Osteoarthritis (OA) remains a major contributor to global disability and functional decline, particularly in the aging population (1). The condition is marked by progressive degeneration of the articular cartilage and structural compromise of the joint, leading to chronic pain and restricted movement (2). In 2019, the global burden of hip and knee OA was estimated to affect around 300 million individuals (2).

Total joint arthroplasty has emerged as the gold standard treatment for end-stage OA of the hip and knee, offering substantial improvements in pain relief and mobility (3,4). Globally, nearly 20 million total hip and knee replacements are performed annually, a figure projected to rise steadily due to increasing life expectancy and OA prevalence (1,3,5).

Despite the overall success of the procedure, around 1 in 5 patients remain dissatisfied postoperatively due to unresolved pain and limited functional recovery (3,6,7). This underscores the need to identify predictors of suboptimal surgical outcomes to enhance preoperative patient stratification and optimize postoperative results.

Socioeconomic status (SES) plays a crucial role in influencing health trajectories and treatment outcomes. Individuals from socioeconomically disadvantaged backgrounds often experience greater disease burden, delayed surgical intervention, and poorer perioperative health, leading to increased risks of postoperative complications, longer hospital stays, and higher readmission rates (6,8–11). Moreover, lower educational levels have also been linked with more severe symptom reporting and poorer health literacy (12).

Individuals with lower educational qualifications and reduced income levels have been observed to have an increased demand for joint replacement procedures (13). Additionally, factors such as race and ethnicity have been independently associated with less favorable surgical outcomes (9). Variations in healthcare accessibility and symptom perception across different countries (14,15).

In light of these factors, the current study was designed to explore the association between socioeconomic status and symptom burden both prior to and one year following total knee arthroplasty (TKA) or total hip arthroplasty (THA) in an Indian cohort. It was hypothesized that patients from lower SES backgrounds would exhibit more severe baseline symptoms, demonstrate less significant clinical improvement postoperatively, and may benefit differently from mindfulness-based rehabilitation support compared to their higher SES counterparts.

This observational cohort study was conducted at Government Medical College (GMC), Patiala, Punjab, India, to examine the relationship between socioeconomic status (SES) and patient-reported outcomes in individuals undergoing total knee arthroplasty (TKA) or total hip arthroplasty (THA). Clinical data and patient-reported outcome measures (PROMs) were collected from patients undergoing primary TKA or THA between September 2023 and August 2024 as part of routine pre- and postoperative care. Patients were eligible for inclusion if they were ≥45 years old, diagnosed with primary osteoarthritis, and underwent primary joint replacement during the study period. Patients were excluded if they had joint replacement due to trauma, implant failure/revision, inflammatory arthritis, or if PROM data was incomplete or missing. The final sample included 101 patients. Patient Characteristics Demographic and clinical parameters recorded included: • Age • Sex • Body Mass Index (BMI) • ASA (American Society of Anesthesiologists) physical status classification • Charnley classification • Smoking status • Alcohol consumption habits Socioeconomic Status SES was evaluated using a modified Kuppuswamy socioeconomic scale, based on: • Education level • Occupation of the head of household • Total monthly family income Patients were categorized into five SES groups (SES 1 = lowest; SES 5 = highest) based on combined scoring from the above domains. Area of residence was also factored in to adjust for urban versus rural access to healthcare. Patient-Reported Outcome Measures (PROMs) All PROMs were assessed both preoperatively and at one-year follow-up. The following validated instruments were used: • Oxford Knee Score (OKS) and Oxford Hip Score (OHS): Each consists of 12 items on a 5-point Likert scale. A Minimal Clinically Important Change (MIC) of 6.5 points for OKS and 7.5 for OHS was considered significant (18). • Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC): A 24-item tool divided into three subscales: pain, stiffness, and physical function. Each item was scored on a 5-point Likert scale. For TKA: MIC – Pain = 20.9, Stiffness = 12.5, Function = 16.2 For THA: MIC – Pain = 29.3, Stiffness = 25.9, Function = 26.5 (19,20) • Numeric Rating Scale (NRS) for pain during walking in the past 24 hours. The scale ranges from 0 (no pain) to 10 (worst pain). A change of ≥2 points was considered clinically relevant. • EuroQol 5-Dimension (EQ-5D): This instrument assessed health-related quality of life across five domains: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression, with three response levels. It also included a visual analogue scale (EQ-VAS) for overall self-rated health status (21). Statistical Analysis Continuous data were summarized as means ± standard deviation, and categorical variables as frequency and percentage. Separate analyses were conducted for TKA and THA groups, using the same statistical approach. The association between SES and PROMs (preoperative, postoperative, and change scores) was analyzed using linear mixed-effects regression models. Random intercept models were constructed to account for individual variation. The initial model included only SES and timepoint as fixed effects. Subsequent models were adjusted for age and sex, and further included potential confounders: • BMI • ASA classification • Charnley classification • Smoking status • Alcohol use Backward stepwise elimination was used to refine the final model, retaining variables that significantly affected outcomes.

