A New Index for Cervical Curvature Evaluation - Relative Cervical Curvature Area.

OBJECTIVE: To put forward a new index of cervical curvature evaluation - relative cervical curvature area, and a new classification of cervical spine was proposed according to the relative cervical curvature area. METHODS: A total of 167 subjects with cervical spondylosis were included in the study. Firstly, 119 subjects were selected to measure C2-C7 lordosis angle by Cobb angle method, Harrison posterior tangent method, and Jackson physiological stress line method, and then their relative cervical curvature area, C1-C7 Cobb angle, C7 slope, and T1 slope were measured. The correlation between relative cervical curvature area and 3 measurement methods and common sagittal parameters was analyzed. According to the angle classification method, we calculated the diagnostic boundary value of the relative cervical curvature area classification, and selected 48 subjects to evaluate its diagnostic efficacy. Finally, 119 subjects were re-evaluated according to the diagnostic threshold and the number of intersections to verify the feasibility of the new classification. RESULTS: The results showed that the relative cervical curvature area index had good intraobserver and interobserver repeatability. Relative cervical curvature area was correlated with Harrison posterior tangent method (r = 0.930), Cobb angle method (r = 0.886), and Jackson physiological stress line method (r = 0.920), and correlated with C1-C7 Cobb angle, C7 slope, and T1 slope. The relative cervical curvature area has a good diagnostic performance for distinguishing patients with lordosis, straightening, and kyphosis. According to the new classification of cervical spine, 119 subjects were divided into 57 simple lordosis, 11 simple straightening, 4 simple kyphosis, 26 S-type, and 21 RS-type. CONCLUSIONS: The relative cervical curvature area uses the area parameter instead of the original angle parameter and distance parameter to incorporate the change of segmental curvature, which makes up for the shortcomings of the Cobb angle method that only evaluates the curvature of 2 vertebrae, and better reflects the cervical curvature. Studies have shown that relative cervical curvature area has good repeatability and diagnostic value, and found that it has a good correlation with common cervical sagittal parameters. The new classification of cervical spine makes up for the disadvantage that the angle classification method cannot distinguish between S-type and RS-type, and initially proposes to use the number of intersections and the relative absolute value area to reflect the severity of S-type.

Associations of nirmatrelvir-ritonavir treatment with death and clinical improvement in hospitalized patients with COVID-19 during the Omicron wave in Beijing, China: a multicentre, retrospective cohort study.

BACKGROUND: The effectiveness of nirmatrelvir-ritonavir has mainly been shown in non-hospitalized patients with mild-to-moderate coronavirus disease 2019 (COVID-19). The real-world effectiveness of nirmatrelvir-ritonavir urgently needs to be determined using representative in-hospital patients with COVID-19 during the Omicron wave of the pandemic. METHODS: We performed a multicentre, retrospective study in five Chinese PLA General Hospital medical centers in Beijing, China. Patients hospitalized with COVID-19 from 10 December 2022 to 20 February 2023 were eligible for inclusion. A 1:1 propensity score matching was performed between the nirmatrelvir-ritonavir group and the control group. RESULTS: 1010 recipients of nirmatrelvir-ritonavir and 1010 matched controls were finally analyzed after matching. Compared with matched controls, the nirmatrelvir-ritonavir group had a lower incidence rate of all-cause death (4.6/1000 vs. 6.3/1000 person-days, p = 0.013) and a higher incidence rate of clinical improvement (47.6/1000 vs. 45.8/1000 person-days, p = 0.012). Nirmatrelvir-ritonavir was associated with a 22% lower all-cause mortality and a 14% higher incidence of clinical improvement. Initiation of nirmatrelvir-ritonavir within 5 days after symptom onset was associated with a 50% lower mortality and a 26% higher clinical improvement rate. By contrast, no significant associations were identified among patients receiving nirmatrelvir-ritonavir treatment more than 5 days after symptom onset. Nirmatrelvir-ritonavir was also associated with a 50% increase in survival days and a 12% decrease in days to clinical improvement. CONCLUSION: Among hospitalized patients with COVID-19 during the Omicron wave in Beijing, China, the early initiation of nirmatrelvir-ritonavir was associated with clinical benefits of lowering mortality and improving clinical recovery.