Health Utility Values as an Outcome Measure in Patients Undergoing Functional Septorhinoplasty

Key Points

Question

Can health utility values derived from patient scores on the EuroQol 5-Dimension questionnaire be used to measure outcomes of septorhinoplasty?

Findings

In this cohort study of 463 patients undergoing septorhinoplasty, the mean preoperative health utility value was significantly increased 12 months after surgery.

Meaning

Health utility values can be used to measure outcomes in patients undergoing septorhinoplasty, and nasal obstruction is associated with a substantial detriment to overall health in line with other chronic conditions.

This cohort study evaluates health utility values derived from the EuroQol 5-Dimension questionnaire and patient factors associated with postoperative improvements in these values among patients undergoing functional septorhinoplasty.

Abstract

Importance

By measuring health utility values (HUVs) for patients with nasal obstruction after septorhinoplasty, the association of nasal congestion with overall health can be measured and the functional outcomes of septorhinoplasty can be determined.

Objective

To use the EuroQol 5-Dimension (EQ-5D) questionnaire to evaluate nasal obstruction outcomes after septorhinoplasty and to determine HUVs.

Design, Setting, and Participants

This prospective cohort study included patients who underwent septorhinoplasty for nasal obstruction at a single institution by a single surgeon from January 1, 2013, through December 31, 2017. Participants completed the EQ-5D questionnaire immediately before surgery and postoperatively at 2, 4, 6, and 12 months. The EQ-5D scores were converted to HUVs using population-based data for individuals with chronic diseases. Data were analyzed from May 1 through December 31, 2018.

Exposure

Functional septorhinoplasty.

Main Outcomes and Measures

Preoperative and postoperative EQ-5D scores were compared to evaluate improvement in overall health after septorhinoplasty.

Results

A total of 463 patients (53.8% women; mean [SD] age, 36.8 [15.7] years) who underwent septorhinoplasty and completed EQ-5D surveys at baseline and postoperatively were included in the study population. Overall mean (SD) preoperative HUV was 0.872 (0.01), compared with 1.00 for those with a perfect state of health. On univariate analysis, female sex (mean [SD] HUV, 0.853 [0.01]; P = .004), previous nasal surgery (mean [SD] HUV, 0.85 [0.16]; P = .02), previous septoplasty (mean [SD] HUV, 0.88 [0.15]; P = .02), and previous sinus surgery (mean [SD] HUV, 0.79 [0.20]; P = .009) were associated with significantly lower baseline HUVs. On multivariate regression including these variables, only previous septoplasty was significantly associated with a positive change in mean (SD) HUV (0.88 [0.15] vs 0.85 [0.16]; P = .02). Mean (SD) HUV was significantly improved at 2 months postoperatively to 0.91 (0.14; P = .001) and remained significantly improved from baseline at 12 months, at 0.93 (0.13; P < .001).

Conclusions and Relevance

Nasal obstruction is associated with significant detriment to overall health, in line with other chronic conditions affecting the US population. Functional septorhinoplasty appears to substantially improve overall health, as measured by HUV, in an immediate and sustained fashion.

Level of Evidence

3.

Introduction

Nasal obstruction is one of the most common presenting complaints of patients seen in otolaryngology and facial plastic surgery clinics. Medical management options include topical nasal sprays, oral allergy medications, and nasal strips to physically aid in alleviating obstruction, among other interventions. Surgical options are variable and tailored specifically to the patient and may include septoplasty, septorhinoplasty with correction of nasal valve dysfunction, osteotomy, and/or turbinoplasty.¹ The detrimental effect of nasal obstruction on overall health status and the effects of surgical treatment have not been well studied. Fortunately, valid and reliable patient-reported outcome measures assessing overall health status provide a means to evaluate the association of chronic conditions, including nasal obstruction, with global health.

The EuroQol 5-Dimension (EQ-5D) questionnaire is a global health-related quality-of-life (HRQOL) assessment tool in which patients are asked to rate their own overall health status.^2,3 The questionnaire consists of 5 domain-specific questions and a visual analog scale (VAS) that quantifies health on a continuous scale. The EQ-5D has been widely used and provides a means to quantify overall health. As such, the US Department of Health and Human Services has collected EQ-5D scores from a large portion of the US population, allowing these scores to be converted into health utility values (HUVs).

The use of HUVs derived from the EQ-5D has not, to our knowledge, previously been explored for patients undergoing functional septorhinoplasty for nasal obstruction. These values, converted from scores on EQ-5D surveys and based on population-specific data, are used as a measure of overall health status and allow comparison of nasal obstruction with several other chronic health states. The purpose of this study was to evaluate outcomes of functional septorhinoplasty using EQ-5D–derived HUVs and patient factors associated with postoperative improvements in HUVs.

