What are c statistics

C-statistic gives the probability a randomly selected patient who experienced an event (e.g. a disease or condition) had a higher risk score than a patient who had not experienced the event.

Obviously there are people with low scores that still have events and people with high scores that never have events but the goal is the decision score gives us an idea of who is most likely.

· The idea or educated estimate can be turned into a C score- and c scores are kind of like grades== a score of 1 is absolue perfect model it means the model perfectly predicts those group members who will experience a certain outcome and those who will not.

· But we know in medicine that isn’t possible

IF

· A value of 0.5 means that the model is no better than predicting an outcome than random chance.

· Values over 0.7 indicate a good model.

· Values over 0.8 indicate a strong model.

https://pubmed.ncbi.nlm.nih.gov/38598573/

In fully vaccinated adults with a risk factor or unvaccinated patients without a risk factor who have symptomatic COVID-19, does paxlovid--nirmatrelvir-ritonavir reduce the duration of symptoms or the likelihood of hospitalization?

Nirmatrelvir-ritonavir (Paxlovid) was shown in its initial randomized trial to reduce hospitalization and death in unvaccinated adults with at least one risk factor for severe disease when the ancestral variant of SARS-CoV-2 was predominant.

But it is important that drugs be evaluated in the correct target population patients who have been vaccinated or have the Omicron variant.

This industry-sponsored study enrolled 2 groups of patients: (1) fully vaccinated adults with symptomatic, confirmed infection with SARS-CoV-2 and at least one risk factor for severe disease,

(2) unvaccinated adults with a symptomatic infection but no risk factors

The onset of symptoms was within the past 5 days. Patients (N = 1296) were randomized to receive the standard 5-day course of nirmatrelvir-ritonavir or matching placebo.

the 1440 participants who were initially randomized There was no difference in duration of symptoms between groups, and no significant difference in the likelihood of hospitalization or death (0.8% vs 1.6% for placebo; difference -0.8%; 95% CI -2.0 to 0.4).

https://www.nejm.org/doi/10.1056/NEJMoa2314063

Randomized trials have shown the benefit of endovascular thrombectomy in patients with acute stroke due to large-artery occlusion in the anterior circulation and a large baseline infarct (core) In these trials,1-5 a large core was defined by an ASPECTS value of 5 or less, but because of concerns about the deleterious effects associated with the reperfusion of large infarcts,8 patients with the largest infarcts (ASPECTS value, 0 or 1) were excluded from enrollment

Now, researchers have compared EVT plus medical therapy to medical therapy alone in patients who could be treated within 6.5 hours of stroke onset and had a large amount of ischemic tissue

The primary outcome was the modified Rankin scale (mRS) score and the major safety outcome was all-cause mortality, both at 90 days.

a 3-year period, 333 patients cerebral vessel occlusion in the anterior circulation

The median NIH Stroke Scale score was 21, and the median baseline infarct volume was 135 mL;

Median time to randomization was 270 minutes after symptom onset. The EVT group had a lower median mRS score at 90 days than the medical-therapy group (4 vs. 6) and also lower mortality (36% vs. 56%).

The overall rate of death or dependency (mRS score ≥4) at 90 days was high in both groups but lower with thrombectomy (67% vs. 88%). NNT of 5

Symptomatic intracranial hemorrhage was more common with EVT (9.6% vs. 5.7%).—NNH of 25