Simulation modeling with system dynamics (SD) to plan osteoarthritis care delivery in Alberta

Abstract

Methods: This cross-sectional study includes members of the Framingham Foot Study. A validated exam of the foot was used to assess the presence of hallux valgus, hallux rigidus, and plantar fasciitis. To determine foot type, center of pressure excursion index (CPEI) measurements were recorded using the TekScan Matscan (1.4 sensors/ cm2) system. CPEI is a dynamic measure of foot type that uses the concavity of the center of pressure curve in the metatarsal head region, normalized to foot width during the stance phase of gait. In a prior study by Hillstrom et al., utilizing the emed-x plantar pressure system (4 sensors/cm2), CPEI thresholds discriminated planus, rectus (normal arch), and cavus (high arch) feet. Due to the differences in system resolution, a scaling equation was developed in order to determine the equivalent CPEI threshold on a TekScan Matscan system that differentiated planus from non-planus (rectus and cavus) feet. This threshold was defined as a CPEI 19.4% on a TekScan Matscan system. Crude and adjusted logistic regression models, using generalized estimating equations (GEE) to account for the correlation between left and right feet, were used to calculate odds ratios for the relation between foot type and the prevalence of hallux rigidus, hallux valgus, and plantar fasciitis. Adjusted models included age, sex and body mass index (BMI). Results: This study included 2,994 participants (5,778 feet) with an age range of 36-98 years and 55% women. The results are shown in Table 1. Approximately 74% of the study population (mean age¼65.5AE9.9 years) was classified as having pes planus in at least one foot. Those with flat feet were at an increased odds for hallux valgus (OR 1.6, 95% CI 1.4, 1.8) and hallux rigidus (OR 1.6, 95% CI 1.1, 2.3). These results remained significant when adjusted for age, gender, and BMI. Conclusions: Those with planus foot type had a higher odds of hallux valgus and hallux rigidus, but not plantar fasciitis. The high prevalence rate of pes planus in the Framingham cohort may be because the average participant is 66 years old and arch height has been shown to decrease with age. Further, CPEI recordings may be more sensitive to less severe cases of pes planus, contributing to this high prevalence rate. Hallux valgus and hallux rigidus was more prevalent in pes planus versus non-planus feet. This is important because foot structure and function are potentially modifiable factors for these pathologies that have implications for prevention and treatment.

Modelling workload to quality using system dynamics in manufacturing and healthcare

“…System Dynamics has been previously used by researchers in healthcare to explore a diverse set of problems: to study the factors that contribute to waiting times in accident and emergency units (Lane, Monefeldt, & Rosenhead, 2000); to model patient satisfaction in a sustainable healthcare system (Faezipour & Ferreira, 2013;Marshall et al, 2013); to plan and design chronic illness management programs (Hirsch & Homer, 2004); and to study the effect of various healthcare policies on different care units (Cooke et al, 2007). However, the technique has not been used to address the problem of nursing workload and staffing, and its consequences on both nurses' health as well as patient quality of care.…”

Modelling workload to quality using system dynamics in manufacturing and healthcare

“…System Dynamics has been previously used by researchers in healthcare to explore a diverse set of problems: to study the factors that contribute to waiting times in accident and emergency units (Lane, Monefeldt, & Rosenhead, 2000); to model patient satisfaction in a sustainable healthcare system (Faezipour & Ferreira, 2013;Marshall et al, 2013); to plan and design chronic illness management programs (Hirsch & Homer, 2004); and to study the effect of various healthcare policies on different care units (Cooke et al, 2007). However, the technique has not been used to address the problem of nursing workload and staffing, and its consequences on both nurses' health as well as patient quality of care.…”