Social Support and Self-Acceptance in Patients With Diabetic Retinopathy: The Mediating Role of Psychological Capital in a Cross-Sectional Study

Introduction

According to the World Health Organization, the global prevalence of diabetes is increasing rapidly, with China experiencing particularly dramatic growth from 20.8 million cases in 2000 to a projected 42.3 million by 2030 [1]. Diabetic retinopathy (DR), a major microvascular complication of diabetes, affects approximately 35% of patients with diabetes and remains a leading cause of vision impairment and blindness worldwide [2,3]. Beyond physical health impacts, DR significantly affects patients’ psychological wellbeing, with studies documenting elevated rates of depression and anxiety and reduced quality of life among affected individuals [4,5].

Self-acceptance, defined as positive attitudes toward oneself and one’s attributes, is a vital component of psychological wellbeing that influences social adaptability and disease outcomes [6,7]. Research has demonstrated that patients with chronic diseases who exhibit low self-acceptance experience poorer treatment adherence, reduced quality of life, and increased psychological distress [8,9]. In diabetic populations specifically, self-acceptance has been associated with better glycemic control and enhanced coping strategies [10]. However, self-acceptance levels among patients with DR remain underexplored, particularly regarding factors that may enhance or diminish this psychological resource.

Social support, encompassing the resources and assistance individuals receive through social relationships, has been consistently linked to positive health outcomes in populations with chronic disease [11,12]. International studies have documented the protective effects of social support across diverse cultural contexts. For instance, research in Haiti demonstrated associations between perceived social support and blood pressure control [13], while studies in Malaysia highlighted the critical role of social support in the wellbeing of older adult populations [14]. In gestational diabetes, social support has been associated with improved self-management behaviors [15]. Despite these documented associations, the mechanisms through which social support relates to psychological outcomes such as self-acceptance remain incompletely understood.

Psychological capital, consisting of 4 dimensions – self-efficacy, resilience, hope, and optimism – is a modifiable positive psychological state that develops throughout an individual’s growth [16]. This construct has gained attention for its potential role in explaining relationships between environmental factors and psychological outcomes. Studies in undergraduate populations have suggested associations between social support and self-acceptance through self-esteem pathways [17]. Research in Muslim communities has explored relationships among social support, spirituality, and happiness, with self-acceptance as a potential mediator [18]. A recent study in patients with multiple chronic conditions reported that perceived stress and psychological capital interacted to influence health literacy, underscoring the relevance of psychological capital in populations with chronic disease [19]. However, the specific role of psychological capital in mediating the relationship between social support and self-acceptance has not been examined in DR patient populations.

While previous research has confirmed positive associations among social support, psychological capital, and self-acceptance in various populations, the underlying mechanisms linking these variables in patients with DR remain unclear. Understanding these relationships is particularly important given the unique challenges faced by patients with DR, including vision-related functional limitations and the progressive nature of the disease. The conservation of resources theory suggests that individuals seek to acquire and maintain resources, and that resource loss can trigger psychological distress [20]. Social support may serve as an external resource that helps preserve or enhance internal psychological resources, such as psychological capital, which in turn may be associated with self-acceptance. However, this theoretical framework has not been empirically tested in DR populations.

Using structural equation modeling in this study, we aimed to examine the relationships among social support, psychological capital, and self-acceptance in hospitalized patients with DR. Based on the existing literature and theoretical framework, we formulated 4 specific hypotheses: (H1) social support is positively associated with self-acceptance in DR patients; (H2) social support is positively associated with psychological capital in DR patients; (H3) psychological capital is positively associated with self-acceptance in DR patients; and (H4) psychological capital mediates the relationship between social support and self-acceptance in patients with DR. By elucidating these relationships, this study seeks to provide empirical evidence that may inform the development of psychological interventions for patients with DR; however, the cross-sectional design precludes causal inferences.

Material and Methods

STUDY DESIGN:

We used a descriptive cross-sectional study design with path analysis and structural equation modeling to examine associations among study variables. This design was chosen to explore relationships among variables at a single time point, acknowledging that causal inferences cannot be established (Figure 1).

