Using concept mapping to explore the challenges associated with affording and accessing medications among people living with HIV in Ontario, Canada.

Antiretroviral medications are expensive, and people living with HIV often experience challenges accessing and paying for medication due to various obstacles. We used concept mapping to explore the challenges people living with HIV in Ontario, Canada, face when accessing medication. In brainstorming, 68 participants generated 447 statements in response to the focus prompt "Some people living with HIV have trouble getting and paying for prescription drugs because … ". These were consolidated into 77 statements, which were sorted (n = 30) and rated (n = 32) on importance and commonality. A ten-cluster concept map consisting of individual- and health system-related clusters was generated. Clusters included: (1) Stigma, (2) Medication-Related Issues, (3) Individual Challenges, (4) Basic Needs, (5) Immigration, (6) Coverage, (7) Trillium Drug Program, (8) Access to Services, (9) System-Level Issues and (10) Access to Professional Services. Statements in Coverage and Basic Needs were rated most important and common although there was variability by Ontario residence and drug coverage mechanisms. Strategies to address challenges were generated in Interpretation (n = 25 participants). Given that continuous access to antiretroviral therapy is necessary to fully realize treatment benefits, policies and interventions that address these challenges are needed.

A lumped parameter model of the single free-flooded ring transducer.

A free-flooded ring (FFR) transducer can generate low-frequency sound in a small device and has a wide operating frequency bandwidth. Many studies have been performed that can predict the characteristics of an FFR transducer using analytical techniques and an equivalent circuit model (ECM), and methods to predict properties using numerical simulations have recently been developed. However, an ECM, a type of lumped parameter model (LPM), is still widely used to interpret the properties of such transducers in the design process. In this study, the authors investigated an ECM of an FFR transducer. The ECM consists of three parts: the piezoelectric ring, the cylindrical cavity, and the radiation load. Moreover, it can be included readily in a circuit to drive an FFR transducer. Additionally, an LPM was proposed, considering the mutual radiation loads, to improve the accuracy of the model. Each model was tested in comparisons with the finite element method; it was confirmed that an LPM could predict the properties of an FFR transducer with much better accuracy than an ECM. The LPM developed can save much time in designing FFR transducers.