How should we define clinically significant improvement on Patient-Reported Outcomes Measurement Information System (PROMIS) for patients undergoing Knee Meniscal Surgery?

Abstract

Objectives:

The Patient-Reported Outcomes Measurement Information System (PROMIS) attempts to optimize patient reported outcome (PRO) instruments by utilizing item response theory (IRT) and computer adaptive testing (CAT). Relatively little is known about clinically significant outcome (CSO) improvements on the PROMIS Physical Function (PF) CAT. The objective of this study is to define the minimal clinically important difference (MCID), substantial clinical benefit (SCB) and patient-acceptable symptom state (PASS) of the PROMIS PF CAT in arthroscopic meniscal surgery.

Methods:

The PROMIS PF CAT, Short Form-12 Health Survey (SF-12 physical health [PCS] and mental health [MCS]), Veterans Rand-12 Health Survey (VR-12 physical health [PH] and mental health [MH]), and the Marx Activities Ratings Scale were administered pre- and post- operatively to patients undergoing arthroscopic meniscal surgery. Six months postoperatively, patients graded their knee function based on a domain-specific anchor question. Answers to the anchor questions were dichotomized to indicate achievement of SCB and MCID. A satisfaction anchor question was used to indicate achievement of PASS. Receiver operating characteristic (ROC) analysis determined the relevant psychometric values. Cutoff analysis was performed to find preoperative PRO scores predicting CSO achievement.

Results:

Sixty patients (N = 27, 45% female) were included, with mean age of 45.0 ± 14.0 years and average follow up of 24.0 + 1.2 weeks. The most common indication for knee arthroscopy was partial meniscectomy (N = 53; 88.3%) followed by meniscal repair (N = 7; 11.7%). MCID on PROMIS PF was calculated to be 2.08 (AUC: 0.75, 95% CI: 0.57 - 0.94). Net score improvement equivalent to achievement of SCB was found to be 7.41 (AUC: 0.77, 95% CI: 0.55 – 0.99). PASS was found to be 45.47 (AUC: 0.89, 95% CI: 0.79-0.99). Preoperative score below 37.6 on the PROMIS PF CAT predicted achievement of MCID (AUC: 0.76, 95% CI: 0.64-0.88), while scores above 41.7 predicted achievement of PASS (AUC: 0.76, 95% CI: 0.63-0.89). Absence of pre-existing arthritis and higher baseline functional status were also found to be statistically significant predictors of achieving CSOs.

Conclusion:

Our study defined MCID, SCB, and PASS, for the PROMIS PF CAT. We found that a pre-operative score below 37.6 was predictive for achieving a meaningful clinical change with surgery, while a pre-operative score above 41.7 was predictive of achievement of an acceptable post-operative health state.

Table 1.

Patient Demographic and Perioperative Variables

	N	Percent
Total patients	60
Age (Mean±SD)	45.0±14
Male	33	55
Worker’s Compensation	10	16.7
Right-sided	28	46.7
Diabetes	5	8.3
Depression	9	15
Hypertension	10	16.7
Alcohol	35	58.3
Smoking
Never	53	88.3
Former	5	8.3
Current	2	3.3
Days of Exercise Per Week (Mean±SD)	2.57	2.05
History of Narcotics Use within Three Months of Surgery Date (%)	4	6.7
Tear Location
Both	7	11.7
Medial	43	71.7
Lateral	10	16.7
Tear Type
Horizontal Cleavage	9	17.6
Oblique	2	3.9
Peripheral	4	7.8
Degenerative	11	21.6
Flap Tear	5	9.8
Radial	5	9.8
Complex	9	17.6
Root Tear	3	5.9
Bucket Handle	3	5.9
Chronicity*
Traumatic/Acute	24	40.0
Chronic	36	60.0
Pre-Existing Arthritis^	36	60.0
Surgery Type
Partial Menisectomy	53	88.3
Meniscal Repair	7	11.7
Root Repair	2	3.3
Number of Caritlage/Chondral Defects (Mean±SD)	1.22±1.17
Location of Cartilage Defect
MFC	17	28.3
LFC	8	13.3
Trochlea	16	26.7
Patella	18	30.0
MTP	2	3.3
LTP	4	6.7

*Injuries were determined to be acute if they had occurred within three months of the date of surgery.