PARTICIPANTS:

This study used convenience sampling to recruit patients with DR from the ophthalmology ward of a grade A tertiary hospital in Wuxi, China, between June 2024 and February 2025. Convenience sampling was selected due to practical constraints and the specific patient population requirements. The recruitment setting specifically targeted hospitalized patients undergoing active ophthalmological intervention, and, thus, findings should be interpreted within this clinical context and may not be generalized to outpatient or community-based DR populations. The inclusion criteria were as follows: (1) diagnosis with DR according to the 2014 guidelines of the Chinese Ophthalmological Society [21]; (2) age 18 years or older; (3) hospital stay of at least 3 days; (4) able to communicate in Mandarin Chinese; and (5) willingness to participate and provide informed consent. The exclusion criteria were as follows: (1) severe cognitive impairment or psychiatric disorders; (2) other serious ocular diseases not related to diabetes; (3) acute complications of diabetes requiring intensive care; and (4) inability to complete questionnaires due to severe vision impairment (patients with severe vision loss received assistance from trained researchers who read questions aloud).

The study enrolled patients across all DR stages, classified according to the International Clinical Diabetic Retinopathy Disease Severity Scale [22], as follows: mild nonproliferative DR (NPDR), moderate NPDR, severe NPDR, and proliferative DR (PDR). The DR stage used in analyses was derived from fundus fluorescein angiography (FFA) results, dichotomized as PDR vs NPDR, consistent with the FFA-based classification recorded in Table 1. Among the 307 patients, 17 (5.5%) had NPDR (including mild, moderate, and severe stages), while 290 (94.5%) had PDR. Macular edema status was assessed using optical coherence tomography (OCT), with 211 patients (68.7%) presenting with diabetic macular edema; 76 patients (24.8%) having no macular edema, and 20 patients (6.5%) not undergoing OCT examination. The 20 patients without OCT data were excluded from subgroup analyses involving diabetic macular edema status but were retained in all other analyses. Best-corrected visual acuity (BCVA) was measured using standard Snellen charts and converted to logMAR values for analysis. Mean BCVA was 0.64±0.42 logMAR in the better-seeing eye and 1.12±0.58 logMAR in the worse-seeing eye.

Regarding employment status, this study adopted a 2-category classification reflecting the primary social role distinction relevant to this population: (1) retired and currently not working (n=180, 58.6%) and (2) retired but re-employed or still employed (n=127, 41.4%). In contemporary China, official retirement age does not necessarily correspond to economic inactivity; many individuals continue part-time or flexible work after formal retirement. This simplified categorization was used because it directly captured the employment-related social engagement dimension most relevant to social support and psychological capital analyses. The detailed 4-category classification initially described during data collection was collapsed into this 2-category variable for analytic purposes and consistency with Table 2.

SAMPLE SIZE DETERMINATION:

Sample size was calculated using G*Power 3.1 software with the parameters α=0.05, statistical power=0.80, medium effect size f²=0.15, and 2 predictors in the regression model. This yielded a minimum required sample of 92 patients. To account for potential incomplete responses and enhance statistical power for planned subgroup analyses, we recruited 320 patients. After excluding 13 questionnaires with missing data exceeding 20%, 307 valid responses were analyzed, providing adequate statistical power (achieved power=0.98) for the main analyses and subgroup comparisons.

DEMOGRAPHIC AND CLINICAL CHARACTERISTICS:

A self-designed questionnaire collected data on age, sex, education level, marital status, employment status, monthly income, religious beliefs, diabetes duration, glycated hemoglobin (HbA1c), DR stage (derived from FFA), presence of diabetic macular edema (derived from OCT), and visual acuity in both eyes.

SCORE INTERPRETATION AND NORMATIVE REFERENCES: For the PPCQ-DR, the theoretical midpoint is 54 (representing a neutral response of 3 on each of the 18 items); scores below this value indicate below-average psychological capital. For the SAQ, the theoretical midpoint is 40 (representing a neutral response of 2.5 on each of the 16 items); scores below 40 indicate below-average self-acceptance. Normative references for the Chinese general adult population have reported mean SAQ scores of 42.6±8.9 and mean SSRS scores of 34.5±5.6 [23,24]. These normative samples consisted of community-dwelling Chinese adults with comparable age distributions, providing a meaningful benchmark for interpreting scores in the present clinical sample.

