Impact evaluation of an interdisciplinary approach to patients with chronic non-cancer pain in Chilean primary care

Abstract

Introduction

Chronic non-cancer pain affects one-third of the global population. In Chile, its prevalence is estimated at 34%, surpassing the prevalence of diabetes mellitus and hypertension. Its high costs reveal that clinical treatment causes the greatest economic impact, followed by days of work absenteeism.

Objective

This study aims to evaluate the impact on resource consumption, quality of life, and pain perception in patients with CNCP, an interdisciplinary approach implemented in Chilean primary care public health.

Methods

A concurrent cohort study was conducted with patients aged 25 to 64 with chronic non-cancer musculoskeletal pain. The population studied was 698 patients receiving primary health services in centers with similar size and territorial proximity. The clinical intervention introduced patient-centered care, psychotherapy and physiotherapy from the perspective of the neuroscience of pain. The impact analysis was conducted using negative binomial regression models, generalized linear models, and ordered logistic regressions.

Results

Results show that the patients who were intervened increased the number of physician consultations at primary care (IRR: 1.56; 95% CI 1.30–1.87) and increased medication consumption (coef 2.38; 95% CI 2.10–2.67) compared to control patients. Intervened patients improved their quality of life (COEF 0.14; 95% CI 0.09–0.19), and pain perception was statistically significant. Despite the health system’s structural, cultural, and organizational barriers, the intervention was implemented and consolidated in daily operation, providing learnings for a further scale-up.

Conclusion

The study demonstrates that an interdisciplinary approach to chronic non-cancer pain management in Chilean primary care improves quality of life and pain perception while increasing healthcare resource use. Despite system barriers, the intervention was successfully implemented and sustained within patient-centered care. These findings highlight the need for resource reallocation to ensure long-term sustainability and scalability through the public health system.

Introduction

Chronic non-cancer pain (CNCP) is a public health challenge, affecting approximately one-third of the global population [1, 2]. Pain is multifactorial in its origin and has physical, psychological, and social repercussions for the individual and the healthcare system [3] which makes it challenging to manage effectively [4, 5]. Most healthcare systems rely heavily on pharmacological treatments, despite growing concerns over opioid dependency and limited long-term effectiveness [6]. On the other hand, access to non-drug interventions, such as physiotherapy and psychological support, is often restricted due to financial and structural barriers [7]. These challenges result in increased healthcare costs, reduced quality of life for patients, and economic burdens caused by productivity losses and work absenteeism [8].

To address these issues, countries have implemented interdisciplinary approaches that integrate medical, psychological, and rehabilitation interventions [9, 10]. In Europe, the Joint Action CHRODIS-PLUS initiative has developed an Integrated Multimorbidity Care Model to improve coordination and continuity of care for patients with multimorbidity [11]. Similarly, pilot programs targeting frail older adults have shown that individualized care plans, case management, and patient education can lead to improved pain management outcomes [12]. In the United States, interdisciplinary pain clinics have adopted interdisciplinary treatment strategies, combining pharmacological, physical, and cognitive-behavioral therapies to enhance patient outcomes [13, 14]. While these models have demonstrated effectiveness, their implementation and scalability depend on healthcare system resources, policy support, and provider training.

Despite evidence supporting interdisciplinary approaches [10] significant gaps persist between research findings and policy implementation [15, 16]. Guidelines advocate for multimodal pain management; however, health systems often struggle to operationalize these recommendations due to funding constraints, workforce shortages, and rigid care structures [17]. In Chile, the CNCP approach is primarily delivered through primary healthcare (PHC), which offers medical and medication and community rehabilitation. A recent study revealed a prevalence of CNCP of 34%, whereas 20% suffer from musculoskeletal pain [18]. The economic burden represents an annual national cost of USD 1.3872 billion for musculoskeletal CNCP, equivalent to 0.417% of the Gross Domestic Product. The Chilean healthcare system’s current response to these individuals’ needs entails a high cost from frequent health services utilization [8]. Other studies on costs, productivity losses, and public policy proposals have also demonstrated the magnitude of the problem [8, 16], raising awareness to mobilize the ministry on the issue.

The [8, 16, 18,19,20,21,22,23,24,25,26,27,28,29] study aims to evaluate the impact of an interdisciplinary approach—incorporating patient-centered care, physiotherapy, and psychotherapy—on resource consumption, quality of life, and pain perception in CNCP patients of Chile’s public primary healthcare public system. By assessing feasibility and effectiveness, the study seeks to contribute to the ongoing discussion [10] on scalable and sustainable CNCP management strategies.

