Counts data with excessive zeros are frequently encountered in practice. For example, the
number of health services visits often includes many zeros representing the patients with no …

The propensity score is defined as a subject's probability of treatment selection, conditional
on observed baseline covariates. Weighting subjects by the inverse probability of treatment …

Background COVID-19 manifests with respiratory, systemic, and gastrointestinal (GI)
symptoms. 1, SARS-CoV-2 RNA is detected in respiratory and fecal samples, and recent …

Abstract SARS-CoV-2 Omicron BA. 1 and BA. 2 subvariants are genetically divergent. We
conducted a matched, test-negative, case-control study to estimate duration of protection of …

Background Waning of vaccine protection against coronavirus disease 2019 (Covid-19) and
the emergence of the omicron (or B. 1.1. 529) variant of the severe acute respiratory …

Background The protection conferred by natural immunity, vaccination, and both against
symptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection with …

Background Differences in the incidence of cardiopulmonary resuscitation (CPR) provided
by bystanders contribute to survival disparities among persons with out-of-hospital cardiac …

Rationale & Objective Underlying kidney disease is an emerging risk factor for more severe
coronavirus disease 2019 (COVID-19) illness. We examined the clinical courses of critically …

Study objective Semaglutide is a long-acting glucagon-like peptide-1 receptor agonist used
for management of type 2 diabetes and/or obesity. To test the hypothesis that perioperative …

Importance Sex-and gender-based differences in a surgeon's medical practice and
communication may be factors in patients' perioperative outcomes. Patients treated by …