POSITIVE PSYCHOLOGICAL CAPITAL QUESTIONNAIRE FOR DIABETIC RETINOPATHY: Psychological capital was measured using the PPCQ-DR developed by Zhongfei et al [25], which includes 18 items across 4 dimensions: self-efficacy (6 items), resilience (6 items), hope (3 items), and optimism (3 items). Items are rated on a 5-point Likert scale (1=strongly disagree to 5=strongly agree), with total scores ranging from 18 to 90. Higher scores indicate greater psychological capital. Confirmatory factor analysis in this sample confirmed the 4-factor structure with acceptable fit indices: chi-square/degrees of freedom ratio (χ2/df)=2.312, comparative fit index (CFI)=0.942, Tucker-Lewis index (TLI)=0.931, root mean square error of approximation (RMSEA)=0.065, and standardized root mean square residual (SRMR)=0.048. The scale demonstrated good reliability in this study (Cronbach α=0.892 for total scale; dimension α ranged from 0.846 to 0.878).

SOCIAL SUPPORT RATING SCALE: Social support was assessed using the SSRS developed by Xiao [23], consisting of 10 items across 3 dimensions: objective support (3 items), subjective support (4 items), and support utilization (3 items). Total scores range from 10 to 50, with higher scores reflecting greater social support. Confirmatory factor analysis results supported the 3-factor structure: χ2/df=2.187, CFI=0.951, TLI=0.938, RMSEA=0.062, and SRMR=0.044. The scale showed satisfactory internal consistency in this sample (Cronbach α=0.825).

SELF-ACCEPTANCE QUESTIONNAIRE: Self-acceptance was measured using the SAQ developed by Wenfeng et al [24], containing 16 items across 2 dimensions: self-acceptance factor (8 items) and self-evaluation factor (8 items). Items are rated on a 4-point scale (1=very inconsistent to 4=very consistent), with total scores ranging from 16 to 64. Higher scores indicate greater self-acceptance. Confirmatory factor analysis confirmed the 2-factor structure: χ2/df=2.456, CFI=0.938, TLI=0.925, RMSEA=0.069, and SRMR=0.051. The scale demonstrated good reliability (Cronbach α=0.884).

MODEL STRUCTURE SPECIFICATION:

In the structural equation model, the total scale scores of the SSRS, PPCQ-DR, and SAQ were used as observed variables rather than item-level scores. This approach was adopted because (1) the measurement models for each instrument were validated through confirmatory factor analysis as described above, (2) using total scores reduced model complexity while maintaining theoretical coherence, and (3) the sample size of 307 was adequate for a path model with 3 observed variables but may have been insufficient for a full latent variable model with multiple indicators per construct. The path model therefore tested the hypothesized mediation among social support (total SSRS score), psychological capital (total PPCQ-DR score), and self-acceptance (total SAQ score).

QUESTIONNAIRE ADMINISTRATION PROCEDURES:

All questionnaires were interviewer-administered by 4 trained research assistants. Prior to data collection, all assistants completed a standardized 2-day training program covering instrument content, standardized reading scripts, neutral probing techniques, and ethical considerations. Standardized reading scripts were developed for each questionnaire item to ensure consistent delivery across interviewers. To minimize interviewer bias, assistants were instructed to read items verbatim from the script without providing interpretation, examples, or emotional cues. Inter-rater consistency was assessed during the training phase using a pilot sample of 20 patients (not included in the final sample), yielding intraclass correlation coefficients (ICCs) exceeding 0.90 for all 3 instruments (PPCQ-DR ICC=0.94; SSRS ICC=0.92; SAQ ICC=0.93). For patients with severe visual impairment, the same standardized scripts and procedures were used; the only difference was that the research assistant also recorded responses verbatim as indicated by the patient.

ETHICAL CONSIDERATIONS:

This study received approval from the Ethics Committee of Jiangnan University (approval number: JNU20221201IRB26). After obtaining institutional permission, eligible patients were informed about the study purpose, procedures, confidentiality measures, and their right to withdraw. Written informed consent was obtained from all patients prior to data collection.

DATA COLLECTION PROCEDURES:

Trained research assistants identified eligible patients based on medical records and physician referrals. After explaining the study purpose and obtaining consent, patients completed questionnaires in a quiet setting. Questionnaires were administered using the standardized interviewer-administered protocol described above. The researcher remained available to clarify questions without influencing responses. Questionnaire completion required approximately 20 to 25 minutes. All data were anonymous and assigned unique identification codes. Of 320 distributed questionnaires, 307 valid responses were collected (response rate: 95.9%). The 13 excluded questionnaires had more than 20% missing data.

