Development of a theoretical model to predict pMDI spray force, using alternative propellant systems

Continued success in the treatment of asthma and COPD requires new pMDI propellants for delivering aerosols with good patient comfort and acceptable levels of oral cavity deposition. The purpose of this work is to develop a theoretical model capable of predicting pMDI spray force as a function of metering valve geometric parameters and different propellant systems: HFA134a, HFA227ea and HFA152a. Such theoretical tool can be used in combination with lab-based measurements for device characterisation and potentially to reduce the number of experimental trials. The outcome of the model is compared against measurements of plume force with Copley Scientific Spray Force Tester SFT 1000. Results suggest that the size of the spray orifice has a significant direct effect on the spray force. We have also observed HFA134a and HFA152a generates similar magnitude of spray force and velocity where HFA227ea generates the lowest velocity and force values. These findings could potentially mean HFA152a sprays are expected to show similar levels of mouth-throat deposition to HFA134a sprays rather than HFA227ea sprays

Data_Sheet_1_Assessing the sustainability capacity of evidence-based programs in community and health settings.pdf

BackgroundWithin many public health settings, there remain large challenges to sustaining evidence-based practices. The Program Sustainability Assessment Tool has been developed and validated to measure sustainability capacity of public health, social service, and educational programs. This paper describes how this tool was utilized between January 2014 and January 2019. We describe characteristics of programs that are associated with increased capacity for sustainability and ultimately describe the utility of the PSAT in sustainability research and practice.MethodsThe PSAT is comprised of 8 subscales, measuring sustainability capacity in eight distinct conceptual domains. Each subscale is made up of five items, all assessed on a 7-point Likert scale. Data were obtained from persons who used the PSAT on the online website (https://sustaintool.org/), from 2014 to 2019. In addition to the PSAT scale, participants were asked about four program-level characteristics. The resulting dataset includes 5,706 individual assessments reporting on 2,892 programs.ResultsThe mean overall PSAT score was 4.73, with the lowest and highest scoring subscales being funding stability and program adaptation, respectively. Internal consistency for each subscale was excellent (average Cronbach's alpha = 0.90, ranging from 0.85 to 0.94). Confirmatory factor analysis highlighted good to excellent fit of the PSAT measurement model (eight distinct conceptual domains) to the observed data, with a comparative fit index of 0.902, root mean square error of approximation equal to 0.054, and standardized root mean square residual of 0.054. Overall sustainability capacity was significantly related to program size (F = 25.6; p DiscussionThe PSAT maintained its excellent reliability when tested with a large and diverse sample over time. Initial criterion validity was explored through the assessment of program characteristics, including program type and program size. The data collected reinforces the ability of the PSAT to assess sustainability capacity for a wide variety of public health and social programs.</p