Disease control after surgery for chronic rhinosinusitis: Prospective, multi-institutional validation of the Sinus Control Test (SCT)

Abstract

Background:

The Sinus Control Test (SCT) is a 4 question, patient-reported questionnaire that assesses disease control in chronic rhinosinusitis (CRS). This prospective, multicenter study examines SCT outcomes following endoscopic sinus surgery (ESS), further validating its use as a control instrument for CRS.

Methods:

Adults with CRS undergoing ESS were prospectively enrolled from 5 centers across North America. The SCT was administered at baseline and once 6 months after surgery. Quality of life and disease burden were evaluated using the Sino-Nasal Outcome Test 22 (SNOT-22) and Lund-Kennedy endoscopy scores. Linear regression was used to determine whether specific demographic, comorbidity or disease severity measures were independently associated with changes in SCT scores postoperatively.

Results:

Two hundred and eighteen patients, 111 females (50.9%) and 107 males (49.1%), were enrolled with mean age of 50.1±15.6 years. Mean SCT score improved from 8.9±3.5 to 4.3±3.7 postoperatively (p<0.001). Preoperatively 21.6% were uncontrolled, 71.5% partially controlled and 6.9% controlled. Postoperatively 6.0% were uncontrolled, 42.6% partially controlled, and 51.4% controlled (p<0.001). Change in SCT score correlated independently with change in SNOT-22 (r=0.500, p<0.001) and endoscopy scores (r=0.310, p<0.001). Endoscopy scores did not correlate with control status among CRSsNP nor between uncontrolled and partially controlled patients. Demographics and comorbidities were not associated with changes in SCT.

Conclusion:

Improvement in disease control following ESS as measured by the SCT correlated with improvements in SNOT-22 and endoscopy scores. The SCT is an easily administered instrument that provides information complementary to existing patient-reported and objective measures of disease severity.

INTRODUCTION

There is an increased interest in measuring disease control from the perspective of the patient, so that physicians might better understand an individual’s burden of disease and better align treatment decisions with patient preferences. The Sinus Control Test (SCT) is a patient-reported questionnaire developed to assess CRS control by accounting for sinonasal and systemic symptoms, productivity and rescue medication use (Figure 1).¹ The SCT involves four questions, three of which are answered using a 5-point Likert scale and one dichotomous question. The SCT total score is used to categorize patient control status into three groups: controlled (total score 0–3), partially controlled (total score 4–11), and uncontrolled (total score 12–16). Similar to the Asthma Control Test (ACT), which allows physicians to detect uncontrolled asthma and appropriately escalate treatment, the SCT may be of particular importance for non-otolaryngology providers, where procedures like nasal endoscopy are not feasible.²

Figure 1.

The Sinus Control Test (SCT) for the assessment of disease control in chronic rhinosinusitis (CRS).

Many validated patient-reported outcome measures (PROMs) exist for use in patients with CRS, however few are focused on capturing the concept of disease control.^3–4 Additionally, several studies have demonstrated significant improvements in quality of life (QOL), symptom severity, and objective outcome measures of disease severity following ESS.^5–7 However, many of these existing instruments are limited in their ability to fully capture disease control status in its current state. The presence of sinonasal symptoms, subsequent impact on QOL, and whether or not adjuvant medical therapies are required to achieve a given QOL are implicit to the concept of disease control in CRS. Furthermore, advancing our ability to efficiently measure and effectively communicate these concepts of disease control are essential to further optimizing the quality of care and outcomes for patients with CRS.

The SCT instrument was developed through systematic literature review, focus groups of CRS patients and a multidisciplinary group of experts in the fields of rhinosinusitis, allergy, pediatric and primary care.¹ The SCT development incorporated methodology as outlined by the United States Department of Health and Human Services.⁸ A 12-item survey was developed and prospectively administered to 50 patients with CRS to determine which questions independently contributed to CRS disease control. The treating physicians were blinded to the survey scores, SNOT-22 data, and patient global assessments until study completion. The resultant 4-item survey (SCT) was assessed for reliability and empirically validated by correlating the SCT scores to SNOT-22 scores and physician’s rating of disease control.¹