Methods

The study population consisted of 463 patients who underwent functional septorhinoplasty for nasal obstruction at the Department of Otolaryngology–Head and Neck Surgery, Massachusetts Eye and Ear, Boston, by a single surgeon (R.W.L.) from January 1, 2013, through December 31, 2017. Patients were required to have completed a preoperative (baseline) EQ-5D questionnaire as well as at least 1 postoperative EQ-5D questionnaire. Postoperative EQ-5D questionnaires were administered to patients at the 2-, 4-, 6-, and 12-month postoperative points. Patient medical records were reviewed for comorbidities, including previous sinonasal surgery. Preoperative and postoperative scores were compared to evaluate improvement in overall health after functional septorhinoplasty. This study was approved by the Human Subjects Research Committee of the Massachusetts Eye and Ear Infirmary institutional review board. All participants provided written informed consent. Data and analyses are presented in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline for cross-sectional studies.⁴

EQ-5D Questionnaire

The administered EQ-5D questionnaire measures health across the 5 domains of mobility, self-care, usual activity, pain/discomfort, and anxiety/depression. All EQ-5D questionnaires used the 3L version of the survey, which allowed each domain to be rated with 3 options. Each domain was rated on a range from 1 (no problems) to 3 (extreme problems or inability to function). In addition, patients rated their overall health on a VAS from 1 to 100, with 100 being best imaginable health and 0 being worst imaginable health.³

Health Utility Values

We used EQ-5D scores to derive HUVs from population-based data. The EQ-5D scores can be differentiated in 3125 unique health states. These scores can be converted to HUVs using population-based data from national surveys of the adult US population, with each health state having a corresponding HUV.^5,6,7 We used the HUVs to compare outcomes after septorhinoplasty as measured by absolute postoperative HUVs and by change in HUV from baseline. An HUV of 1.00 is defined as the perfect state of health.

Statistical Analysis

Data were analyzed from May 1 through December 31, 2018. All statistical analysis was performed using Stata, version 12.0 (StataCorp). We used χ² tests for normally distributed categorical variables and 2-tailed t tests for continuous variables that were stratified into 2 groups. Analysis of variance tests were used to compare parametric continuous variables. A Holm-Sidak post hoc pairwise multiple comparison analysis⁸ was used to examine whether postoperative HUVs were significantly improved from baseline. For multivariate regression models, all outcome variables were initially tested with univariate analysis. The multivariate regression was used to test surgical history and demographic characteristics for their association with change in HUV. Two-sided P < .05 was considered statistically significant.

Results

A total of 463 patients (214 men [46.2%] and 249 women [53.8%]; mean [SD] age, 36.8 [15.7] years) who underwent septorhinoplasty for nasal obstruction and completed EQ-5D surveys before and after surgery were included in the study population. All patients completed the initial survey. Subsequently, 419 patients completed surveys at 2 months, 270 at 4 months, 210 at 6 months, and 160 at 1 year. Overall, the mean (SD) preoperative HUV score was 0.87 (0.01). Most patients undergoing septorhinoplasty in the study population were younger than 40 years (300 [64.8%]) and, among the 458 with available data, did not have any previous nasal surgery (273 [59.6%]). On univariate analysis, female sex (mean [SD] HUV, 085 [0.01]; P = .004), previous nasal surgery (mean [SD] HUV, 0.85 [0.16]; P = .02), previous septoplasty (mean [SD] HUV, 0.88 [0.15]; P = .02), and previous sinus surgery (mean [SD] HUV, 0.79 [0.20]; P = .009) were associated with significantly lower baseline HUVs (Table).

Table. Univariate Regression of Factors Associated With Baseline HUV.

Variable	No./Total No. (%) of Patients	HUV, Mean (SD)	P Valuea
Sex
Male	214/463 (46.2)	0.89 (0.13)	.004
Female	249/463 (53.8)	0.85 (0.01)
Age, y
<40	300/463 (64.8)	0.88 (0.15)	.17
≥40	163/463 (35.2)	0.86 (0.16)
Sinus disease
Yes	102/458 (22.3)	0.86 (0.02)	.26
No	356/458 (77.7)	0.01 (0.15)
Sleep apnea
Yes	57/412 (13.8)	0.86 (0.02)	.58
No	355/412 (86.2)	0.88 (0.01)
Allergies
Yes	261/457 (57.1)	0.86 (0.01)	.07
No	196/457 (42.9)	0.89 (0.01)
History of nasal fracture
Yes	231/456 (50.7)	0.87 (0.01)	.80
No	225/456 (49.3)	0.87 (0.01)
Previous nasal surgery
Yes	185/458 (40.4)	0.85 (0.16)	.02
No	273/458 (59.6)	0.89 (0.14)
Closed nasal reduction
Yes	39/463 (8.4)	0.88 (0.11)	.68
No	424/463 (91.6)	0.87 (0.15)
Previous rhinoplasty
Yes	57/463 (12.3)	0.85 (0.15)	.18
No	406/463 (87.7)	0.88 (0.15)
Previous septoplasty
Yes	130/463 (28.1)	0.88 (0.15)	.02
No	333/463 (71.9)	0.85 (0.16)
Previous sinus surgery
Yes	22/463 (4.8)	0.79 (0.20)	.009
No	441/463 (95.2)	0.88 (0.15)
Turbinoplasty
Yes	33/463 (7.1)	0.86 (0.16)	.76
No	430/463 (92.9)	0.87 (0.15)