Participant Characteristics

From September 2023 to August 2024, a total of 116 individuals underwent primary total knee or hip arthroplasty at GMC Patiala. Among them, 15 patients (12.9%) were excluded from the study: 7 declined to provide informed consent, 5 had incomplete patient-reported outcome measures (PROMs), and 3 met exclusion criteria (e.g., post-traumatic arthritis or revision surgery).

A total of 101 patients were included in the final analysis. Compared to the included cohort, excluded patients were slightly older (mean difference: 2.1 years), and more frequently had ASA grade III and Charnley Class C status.

PROM data completion rates were 76.2% preoperatively and 65.3% at one-year follow-up. Patients undergoing either TKA or THA demonstrated substantial improvements in PROMs at the one-year follow-up (Tables 2 & 3).

Of the 101 patients, 51 were enrolled in a structured MBI program (guided meditation, breathing exercises, and weekly group mindfulness sessions), while 50 patients received standard postoperative rehabilitation without MBIs.

Influence of Socioeconomic Status (SES)

Among TKA patients, unadjusted analysis indicated a significant relationship between lower SES and poorer Oxford Knee Scores (OKS) at baseline (Table 4). However, after adjusting for age, sex, BMI, ASA classification, Charnley classification, smoking, and alcohol use, this association became statistically non-significant, although covariates like BMI and ASA classification remained independent predictors of OKS.

This pattern was similarly seen for WOMAC scores and VAS pain levels in TKA patients.

Among THA patients, lower SES was consistently associated with worse Oxford Hip Scores (OHS), WOMAC scores, and VAS pain scores. These associations remained statistically significant even after adjusting for potential confounders.

Notably, no significant interaction was detected between SES and time, suggesting that although patients from lower SES groups started with worse scores, their degree of improvement over one year was comparable to that of higher SES groups.

Clinically Meaningful Improvements (MIC)

Overall, 89.1% of the cohort achieved an improvement in OKS or OHS that met or exceeded the Minimal Clinically Important Change (MIC) thresholds (Fig. 1).

• In TKA patients, the proportion of patients achieving MIC did not differ significantly between SES categories.
• In THA patients, fewer individuals from the lower SES group (SES2) achieved MIC in OHS compared to those in the highest SES group (SES5) (P = 0.02).
• For WOMAC subdomains (pain, stiffness, function), there were no SES-based differences in the proportion of patients reaching MIC in either group.

Randomization ensured balanced distribution across age, sex, BMI, SES category, and surgical procedure (TKA/THA) at baseline between both groups.

Patients who underwent MBI showed statistically significant improvements across all SF-36 domains. Particularly notable gains were observed in:

• Bodily Pain, indicating better pain control.
• Mental Health and MCS, reflecting enhanced psychological well-being.
• Physical Functioning and PCS, suggesting improved functional recovery.

These results highlight that mindfulness-based interventions contribute meaningfully not only to pain reduction and emotional well-being but also to physical performance and recovery after TKA or THA. The consistent statistical significance (P = 0.0001 across all parameters) suggests a robust association.

Furthermore, subgroup analysis indicated that patients from lower SES backgrounds in the MBI group also demonstrated greater improvements in mental health and social functioning domains, suggesting that MBI may help bridge disparities linked to socioeconomic barriers in recovery

Table 1. Patient Characteristics (N = 101)

Abbreviations: ASA, American Society of Anaesthesiologist physical status

classification system; OA, osteoarthritis; TKA, total knee arthroplasty; THA, total

hip arthroplasty.

a Reported as n (%) unless otherwise specified.

b Incomplete data accounts for percentages not leading up to 100%.

c Average SES score per quintile based on the standardized 0–1 SES scale.

Table 2. PROMs before and after joint arthroplasty (GMC Patiala, N = 101)

Table 3. EQ-5D-3L Over Time (TKA, GMC Patiala)

Table 4. Linear Mixed Models: SES and PROMs (GMC Patiala Study, N = 101)

This is one of the first Indian studies to examine the association between socioeconomic status (SES) and osteoarthritis symptom patterns before and one year after total joint arthroplasty (TKA and THA). The findings from this single-center cohort suggest that patients undergoing THA with lower SES reported more severe symptoms both pre- and postoperatively, and experienced less clinically meaningful improvement compared to higher SES groups (Fig. 1).

Fig 1

In both surgical groups, symptom severity was higher among patients from lower SES categories, but this trend was more pronounced in the THA subgroup. The reasons behind the differential SES impact between THA and TKA patients remain speculative. In our cohort, TKA recipients had a higher BMI, were more often male, and showed slightly better preoperative symptom control, which may have influenced postoperative improvements.