STATISTICAL ANALYSIS:

Data were analyzed using IBM SPSS version 23.0 and AMOS 24.0. Descriptive statistics (means, standard deviations, frequencies, percentages) summarize the patient characteristics and main study variables. Data normality was assessed using Kolmogorov-Smirnov tests. Independent samples t tests and one-way ANOVA examined differences in continuous variables across demographic groups, while chi-square tests examined categorical variables. Effect sizes were calculated (Cohen’s d for t tests, η² for ANOVA).

Pearson correlation coefficients examined bivariate associations among social support, psychological capital, self-acceptance, and their dimensions; 95% CIs for correlation coefficients were computed using Fisher’s z-transformation. Structural equation modeling with maximum likelihood estimation tested the hypothesized mediation model. Total scale scores were used as observed variables in the path model (see Model Structure Specification above). Model fit was evaluated using multiple indices: χ²/df <3, CFI >0.90, TLI >0.90, RMSEA <0.08, and SRMR <0.08. Bootstrap analysis with 5000 resamples tested indirect effects, with 95% bias-corrected CIs that exclude zero indicating significant mediation.

Planned subgroup analyses examined the potential moderating effects of the following: (1) DR stage (NPDR vs PDR, based on FFA classification); (2) presence of diabetic macular edema (yes vs no; 20 patients without OCT data were excluded from this subgroup); (3) visual acuity category based on better-seeing eye (<0.5 logMAR vs ≥0.5 logMAR); (4) age group (≤65 years vs >65 years); (5) sex (male vs female); and (6) diabetes duration (<10 years vs ≥10 years). Multi-group structural equation modeling tested whether path coefficients differed significantly across subgroups. A predefined significance threshold of P<0.01 was adopted for main analyses to control Type I error, given multiple comparisons; this threshold is applied consistently throughout the manuscript and all tables. All reported P values are 2-tailed. Additionally, a sensitivity analysis was conducted by re-running the primary mediation model excluding the 17 patients in the NPDR subgroup to assess the stability of results in the PDR-only subgroup.

Results

PATIENT CHARACTERISTICS:

A total of 307 patients with DR were included in this study. Table 2 presents the demographic characteristics. The sample included 161 men (52.4%) and 146 women (47.6%), with a mean age of 62.8±10.3 years. Most patients were married (n=242, 78.8%), had education of middle school level or below (n=223, 72.6%), and had monthly income below 5000 RMB (n=165, 53.7%). Regarding employment status, 180 patients (58.6%) were retired and not currently working, while 127 (41.4%) were retired but re-employed or still actively employed, as presented in Table 1.

Regarding disease-related characteristics (Table 1), diabetes duration ranged from 1 to over 20 years, with the largest proportion (n=128, 41.7%) having diabetes for 6 to 10 years. Most patients (n=270, 87.9%) had abnormal HbA1c levels (> 7.0%). Based on FFA results, 290 patients (94.5%) presented with PDR, while 17 (5.5%) had NPDR. Diabetic macular edema was present in 211 patients (68.7%) based on OCT; 76 (24.8%) had no diabetic macular edema, and 20 (6.5%) did not undergo OCT examination. Mean BCVA in the better-seeing eye was 0.64±0.42 logMAR (approximate Snellen equivalent 20/85), with 156 patients (50.8%) having BCVA ≥0.5 logMAR, indicating moderate to severe vision impairment. Mean BCVA in the worse-seeing eye was 1.12±0.58 logMAR (approximate Snellen equivalent 20/260).

PSYCHOLOGICAL CAPITAL, SOCIAL SUPPORT, AND SELF-ACCEPTANCE SCORES:

Table 3 presents the mean scores for the PPCQ-DR, SSRS, and SAQ. The mean psychological capital score was 62.60±14.58 (item mean: 3.48±0.81), indicating moderately low levels when compared with the theoretical midpoint of 54 (neutral response across all items) and published Chinese normative data. Among the 4 dimensions, self-efficacy scored highest (item mean: 3.69±0.86), followed by optimism (3.46±1.01), hope (3.37±1.10), and resilience (3.32±0.99).

The mean social support score was 27.40±6.99 (item mean: 2.74±0.70), lower than the reported norms for the Chinese general population (mean: 34.5, as reported by Xiao [23]) and other chronic disease populations. Objective support (10.12±2.81) and subjective support (10.05±2.79) subscales scored similarly, while support utilization scores were lower (7.24±2.49).