Abbreviation: HUV, health utility value.

^aCalculated using χ² tests for normally distributed categorical variables and 2-tailed t tests for continuous variables that were stratified into 2 groups.

Mean (SD) HUV was significantly improved at 2 months postoperatively to 0.91 (0.14; P = .001) and remained significantly improved from baseline at 12 months to 0.93 (0.13; P < .001). A higher proportion of patients achieved a perfect HUV (1.00) as time from surgery increased, from 203 of 463 (43.8%) at baseline to 105 of 160 (65.6%) at 12 months after surgery, and the SD of the mean cohort HUV decreased over time (Figure 1).

Figure 1. Health Utility Values (HUVs) Before and After Septorhinoplasty.

HUVs are stratified by time from functional septorhinoplasty and range from 0 to 1.00, with 1.00 representing best possible health status. Horizontal line represents the median value for each HUV group. Error bars indicate SDs. After the plotting of the SD, outliers are not included.

The mean (SD) VAS score was 73.8 (19.2) at baseline, increased to 81.2 (15.2) at 2 months, and remained consistently improved at 81.3 (17.2) at 12 postoperative months. This change in VAS at 2 and 12 months, similar to the change in HUVs, indicated significant improvement from baseline (P < .001 for both). Results for the change in VAS and HUV from baseline to 12 months were plotted and showed a positive correlation (r = 0.22) (Figure 2). The improvement in HUV from baseline to 12 months had a positive correlation (r = 0.22) with change in VAS in the EQ-5D. On multivariate regression, only previous septoplasty was significantly associated with a positive change in HUV (mean [SD], 0.88 [0.15] vs 0.85 [0.16]; P = .02).

Figure 2. Change in Health Utility Values (HUVs) Compared With Change in EuroQol 5-Dimension Visual Analog Scale (VAS) Scores at 12 Months.

HUVs range from 0 to 1.00, with 1.00 representing best possible health status. VAS scores range from 1 to 100, with 100 being best imaginable health and 0 being worst imaginable health.

Discussion

This study establishes baseline EQ-5D–derived HUVs for patients with nasal obstruction who undergo functional septorhinoplasty for correction. In addition, outcomes show a rapid, sustained, and significant increase in HUV after surgical intervention, mirroring findings of previous studies showing positive outcomes after functional septorhinoplasty.^9,10 A positive correlation between EQ-5D VAS scores and change in HUVs, as expected, further supports the use of HUV in evaluating disease states for nasal obstruction. Previous nasal surgery is significantly associated with baseline HUV before intervention and may influence HUV outcomes; however, this association requires further study, because this patient population may have unique chief complaints and may value improvement after septorhinoplasty differently.

Health utility values can be derived from a number of HRQOL patient questionnaires and are indicative of an individual’s valuation of being in a particular health state.⁷ A number of patient questionnaires exist, including the 36-Item Short Form Health Survey, which is used to generate the SF-6D; the Quality of Well-Being–Self-Administered; EQ-5D; Health and Activities Limitations Index; Health Utility Index Mark 2; and Health Utility Index Mark 3.¹¹ Most commonly, the SF-6D and EQ-5D surveys are used to assess overall health in patients with chronic conditions and have been widely accepted as general measures of overall health across populations.¹¹ The value of describing outcomes with HUVs revolves around the ability to translate this information into quality-adjusted life-year data and use it in cost utility analyses.