The SCT has previously been shown to be a reliable and responsive tool to monitor changes in disease control status in patients with CRS undergoing surgery.⁷ Rudmik and colleagues performed a systematic review of 38 studies involving the development and validation of 15 PROMs for adults with CRS.⁹ Quality assessment criteria were utilized to score the quality of PROM development and psychometric performance.^10–11 The highest quality validated PROMs for adult CRS were SNOT-22, the Questionnaire of Olfactory Disorders (QOD), the SCT, and the EuroQol five-dimensional questionnaire (EQ-5D). Importantly, each of these instruments provides insight on different aspects of CRS. The SNOT-22 examines sinus-specific QOL. The QOD examines olfactory-specific QOL. The SCT measures disease control. The EQ-5D assesses general QOL. However, the process of externally validating any instrument is a continuous and ongoing process. One limitation of the SCT was that its original validation studies were done in a single institution and the sample size limited subgroup analyses.⁷ The aim of this study was to provide further external validation of the SCT in a multi-institutional cohort of prospectively enrolled patients with CRS undergoing ESS. The goals of this study were to assess the responsiveness of the SCT to surgery and evaluate associations between the SCT and patient characteristics, comorbidities, and CRS-specific validated outcome measures.

METHODS

Study population

Adult (≥ 18 years) patients with CRS were recruited from rhinology clinics at the Medical University of South Carolina (MUSC, Charleston, South Carolina), Oregon Health and Science University (OHSU, Portland, Oregon), the University of Utah (Salt Lake City, Utah), the University of Colorado (Aurora, Colorado) and the University of Virginia (Charlottesville, Virginia), as part of an ongoing prospective cohort study. This study was approved in advance by the Institutional Review Boards at each institution and all subjects were provided written, informed consent in English. Each patient fulfilled diagnostic criteria for CRS according to the Clinical Practice Guideline of the American Academy of Otolaryngology—Head and Neck Surgery.¹² Each study participant self-selected ESS for treatment of recalcitrant symptoms associated with CRS. Extent of surgical treatment was left to individual surgeon discretion, although similar surgical strategies were utilized among sites. Using standardized questionnaires, preoperative characteristics related to demographics and medical comorbidities were collected for each patient and when necessary by medical chart review, including presence of aspirin-exacerbated respiratory disease (AERD), asthma, chronic obstructive pulmonary disease (COPD), depression, fibromyalgia, diabetes, allergic rhinitis confirmed by testing, and prior sinus surgery. High-resolution computed-tomography (CT) scans were obtained on every patient prior to sinus surgery in all instances. Baseline preoperative assessments included the SCT and SNOT-22; and nasal endoscopy exams were scored using the Lund-Kennedy endoscopy score (LKES) and polyp grade.¹³ Those with visible polyps were classified as chronic rhinosinusitis with nasal polyposis (CRSwNP) and those without visible polyps as chronic rhinosinusitis without nasal polyposis (CRSsNP). Baseline preoperative SCT assessments were administered prior to any preoperative systemic medications. Oral antibiotics and/or systemic corticosteroids were prescribed following ESS when indicated. These assessments were repeated once postoperatively at the follow-up interval of approximately 6 months (range 4 to 23 months) to allow for complete recovery after ESS.

Statistical analysis

Statistical analyses were performed using SPSS Version 25 (IBM Corporation, Armonk, NY). In order to describe patient characteristics and comorbidities, means and standard deviations were produced for continuous variables and frequencies and percentages for categorical variables. Chi-square tests and t tests were performed to compare patient characteristics and comorbidities by nasal polyp status. Change in SCT, LKES, SNOT-22, and polyp grade after surgery were compared using the Wilcoxon test which takes into account both the paired nature and non-parametric distribution of the variables. Disease control pre- and postoperatively was evaluated using the Marginal Homogeneity Test as more than two categories were assessed at two time-points. Mann-Whitney tests were used to compare postoperative SNOT-22 and endoscopy scores between two of the three SCT disease status groups at a time, and correction for multiple comparisons of all three groups was carried out using the Holm Test. Categories with three people or less (AERD alone) were excluded from the analysis due to small sample size. Associations between postoperative change in SCT and patient characteristics, comorbidities, and outcome measures were assessed using Pearson correlations (r), t tests, and Median tests based upon their distributions. Linear regression was performed using forward selection on patient characteristics, comorbidities, and outcome measures associated with change in SCT (having p values of 0.25 or lower) until only those remaining in the model were statistically significant. Assumptions of linearity, normality, homoscedasticity, and absence of multicollinearity were met for linear regression. The r square value for the regression indicated that the model explains 35.5% of the variance in change in SCT, indicating a relatively good model fit. Median tests and chi-square tests were used to compare polyp status, and the 4 SCT questions between two of the three SCT disease status groups at a time, and correction for multiple comparisons of all three groups was done using the Holm test. P values of ≤ 0.05 were considered statistically significant.

