Small prospective study of 30 ICU patients, showing higher mortality risk for low vitamin D levels. When divided into two groups at the median level, there was 5 of 15 deaths for the low vitamin D group compared to 0 of 15 in the high vitamin D group.
Vassiliou et al., 12/9/2020, prospective, Greece, Europe, peer-reviewed, 6 authors.
risk of death, 90.9% lower, RR 0.09, p = 0.04, high D levels 0 of 15 (0.0%), low D levels 5 of 15 (33.3%), continuity correction due to zero event (with reciprocal of the contrasting arm), >15.2ng/mL.
Effect extraction follows pre-specified rules
prioritizing more serious outcomes. For an individual study the most serious
outcome may have a smaller number of events and lower statistical signficance,
however this provides the strongest evidence for the most serious outcomes
when combining the results of many trials.