Structural equation modeling on symptom clusters and health related quality of life among advanced colorectal cancer patients receiving chemotherapy

Patients with advanced Colorectal cancer (CRC) undergoing chemotherapy may have a variety of concurrent symptoms associated with the cancer itself, chemotherapy, or both. Symptom experiences often occur with multiple symptoms at the same time causing advanced CRC patients to experience physical, psychological, and social impacts. Additionally, there are contextual variables such as social support and palliative care outcomes that are related to the symptom experiences that affect the Health related Quality of Life (HRQoL) of advanced CRC patients. Currently, little is known about symptom clusters and contextual variables influencing HRQoL among these patients. These is a need to understand the relationship between symptom clusters and contextual variables that affect HRQoL among advanced CRC patients. This study is a descriptive research divided into two phases. In Phase I, the research aimed to investigate symptom clusters in terms of both severity and distress. During Phase II, the objective was to test the causal relationship among symptom dimensions of severity and distress from Phase I, contextual variables on HRQoL among Thai patients with advanced CRC receiving chemotherapy. Based on inclusion criteria, three hundred and twenty (Phase I) and three hundred (Phase II) chemotherapy-treated patients with advanced CRC were selected from five hospitals in Bangkok, Thailand. For Phase I, data were gathered from August 2022 to January 2023 using a participants’ characteristics record form and the Memorial Symptom Assessment Scale (MSAS). The analysis of the data involved the application of descriptive Statistics and Exploratory Factor Analysis (EFA). In Phase II, the participants completed five questionnaires on demographics, the MSAS, the Multidimensional Scale of Perceived Social Support (MSPSS), the Palliative Care Outcome Scale (POS), and the Functional Assessment of Cancer Therapy-Colon (FACT-C) between March 2023 to July 2023. The data was analyzed using Descriptive Statistics and Structural Equation Modeling (SEM).In Phase, I the findings indicated that the top five most prevalent symptoms included numbness or tingling in hands or feet, lack of energy, changes in skin, lack of appetite, and “I don’t look like myself” reaction. Numbness or tingling in the hands or feet emerged as the most frequently occurring symptom in terms of severity, while difficulty in sleeping was identified as the most frequently reported distress symptom. Within the dimension of symptom severity, there were five symptom clusters, explaining a 38.474% variance in all symptoms. These clusters included emotion-related symptoms, gastrointestinal (GI) and fatigue-related symptoms, lack of appetite and difficulty sleeping-related symptoms, discomfort-related symptoms and image-related cutaneous symptoms. Additionally, in the symptom distress dimension, five symptom clusters were identified, explaining a 43.210% variance in all the symptoms. These clusters included emotion-related symptoms, lack of appetite and difficulty sleeping-related symptoms, discomfort-related symptoms, image-related cutaneous symptoms and GI and pain-related symptoms. In phase II, the findings showed symptom severity cluster dimension, symptom distress cluster dimension, social support, and palliative care outcomes predicting HRQoL at a rate of 78 %. Symptom severity cluster and symptom distress cluster dimensions demonstrated a significant negative direction to HRQoL. Meanwhile, the symptom severity cluster and symptom distress cluster dimensions reflected a positive indirect influence on HRQoL through palliative care outcomes. Palliative care outcomes have a significant negative direct influence on HRQoL. Social support has a positive direct on HRQoL and negative indirect influence on HRQoL through palliative care outcomes. This study highlights that symptom severity cluster and symptom distress cluster dimensions, social support, and palliative care outcomes are predictors of HRQoL among advanced CRC patients receiving chemotherapy. These predictors had direct and indirect effects on HRQoL. Understanding the relationship between symptom severity cluster and symptom distress cluster dimensions, social support, palliative care outcomes, and HRQoL may help medical professionals develop effective interventions for better symptom management with social support and palliative care outcomes for advanced CRC patients receiving chemotherapy to improve HRQoL.