Methodology

A cohort pilot study was conducted to compare the intervention group with the non-intervention group from two intervention centers and two control centers. The non-intervention group received the usual standard care based on medical consultations and medication treatment in PHC. Centers were selected based on territorial proximity and the health center’s size. The follow-up period was from July 2022 to July 2024, during which anonymized data was collected from the health service’s Analysis and Information Management Unit (UNAGIS) for impact evaluation.

Population

The target population was selected according to age and diagnostic inclusion criteria as follows: adults (≥ 25 years and < 65 years) with musculoskeletal CNCP (lumbar pain, fibromyalgia, coxarthrosis, Knee arthrosis, shoulder pain, and/or rheumatoid arthritis). Patients with the following diagnoses were excluded: palliative care, active cancer, stage 5 chronic kidney disease, severe physical dependence, and alcohol and drug addiction, as the health system already offers a service portfolio in PHC. Healthcare professionals carried out the selection process during clinical check-ups. 75% of people with CNCP attended by healthcare professionals were eligible for the intervention. A total of 400 individuals received the intervention, which was compared with 298 control individuals. A matching process based on age and sex was conducted for the impact analysis. The patient dropout rate during the study was 16%.

Clinical intervention

The clinical intervention is based on diversifying and expanding existing services in PHC through interdisciplinary care and access to an expanded pharmaceutical basket, as described in the technical guidelines of the Chilean Ministry of Health [19]) (Fig. 1).

Fig. 1

Clinical intervention for non-cancer chronic pain. Source: Own elaboration. ECICEP: Comprehensive Care Strategy for people with multimorbidity [20]. RBC: Community based rehabilitation. Source: Own elaboration. ECICEP: Comprehensive Care Strategy for people with multimorbidity [20]. RBC: Community based rehabilitation

Enrollment in the pilot program begins with a primary health care (PHC) clinical check-up with a physician or other healthcare professionals (for individuals already diagnosed with non-oncological chronic pain). After this evaluation, the patient accesses services based on what is agreed upon in their comprehensive care plan. Each patient receiving the intervention was assessed using the EuroQol-5D (EQ-5D) and the Pain Analog Rating Scale (VAS) [21] at enrollment and again three months after the intervention began to detect changes in pain assessment and health-related quality of life.

Clinical follow-up - neuroscience education and psychoeducation for the treatment of non-oncological chronic pain based on neuroscience and psychoeducation of pain

The new physical therapy and psychology services are described, which enabled the diversification of the current portfolio available for people with Chronic non-cancer pain in PHC (Fig. 2).

Fig. 2

Organization of workshops based on education in neurosciences and pain psychoeducation and individual sessions for patients with chronic non-cancer pain. Source: Own elaboration

Pain psychology

A psychologist led psychoeducational group sessions focused on educating participants about relaxation techniques, identifying thoughts and emotions related to pain, and understanding how these factors affect various areas of a person’s life, their context, pain triggers, characteristics, and causes, among other activities. The sessions lasted 60 min each; they included an introduction to cognitive-behavioral therapy, breathing and relaxation training, attention management, cognitive restructuring, emotion management, assertiveness, problem-solving, time management, and reinforcement activities (Table 1).

Physiotherapy based on pain neuroscience education

It begins with applying the Start MSK Screening tool [22] and the Pain Analog Rating Scale (VAS). The treatment emphasizes a comprehensive understanding of pain as a complex physical, psychological, and social condition. It is based on four pillars: pain education, therapeutic exercise, sleep management, and stress management. The treatment plan is divided between individual (30 min each) and group interventions (60 min each) (Table 1) depending on the Start MSK Screening tool risk level, with higher-risk patients receiving more individual sessions.

Table 1 List of group psychoeducational and physiotherapy workshops for people with chronic non-cancer pain

Individual physiotherapy sessions

Therapeutic exercise, individualized and gradual, is presented as key to reducing pain and improving quality of life. The relationship between sleep and pain is addressed, highlighting the importance of sleep hygiene. The sessions seek to empower patients, making them active agents in their rehabilitation. The treatment plan consists of individual and group interventions depending on the risk:

• Low risk: 4 workshops sessions only as described in Table 1.

• Medium risk: 4 group work sessions as described in Table 1 plus 6 individual sessions (education in pain neuroscience, graded activity/exercise and promotion of healthy lifestyle habits.

• High risk: 4 group work sessions as described in Table 1 plus 10 individual sessions (education in pain neuroscience, symptom management exercises, graded exposure and promotion of healthy lifestyle habits).

