This study (https://academic.oup.com/cid/article/65/1/100/3097834) seems to conduct a cox proportional hazard regression on survival data, but reports hazard ratios for 30- and 90-day mortality:
Patients who received cefazolin had a 37% reduction in 30-day mortality (hazard ratio [HR], 0.63; 95% confidence interval [CI], .51–.78) and a 23% reduction in 90-day mortality (HR, 0.77; 95% CI, .66–.90) compared with patients receiving nafcillin or oxacillin, after controlling for other factors.
How is this possible? I understood that hazard ratios are ratios of rates over time and therefore do not reflect a hard end point, and a more accurate measure would have been adjusted OR from logistic regression for 30/90 day mortality.
