Stratification of the severity of Chronic Obstructive Sialadenitis based on its impact on Quality of Life

Abstract

Introduction

Chronic Obstructive Sialadenitis (COS) is a debilitating condition characterized by recurrent inflammation of the salivary glands due to excretory obstruction, significantly impacting patients’ quality of life (QoL). The COS Quality of Life Questionnaire (COSQ) has been validated to evaluate QoL in affected patients and to monitor changes post-treatment.

Materials and methods

This study included two patient groups with COS-affected glands. The first group of 342 patients completed the COSQ before minimally invasive surgery, while the second group of 215 patients completed both the COSQ and a Visual Analog Scale (VAS). Scores were analyzed and stratified into four severity categories: mild, moderate, severe, and very severe, based on COSQ outcomes.

Results

COSQ scores were distributed as follows: mild (12.87%), moderate (37.13%), severe (34.5%), and very severe (15.21%). A significant correlation was observed between COSQ and VAS scores, particularly in the moderate and severe categories. Stratification allowed for identification of patients with severe symptoms, aiding in tailored management.

Conclusion

The COSQ effectively assesses QoL in COS patients and aids in stratifying severity. This stratification can guide clinicians in developing personalized treatment strategies, monitoring disease progression, and evaluating treatment outcomes.

Resumen

Introducción

La sialoadenitis obstructiva crónica (SOC) es una condición debilitante caracterizada por la inflamación recurrente de las glándulas salivales debido a la obstrucción de su excreción, lo cual impacta significativamente la calidad de vida (CV) de los pacientes. El Cuestionario de Calidad de Vida en SOC (CSOC) ha sido validado para evaluar la CV en pacientes afectados y monitorear los cambios tras el tratamiento.

Materiales y métodos

Este estudio incluyó dos grupos de pacientes con glándulas afectadas por SOC. El primer grupo de 342 pacientes completó el CSOC antes de la cirugía mínimamente invasiva, mientras que el segundo grupo de 215 pacientes completó tanto el CSOC como una Escala Visual Analógica (EVA). Las puntuaciones fueron analizadas y estratificadas en cuatro categorías de severidad: leve, moderado, severo y muy severo, según los resultados del CSOC.

Resultados

Las puntuaciones del CSOC se distribuyeron de la siguiente manera: leve (12.87%), moderado (37.13%), severo (34.5%) y muy severo (15.21%). Se observó una correlación significativa entre las puntuaciones del CSOC y la EVA, particularmente en las categorías moderada y severa. La estratificación permitió identificar pacientes con síntomas graves, facilitando un manejo personalizado.

Conclusión

El CSOC evalúa eficazmente la CV en pacientes con SOC y ayuda a estratificar la severidad. Esta estratificación puede guiar a los clínicos en el desarrollo de estrategias de tratamiento personalizadas, el monitoreo de la progresión de la enfermedad y la evaluación de los resultados del tratamiento.

Introduction

Chronic Obstructive Sialadenitis (COS) is a debilitating condition characterized by recurrent inflammation of the salivary glands due to an obstruction in their excretion.¹ This leads to discomfort, pain, and swelling of the affected gland, usually triggered by salivary stimulation.²

The growing understanding of different obstructive causes³ and the parallel development of minimally invasive surgical techniques, either assisted or not by sialendoscopy, have highlighted the significant loss in quality of life (QoL) associated with COS (QoL-COS). Therefore, research aimed at developing tools to assess QoL-COS and track changes after a therapeutic intervention is essential.^2–7

Symptoms such as recurrent swelling, xerostomia, and lifestyle changes, like avoiding certain foods, significantly affect patients' QoL, contributing to physical discomfort, salivary dysfunction, and social and emotional stress.^6–8 The recently validated Chronic Obstructive Sialadenitis Questionnaire (COSQ) captures and quantifies the multidimensional spectrum of the disease.^6,7 It can also be used to determine COS severity and monitor changes after therapeutic intervention,⁹ such as sialendoscopy or minimally invasive approaches. The COSQ focuses on the affected gland and consists of 18 questions with five possible responses on a Likert-type scale, with a final score ranging from 0 (no impairment) to 72 (maximum impairment).^6,7

Our research delves into the impact of QoL-COS and seeks to stratify patients based on their responses and COSQ scores. This categorization facilitates the identification of high-risk patients who may benefit from early intervention and targeted management, as well as allows for comparing treatment outcomes and efficacy among different severity levels.

The importance of a severity scale based on COSQ scores is essential for clinicians, as it provides a standardized framework to determine disease progression, establish associations of obstructive causes and their impact on QoL-COS, monitor treatment responses,³ and improve overall disease management, addressing not only the physical manifestations but also the psychosocial impact of the disease.