RESULTS

Study cohort baseline characteristics

The study cohort included 218 patients with CRS, with even distribution across gender and polyp status groups as summarized in Table 1. Average follow-up was 7.8 with standard deviation of 3.0 months. As shown in Table 2 and Table 3, at baseline the majority of patients were partially controlled with a mean SCT score of 8.9 ± 3.5. Baseline SNOT-22 was 50.3 ± 21.4. Of the overall cohort, 56% of patients were diagnosed as CRSwNP and 44% were diagnosed as CRSsNP. Baseline SCT score was higher for CRSwNP than CRSsNP (9.5 ± 3.4 versus 8.2 ± 3.6, p = 0.009), as was the baseline SNOT-22 (52.8 ± 21.6 versus 47.0 ± 20.9, p = 0.048). Baseline LKES was 7.4 ± 3.7 with polyp grade of 1.8 ± 1.7 with significant differences between CRSwNP and CRSsNP (p < 0.0001).

Table 1.

Patient baseline characteristics and comorbidities

Demographics		All Patients (n=218) mean (SD), n (%)	CRSwNP (n=123) mean (SD), n (%)	CRSsNP (n=95) mean (SD), n (%)	P Value difference sNP vs. wNP
Age		50.1 ± 15.6	48.8 ± 15.1	51.9 ± 16.1	.142
Gender	Male	107 (49.1%)	59 (48.0%)	48 (50.5%)	.708
	Female	111 (50.9%)	64 (52.0%)	47 (49.5%)
Ethnicity	Hispanic	9 (4.1%)	6 (4.9%)	3 (3.2%)	.735
	Non-Hispanic	209 (95.9%)	117 (95.1%)	92 (96.8%)
Race	White	191 (87.6%)	100 (81.3%)	91 (95.8%)	.003
	Black	22 (10.1%)	19 (15.4%)	3 (3.2%)
	Other	5 (2.3%)	4 (3.3%)	1 (1.1%)
Comorbidities
Asthma		91 (41.7%)	59 (48.0%)	32 (33.7%)	.034
COPD		12 (5.5%)	6 (4.9%)	6 (6.3%)	.644
Depression		47 (21.6%)	25 (20.3%)	22 (23.2%)	.614
Fibromyalgia		7 (3.2%)	2 (1.6%)	5 (5.3%)	.244
Diabetes		19 (8.7%)	9 (7.3%)	10 (10.5%)	.405
Allergic Rhinitis Confirmed by Test		74 (33.9%)	52 (42.3%)	22 (23.2%)	.003
Revision Surgery*		72 (33.0%)	50 (40.7%)	22 (23.2%)	.006

CRSwNP: chronic rhinosinusitis with nasal polyps; CRSsNP: chronic rhinosinusitis without nasal polyps; COPD: chronic obstructive pulmonary disease; SD: standard deviation;

^*history of revision surgery not available for 66 patients

Table 2.

Change in SCT, SNOT-22, Lund-Kennedy, and polyp grade after endoscopic sinus surgery

	SCT				SNOT-22				LK Endoscopy				Polyp Grade
	n	Preop SCT Total Score	Postop SCT Total Score	P Value	n	Preop SNOT-22	Postop SNOT-22	P Value	n	Preop LK Endoscopy Score	Postop LK Endoscopy Score	P Value	n	Preop Polyp Grade	Postop Polyp Grade	P Value
All patients	218	8.9 (3.5)	4.3 (3.7)	<.001	213	50.3 (21.4)	23.6 (19.5)	<.001	145	7.4 (3.7)	3.9 (3.7)	<.001	144	1.8 (1.7)	0.6 (1.1)	<.001
All CRSsNP	95	8.2 (3.6)	4.4 (3.8)	<.001	93	47.3 (20.8)	24.1 (18.5)	<.001	57	5.1 (2.9)	2.7 (3.5)	<.001	57	0.4 (1.0)	0.2 (0.7)	.217
All CRSwNP	123	9.5 (3.4)	4.2 (3.6)	<.001	120	52.5 (21.7)	23.2 (20.3)	<.001	87	8.9 (3.2)	4.7 (3.5)	<.001	87	2.9 (1.3)	0.9 (1.2)	<.001
AFRS	10	10.2 (3.1)	3.8 (3.1)	.005	9	54.8 (25.1)	22.9 (26.8)	.008	8	8.8 (3.9)	5.5 (3.7)	.018	8	2.9 (1.0)	0.9 (1.5)	.016
AERD	23	8.8 (3.2)	3.8 (4.0)	<.001	23	54.2 (16.6)	27.5 (20.5)	<.001	17	9.9 (3.2)	5.2 (3.7)	.006	17	3.4 (1.1)	1.0 (1.2)	.001