The EQ-5D questions measure individual health at the time of the survey. As previously described, the EQ-5D measures health across 5 domains (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression), with each domain being rated as no problems, moderate problems, or severe problems.^3,5 In addition, participants are asked to score their health from 0 to 100 on a VAS, with 100 referring to best imaginable health and 0 indicating worst imaginable health. Studies have compared the HRQOL surveys and found that the EQ-5D provides an acceptable and accurate gauge of overall health.^11,12 Specifically, in the context of nasal obstruction, the EQ-5D has been shown to have a positive correlation with Nasal Obstruction Symptom Evaluation scores for comprehensively evaluating symptom burden.^9,13

In the present study, women with nasal obstruction had a significantly lower baseline HUV than men, which mirrors data across the general United States population, among whom women overall reported lower baseline HUV scores.¹¹ Patients who had undergone previous nasal surgery or septoplasty also had significantly lower baseline HUV scores, which might indicate that these patients may have received the wrong diagnosis and been treated with septoplasty when a septorhinoplasty may have been more appropriate. As a result, these patients may have had problems due to inappropriate treatment.¹⁴ Studies have shown that patients undergoing revision septorhinoplasty may, at baseline, constitute a unique population, although studies examining patient satisfaction after revision septorhinoplasty show substantial improvement in outcomes that mirror those of patients undergoing standard septorhinoplasty.¹⁵ In this study, the positive association of change in HUV at 12 months and history of previous septoplasty on multivariate regression analysis suggests that the benefits of appropriate treatment could be substantial and improve the overall health of these patients to a greater degree than that of patients who did not have previous surgery. Although chronic sinusitis has been shown to have a significant effect on HUV in isolation, prior septoplasty remained significantly associated on multivariate analysis, suggesting that sinus disease was not confounding this finding.⁵ Outcomes assessing HUVs for patients undergoing revision functional septorhinoplasty specifically require further study.

Nasal obstruction appears to be associated with meaningful detriment to overall health in the context of other diseases. Patients with nasal obstruction had a lower HUV than patients with seasonal allergies (HUV, 0.98), peptic ulcer disease (HUV, 0.95), and migraines (HUV, 0.92) and a higher HUV than patients with renal failure (HUV, 0.68), liver failure (HUV range, 0.72-0.75), chronic rhinosinusitis (HUV, 0.80), and chronic obstructive pulmonary disease (HUV range, 0.71-0.80).^5,16 However, the rated severity of each of these diseases may vary by individual. In addition, disease-specific HUVs may depend on the type of HRQOL survey used to derive HUV.¹⁷ In addition, comparing HUVs across diseases requires caution because, in some diseases, HUVs can rapidly fluctuate with medical management.¹⁷ Despite this fluctuation, HUVs have utility as a standard measure of how individuals rate the detriment to their overall health caused by a disease state, how they value that disease state, the relative benefit of an intervention in achieving an improved health state, and whether knowledge of the possible improvement in health state is worth an intervention to achieve that health state. These findings are particularly true in instances when individual-focused HUV decision-making is implemented over general population preference-focused HUV decision-making.¹⁸

Limitations

This study has several limitations. Patients were only included in the study if they were able to complete a preoperative and postoperative EQ-5D survey. Some patients may have been lost to follow-up who may have preferentially had a lower EQ-5D score due to unhappiness with the results of surgery and subjectively poorer outcomes after their surgery. Patents completed the baseline EQ-5D on the day of initial clinic visit, which may have caused patients to focus on their disease and rate their disease as having a more negative effect on their quality of life compared with their mean baseline state. Those who had partial responses to medication before surgical treatment may have rated their preoperative EQ-5D as falsely elevated owing to the effect of the medication. Septorhinoplasty was considered a single procedure for the purposes of this study. A minority of patients underwent turbinoplasty as a portion of their procedure, but the individual portions of the procedure, which may contribute to improvement in HUV differentially, were not separately analyzed in this study.

In addition, this study used the experience of a single surgeon, which may limit generalizability; however, it still provides a large amount of preoperative health valuation data with the baseline EQ-5D data that are generalizable. Furthermore, this study demonstrates that patients who undergo successful surgical intervention have improvement in health quality as measured by HUV, which should be generalizable. Fewer patients at each subsequent visit completed the survey, introducing attrition bias in that only those patients who had continued difficulty with breathing may continue long-term follow-up. Conversely, those patients extremely unhappy with their outcomes may leave the practice; however, these patients are unlikely to leave suddenly in the postoperative period. Despite these limitations, this study had a large sample size of patients and followed up these patients for 12 months postoperatively, providing a valuable baseline study for HUV-based outcomes after functional septorhinoplasty.

Conclusions

Patients with nasal obstruction report significant detriment to overall health status as a function of the disease when compared with the general population. Functional septorhinoplasty is associated with significant improvement in health status in the short-term postoperative period and sustained improvement in overall health status. Future studies are required to use the HUVs associated with nasal obstruction to evaluate the cost-effectiveness of operative intervention and to evaluate the appropriate role and duration of medical management in the treatment of nasal obstruction.