The primary objective of this study was to stratify patients with COS into severity categories based on CSOQ scores. This approach will enable monitoring of disease progression and response to potential treatments using validated tools.

Materials and methods

Ethical approval and consent

The study was approved by the Ethics Committee of the Fundación Jiménez Díaz University Hospital (FJD-SAC-16-01). All participants were duly informed about the study details and provided their informed consent, authorizing the analysis of their clinical data. Only patients over 18 years of age, capable of reading and understanding the questionnaire, were included.

Study population

An observational, descriptive, and cross-sectional study was conducted based on data obtained from patients treated at the Otolaryngology and Cervicofacial Pathology Department of Fundación Jiménez Díaz University Hospital and General de Villalba University Hospital. The study period spanned from January 1, 2021, to December 31, 2022. During this time, quality-of-life questionnaires relevant to chronic obstructive sialadenitis (COS) were collected and analyzed.

The study was conducted with two distinct sample groups. The first group consisted of 342 COSQ questionnaires from patients with affected glands due to COS before undergoing minimally invasive surgery. The second group included 215 cases of patients with COS-affected salivary glands who had completed both the COSQ and a Visual Analog Scale (VAS) assessment.¹⁰

Statistical analysis

In the first group, a histogram was used to evaluate the COSQ score distribution, and a Shapiro-Wilk test was performed. Additionally, the 25th, 50th, and 75th percentiles, as well as the mean and standard deviation of the scores, were calculated. Based on the mean and standard deviation values obtained from the first group, COSQ scores were divided into four severity categories: mild, moderate, severe, and very severe. Despite the lack of normality confirmed by the Shapiro-Wilk test, the mean and standard deviation were used to establish COSQ severity categories, given the tendency toward a symmetrical distribution around the mean. Although the distribution was not perfectly symmetrical, most data clustered around the mean.

For the second group, a comparative analysis was performed between the categorized COSQ scores and the VAS scores. For the VAS, scores were grouped into three severity categories: mild,^1–3 moderate,^4–7 and severe,^8–10 as previously described in the literature.^2,5,6,10 Contingency tables were created for this analysis, which were evaluated using Fisher's exact test to determine the association between scales.

All statistical calculations were performed using RStudio® software.

Results

The 25th (COSQ 19), 50th (COSQ 29), and 75th (COSQ 40) percentiles of the results distribution, along with the mean ± standard deviation (COSQ 30.38 ± 14.12), were obtained. The normality test indicated that the sample did not follow a normal distribution.

We analyzed the distribution of the mean and variability (standard deviation) of values in our sample based on COSQ scores. The following patterns were observed (Fig. 1): 12.87% of the sample fell between 0 and 1 standard deviation below the mean, ranging from 2.12433 to 16.25278. Additionally, 37.13% of the sample ranged from 1 standard deviation below the mean to the mean itself, covering 16.25278 to 30.38123. Another 34.5% of the sample was between the mean and 1 standard deviation above it, covering the range from 30.38123 to 44.50. Finally, 15.21% of the sample scored more than 1 standard deviation above the mean, exceeding 44.50 points.

Figure 1.

Histogram showing the distribution of COSQ scores in patients prior to undergoing sialendoscopy.

The histogram in Fig. 1 shows the distribution of COSQ scores in patients prior to undergoing sialendoscopy. These results approximate a normal distribution, so we decided to establish the following classification to facilitate stratification, as the 25th, 50th, and 75th percentiles deviated from the clinical spectrum of the patients and proved impractical. Consequently, severity was classified as mild (COSQ 0–15), moderate (COSQ 16–30), severe (COSQ 31–45), and very severe (COSQ 45–72). Applying this stratification, the total number of cases categorized as mild was 44 (12.87%), moderate 127 (37.13%), severe 118 (34.5%), and very severe 52 (15.21%).

A notable correlation was observed between COSQ scores and the Visual Analog Scale (VAS), especially in the moderate and severe categories. As shown in Fig. 2, most patients classified in the moderate COSQ category had VAS scores between 4 and 7, while those in the severe category had scores above 7.

Figure 2.

Graphical representation of the contingency table between the proposed stratification and the VAS. Note that the highest correlation is observed in the moderate values, which encompass most of the sample.

Based on our results, the original COSQ would be adapted to include the severity levels (Fig. 3).

Figure 3.

COSQ with severity scales (modified from Santillán Coello, et al. 2023).

Modified from Santillán Coello, et al. 2023.

Discussion

Chronic Obstructive Sialadenitis (COS) represents a significant reduction in the quality of life of patients due to its impact on physical, emotional, and social well-being.^2,3,5–12

Having validated tools to measure QoL-COS is essential. Additionally, stratifying this impact is equally essential for obtaining a more practical measurement of change after applying specific therapeutic measures. Similar uses have been adapted in other pathologies, such as tinnitus, where quality of life is evaluated with the Tinnitus Handicap Inventory (THI),^13,14 and the results are stratified, facilitating clinical decisions.

