HSS Dysphagia and Dysphonia Inventory (HSS-DDI) Following Anterior Cervical Fusion: Patient-Derived, Validated, Condition-Specific Patient-Reported Outcome Measure Outperforms Existing Indices

Validated patient reported outcome measures in speech-language pathology: A scoping review of adult practice

PURPOSE

Patient reported outcome measures (PROMs) are increasingly used to inform value-based healthcare. Within speech-language pathology (SLP), there is no synthesis of validated PROMs to guide professional practice. This scoping review systematically identifies and evaluates condition-specific PROMs across adult SLP practice.

METHOD

A literature search was performed to identify studies published until 18th February 2022 from MEDLINE, Embase, CINAHL, PsycInfo, Scopus, Cochrane Collaboration, and Web of Science. Abstracts and full texts were screened in Covidence. Relevant studies that validated PROMs in English were extracted and assessed using the "Checklist to operationalise measurement characteristics of PROMs" by two independent reviewers.

RESULT

Ninety-seven articles provided validation data for 71 PROMS across seven SLP practice areas. These included voice (n = 18), swallowing (n = 14), language (n = 11), fluency (n = 8), speech (n = 4), laryngectomy (n = 3), and cognitive-communication (n = 2). No PROMs were identified for augmentative and alternative communication (AAC) (n = 0). Quality ratings were variable on the Francis et al. checklist.

CONCLUSION

A range of validated PROMs were identified to guide SLP practice in measuring patient perceptions across a range of practice areas in adults. Opportunities for further development in SLP practice areas with limited PROMs, such as speech, cognitive-communication, and AAC are also highlighted.

Evaluation of outcome measures for post-operative dysphagia after anterior cervical discectomy and fusion

PURPOSE

The goal is to conduct a review of the current literature to determine and evaluate the current classification metrics available for quantifying post-operative dysphagia.

METHODS

We surveyed the literature for the subjective and objective measures used to classify dysphagia, and further described and analyzed them in the context of post-operative dysphagia (PD) after anterior cervical spine surgery, with a focus on anterior cervical discectomy and fusion (ACDF). We searched PubMed from the years 2005-2021 using the terms "anterior cervical discectomy and fusion" and "dysphagia or postoperative dysphagia." We included papers that were meta-analyses, systemic reviews, prospective, or retrospective studies. Our selection was further consolidated via abstract and title screening. Ultimately, nineteen articles were included and had full-text reviews.

RESULTS

EAT-10 tool was shown to be more valid and reliable than the commonly used Bazaz grading system. HSS-DDI was found to have a high diagnostic accuracy in stratifying mild, moderate, and severe PD. A shortened 16-item version of the original 44-item SWAL-QOL was found to be statistically and clinically significant. When compared to PROMs, objective tests more accurately diagnose PD.

CONCLUSION

We found that the most valuable subjective tests were the EAT-10 and HSS-DI because they are quick, sensitive, and correlated strongly with the well-established measurements of PD. The MBS and FEES provided accurate measurements of the severity of PD, but they required more time and equipment than the surveys. In some patient populations, such as those with pre-surgical dysphagia, objective testing should always be done.

A scoping review of the methods used to capture dysphagia after anterior cervical discectomy and fusion: the need for a paradigm shift

OBJECTIVE

Dysphagia is the most commonly reported complication of annterior cervical discectomy and fusion (ACDF) surgery. However, the incidence of dysphagia post-ACDF varies widely-partly attributable to differing outcome measures used to capture dysphagia. Our objective was to conduct a scoping review of the literature to quantify which dysphagia outcome measures have been employed post-ACDF and examine trends by study design, year, and location.

METHODS

After removing duplicates, 2396 abstracts were screened for inclusion. A total of 480 studies were eligible for full-text review. After applying exclusion criteria, data was extracted from 280 studies. We extracted the dysphagia outcome measure(s), study design (prospective vs retrospective), year, and location (country). Approximately 10% of studies were repeated for intra-rater agreement.