The mean self-acceptance score was 36.34±10.90 (item mean: 2.27±0.68), which falls below the theoretical midpoint of 40 (indicating neutral self-acceptance) and is lower than the normative values reported for Chinese adults (mean: 42.6, as reported by Wenfeng et al [24]) and other chronic disease populations. The term “moderately low” self-acceptance is used to characterize this sample based on its position between the scale floor and the theoretical midpoint and its distance below population norms. The self-acceptance factor (18.54±6.22) and self-evaluation factor (17.79±6.19) demonstrated similar mean scores.

CORRELATION ANALYSIS:

Pearson correlation analysis revealed significant positive associations among all study variables (Table 4). Social support was positively correlated with psychological capital (r=0.598, P=0.000, 95% CI: 0.521–0.665) and self-acceptance (r=0.526, P=0.000, 95% CI: 0.443–0.600). Psychological capital was positively correlated with self-acceptance (r=0.564, P=0.000, 95% CI: 0.484–0.634).

Dimensional correlation analysis (Table 5) showed that all dimensions of social support (objective support, subjective support, support utilization) were significantly positively correlated with all dimensions of psychological capital (self-efficacy, hope, optimism, resilience) and self-acceptance (self-acceptance factor, self-evaluation factor), with correlation coefficients ranging from r=0.300 to r=0.668 (all P<0.01). The 95% CIs for all dimensional correlations are presented in Table 5. The strongest correlations were observed between support utilization and objective support (r=0.668, 95% CI: 0.607–0.721), and between self-efficacy and resilience (r=0.619, 95% CI: 0.545–0.684).

STRUCTURAL EQUATION MODELING:

The hypothesized mediation model demonstrated excellent fit to the observed data: χ²=2.456, df=1, χ²/df=2.456, CFI=0.998, TLI=0.993, RMSEA=0.069 (90% CI: 0.028–0.125), and SRMR=0.012. All fit indices met recommended criteria, indicating the model adequately represented the relationships among variables.

Path analysis results (Table 6) revealed that social support had a significant positive association with psychological capital (β=0.720, SE=0.126, z=10.486, P=0.000), supporting H2. Social support also demonstrated a significant positive association with self-acceptance (β=0.332, SE=0.186, z=3.308, P=0.001), supporting H1. Psychological capital showed a significant positive association with self-acceptance (β=0.494, SE=0.105, z=4.742, P=0.001), supporting H3. Together, social support and psychological capital explained 53.8% of the variance in self-acceptance (R2=0.538).

MEDIATING EFFECT OF PSYCHOLOGICAL CAPITAL:

Bootstrap analysis with 5000 resamples tested the mediating role of psychological capital (Table 7). The total effect of social support on self-acceptance was 0.688 (95% bias-corrected CI: 0.559–0.798; 95% percentile CI: 0.566–0.803). The direct effect of social support on self-acceptance, after controlling for psychological capital, was 0.332 (95% bias-corrected CI: 0.070–0.553; 95% percentile CI: 0.079–0.561). The indirect effect through psychological capital was 0.355 (95% bias-corrected CI: 0.195–0.560; 95% percentile CI: 0.190–0.554). Since neither confidence interval included zero, the indirect effect was statistically significant, supporting H4.

The proportion of the total statistical association mediated was calculated as indirect effect/total effect=0.355/0.688=0.516, indicating that psychological capital accounted for 51.6% of the total statistical association between social support and self-acceptance. This partial mediation suggests that while social support has direct and indirect associations with self-acceptance, approximately half of its statistical association operates through its relationship with psychological capital. This proportion represents the share of the total statistical association rather than a causal mediation effect, given the cross-sectional design.

SUBGROUP ANALYSES:

Multi-group structural equation modeling examined whether the observed associations differed across key clinical and demographic subgroups. For DR stage, the path coefficient from social support to psychological capital was slightly higher in patients with PDR (β=0.735, P<0.01) than in patients with NPDR (β=0.682, P<0.01), although this difference was not statistically significant (Δχ²=2.18, P=0.14, Cohen’s d=0.12). Similarly, no significant differences emerged in path coefficients between patients with and without diabetic macular edema (Δχ²=3.42, P=0.18, Cohen’s d=0.15; 20 patients without OCT data were excluded from this comparison).

Visual acuity in the better-seeing eye demonstrated a moderating effect on the relationship between psychological capital and self-acceptance. Patients with better visual acuity (BCVA <0.5 logMAR) showed a stronger association between psychological capital and self-acceptance (β=0.563, P<0.01) compared with those with poorer visual acuity (β=0.421, P<0.01), with this difference approaching statistical significance (Δχ²=3.76, P=0.052, Cohen’s d=0.22). This suggests that the protective role of psychological capital for self-acceptance may be somewhat more pronounced among patients with relatively preserved vision.