CRSsNP: chronic rhinosinusitis without nasal polyps; CRSwNP: chronic rhinosinusitis with nasal polyps; AFRS: allergic fungal rhinosinusitis; AERD: aspirin-exacerbated respiratory disease; SCT: Sinus Control Test; SNOT-22: Sino-Nasal Outcome Test 22; LK: Lund-Kennedy; Preop: preoperative; Postop: postoperative

Table 3.

Disease control as categorized by the SCT after endoscopic sinus surgery

	Preoperative Baseline, Frequency (%)			Postoperative at 6 Months, Frequency (%)			P Value
	Uncontrolled	Partially Controlled	Controlled	Uncontrolled	Partially Controlled	Controlled
All patients (n=218)	47 (21.6%)	156 (71.5%)	15 (6.9%)	13 (6.0%)	93 (42.6%)	112 (51.4%)	<.001
All CRSsNP (n=95)	18 (18.9%)	68 (71.6%)	9 (9.5%)	7 (7.4%)	40 (42.1%)	48 (50.5%)	<.001
All CRSwNP (n=123)	29 (23.6%)	88 (71.5%)	6 (4.9%)	6 (4.9%)	53 (43.1%)	64 (52.0%)	<.001
AFRS (n=10)	3 (30.0%)	7 (70.0%)	0 (0.0%)	0 (0.0%)	5 (50.0%)	5 (50.0%)	.011
AERD (n=23)	4 (17.4%)	18 (78.3%)	1 (4.3%)	2 (8.7%)	5 (21.7%)	16 (69.6%)	<.001

CRSsNP: chronic rhinosinusitis without nasal polyps; CRSwNP: chronic rhinosinusitis with nasal polyps; AFRS: allergic fungal rhinosinusitis; AERD: aspirin-exacerbated respiratory disease; SCT: Sinus Control Test; Uncontrolled (12 to 16); Partially Controlled (4 to 11); Controlled (0 to 3)

Disease control after surgery

Postoperative SCT scores and disease control status were evaluated for all patients and each CRS subgroup including AERD and AFRS (Table 3). The mean SCT score was 4.3 ± 3.7 following ESS, resulting in the majority of patients being categorized as controlled. Significant improvements in SNOT-22 (mean change 26.6 ± 20.6) and LKES (mean change 3.5 ± 4.0) were observed for the overall cohort postoperatively (p < 0.001). The mean change in SCT was 5.2 ± 3.9 for CRSwNP and 3.8 ± 4.6 for CRSsNP (p = 0.015). No differences in postoperative SCT and SNOT-22 were observed on the basis of polyp status (p > 0.4) or AERD/AFRS subgroup (p > 0.2). Among CRSwNP, postoperative polyp grade was significantly improved (mean change 2.0 ± 1.3, p < 0.001). As shown in Table 4, postoperative SNOT-22 and LKES were evaluated according to postoperative SCT disease control status. Among the overall cohort and patients with CRSwNP, SNOT-22 scores were significantly different between all disease control status categories (p < 0.001). LKES among all patients and CRSwNP were also significantly different for partially controlled versus controlled; and controlled versus uncontrolled (p < 0.001). However, no difference in LKES was observed between uncontrolled and partially controlled patients. Among CRSsNP, SNOT-22 scores were significantly different between partially controlled versus controlled; and controlled versus uncontrolled (p < 0.001). No difference in SNOT-22 score was observed between uncontrolled and partially controlled CRSsNP. Among CRSsNP, LKES did not correlate with any disease control status category (p > 0.06 for all).

Table 4.