RESULTS

In total, 317 dysphagia outcome measures were reported in 280 studies (primarily retrospective-63%). The largest proportion of outcome measures were categorized as "unvalidated patient-reported outcome measures" (46%), largely driven by use of the popular Bazaz scale. The next most common categories were "insufficient detail" and "validated patient-reported outcome measures" (both 16%) followed by "chart review/database" (13%) and instrumental assessment (7%). Studies examining dysphagia post-ACDF steadily increased over the years and the use of validated measures increased in the past 10 years.

CONCLUSIONS

This scoping review of the literature highlights that nearly half of the ACDF dysphagia literature relies on unvalidated patient-reported outcome measures. The current understanding of the mechanism, timeline, and presentation of dysphagia post-ACDF are likely limited due to the metrics that are most commonly reported in the literature.

Dysphagia after cervical spine surgery: a review of risk factors and preventative measures

Dysphagia is a regular occurrence after cervical spine surgery, and the development of dysphagia postoperatively is associated with worsened quality of life for patients. Despite the frequency and negative implications of this adverse outcome, there is no clear consensus for defining dysphagia within the spinal literature. Numerous patient-reported outcomes questionnaires are currently used to elucidate the presence and severity of postoperative dysphagia, several of which are not validated instruments. This variability in reporting creates difficulty when trying to determine the prevalence of dysphagia and any potential mitigating factors. In the current review, the authors discuss the causes of postoperative dysphagia after cervical spine surgery, metrics for evaluating postoperative dysphagia, risk factors for the development of this adverse outcome, and strategies for preventing its development. Readers will be able to use this information to improve patient outcomes after cervical spine surgery.

Predictors of Dysphagia After Anterior Cervical Discectomy and Fusion: A Prospective Multicenter Study

STUDY DESIGN

Multicenter prospective study.

OBJECTIVE

Our aim was to evaluate the incidence and predictors of postoperative dysphagia in patients undergoing anterior cervical discectomy and fusion (ACDF).

SUMMARY OF BACKGROUND DATA

Dysphagia is a common complication after ACDF that can have significant effect on patients' quality of life, but the frequency of occurrence and potential risk factors are not known.

METHODS

A multicenter prospective study was undertaken at three academic sites to evaluate patients undergoing ACDF between September 2018 and September 2020. Included patients were aged 18 to 80 years and were undergoing primary or revision ACDF for a degenerative condition. Dysphagia was assessed using the validated Eating Assessment Tool (EAT-10) questionnaire, with dysphagia defined as EAT-10 ≥ 3.

RESULTS

A total of 170 patients (53.5% female; mean age at surgery 55.0 yr) were included. At preoperative baseline, 23 patients (13.5%) had dysphagia. Rates of dysphagia increased to 45.3% at 2 weeks postoperatively but gradually decreased to 15.3% at 24weeks. On univariate analysis, patients with dysphagia at 2weeks had longer operations (113.1 ± 58.4 vs. 89.0 ± 39.8 minutes, P   =  0.003) and higher baseline dysphagia rates (18.2% vs. 6.2%, P   =  0.018) and were more likely to be female (66.2% vs. 45.7%, P   =  0.009). Patients with prolonged dysphagia had more levels fused (2.1 ± 1.0 vs. 1.7 ± 0.7, P   =  0.020), longer operations (131.8 ± 63.1 vs. 89.3 ± 44.3 min-minutes, P   <  0.001), and higher baseline dysphagia rates (32% vs. 7.1%, P   <  0.001) and were more likely to be smokers (24% vs. 8%, P   =  0.021). On multivariate analysis to determine associations with prolonged dysphagia, only smoking status (OR 6.2, 95% CI 1.57-24.5, P   =  0.009) and baseline dysphagia (OR 5.1, 95% CI 1.47-17.6, P   =  0.01) remained significant.

CONCLUSION

Dysphagia is common immediately after ACDF, but rates of prolonged dysphagia are similar to preoperative baseline rates. We identified dysphagia rates over time and several patient factors associated with development of short- and long-term postoperative dysphagia.Level of Evidence: 3.