Age-based subgroup analysis revealed no significant differences in path coefficients between patients aged 65 years and below and those over 65 years (Δχ²=1.89, P=0.17, Cohen’s d=0.11). Similarly, sex-based comparisons showed comparable path coefficients for male and female patients (Δχ²=2.34, P=0.13, Cohen’s d=0.14). Diabetes duration (<10 years vs ≥10 years) also did not significantly moderate the observed relationships (Δχ²=1.62, P=0.20, Cohen’s d=0.09).

Mean scores for psychological capital, social support, and self-acceptance did not differ significantly across DR stages or diabetic macular edema presence (all P>0.05). However, patients with better visual acuity in the better-seeing eye had significantly higher psychological capital (67.24±13.86 vs 58.12±14.52, t=5.48, P<0.01, d=0.63) and self-acceptance scores (39.82±10.24 vs 32.96±10.72, t=5.62, P<0.01, d=0.65) compared with those with poorer visual acuity.

SENSITIVITY ANALYSIS:

The primary mediation model was re-estimated after excluding the 17 patients with NPDR (n=290 PDR-only sample). Results remained highly consistent: social support predicted psychological capital (β=0.724, P<0.01), social support predicted self-acceptance (β=0.328, P<0.01), and psychological capital predicted self-acceptance (β=0.498, P<0.01). The indirect effect was 0.361 (95% CI: 0.201–0.568), confirming the stability of the mediation finding in the predominant PDR subgroup.

Discussion

This cross-sectional study examined associations among social support, psychological capital, and self-acceptance in hospitalized patients with DR, testing 4 predefined hypotheses through structural equation modeling. The findings provide empirical evidence supporting all 4 hypotheses, demonstrating that social support was positively associated with both self-acceptance (H1) and psychological capital (H2), psychological capital was positively associated with self-acceptance (H3), and psychological capital partially mediated the relationship between social support and self-acceptance (H4), accounting for 51.6% of the total statistical association. These findings contribute to understanding psychological mechanisms in this specific patient population, although the cross-sectional design precludes establishment of temporal sequence or causal relationships.

The mean psychological capital score (62.60±14.58) in this sample indicates moderately low levels compared with the theoretical midpoint (54 represents neutral responses) and published norms. Previous research in Chinese patients with diabetes and without retinopathy reported mean scores of 68.4±12.3 [19], suggesting patients with DR may experience additional psychological challenges beyond diabetes itself. International studies have documented similar patterns, with chronic disease complications associated with reduced psychological resources [26]. The relatively low psychological capital observed in our sample may reflect multiple factors, including disease progression, vision-related functional limitations, treatment burden, and concerns about future vision loss. Among the 4 dimensions, self-efficacy scored relatively higher, possibly reflecting perceived competence in specific disease management tasks, while resilience scored lowest, potentially reflecting the cumulative impact of progressive vision loss on adaptive capacity.

Social support scores (27.40±6.99) were substantially lower than those reported in Chinese diabetic patients (34.2±7.8) [27] and lower than general Chinese population norms (34.5±5.6) [23]. It should be noted that these normative samples were community-dwelling adults, and the comparison with our hospitalized clinical sample requires cautious interpretation given potential demographic and clinical differences. This finding aligns with international evidence suggesting that individuals with chronic complications may experience reduced social engagement. Research in Haiti documented associations between social support and health outcomes [13], while a Malaysian study emphasized social support’s role in older adult populations [14]. The lower social support in our sample may stem from multiple sources: activity restrictions due to vision impairment, psychological withdrawal related to disease burden, reduced ability to reciprocate support, or social stigma associated with visual impairment. Notably, support utilization scored lower than objective and subjective support, suggesting potential intervention targets focused on enhancing patients’ capacity to actively seek and utilize available support resources.