Based on our previous experience, we believe that the COSQ is an ideal questionnaire for measuring QoL-COS. The questionnaire allows clinicians to systematically assess the impact of the disease and ensures a comprehensive patient evaluation. The reliability and specificity of the COSQ^6,7 make it especially useful for stratifying patients by disease severity. Additionally, using the COSQ to evaluate the results of transoral sialolith removal in submaxillary hilar lithiasis⁹ highlights its role in assessing postoperative recovery and QoL improvements, underscoring the importance of the COSQ in monitoring different treatment schemes.

In our study, we propose categorizing the impact of QoL-COS into four groups based on scores from our COSQ: mild (COSQ 0–15), moderate (COSQ 16–30), severe (COSQ 31–45), and very severe (COSQ 45–72).

The COSQ confirmed that most patients in our study scored between 16 and 45 points, with more than 70% of our population stratified into the moderate (16–30 points) and severe (31–45 points) categories. Consistent with the literature, a considerable number of patients experience moderate to severe symptoms. Previous studies have reported that 60–70%¹ of patients experience symptoms that significantly impact their QoL, similar findings to those described in studies using validated QoL surveys, such as SF-8,¹⁵ SF-36,⁵ and the Multidisciplinary Salivary Gland Society (MSGS) questionnaire.⁴

The COSQ values were comparable to those obtained in other quality of life questionnaires, such as the Visual Analog Scale (VAS). Thus, our patients were classified into four groups (mild, moderate, severe, and very severe) that showed a correlation with the scores obtained on the VAS (1–3, 4–7, and >7, respectively). This scale has already been previously used to evaluate the efficacy of sialendoscopy and the severity of COS symptoms.^4,10 Therefore, our study demonstrates the usefulness of the COSQ and the proposed stratification in assessing disease severity and serves as a guide for therapeutic decisions. Higher scores on the COSQ and patients classified in the severe and very severe categories exhibit a poorer baseline QoL. In other words, the COSQ is consolidated as a Patient-Reported Outcome Measure (PROM), aligning with other studies on chronic diseases,¹⁶ where the values obtained through these tools are considered objective measures of disease impact.

It is relevant to compare the CSOQ with other specific questionnaires designed to evaluate chronic obstructive sialadenitis (COS), such as the Chronic Obstructive Sialadenitis Symptoms Questionnaire (COSS).² The COSS focuses on the physical symptoms of COS, while the CSOQ also addresses emotional and social impacts, allowing for a more comprehensive assessment of the patient. Furthermore, with its 18 Likert-type questions, the CSOQ facilitates precise stratification into severity categories, making it particularly useful for longitudinal studies and therapeutic monitoring. However, it would be interesting to conduct future comparative studies to evaluate the correlation between both scales and their applicability in different clinical contexts.

It is important to recognize the limitations of our study. As is common in research on QoL in complex pathologies such as COS, the subjectivity of responses, which depend on patient-provided data, may introduce various biases.¹⁷ These include recall and response biases, as well as variability in responses based on individual tolerance. Cultural and interpretative differences may influence responses and complicate cross-cultural comparisons, making it essential to validate a questionnaire for a specific population.^6,7

The non-normal distribution of scores could have introduced biases in interpreting the results. Although we used a non-parametric stratification approach (median and percentiles), we believe that this method might not accurately reflect the population's reality. First, the sample comes from a specific referral center for treating salivary gland pathology and performing sialendoscopy, which generated a higher volume of patients with moderate symptoms. Second, there may be an underrepresentation of patients with very severe symptoms, as these individuals may end up with gland excision if treated at centers without specialization in minimally invasive salivary gland surgery. This situation could explain the scarcity of patients in the highest severity quartile.

Future research should explore the integration of COS severity stratification, based on COSQ scores, with other clinical parameters, such as imaging findings^18,19 or different causes of obstruction, to predict responses to various therapeutic approaches. This would help clinicians set expectations for outcomes and highlight the need to develop an abbreviated version of the COSQ that more accurately reflects the severity levels of this pathology.

Conclusion

Stratifying COS patients into severity groups (mild, moderate, severe, and very severe) enables the development of precise treatment strategies, appropriate disease progression monitoring, and response to treatment. By categorizing patients using a comprehensive and validated QoL questionnaire, such as the COSQ, we demonstrate the usefulness of this tool in analyzing the full impact of COS on patients’ QoL.

CRediT authorship contribution statement

All authors have made significant contributions to the idea and design of the work, acquisition, analysis and interpretation of the data.

Funding

None.