Workers' Compensation Status in Association with a High NDI Score Negatively Impacts Post-Operative Dysphagia and Dysphonia Following Anterior Cervical Fusion

BACKGROUND

Anterior cervical discectomy and fusion (ACDF) is a safe and effective procedure but has approach-related complications like postoperative dysphagia and dysphonia (PDD). Patient-reported outcome measures including the Hospital for Special Surgery Dysphagia and Dysphonia Inventory (HSS-DDI) have been used for the assessment of PDD. Various factors have been described that affect ACDF outcomes, and our aim was to investigate the effect of workers' compensation (WC) status.

METHODS

We included patients who underwent ACDF from 2015 to 2018 stratified according to insurance status: WC/non-WC. PDDs were assessed using the HSS-DDI score. We conducted logistic regression analyses. Statistical significance was set at P < 0.05.

RESULTS

We included 287 patients, 44 (15.33%) WC and 243 (84.67%) non-WC. A statistical comparison revealed a clinically relevant difference in the HSS-DDI total score and both subdomains (P = 0.015; dysphagia P = 0.021; dysphonia P = 0.002). Additional logistic regression analysis adjusting for preoperative Neck Disability Index scores resulted in no clinically relevant differences in the HSS-DDI total score and both subdomains (total score P = 0.420; dysphagia P = 0.531; dysphonia 0.315).

CONCLUSIONS

WC status was associated with a worse HSS-DDI score but could not be shown to be an independent risk factor for PDD. The preoperative NDI score was a strong predictor for PDD with a clinically relevant difference in the HSS DDI score (P < 0.0001). Surgeon awareness of risk factors for PDD such as WC status, even if it could not be shown as independent, is important as it may influence surgical decision making and managing patient expectations.

Risk factors for postoperative dysphagia and dysphonia following anterior cervical spine surgery: a comprehensive study utilizing the hospital for special surgery dysphagia and dysphonia inventory (HSS-DDI)

BACKGROUND CONTEXT

Postoperative dysphagia and dysphonia (PDD) are prevalent complications after anterior cervical discectomy and fusion (ACDF). Identification of risk factors for these complications is necessary for effective prevention. Recently, patient reported outcome measures (PROM) have been used to determine PDD after ACDF. The Hospital for Special Surgery Dysphagia and Dysphonia Inventory (HSS-DDI) is a validated PROM that specifically assesses dysphagia and dysphonia after anterior cervical spine surgery.

PURPOSE

To identify the perioperative risk factors for PDD utilizing the HSS-DDI.

STUDY DESIGN/SETTING

Observational study of prospectively collected data at a single academic institution.

PATIENT SAMPLE

Patients undergoing anterior cervical discectomy and fusion from 2015 to 2019 who enrolled in the prospective data collection.

OUTCOME MEASURE

The HSS-DDI administered 4 weeks, 8 weeks, and 4-6 months after surgery.

METHODS

As potential risk factors, the data on demographic factors, analgesic medications, history of psychiatric illness, preoperative sagittal alignment, surgical factors, preoperative diagnoses, and preoperative Neck Disability Index (NDI) scores were collected. Bivariate and multivariable regression analyses utilizing the Tobit model were conducted.

RESULTS

291 patients were included in the final analysis. The median HSS-DDI at 4-weeks, 8 weeks, and 4-6 months postoperatively, were 80.7, 92.7, and 98.4, respectively. Multivariable analysis demonstrated that current smoking, previous cervical spine surgery, preoperative C2-7 angle, upper level surgery, multilevel surgery, opioid use, and a high preoperative NDI score, were independent contributing factors to a low HSS-DDI score at 4-weeks follow-up. Intraoperative topical steroid use was an independent protective factor for a low HSS-DDI score. Opioid use and high NDI score remained independent factors at 4-6 months. Sub-domain analysis demonstrated that prior cervical surgery, preoperative C2-7 angle, multilevel surgery, and intraoperative topical steroid use were significant for dysphagia only. Current smoking was significant for dysphonia only.

