Introduction

Colorectal cancer (CRC) is among the most prevalent malignancies worldwide, with an increasing incidence observed in both developed and developing countries. It currently ranks as the third most common cancer globally and remains a major contributor to cancer-related mortality (1). Whilst advances in diagnostic methods, surgical techniques, and multimodal therapies have significantly improved survival rates, (2) the increasing life expectancy of CRC survivors has shifted clinical focus from mere survival to the optimisation of quality of life (QoL) (3).

Surgical intervention remains the cornerstone of CRC management, with techniques ranging from anterior resection (AR) and low anterior resection (LAR) to abdominoperineal resection (APR). Although these procedures are effective for local tumour control, they often result in considerable functional impairments, including defecatory dysfunction, urinary and sexual complications, and the potential necessity for a permanent stoma (4-6). Up to 50% of long-term CRC survivors report chronic gastrointestinal symptoms that adversely impact their QoL (7-8). Furthermore, neoadjuvant chemoradiation-despite its role in local control-may exacerbate these complications, including bowel dysfunction, fatigue, and emotional distress (9).

The World Health Organization defines QoL as an individual’s perception of their position in life within the context of the culture and value systems in which they live, and in relation to their goals, expectations, standards, and concerns (10). Health-related QoL (HRQoL) has consequently become a critical endpoint in oncology research, as it serves as a comprehensive indicator of clinical effectiveness, psychosocial outcomes, and patient satisfaction (11). Whilst QoL assessments for cancer patients are now widely established, the psychological and emotional impact of CRC surgery on caregivers-particularly spouses-remains under-explored.

Spouses frequently serve as the primary source of support; therefore, the burden they endure can significantly affect their own long-term well-being. Existing literature demonstrates that caregiver distress is closely correlated with the functional limitations and emotional states of patients (12). For instance, Aylaz et al. (2021) demonstrated a strong positive correlation between patients’ disability scores and their spouses’ burden levels, as measured by the WHODAS-II and the Zarit Burden Interview (13).

Despite the global attention devoted to QoL in cancer survivors, research evaluating the reciprocal impact of CRC surgery on both patients and their spouses is rare within the Iranian context. Cultural norms, religious practices, and limited psychosocial resources may significantly influence both the perception of, and adaptation to, disease-related disability. Consequently, this study aims to assess the QoL of patients following colorectal surgery and to examine its association with caregiver burden among their spouses. By identifying the most affected domains and elucidating the interrelation between patient disability and caregiver stress, this research seeks to advocate for family-centred care and inform the development of targeted postoperative support strategies.

Materials and methods

Study Design and Setting

This descriptive, cross-sectional study was conducted in 2023 at two tertiary referral centres—Imam Khomeini Hospital and Shafa Hospital—in Sari, Iran, under the auspices of the Mazandaran University of Medical Sciences. The primary objective of this study was to evaluate the quality of life (QoL) in patients who had undergone colorectal cancer surgery and to examine the corresponding psychological burden experienced by their spousal caregivers.

Study Population and Sampling

The study population comprised patients who had undergone surgical treatment for colorectal adenocarcinoma within the previous ten years, were currently married, and resided with their spouse. A total of 99 patient–spouse dyads were recruited using a convenience sampling method during scheduled follow-up visits. The inclusion criteria for patients were: age ≥18 years, absence of concurrent major medical or psychiatric comorbidities, no chemotherapy administered within the preceding eight weeks, no recent hospitalisation (excluding elective stoma closure), and no evidence of tumour recurrence or metastatic disease at the time of recruitment. Patients were excluded if they had experienced major postoperative complications, such as anastomotic leakage, sepsis, or a history of intensive care unit (ICU) admission. Furthermore, any patient–spouse dyad in which either party was unwilling to participate or unable to complete the questionnaires was excluded from the study.

Data Collection Instruments

Data were collected using three validated instruments, alongside a structured demographic and clinical checklist.

WHO Disability Assessment Schedule II(WHODAS -II):

This 36-item instrument evaluates functional disability across six domains: cognition, mobility, self-care, interpersonal interactions, life activities, and social participation. Higher scores denote greater functional limitation. The Persian version has been previously validated and demonstrated high internal consistency (Cronbach’s alpha = 0.92) (14).

Short Form-36 Health Survey (SF-36):

This 36-item questionnaire assesses health-related quality of life (HRQoL) across eight domains: physical functioning, role limitations due to physical health, bodily pain, general health, vitality, social functioning, role limitations due to emotional problems, and mental health. Two summary component scores-the Physical Component Summary (PCS) and the Mental Component Summary (MCS)-are derived from these domains. The validated Persian version was utilised (15).

Zarit Burden Interview (ZBI):

This 22-item scale assesses the subjective burden experienced by caregivers, rated on a five-point Likert scale. It is a widely recognised tool for evaluating caregiver stress and has demonstrated excellent reliability within Iranian populations (16). In addition to these validated instruments, a demographic and clinical checklist was employed to record data regarding age, gender, educational attainment, occupation, and surgical history.

Surgical Classification

Patients were categorised into three groups based on the surgical approach, the extent of the colonic or rectal resection, and the anatomical level of the anastomosis relative to the anal verge:

Abdominoperineal Resection (APR):

This procedure involves the radical resection of the rectum and anal canal, resulting in a permanent end-colostomy. As the anal sphincter mechanism is not retained, patients experience significant alterations to bowel function, necessitating substantial lifestyle adjustments and ongoing stoma-related care.

