Understanding the complexity of population health interventions: assessing intervention system theory (ISyT)

Given their inherent complexity, we need a better understanding of what is happening inside the “black box” of population health interventions. The theory-driven intervention/evaluation paradigm is one approach to addressing this question. However, barriers related to semantic or practical issues stand in the way of its complete integration into evaluation designs. In this paper, we attempt to clarify how various theories, models and frameworks can contribute to developing a context-dependent theory, helping us to understand the black box of population health interventions and to acknowledge their complexity. To achieve this goal, we clarify what could be referred to as “theory” in the theory-driven evaluation of the interventional system, distinguishing it from other models, frameworks and classical theories. In order to evaluate the interventional system with a theory-driven paradigm, we put forward the concept of interventional system theory (ISyT), which combines a causal theory and an action model. We suggest that an ISyT could guide evaluation processes, whatever evaluation design is applied, and illustrate this alternative method through different examples of studies. We believe that such a clarification can help to promote the use of theories in complex intervention evaluations, and to identify ways of considering the transferability and scalability of interventions.

OP0088 A COHORT STUDY ON THE BIDIRECTIONAL RELATIONSHIP BETWEEN FIBROMYALGIA AND PERIODONTITIS OVER A 15-YEAR FOLLOW-UP

Background:Fibromyalgia has been proposed to be driven by chronic inflammation and infections that are associated with early rheumatoid arthritis and inflammatory arthritis. Other than the central sensitization model, our knowledge of fibromyalgia pathogenesis has been expanded with an inflammation-dependent theory, which is stimulated by prolonged spinal cord hyperexcitability.Objectives:To determine the relationship between periodontitis and fibromyalgia.Methods:In this cohort study, 196,428 periodontitis patients and 196,428 propensity score-matched non-periodontitis controls were enrolled. A Cox proportional hazard model was utilized to estimate the risk of fibromyalgia and survival analysis was adopted to assess the time-dependent effect of periodontitis on fibromyalgia. Subgroup analyses stratified by age, gender, and follow-up years were conducted to identify susceptible populations. A symmetrical cohort was designed to ascertain the relationship between fibromyalgia and the risk of periodontitis.Results:Patients with history of periodontitis were more likely to develop fibromyalgia than non-periodontitis controls (HR =1.42, 95% CI =1.39–1.44, P < 0.001), which persisted in the survival analysis (log-rank test P < 0.0001). This effect was significant in both genders and all age subgroups, and was particularly evident in males (HR=1.52, 95% CI = 1.48–1.56, P < 0.001) and younger periodontitis patients (HR= 1.55, 95% CI =1.50-1.60, P < 0.001). Fibromyalgia patients who never had periodontitis presented with higher risk for periodontitis over time (HR = 1.43, 95% CI = 1.40 - 1.45, P < 0.001).Conclusion:This is the first longitudinal study that addresses the bidirectional relationship between fibromyalgia and periodontitis, in which periodontitis may serve as a risk factor or early sign of fibromyalgia. Based on the observed relationship between fibromyalgia and periodontitis, regular follow-ups and patient education are recommended for patients with either disease.Disclosure of Interests:None declared

The Nepal’s Political Relationship with India: Under the Lens of Path Dependency Theory

The recent developments in Nepal’s politics from the abolition of autocratic monarchy, promulgation of a new constitution to successful completion of local, provincial, and federal level elections can be perceived as Nepal’s politics achieving miraculous success in forming democracy. Throughout the history, heavy reliance on the Indian economy has been considered as a major hurdle to Nepal’s sovereignty. This paper analyzes the Nepal-India relationship through path-dependent theory and argues that with series of above mentioned democratic success, the contemporary Nepali foreign policy towards India is at a critical juncture where Nepal can incorporate new changes to make its policies independent and uninfluenced by the Indian government. Analyzing the series of political and democratic events and foreign policies implemented to date, this paper aims to understand how the Nepali leadership can utilize these recent series of democratic successes as a turning point to break the traditional approach of forming policies to appease the Indian government and receive political and economic support and implement new policy changes leveraging on the multilateral organizations and developmental partners for its support economically and politically.

Effect of voids in a heat-flux dependent theory for thermoelastic bodies with dipolar structure

In our paper we formulate a theory for thermoelastic porous dipolar bodies in which we consider a new independent variable, namely the heat-flux vector. Furthermore, we add, to the differential equations that describe the behavior of the body, a new differential equation which is an equation of evolution which is satisfied by the components of the heat-flux vector. The basic system of the mixed initial-boundary value problem in this context consists of equations of the hyperbolic type. In order to ensure the consistency of the constructed theory, we formulate and prove an uniqueness result, with regards to the solution of the mixed problem.