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Table 1 Description of the included trials

From: Vitamin C may reduce the duration of mechanical ventilation in critically ill patients: a meta-regression analysis

Trial [ref.]NSettingVitamin CLength of mechanical ventilation (hours)RoM
RouteDose (g/day)Vitamin CControl 
Bjordahl et al. [11]185Cardiacpo228.819.233.624.00.86
Amini et al. [12]137Cardiacpo37.
Dehghani et al .[13]100Cardiacpo113.42.015.414.30.87
Habib et al. [14]100Sepsisiv611050189720.58
Safaei et al. [15]58Cardiaciv215.15.3922.920.460.66
Ebade et al. [16]40Cardiaciv32.040.351.990.311.02
Tanaka et al. [17]37Burnsiv90*2902115113740.57
Zabet et al. [18]28Sepsisiv6*36.616.146.810.10.78
Sadeghpour et al. [19]**290Cardiacpo111.83.914.19.50.84
  1. The trials are listed by the number of patients (N). The mean age in the trials ranged from 42 to 64 years, with a median of 60 years. The proportion of males varied from 58% to 75%. Five trials were carried out in Iran [12, 13, 15, 18, 19], two in Egypt [14, 16], one in the USA [11], and one in Japan [17]. For detailed descriptions of the trials, see Additional file 1: Table S1. The Amini trial [12] results are modified as described previously [1]
  2. *Estimated vitamin C dose, see the “Methods” section
  3. **Sadeghpour et al. [19] recruited 500 participants but reported the results for just 290 participants [1]. Because of the high dropout rate (42%), we did not include this trial in our calculations, but we overlay the findings in Fig. 4
  4. iv intravenous, po per oral, RoM ratio of means [22]: e.g., for the Bjordahl trial [11], RoM = 0.86, based on 28.8/33.6, and RoM = 0.86 indicates that ventilation time in the vitamin C group was 14% shorter than in the placebo group