Low Anterior Resection (LAR):

This procedure involves the resection of the lower rectum while preserving the anal sphincter. In LAR, the anastomosis is performed within 6 cm of the anal verge, facilitating bowel continuity and negating the requirement for a permanent stoma, which generally supports a more favourable postoperative quality
of life.

Anterior Resection (AR):

In this operation, the affected segment of the colon or upper rectum is resected, with the anastomosis situated at or above 7 cm from the anal verge. This category includes procedures such as sigmoid colectomy; these generally present different functional outcomes compared with LAR and APR, as they typically allow for more conventional bowel management (17).

This classification system enabled a comparative analysis of functional outcomes and associated caregiver burden relative to the specific surgical intervention performed.

Procedure

Eligible patients and their spouses were interviewed in private consultation rooms within the surgical wards. To ensure participant comfort and cultural sensitivity, each couple was interviewed by a same-gender researcher who had undergone rigorous training in the administration of the study instruments. Interviews were conducted in person and lasted between 30 and 45 minutes. Whilst the interviewers were not blinded to the surgical procedure, standardised protocols were strictly followed to minimise interviewer bias. Prior to participation, all individuals received comprehensive verbal and written information regarding the study objectives, and provided written informed consent.

Ethical Considerations

The study protocol received formal approval from the Research Ethics Committee of Imam Khomeini Hospital, Mazandaran University of Medical Sciences (Approval Code: IR.MAZUMS.IMAMHOSPITAL. REC.1403.067). All participants were provided with comprehensive information regarding the study’s objectives and procedures and subsequently provided written informed consent. Participants were explicitly advised of their right to withdraw from the study at any stage without consequence to their clinical care. To maintain confidentiality, all personal identifiers were removed, and data were anonymised prior to statistical analysis.

Statistical Analysis

Data were analyzed using SPSS version 20. Descriptive statistics including mean, standard deviation, and frequency distributions were used to summarize demographic and clinical characteristics. The Kolmogorov–Smirnov test was applied to assess the normality of continuous variables. Depending on distribution characteristics:

Pearson or Spearman correlation coefficients were calculated to assess associations between WHODAS-II scores and caregiver burden.

Independent t-tests or Mann-Whitney U tests were used for two-group comparisons.

One-way ANOVA or Kruskal–Wallis tests were used for comparisons across more than two groups.

Chi-square or Fisher’s exact tests were applied for categorical variables.

A p-value of less than 0.05 was considered statistically significant.

Results

A total of 99 patient–spouse dyads participated in the study. The mean age of the patients was 61.84 ± 12.10 years, with an approximately equal gender distribution (50.5% male). Regarding educational attainment, 50.5% of patients had completed a high school diploma or less, whilst 21.2% held post-secondary qualifications. A large proportion of the patient cohort were retired or unemployed. The mean age of the spouses was 51.14 ± 13.12 years, with 58.6% being female. Nearly half of the spouses (49.5%) had completed a high school education or less, and 43.4% held higher education degrees; the majority were homemakers or engaged in informal employment.

Regarding the surgical approach, 55.6% of patients had undergone anterior resection (AR), 30.3% low anterior resection (LAR), and 14.1% abdominoperineal resection (APR).

The mean total score on the WHO Disability Assessment Schedule (WHODAS-II) was 22.20 ± 16.86, indicating a moderate degree of functional impairment across the study population. Among the WHODAS-II domains, the most affected areas were ‘life activities’ (mean = 6.28 ± 6.01) and ‘participation in society’ (mean = 4.63 ± 4.08), followed by ‘mobility’ (mean = 4.10 ± 3.51). The lowest mean scores were observed in the ‘understanding/communication’ (1.81 ± 3.45) and ‘getting along with others’ (2.09 ± 2.77) domains (Table 1). The mean caregiver burden score, as assessed by the Zarit Burden Interview (ZBI), was 6.98 ± 8.97, reflecting a mild to moderate level of burden among the majority of spouses.

Statistical analysis revealed a significant positive correlation between patient limitations in social participation and caregiver burden (Spearman’s rho = 0.308, p = 0.002), indicating that greater patient difficulty in social engagement is associated with increased emotional and caregiving stress. A weaker but significant association was also identified between communication difficulties and caregiver burden (rho = 0.202, p = 0.045). No significant correlation was observed between the overall disability score and the level of burden reported by spouses (Table 2).

Comparative analysis across surgical subgroups revealed no statistically significant differences in the total WHODAS-II score or the caregiver burden score between patients who underwent AR, LAR, or APR (p > 0.05 for all comparisons). Although patients who underwent LAR exhibited slightly higher mean scores in the ‘mobility’ and ‘interpersonal functioning’ domains, these differences did not reach statistical significance. Similarly, subgroup analysis by gender revealed no significant differences in disability or caregiver burden scores, although female patients reported marginally lower scores in physical domains. Education level was not significantly associated with total disability or caregiver burden; however, patients with an educational attainment below a high school diploma presented with numerically higher total disability scores, suggesting a potential trend. Finally, patient age was significantly correlated with disability in the communication domain (rho = 0.229, p = 0.023), suggesting that older patients experienced greater impairment in cognitive and communicative functions. No significant correlation was found between age and overall disability or burden.