Resiliency of on-demand multimodal transit systems during a pandemic.

During the COVID-19 pandemic, the collapse of the public transit ridership led to significant budget deficits due to dramatic decreases in fare revenues. Additionally, public transit agencies are facing challenges of reduced vehicle capacity due to social distancing requirements, additional costs of cleaning and protective equipment, and increased downtime for vehicle cleaning. Due to these constraints on resources and budgets, many transit agencies have adopted essential service plans with reduced service hours, number of routes, or frequencies. This paper studies the resiliency during a pandemic of On-Demand Multimodal Transit Systems (ODMTS), a new generation of transit systems that combine a network of high-frequency trains and buses with on-demand shuttles to serve the first and last miles and act as feeders to the fixed network. It presents a case study for the city of Atlanta and evaluates ODMTS for multiple scenarios of depressed demand and social distancing representing various stages of the pandemic. The case study relies on an optimization pipeline that provides an end-to-end ODMTS solution by bringing together methods for demand estimation, network design, fleet sizing, and real-time dispatching. These methods are adapted to work in a multimodal setting and to satisfy practical constraints. In particular, a limit is imposed on the number of passenger transfers, and a new network design model is introduced to avoid the computational burden stemming from this constraint. Real data from the Metropolitan Atlanta Rapid Transit Authority (MARTA) is used to conduct the case study, and the results are evaluated with a high-fidelity simulation. The case study demonstrates how ODMTS provide a resilient solution in terms of cost, convenience, and accessibility for this wide range of scenarios.

The Efficacy and Safety of Nonsteroidal Anti-Inflammatory Drugs in Total Joint Arthroplasty: Systematic Review and Direct Meta-Analysis.

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) have become widely used to manage perioperative pain following total joint arthroplasty (TJA). The purpose of our study is to evaluate the efficacy and safety of NSAIDs in support of the combined clinical practice guidelines of the American Association of Hip and Knee Surgeons, American Academy of Orthopaedic Surgeons, Hip Society, Knee Society, and American Society of Regional Anesthesia and Pain Management. METHODS: Databases including MEDLINE, EMBASE, and the Cochrane Central Registry of Controlled Trials were searched for studies published prior to November 2018 on NSAIDs in TJA. Studies included after a systematic review evaluated through direct comparisons and/or meta-analysis, including qualitative and quantitative heterogeneity testing, to evaluate effectiveness and safety of NSAIDs. RESULTS: After critical appraisal of 2921 publications, 25 articles represented the best available evidence for inclusion in the analysis. Oral selective cyclooxygenase (COX)-2 and non-selective NSAIDs and intravenous ketorolac safely reduce postoperative pain and opioid consumption during the hospitalization for primary TJA. Administration of an oral selective COX-2 NSAID reduced postoperative opioid consumption after discharge from TKA. CONCLUSION: Strong evidence supports the use of an oral selective COX-2 or non-selective NSAID and intravenous ketorolac as adjunctive medications to manage postoperative pain during the hospitalization for TJA. Although no safety concerns were observed, prescribers need to remain vigilant when prescribing NSAIDs.

The Efficacy and Safety of Opioids in Total Joint Arthroplasty: Systematic Review and Direct Meta-Analysis.

BACKGROUND: Opioids are frequently used to treat pain after total joint arthroplasty (TJA). The purpose of this study was to evaluate the efficacy and safety of opioids in primary TJA to support the combined clinical practice guidelines of the American Association of Hip and Knee Surgeons, American Academy of Orthopaedic Surgeons, Hip Society, Knee Society, and the American Society of Regional Anesthesia and Pain Management. METHODS: The MEDLINE, EMBASE, and Cochrane Central Register of controlled trials were searched for studies published before November 2018 on opioids in TJA. All included studies underwent qualitative and quantitative homogeneity testing followed by a systematic review and direct comparison meta-analysis to assess the efficacy and safety of opioids. RESULTS: Preoperative opioid use leads to increased opioid consumption and complications after TJA along with a higher risk of chronic opioid use and inferior patient-reported outcomes. Scheduled opioids administered preemptively, intraoperatively, or postoperatively reduce the need for additional opioids for breakthrough pain. Prescribing fewer opioid pills after discharge is associated with equivalent functional outcomes and decreased opioid consumption. Tramadol reduces postoperative opioid consumption but increases the risk of postoperative nausea, vomiting, dry mouth, and dizziness. CONCLUSION: Moderate evidence supports the use of opioids in TJA to reduce postoperative pain and opioid consumption. Opioids should be used cautiously as they may increase the risk of complications, such as respiratory depression and sedation, especially if combined with other central nervous system depressants or used in the elderly.