)	9 (2)	444 (100)
NFU	36 (25)	2 (1)	52 (36)	31 (22)	10 (7)	9 (6)	4 (3)	144 (100)
Total	130	14	200	161	33	37	13	588

MOMHR: Metal-on-metal hip resurfacings; UKA: Unicompartmental knee arthroplasties; OFU: Active follow-up in the office; NFU: Non-compliant with office follow-up visits.

Table 3 Comparison of active follow-up in the office and non-compliant with office follow-up visits outcome scores at one year

Group	OFU	NFU	P value
SF12 physical	45.1 ± 11.2	46.2 ± 11.2	0.685
SF12 mental	53.4 ± 9.2	54.1 ± 9.5	0.283
WOMAC pain score	89.1 ± 19.6	88.8 ± 20.5	0.612
WOMAC stiffness score	73.1 ± 24.7	75.3 ± 25.7	0.657
WOMAC function score	80.4 ± 21.7	82.4 ± 21.6	0.849

WOMAC: Western Ontario and McMaster Universities Osteoarthritis Index; OFU: Active follow-up in the office; NFU: Non-compliant with office follow-up visits.