Self-acceptance scores (36.34±10.90) fell below the theoretical midpoint (40) and established normative values for Chinese adults (42.6±8.9) [24], consistent with characterizing this sample as exhibiting moderately low self-acceptance. This characterization is based on the score falling between the scale floor (16) and theoretical midpoint (40) and being substantially below empirical population norms; it is not intended as a diagnostic label but as a descriptive comparison. Previous research in patients with colorectal cancer reported mean scores of 41.2±9.6 [28], while research on mental health in patients with coronary heart disease reported comparably reduced wellbeing [29], suggesting patients with DR may experience similar or slightly lower self-acceptance than patients with other chronic disease populations. The subgroup analysis revealed that patients with poorer visual acuity demonstrated significantly lower self-acceptance, highlighting the potential impact of vision loss on self-perception and psychological adjustment.

The positive association between social support and self-acceptance (H1) extends findings from previous research in other populations to patients with DR specifically. This association aligns with social cognitive theory, which posits that social relationships provide feedback, validation, and comparative information that shapes self-perceptions [30]. However, the cross-sectional nature of this association permits alternative interpretations: individuals with higher self-acceptance may more effectively elicit or perceive social support, or bidirectional relationships may exist. Longitudinal research is needed to establish temporal precedence and examine potential reciprocal effects.

The strong positive association between social support and psychological capital (H2) (β=0.720) represents a key finding. This association suggests that social resources may be linked to enhancement or maintenance of internal psychological resources, consistent with the conservation of resources theory [20]. Social support can provide encouragement, tangible assistance with disease management, and positive appraisal that relates to self-efficacy development. Supportive relationships can offer hope through shared experiences and emotional sustenance, while reducing isolation that could diminish optimism. Resilience development may be fostered through problem-solving assistance and practical guidance from support networks. However, the cross-sectional design of our study prevents determination of whether social support precedes psychological capital development or whether individuals with greater psychological capital more effectively access social support. Notably, recent structural equation modeling–based research in chronic disease populations, such as the study by Zou and Liu [19] examining perceived stress and psychological capital in patients with multiple chronic conditions, has similarly reported strong positive associations between psychosocial resources and internal psychological capital, lending support to our findings.

The positive association between psychological capital and self-acceptance (H3) (β=0.494) suggests that individuals with greater psychological resources may experience more positive self-evaluation. Self-efficacy may relate to self-acceptance through perceived competence in disease management. Hope and optimism may buffer against negative self-evaluation by maintaining positive future expectations despite current challenges. Resilience may relate to self-acceptance through successful navigation of disease-related difficulties, providing evidence of personal capability. Alternative explanations warrant consideration, such as self-acceptance might enable development of psychological capital by reducing self-criticism that could impede resource building.

The partial mediation finding (H4), with psychological capital accounting for 51.6% of the total statistical association between social support and self-acceptance, represents the study’s primary contribution. This suggests 2 pathways through which social support may be associated with self-acceptance: a direct pathway (49.4% of total effect) and an indirect pathway operating through psychological capital (51.6% of total effect). The direct pathway may reflect social validation, belonging, and acceptance from others, directly influencing self-acceptance. The indirect pathway through psychological capital suggests that the association of social support with self-acceptance may partially operate by fostering psychological resources that subsequently relate to self-acceptance. It is important to note that the mediation proportion (51.6%) represents the proportion of the total statistical association explained by the indirect path, not a causal mediation effect; establishing causal mediation requires longitudinal or experimental designs. This mediation model provides a theoretical framework for understanding mechanisms, although alternative models, such as self-acceptance mediating social support–psychological capital relationships, cannot be ruled out given the cross-sectional design.

Regarding DR stage and the presence of diabetic macular edema, the absence of significant associations with psychological outcomes of psychological capital, social support, and self-acceptance requires careful interpretation. One possibility is that being hospitalized with DR, regardless of specific stage or complication, represents a threshold event that uniformly affects psychological wellbeing. Alternatively, this finding may reflect the study’s recruitment setting: hospitalized patients are a selected subgroup experiencing acute problems requiring intervention, potentially compressing variability in psychological responses. The finding that 94.5% of patients had proliferative stage disease limits our ability to detect stage-related differences, highlighting the need for studies sampling across the full DR severity spectrum. The sensitivity analysis excluding patients with NPDR confirmed that mediation results were stable in the PDR-only subgroup, suggesting that the small proportion of patients with NPDR did not meaningfully influence the primary findings. Future research should examine whether psychological trajectories differ across disease stages, using longitudinal designs.