Postoperative SNOT-22 and Lund-Kennedy endoscopy score based on postoperative disease control status

	Uncontrolled mean (SD)	Partially Controlled mean (SD)	Controlled mean (SD)	Uncontrolled vs. Partially Controlled P value	Partially Controlled vs. Controlled P value	Controlled vs. Uncontrolled P value
All Patients
SNOT-22	57.2 (23.4) n=13	30.4 (18.8) n=91	14.0 (11.1) n=110	<.001	<.001	<.001
LK Endoscopy Score	7.1 (3.9) n=9	5.0 (4.2) n=64	2.6 (2.5) n=74	.120	<.001	.001
CRSsNP
SNOT-22	49.7 (24.9) n=7	31.1 (17.7) n=39	14.5 (10.6) n=48	.057	<.001	<.001
LK Endoscopy Score	6.0 (5.7) n=4	3.5 (4.0) n=27	1.7 (1.9) n=29	.288	.087	.063
CRSwNP
SNOT-22	66.0 (20.0) n=6	29.8 (19.8) n=52	13.5 (11.6) n=62	<.001	<.001	<.001
LK Endoscopy Score	8.0 (1.9) n=5	6.2 (3.9) n=37	3.2 (2.6) n=45	.269	<.001	<.001
AFRS
SNOT-22	n=0	37.4 (28.7) n=5	4.8 (4.5) n=4	n/a	.032	n/a
LK Endoscopy Score	n=0	6.8 (4.4) n=4	4.3 (2.9) n=4	n/a	.486	n/a

CRSsNP: chronic rhinosinusitis without nasal polyps; CRSwNP: chronic rhinosinusitis with nasal polyps; AFRS: allergic fungal rhinosinusitis; SNOT-22: Sino-Nasal Outcome Test 22; LK: Lund-Kennedy; SCT: Sinus Control Test; Uncontrolled (12 to 16); Partially Controlled (4 to 11); Controlled (0 to 3); SD: standard deviation All significant p values remain significant after using Holm correction for multiple comparisons.

Factors associated with postoperative change in SCT score

None of the demographic factors or comorbidities listed in Table 1 were associated with change in SCT (p > 0.2 for all). Similarly, the correlations between change in the SCT score and months to follow-up were weak and did not reach statistical significance (r = −0.124, p = 0.068). The change in SNOT-22 was significantly associated with change in SCT score, with a moderate strength of correlation (r = 0.500, p < 0.001). Change in LKES were also associated with change in SCT score (r = 0.310, p < 0.001). Regression analysis was performed on demographic, comorbidities and outcome measures to determine independent predictors of disease control. As shown in Table 5, change in SNOT-22 and change in LKES were independently associated with change in SCT score. Multiple regression analysis among CRSwNP demonstrated a similar association between SCT score, SNOT-22 and LKES; however for CRSsNP change in LKES was not associated with change in SCT score (r = 0.179, p = 0.125). After adjusting for change in LKES, on average, for a one-unit increase in change in SNOT-22 score, change in SCT increases by 0.10 (Figure 2). Likewise, for a one-unit increase in change in endoscopy, change in SCT increases by 0.25 after adjusting for change in SNOT-22 (Figure 3). Each of the four SCT questions were then examined according to the postoperative disease control category to determine if any individual question(s) were driving the overall score. As shown in Table 6, each of the four SCT items differed in a similar magnitude between controlled, partially controlled, and uncontrolled patients postoperatively indicating that each separate item contributed uniformly to the SCT construct (p < 0.004 for all).

Table 5.

Linear regression of predictors of change in SCT score

Independent Variables	Unstandardized β (95% CI)	Standardized β	t	P value	R Square
All Patients (n = 143)
Change in SNOT-22 Score	.104 (.076, .132)	.510	7.385	<.001	.354
Change in LK Endoscopy Score	.245 (.099, .391)	.229	3.311	.001
CRSsNP, n = 57
Change in SNOT-22 Score	.109 (.058, .159)	.498	4.340	<.001	.308
Change in LK Endoscopy Score	.243 (−.069, .555)	.179	1.560	.125
CRSwNP, n = 86
Change in SNOT-22 Score	.100 (.066, .135)	.510	5.788	<.001	.365
Change in LK Endoscopy Score	.247 (.087, .408)	.271	3.074	.003

CRSsNP: chronic rhinosinusitis without nasal polyps; CRSwNP: chronic rhinosinusitis with nasal polyps; SNOT-22: Sino-Nasal Outcome Test 22; LK: Lund-Kennedy; SCT: Sinus Control Test

Figure 2.