CONCLUSIONS

Our results showed that preoperative opioid use and a high preoperative NDI score are novel independent risk factors for postoperative dysphagia and dysphonia in addition to other known factors.

Comparison of Bazaz scale, Dysphagia Short Questionnaire, and Hospital for Special Surgery-Dysphagia and Dysphonia Inventory for Assessing Dysphagia Symptoms After Anterior Cervical Spine Surgery in Chinese Population

Dysphagia is one of the most common complaints after anterior cervical spine surgery. The Bazaz scale, the Dysphagia Short Questionnaire (DSQ), and the Hospital for Special Surgery-Dysphagia and Dysphonia Inventory (HSS-DDI) were patient-reported outcome measures assessing the patients' perceptions of their swallowing functions after surgery. This prospective diagnostic test study aimed to compare these surveys' psychometric properties in the Chinese population. We evaluated 150 consecutive patients after anterior cervical spine surgery with the Bazaz scale, DSQ, HSS-DDI, and M.D. Anderson Dysphagia Inventory (MDADI). The reliability and validity of the Bazaz scale, DSQ, and HSS-DDI were compared. Receiver operating characteristic (ROC) curves of the DSQ, Bazaz scale, and HSS-DDI were constructed using the MDADI as a reference criterion. Their areas under the curve (AUCs) were further analyzed. In total, 132 participants completed all of the surveys. The results showed that all surveys were significantly correlated with each other. The HSS-DDI and HSS-Dysphagia subscale showed near-perfect reliability (Cronbach α = 0.969 and 0.957, respectively). ROC curves showed both HSS-DDI and HSS-Dysphagia subscale had greater accuracy (AUCs > 0.9) in detecting mild dysphagia and moderate/severe dysphagia. The HSS-Dysphagia subscale achieved higher accuracy in assessing the dysphagia symptoms after anterior cervical spine surgery. The Bazaz scale was considered less accurate than other scales. Our results provided guidance for selecting the appropriate measuring tool during clinical and research practices.

Minimum Clinically Important Differences of the Hospital for Special Surgery Dysphagia and Dysphonia Inventory and Other Dysphagia Measurements in Patients Undergoing ACDF

BACKGROUND

Postoperative dysphagia is a common complication after anterior cervical surgery, and it can be measured using patient-reported outcome measures (PROMs). The Hospital for Special Surgery Dysphagia and Dysphonia Inventory (HSS-DDI) is a condition-specific PROM to evaluate dysphagia and dysphonia after anterior cervical discectomy and fusion (ACDF). The minimum clinically important difference (MCID) of the HSS-DDI has not, to our knowledge, been established. Other PROMs have been used to assess dysphagia (SWAL-QOL and MD Anderson Dysphagia Inventory [MDADI]) in ACDF. Currently, few studies have addressed the MCIDs of these PROMs.

QUESTIONS/PURPOSES

To determine (1) the minimum detectable changes (MDC) of the HSS-DDI, SWAL-QOL, and MDADI using a distribution-based approach, and (2) the MCID of the HSS-DDI, SWAL-QOL, and MDADI, using an anchor-based approach.

