Case control study examining medication usage with a healthcare database in Israel, showing lower risk of hospitalization with calcium + zinc supplements (defined as being picked up within 35 days prior to PCR+), however only 10 patients took the supplements. Other patients may have acquired supplements outside of the healthcare system.
Israel et al., 7/27/2021, retrospective, Israel, Middle East, peer-reviewed, 10 authors, this trial uses multiple treatments in the treatment arm (combined with calcium) - results of individual treatments may vary.
risk of hospitalization, >99.9% lower, RR <0.001, p = 0.04, treatment 0 of 10 (0.0%), control 6953 of 20849 (33.3%), odds ratio converted to relative risk, continuity correction due to zero event (with reciprocal of the contrasting arm), PCR+, cohort 2.
This study is excluded in the after exclusion results of meta analysis: treatment or control group size extremely small.
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.