Access to Medications. Restrictions on the quantity and limitations related to GES health conditions for prescribing tramadol and paracetamol were removed. Pregabalin, duloxetine, and buprenorphine patches were added to the PHC medication arsenal.

Reevaluation

Once the proposed intervention cycle is completed, the patient can continue treatment in primary care, undergo community rehabilitation, or be referred to a specialized level, depending on the case.

Referral to pain units in specialized centers

The study established the following referral criteria from PHC to specialized secondary pain units. After having accesssed the services mentioned above, if the patient remains with a VAS greater than 6, if there is still diagnostic doubt about the type of pain, or if there has not been a 2-point improvement in VAS, the patient meets the criteria to be referred to the secondary level.

Implementation process

The implementation process was carried out in three stages. First, the clinical teams received induction on the intervention, its objectives, requirements, co-creation aspects, and expected outcomes. Healthcare professionals were assigned for the intervention and completed courses on interdisciplinary chronic pain management along with internships to apply the new knowledge and tools daily. The second stage involved clinical activities, biweekly clinical consultations, and expert case reviews organized and supervised by the ANCORA UC Innovation teams. The final stage focused on data collection, concluding the pilot, distributing workshop materials, and consolidating the intervention for future national replication.

Data analysis

The impact of the intervention was evaluated in terms of (1) the number of visits to primary emergency services, (2) the number of visits to hospital emergency services, (3) the number of medical consultations in PHC, (4) the cost of medication consumption; (5) days of medical leave; and health-related quality of life (HRQoL) measured by EuroQol-5D (EQ5D) [23] and a specific pain question from the EQ5D questionnaire. The following adjustment variables were studied to estimate the effect: sex, age, number of comorbidities, diagnosis, insurance, and resource use according to ACG [24]. A univariate analysis was performed, with chi-square tests for discrete variables and t-tests for continuous variables. The effect analysis used negative binomial regression models, generalized linear models, and ordered logistic regressions. The statistical analysis was carried out in Stata 14.

Results

The baseline characteristics of the target population are presented in Table 2. The only variable that showed statistically significant differences was age.

Table 2 Population’s baseline characteristics

Health services utilization results

The study shows that intervened patients have a 1.5 times higher risk of visiting primary care emergency services than control patients, which is statistically significant (Table 3). However, they have a lower risk of visiting hospital emergency services. Regarding medical consultations at PHC, intervened patients have a 3.5 times higher risk of consulting than control patients, which is also statistically significant.

It is important to note that, when analyzing medical consultation data from the year before the intervention, those who already had more frequent consultations continued to have more visits than those who previously consulted less. Medication consumption among intervened patients is 2.38 times higher (refer to supplementary materials for details on consumption), with a 24% increase in days of medical leave. However, this increase is not statistically significant.

Regarding quality-of-life and pain perception results, health status was analyzed using the Chilean EQ5D [21] validation. The intervention is significantly associated with a 14% improvement in quality of life (Coef: 0.14; 95% CI 0.09–0.19). Regarding question four of the EQ5D questionnaire about pain/discomfort, the intervened patients initially experienced more pain than the controls. The intervention is significantly associated with a greater reduction in pain and a lower likelihood of experiencing severe pain (patients with mild pain are less likely to progress to moderate pain, and those with moderate pain are less likely to progress to severe pain). The results of patient pain reported through the VAS demonstrate that intervened patients have statistically significantly decreased their rest pain by 11% compared to non-intervened patients. However, no significance was found in the decrease in the pain perceived during exercise.

Table 3 Results of the impact analysis

Implementation results

During the pilot phase, adjustments were made to the schedules, new activities were introduced, and clinical records protocols were defined. The priority was placed on delivering comprehensive care to those individuals identified as being at the highest risk according to the ECICEP framework. Regarding medication management, processes for the procurement and dispensation of additional medications, particularly opioids, were established. In addition, physical spaces were reserved for conducting the workshops. The total cost of human resources assigned to the intervention was estimated at USD 2,000 per month, covering 22 weekly hours of physiotherapy, 11 weekly hours of psychological support, and 11 weekly hours of pilot coordination.

Regarding change management, the ANCORA UC Innovation team provided weekly support to the healthcare teams at each CESFAM. This support focused on operational aspects, addressing gaps in human capital, enhancing communication strategies, and fostering an interdisciplinary, patient-centered approach aligned with the ECICEP model. A key element in biweekly clinical consultations was the agreement on a personalized care plan, which enabled patients to better understand the rationale behind their referrals to specific services. To support the training of health teams, technical conferences and UC courses were organized to enhance the skills of primary care professionals. Clinical modeling and medication prescription training were also provided by the physiatry team at Hospital de La Florida.