Association between postoperative change in SNOT-22 and change in SCT.

Figure 3.

Association between postoperative change in Lund-Kennedy Endoscopy Score and change in SCT.

Table 6.

Individual SCT questions by SCT disease control category postoperatively.

		Controlled (n=112)	Partially Controlled (n=93)	Uncontrolled (n=13)	Uncontrolled vs. Partially Controlled Effect Size (P Value)	Partially Controlled vs. Controlled Effect Size (P Value)	Controlled vs. Uncontrolled Effect Size (P Value)
		Mean (SD), n (%)	Mean (SD), n (%)	Mean (SD), n (%)
SCT Question 1 (Nasal Obstruction)		0.6 (0.6)	1.6 (1.1)	3.2 (.6)	.924 (.001)	1.041 (<.001)	1.220 (<.001)
SCT Question 2 (Nasal Discharge)		0.7 (0.6)	1.9 (1.0)	3.2 (.7)	.800 (.004)	1.184 (<.001)	1.213 (<.001)
SCT Question 3 (Productivity)		0.1 (0.3)	1.0 (1.0)	2.8 (.7)	1.013 (.004)	1.020 (<.001)	1.239 (<.001)
SCT Question 4 (Oral Steroid/Antibiotic)	No	112 (100.0%)	45 (48.4%)	0 (0.0%)	.321 (.001)	.607 (<.001)	1.000 (<.001)
	Yes	0 (0.0%)	48 (51.6%)	13 (100.0%)

SCT: Sinus Control Test; Controlled (0 to 3); Partially Controlled (4 to 11); Uncontrolled (12 to 16); SD: standard deviation

All significant p-values remain significant after using Holm correction for multiple comparisons. Cohen’s D and Cramer’s V used for effect sizes.

DISCUSSION

The SCT was developed to address the limitations of existing CRS-specific disease control instruments, specifically their correlation to patient reported outcomes, need for nasal endoscopy, and lack of comprehensive validation. The SCT has strong developmental and psychometric properties, and differs from existing QOL metrics in that it does not assess patients’ perception of disease impact but rather level of CRS control using current medical therapies at a specific point in time.⁹ In a single center validation study of 50 patients with CRS, the SCT was found to be internally consistent and responsive to surgical intervention with a test-retest reliability similar to that of established control tests for asthma and rhinitis.^14–15

In the present study, the level of disease control was classified according to the SCT instrument at baseline and following surgery. The SCT captured the full spectrum of control levels and was responsive to change after ESS with improvement in disease control independently associated with improvements in SNOT-22. Figure 4 illustrates that the distribution of overall SCT scores are skewed in the direction of lower SCT scores following surgery with the majority of patients being categorized as controlled. In our cohort, LKES demonstrated significant improvement following surgery across all patients and CRS subgroups following ESS. Although SCT control status correlated with LKES among CRSwNP, this association was not maintained for partially controlled versus uncontrolled status. When examining LKES according to disease control status in CRSsNP, no significant difference was observed between any of the control status groups. In considering control status for CRSsNP, the SCT instrument may not account for important endoscopy parameters indicative of progression of sinus disease following surgery. However, the SCT was not designed nor intended to replace the need for objective testing, and comprehensive examination by a specialist remains essential to the care of patients with CRS. The SCT is complementary to existing CRS-specific PROMs and objective measures of disease severity. It is possible that this study is underpowered to detect associations between LKES and SCT. Table 4 demonstrates a reasonable progression in mean LKES between SCT categories, however, we had only 4 to 5 patients in the uncontrolled category for each polyp subgroup, thus it is possible we need additional patients to detect such associations. While acknowledging these limitations that it does incorporate endoscopy criteria, we suggest that the SCT may be uniquely applicable to a variety of clinical settings where patients with CRS are often evaluated, including virtual telehealth platforms as well as by primary care providers or other specialists. The SCT is easily calculated and responses can be captured in person or remotely. These attributes might allow for additional longitudinal monitoring of disease control and identifying inadequately controlled symptoms that might prompt referral or escalation of treatment.

Figure 4.

Distribution of preoperative and postoperative SCT scores.

