ABSTRACT
Short-term probabilistic forecasts of the trajectory of the COVID-19 pandemic in the United States have served as a visible and important communication channel between the scientific modeling community and both the general public and decision-makers. Forecasting models provide specific, quantitative, and evaluable predictions that inform short-term decisions such as healthcare staffing needs, school closures, and allocation of medical supplies. Starting in April 2020, the US COVID-19 Forecast Hub (https://covid19forecasthub.org/) collected, disseminated, and synthesized tens of millions of specific predictions from more than 90 different academic, industry, and independent research groups. A multi-model ensemble forecast that combined predictions from dozens of different research groups every week provided the most consistently accurate probabilistic forecasts of incident deaths due to COVID-19 at the state and national level from April 2020 through October 2021. The performance of 27 individual models that submitted complete forecasts of COVID-19 deaths consistently throughout this year showed high variability in forecast skill across time, geospatial units, and forecast horizons. Two-thirds of the models evaluated showed better accuracy than a naive baseline model. Forecast accuracy degraded as models made predictions further into the future, with probabilistic error at a 20-week horizon 3-5 times larger than when predicting at a 1-week horizon. This project underscores the role that collaboration and active coordination between governmental public health agencies, academic modeling teams, and industry partners can play in developing modern modeling capabilities to support local, state, and federal response to outbreaks. Significance StatementThis paper compares the probabilistic accuracy of short-term forecasts of reported deaths due to COVID-19 during the first year and a half of the pandemic in the US. Results show high variation in accuracy between and within stand-alone models, and more consistent accuracy from an ensemble model that combined forecasts from all eligible models. This demonstrates that an ensemble model provided a reliable and comparatively accurate means of forecasting deaths during the COVID-19 pandemic that exceeded the performance of all of the models that contributed to it. This work strengthens the evidence base for synthesizing multiple models to support public health action.
ABSTRACT
BACKGROUND: Senile degenerative lumbar spinal stenosis typically manifests clinically as lower back and leg pain caused by compression of the nerve root. Conventional total laminectomy for degenerative lumbar spinal stenosis can quickly alleviate a patient's symptoms, but produces an unsatisfactory therapeutic effect because of spinal instability caused by degenerative spondylolisthesis, and also has many adverse reactions. OBJECTIVE: The purpose of this study is to investigate whether total laminectomy combined with lumbar pedicle screw fixation for treatment of senile degenerative lumbar spinal stenosis can effectively reduce lower back and leg pain caused by compression of the nerve root, increase lumbar spine stability, and reduce adverse reactions. METHODS: A prospective, single-center, self-control, interventional trial. One hundred and sixty older adult patients with degenerative lumbar spinal stenosis who will receive treatment at the Department of Orthopedics, Qinghai Provincial People's Hospital, China will be included in this study. All patients will undergo total laminectomy combined with lumbar pedicle screw fixation, with follow-up at 3, 6, 9, and 12 months post-surgery. RESULTS AND CONCLUSION: The primary outcome measure of this study is recovery rate in Japanese Orthopedic Society (JOA) score at 12 months post-surgery, which is used to evaluate improvements in patients lower back and leg pain. Secondary outcome measures of this study include changes in JOA score, spinal canal diameter, lumbar spine morphology displayed on computed tomography images, and incidence of adverse events post-surgery. Results of a preliminary study involving 71 older adult patients with degenerative lumbar spinal stenosis who received the same treatment showed that at 3 months post-surgery, JOA score and spinal canal diameter were significantly increased compared with before surgery (P < 0.05). Findings from this study may provide clinical evidence supporting that total laminectomy combined with lumbar pedicle screw fixation is a safe and reliable method for treatment of senile degenerative lumbar spinal stenosis because it rapidly alleviates lower back and leg pain and provides spine stability. This study was approved by Medical Ethics Committee of Qinghai Provincial People's Hospital of China(approval No.QHY201602G).This study will be performed in strict accordance with the Declaration of Helsinki formulated by the World Medical Association.Participants provided signed informed consent prior to participation in the study.This study was designed in December 2017. Patient recruitment and data collection will begin in August 2018. Data analysis will be performed in October 2019. The study will be completed in December 2019. Results will be disseminated through presentations at scientific meetings and/or by publication in a peer-reviewed journal. The version of this study protocol is (1.0). This trial was registered with the Chinese Clinical Trial Registry (registration number: ChiCTR1800014726).