METHODS

We used a longitudinally maintained database that was originally established for the HSS-DDI development and validation study. In all, 323 patients who underwent elective ACDF were assessed for enrollment eligibility; 83% (268 of 323) met the inclusion criteria and completed the HSS-DDI Week 4 survey. We set six outcomes: distribution-based MDCs for the (1) HSS-DDI, (2) SWAL-QOL, (3) MDADI, in addition to anchor-based MCIDs for the (4) HSS-DDI, (5) SWAL-QOL, and (6) MDADI. The HSS-DDI consists of 31 questions and ranges 0 (worst) to 100 (normal). We used the focused SWAL-QOL, which consists of 14 selected items from the original SWAL-QOL and ranges from 0 (worst) to 100 (normal). The MDADI is a 20-item survey and ranges from 20 (worst) to 100 (normal). A distribution-based approach is used to calculate values defined as the smallest difference above the measurement error. An anchor-based approach is used to determine the MCIDs based on an external scale, called an anchor, which indicates the minimal symptom change that is considered clinically important. All 268 patients were used for the distribution-based (0.5 SD) HSS-DDI MDC analysis. The first 16% (44 of 268) of patients completed retesting of the HSS-DDI via a telephone interview and were used for another distribution-based (standard error of measurement: SEM) MDC analysis. The number of patients for the test-retest group was determined based on the previously reported minimum required sample size of reliability studies. The first 63% (169 of 268, SWAL-QOL and 168 of 268, MDADI) of patients completed two other surveys for the external validation of the HSS-DDI, and were used for the SWAL-QOL and MDADI 0.5 SD analyses. Among the patients, 86% (230 of 268) completed the Week 8 HSS-DDI survey that was used for the anchor-based HSS-DDI MCID analysis, and 56% (SWAL-QOL, 150 of 268 and MDADI, 151 of 268) of patients completed the Week 8 surveys that were used for the SWAL-QOL and MDADI MCID analyses. Subjective improvement grades from the previous assessment were used as the anchor. The MCIDs were calculated as the mean score changes among those who reported little better or greater in the improvement assessment and receiver operating characteristic (ROC) curve analyses. We adopted the higher value of these two as the MCID for each PROM.

RESULTS

The distribution-based MDCs for the HSS-DDI total score, SWAL-QOL, and MDADI were 11 of 100, 9 of 100, and 8 of 80 points, respectively, using the 0.5 SD method. Using the SEM-based method, the MDC for the HSS-DDI total score was 9 of 100 points. Regarding the anchor-based MCIDs, the values calculated with the mean score change method were consistently higher than those of ROC analysis and were adopted as the MCIDs. The MCIDs were 10 for the total HSS-DDI total score, 8 for the SWAL-QOL, and 6 for the MDADI.

CONCLUSIONS

Improvements of less than 10 points for the HSS-DDI score, 9 points for the SWAL-QOL, and 6 points for the MDADI are unlikely to be perceived by patients to be clinically important. Future studies on dysphagia after anterior cervical surgery should report between-group differences in light of this, rather than focusing on p values and statistical significance.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Hyoid position as a novel predictive marker for postoperative dysphagia and dysphonia after anterior cervical discectomy and fusion

PURPOSE

The purpose of this study is to investigate the predictive value of the hyoid horizontal positional change on the severity of dysphagia and dysphonia (PDD) after anterior cervical discectomy and fusion (ACDF) comparing pre-vertebral soft-tissue thickness (PVST).

METHODS

This is a retrospective observational study with prospectively collected data at a single academic institution. ACDF patients between 2015 to 2018 who had complete self-reported PDD surveys and pre- and postoperative lateral cervical radiographs were included in the analysis. PDD was assessed utilizing the Hospital for Special Surgery Dysphagia and Dysphonia Inventory (HSS-DDI). The hyoid-vertebral distance (HVD) and PVST (the averages of C2 to C7 levels (PVSTC2-7) and all operating levels (PVSTOP)) were assessed preoperatively and upon discharge. The associations among postoperative changes of HVD, PVSTs, and the 4-week HSS-DDI score were evaluated.

RESULTS

Of the 268 patients with a HSS-DDI score assessment, 209 patients had complete data. In univariate analyses, HVD and PVSTC2-7 changes demonstrated significant correlations with HSS-DDI, whereas PVSTOP showed no significant association. After adjusting with sex and operating level, the changes in HVD (p = 0.019) and PVSTC2-7 (p = 0.009) showed significant associations with the HSS-DDI score and PVSTOP showed no significant association. PVSTC2-7 could not be evaluated in 12% of patients due to measurement difficulties of PVST at lower levels.

CONCLUSION

We introduce a novel potential predictive marker for PDD after ACDF. Our results suggest that HVD can be utilized for the risk assessment of PDD, especially in PVST unmeasurable cases, which accounts for over 10% of ACDF patients.