^Patients were determined to have preexisting arthritis by intraoperative surgeon determination based on the International Cartilage Repairs Society Classification (ICRS), grade II or greater were deemed arthritis.

Table 2.

Univariate analysis of demographic variables after stratification by achievement of CSOs based on score on the PROMIS PF CAT

	MCID			SCB			PASS
	Not Achieved (28)	Achieved (32)	P-value	Not Achieved (38)	Achieved (22)	P-value	Not Achieved (31)	Achieved (29)	P-value
Age (Mean±SD)	44.59±15.52	45.42±12.78	0.82	45.11±14.85	44.90±12.74	0.96	47.28±14.42	42.63±13.37	0.20
Male, %	16 (57.1)	17 (53.1)	0.96	19 (50.0)	14 (63.6)	0.45	15 (48.4)	18 (62.1)	0.42
Worker’s Compensation, %	3 (10.7)	7 (21.9)	0.42	5 (13.2)	5 (22.7)	0.55	8 (25.8)	2 (6.9)	0.11
Brief Resilience Scale Score (Mean±SD)	3.81±0.58	3.93±0.76	0.51	3.82±0.70	3.98±0.65	0.36	3.87 (0.69)	3.89 (0.67)	0.93
Right-sided %	14 (50.0)	15 (46.9)	1	17 (44.7)	12 (54.5)	0.64	15 (48.4)	14 (48.3)	1
Diabetes, %	1 (3.6)	4 (12.5)	0.44	2 (5.3)	3 (13.6)	0.52	3 (9.7)	2 (6.9)	1
Depression, %	5 (17.9)	4 (12.5)	0.83	6 (15.8)	3 (13.6)	1	5 (16.1)	4 (13.8)	1
Dyslipidemia, %	1 (3.6)	1 (3.1)	1	1 (2.6)	1 (4.5)	1	2 (6.5)	0 (0.0)	0.50
Hypertension, %	7 (20.6)	3 (11.5)	0.56	8 (21.1)	2 (9.1)	0.40	5 (16.1)	5 (17.2)	1
Alcohol, %	17 (60.7)	18 (56.2)	0.93	22 (57.9)	13 (59.1)	1	16 (51.6)	19 (65.5)	0.41
Smoking, %			0.38			0.47			0.33
Never	26 (92.9)	27 (84.4)		35 (92.1)	18 (81.8)		29 (93.5)	24 (82.8)
Former	2 (7.1)	3 (9.4)		2 (5.3)	3 (13.6)		1 (3.2)	4 (13.8)
Current	0 (0.0)	2 (6.2)		1 (2.6)	1 (4.5)		1 (3.2)	1 (3.4)
Days of Exercise Per Week (Mean±SD)	2.25±2.10	2.84±2.00	0.27	2.21±2.16	3.18±1.74	0.08	2.29±2.16	2.86±1.92	0.29
Narcotics Use, %	2 (7.1)	2 (6.2)	1	3 (7.9)	1 (4.5)	1	3 (9.7)	1 (3.4)	0.65

Table 3.

Multivariate results of contributors of postoperative score and achievement of CSOs in the PRMOS PF CAT after meniscal surgery

	Significant Contributor	Odd Ratio	Confidence Interval	P-Value
Postoperative PROMIS PF CAT	Preoperative Marx Activity Ratings Scale	2.07	1.28-3.36	0.005
PASS	Preoperative Marx Activity Ratings Scale	1.19	1.04-1.36	0.014
MCID	Preoperative PROMIS PF CAT	0.79	0.63-0.99	0.039
	Preoperative KOOS QoL Subscore	1.16	1.02-1.31	0.021
	Preoperative KOOS Symptoms Subscore	0.90	0.81-0.99	0.029
	Preoperative arthritis	0.0003	5.33E-07-0.13	0.009
SCB	Preoperative PROMIS PF CAT	0.82	0.69-0.96	0.017
	Days of Exercise per Week	1.87	1.14-3.06	0.013
	Preoperative arthritis	0.11	0.02-0.69	0.019

Figure 1.