Alternative instruments for the assessment of disease control in CRS have yet to undergo similar application and validation.^16–18 The 2012 EPOS control criteria were developed by expert opinion and categorized patients into controlled, partly controlled, or uncontrolled CRS.³ Unfortunately, relatively few studies have evaluated these control criteria in a “real-life” CRS population.¹⁶ In the largest retrospective study, 560 patients who had previously undergone ESS for CRS within the previous three to five years completed a modified version of the 2012 EPOS control criteria.⁴ They found that only 19.5% of patients met criteria for controlled, with 36.8% partly controlled and 43.7% uncontrolled. Interestingly, when a subgroup of patients were asked how they perceived CRS control after ESS, 47.6% reported themselves as having controlled CRS despite just 19.1% meeting controlled criteria as set forth by the 2012 EPOS control criteria. It is difficult to reconcile the fact that two thirds of the study population were categorized as uncontrolled when long-term revision rates for ESS are estimated at 14–24%.¹⁷ While many factors influence the decision to undergo revision ESS, control of CRS certainly plays a role. Additionally, what constitutes a short versus long-term course of antibiotics or systemic corticosteroids is not well defined in alternative disease control instruments resulting in a wide spectrum of interpretation. Given the lack of uniformity in these existing disease control instruments, 2020 EPOS included a modified tool for the assessment of current clinical control of CRS.¹⁶ While prior criteria were felt to overestimate the number of uncontrolled patients, the updated criteria include a VAS scale for all symptoms wherein “not bothersome” can be substituted by VAS < 5; and “present/impaired” by VAS > 5. Additionally, the criteria specify that all symptoms, including sleep disturbance and/or fatigue, must be related to CRS. Finally, nasal endoscopy may be included only if available. While a handful of alternative disease control instruments have been proposed over the last decade, few were developed using recommended practices and most are yet to undergo detailed validation.

While our preoperative cohort included 6.9% patients classified as controlled, it is important to recognize that the decision to pursue ESS may involve motivations and disease processes that are not readily captured by the SCT. As such, one would expect the SCT score to be minimally affected in these cases. Similar scenarios have been reported with SNOT-22, and these patients still require surgery to address sinus pathology.¹⁹ The 42.6% of patients remaining partially controlled following ESS is consistent with the spectrum of CRS disease severity, and our cohort may be biased towards more complex disease as evidenced by preoperative characteristics, SNOT-22, and rates of prior ESS. However, the relatively high percentage of patients remaining partially controlled is perhaps not a limitation of this disease control instrument, but rather a reflection of where thresholds are set in a disease process characterized by the need for ongoing maintenance medical therapy and potential for recalcitrant disease. By identifying this group of patients who are inadequately controlled despite surgical intervention, we are further supporting the rationale for the application of a disease control instrument in CRS.

The data collected in this study represents the responsiveness of the SCT instrument in a multi-institutional surgical cohort. It is important to note that the responsiveness of the SCT among patients undergoing treatment with a medical intervention remains unclear. This study design was based on prior literature demonstrating the relatively robust impact of surgery as an intervention as well as the prior validation of the SCT in a smaller surgical cohort.^3–7 Thus, we would expect similar responsiveness following surgical intervention to be reflected in this multi-institutional validation of the SCT. Further investigation is required to assess responsiveness of the SCT to smaller changes in symptoms or endoscopy scores; as well as changes in disease control status among patients treated with medical interventions. The inclusion of additional time points among both surgical and non-surgical cohorts may improve interpretation of this data so as to better generalize these observed correlations in symptoms and endoscopy scores.

Future studies should examine if longitudinal monitoring of disease control results in an increased recognition of inadequately controlled CRS; and if improvement in control is observed with implementation of escalation therapy. Similarly, evaluation of the SCT in a medically managed cohort would provide insight on the association between control status, escalation of medical therapy, and treatment decision-making. Finally, broader application of the SCT for CRS outside of these tertiary rhinology settings may provide further cross-cultural, interdisciplinary validation across different health systems and providers.

CONCLUSION

The Sinus Control Test (SCT) is a validated, four question patient-reported questionnaire developed to identify sub-optimally controlled CRS by accounting for sinonasal symptoms, interference in daily life function and rescue medication use. Improvement in disease control following ESS as measured by the SCT correlated independently with improvements in both SNOT-22 and overall endoscopy scores in this prospective multicenter cohort study. The SCT instrument is easily administered and provides meaningful information about disease burden following surgical intervention that is complementary to existing CRS-specific PROMs and objective measures of disease severity.