In patients who underwent THA, those from lower SES quintiles consistently reported lower Oxford Hip Scores (OHS), as well as poorer WOMAC total and subscale scores, and higher pain levels on the NRS. The estimated score difference between the highest (SES5) and lowest (SES1) quintiles for OHS was approximately 3.5 points, approaching the minimal clinically important difference (MCID) threshold of 5.2 points (Table 4). This finding aligns with previous international reports, such as Neuburger et al., who documented a 3.3-point difference between the least and most deprived THA patients (10), and with Goodman et al., who showed similar SES-related disparities in WOMAC scores (25).

In contrast, for TKA patients, the difference between SES quintiles was relatively smaller—about 0.3 points per quintile or 1.2 points overall, which is well below the established MCID of 4.8 for OKS. These findings are somewhat lower than those reported in Western literature. For instance, Feldman et al. found significantly worse preoperative WOMAC pain and function scores in lower SES TKA patients (11), and Barrack et al. noted a strong association between income level and postoperative knee function (26). The variance may reflect differences in SES definitions and healthcare system contexts.

Importantly, patients with lower SES were less likely to reach the MIC threshold for symptom improvement postoperatively, especially among the THA subgroup. This pattern was consistent with the results of Clement et al., who reported that lower SES correlated with less favorable PROM changes even after adjusting for confounders like length of stay and mental health scores (27). However, in our regression analysis, the interaction between SES and time (pre-op to post-op change) did not achieve statistical significance, suggesting that while SES influences absolute PROM levels, its effect on change over time may be subtle or obscured by variability (Table 4).

These findings are in line with global literature suggesting that MBIs can improve pain perception, physical functioning, stress management, and overall satisfaction following major surgeries. The integration of MBI as an adjunct to conventional rehabilitation could thus be especially beneficial for patients from lower SES backgrounds, who may have limited access to pharmacological or private physical therapy options and may benefit more from low-cost, non-invasive psychosocial support.

A major limitation in SES-related studies is the heterogeneity in SES definition. Some analyses rely on single variables like income or education, while others include occupation, car ownership, or neighborhood quality (10,26–28). Our study utilized neighborhood-based SES indices derived from publicly available Indian socioeconomic zoning data. Although this approach allowed categorization of SES at the population level, individual-level data was not accessible, potentially leading to non-differential misclassification and underestimation of the true SES effect (10).

This single-center study is strengthened by its homogeneous geographic population, limiting inter-regional variability, and its simultaneous assessment of both THA and TKA patients. However, generalizability is restricted to similar tertiary care urban hospital populations in India. Additionally, PROM follow-up was incomplete in 34.7% of cases, and it is possible that patients of lower SES were more likely to default follow-up appointments—though this was not directly observed.

Further limitations include the self-reported nature of PROMs, which are vulnerable to recall bias and ceiling/floor effects, particularly in high-functioning or low-functioning individuals (29).

To mitigate SES-driven disparities, multidisciplinary strategies must be integrated into surgical care pathways. Rehabilitation, tailored patient counseling, pain education, and preoperative expectation management could improve outcomes. Studies have shown that patients with higher preoperative expectations experience better postoperative fulfillment (Jain et al.) (32), and that individuals from disadvantaged backgrounds may lack adequate knowledge of surgical benefits and risks (Italian cohort) (28). Improving health literacy and shared decision-making through culturally sensitive education may enhance satisfaction and recovery (33,34). The addition of mindfulness-based interventions during the rehabilitation period could further optimize recovery, especially in patients facing high psychosocial stress or low SES-related limitations.

This study highlights that individuals from lower socioeconomic backgrounds undergoing total knee or hip arthroplasty reported more intense symptoms both before and after surgery, and they experienced comparatively lower improvements that reached clinical relevance. These findings emphasize the role of socioeconomic status as an important factor affecting patient outcomes, particularly in resource-constrained healthcare environments like ours. These findings are promising, particularly for vulnerable SES groups who may benefit most from such integrative approaches. Efforts should be directed toward identifying at-risk groups preoperatively and offering additional support such as tailored education, rehabilitation programs, and clearer communication around postoperative expectations. Doing so may help bridge the gap in recovery and improve overall satisfaction following surgery. Looking ahead, larger prospective studies are needed that collect individual-level SES data and incorporate frameworks like the International Classification of Functioning, Disability and Health (ICF) to evaluate how socioeconomic and personal circumstances influence recovery(35). Additionally, factors such as physical activity limitations (e.g., via IPAQ), income, education, job status, pain coping mechanisms, mental health status, and expectation management should be integrated to gain a comprehensive view of SES-related disparities in surgical outcomes.(36).

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