Discussion

The study evaluated an interdisciplinary approach integrating physiotherapy, psychotherapy, and patient-centered care to manage chronic non-cancer pain in Chile’s public primary healthcare network. The intervention aimed to improve resource efficiency, reduce pain, and enhance patients’ quality of life. Results showed a significant reduction in pain perception and a 14% improvement in health-related quality of life, though healthcare utilization increased, particularly in primary care consultations and medication prescription. The study highlights the feasibility of a multidisciplinary CNCP management model, emphasizing the need for policy support and continuously work on operational, structural, and cultural conditions, as demonstrated in previous pilots on multimorbidity [26].

The results demonstrate interdisciplinary approach to chronic non-cancer pain (CNCP) in primary healthcare settings significantly enhances patients’ quality of life. The integration of physiotherapy and psychological interventions, alongside pharmacological management, contributed to an observed improvement in health-related quality of life. By addressing both the physical and psychological aspects of pain, this model facilitated better coping mechanisms and functional recovery. Moreover, the reduction in severe pain experiences, as indicated by the EQ-5D pain/discomfort dimension, and pain perception with VAS demonstrate the benefit from comprehensive management as already shown in multimorbidity setting in Chile and other countries [27, 28]. The intervention successfully mitigated pain intensity through patient-centered strategies such as pain neuroscience education, cognitive-behavioral therapy, and graded exercise programs. Notably, while rest pain showed improvement, there was no significant reduction in activity-related pain, indicating potential challenges in addressing movement-related discomfort. This highlights the need for further refinement in the intervention to optimize therapeutic exercise and functional rehabilitation to target pain experienced during activity more effectively. Despite this limitation, these findings underscore the importance of multimodal care approaches in improving the daily lives of individuals with chronic pain.

Health services utilization results reveals that implementing national and international evidence involves higher clinical consultants and drugs consumption. The findings of this study align with prior research, such as Espinoza et al. [8] in Chile, which identified therapeutic approaches as the primary cost driver in chronic pain management. Patients in the intervention group demonstrated increased engagement with primary healthcare services, reflecting the broader trend that improved health services variety and patient awareness can lead to higher healthcare utilization and medical leave notifications. However, this increase raises questions about healthcare system capacity and whether such models can be sustainably integrated into routine practice.

While the study did not explicitly quantify changes in medication use, it was observed an increase in prescription of analgesics, including opioids and nonsteroidal anti-inflammatory drugs (NSAIDs). This finding is likely due to the fact that, before the implementation of the intervention, patients incurred out-of-pocket expenses to acquire them outside the public health system [29]. Currently, these medications are provided directly in their health centers, which could explain the increase observed in our study. For example, patients in the control group do not report consuming duloxetine, pregabalin, or buprenorphine patches, which highlights gaps in access to these treatments. On one side it is positive that the intervention avoids out-of-pocket expenditure, but on the other side, the study expected an inferior increase in mediations costs. Future research should examine how interdisciplinary care impacts long-term medication adherence and whether it leads to a reduction in unnecessary pharmacological treatments minimizing the risks associated with prolonged drug use and overburdened healthcare services.

The main strengths of the study are the completeness of the data analysed can be mentioned since the resource consumption of each individual in the primary, secondary and tertiary network was incorporated. Also, the study was conducted in a real context, which are fundamental for implementing public policies. Regarding limitations, the convenient selection of the intervened centers is a limitation, which was addressed by choosing control centers of similar size and territorial proximity. The intervention group had a higher baseline severity of pain compared to controls, which may have influenced the observed effect sizes. Additionally, the study relied on self-reported measures, which are inherently subject to bias and variability. Another limitation is the relatively short follow-up period of three months post-intervention, which may not capture long-term outcomes or potential relapse in pain perception and quality of life.

In conclusion, this study highlights the benefits of an interdisciplinary approach to managing chronic non-cancer pain (CNCP) in primary healthcare, showing significant improvements in patients’ quality of life and pain perception. The integration of physiotherapy, psychology, and pharmacological management improved quality of life and reduced pain perception. The successful implementation and potential for scaling this model within the ECICEP framework depend on the proper training of healthcare teams, effective change management, and the reallocation of resources to ensure the efficient functioning of the health system. While the intervention shows promising potential in improving patient outcomes, further research is necessary to evaluate its long-term impact and sustainability.