The moderating effect of visual acuity on the psychological capital–self-acceptance relationship provides clinically relevant insights. The stronger association among patients with better vision suggests that the protective role of psychological capital for self-acceptance may be somewhat more pronounced when functional limitations are less severe. This could indicate that psychological resources are more readily deployed when not competing with severe vision-related challenges, or that maintaining self-acceptance becomes more difficult as vision deteriorates, regardless of psychological capital levels. This finding underscores the importance of vision preservation efforts and suggests that psychological interventions may need intensification as vision declines.

The absence of significant moderating effects for age, sex, and diabetes duration suggests the observed associations may generalize across these demographic and clinical characteristics within this population. However, this conclusion requires cautious interpretation given the relatively homogeneous sample (predominantly married, lower education, lower income) and limited statistical power for interaction effects.

From an international perspective, the patterns observed in this Chinese sample show both the similarities and differences compared with studies in other cultural contexts. The protective associations of social support documented here parallel findings in Western populations [15,17], suggesting these relationships may transcend specific cultural contexts. However, the absolute levels of social support and self-acceptance observed in this sample were lower than that of some international reports, potentially reflecting cultural differences in disclosure, help-seeking, or self-evaluation norms. Cross-cultural research is needed to determine whether the mechanisms linking these constructs operate similarly across diverse populations.

Clinical implications of these findings suggest potential value in multi-level interventions. Enhancing social support systems through family education, peer support groups, and community resource connections may relate to improved psychological capital and self-acceptance. Directly targeting psychological capital development through cognitive-behavioral interventions, mindfulness-based approaches, or positive psychology exercises may serve as an additional pathway to self-acceptance enhancement. However, the cross-sectional design prevents firm conclusions about intervention effectiveness, and randomized controlled trials are essential to establish whether manipulating these variables produces predicted outcomes.

Several limitations of this study warrant acknowledgment. First, the cross-sectional design precludes causal inference or determination of temporal relationships among variables. The associations documented here could reflect social support influencing self-acceptance through psychological capital, alternative causal directions, or bidirectional relationships. Longitudinal research with multiple measurement occasions is essential to establish temporal precedence and examine dynamic relationships over time. Second, convenience sampling and single-center recruitment limit generalizability. The sample was predominantly from patients with lower socioeconomic backgrounds with lower education levels, which may not represent all patients with DR. The hospital setting selected for patients requiring intervention potentially excluded those with stable disease or those managing complications in outpatient settings. Third, the predominance of proliferative stage disease (94.5%) limited examination of stage-related differences. Future research should ensure adequate representation across all DR stages to examine whether psychological trajectories differ across disease severity. Fourth, self-report measures may be influenced by response biases, social desirability, or mood states at assessment. Inclusion of objective indicators, such as treatment adherence behaviors and functional assessments, would strengthen future research. Fifth, the study assessed patients at a single time point without considering disease trajectory or recent changes in clinical status. Longitudinal assessment would capture how psychological variables change with disease progression. Sixth, the absence of validated measures for depression, anxiety, or overall psychological distress is a major limitation affecting internal validity. These unmeasured psychological confounders could influence the observed associations among social support, psychological capital, and self-acceptance, and their omission prevents determination of whether the mediation effect is independent of comorbid psychological conditions. Future research should include standardized depression and anxiety screening instruments, such as the Patient Health Questionnaire-9 and Generalized Anxiety Disorder-7 scale, as covariates. In addition, other potential confounders, including general health status, other diabetes complications, and treatment modalities, were not systematically measured and could influence the observed associations. Seventh, the mediating role of psychological capital, while statistically supported, is one of multiple possible models. Alternative models or additional mediators warrant exploration. Finally, the findings are specific to hospitalized patients with DR in a Chinese tertiary care setting, and generalizability to other cultural contexts, healthcare systems, or patient populations requires empirical verification.

Conclusions

In this cross-sectional study of hospitalized patients with DR from a single tertiary center in China, social support demonstrated positive associations with psychological capital and self-acceptance, with psychological capital partially mediating the social support–self-acceptance relationship. These findings suggest potential targets for psychological interventions, specifically among hospitalized patients with DR in tertiary care settings, although the cross-sectional design precludes causal conclusions. The associations observed here may inform hypothesis generation for future longitudinal and experimental research. Visual acuity appeared to moderate some relationships, highlighting the importance of vision preservation. The findings are specific to this hospitalized sample and may not generalize to outpatient or community-based populations, other disease stages, or different cultural contexts. Randomized controlled trials are needed to determine whether interventions targeting social support enhancement or psychological capital development lead to improvements in self-acceptance and other patient-reported outcomes in DR populations.