Table 3.
Subgroup analyses used to assess the effect of sodium bicarbonate in various conditions
| Subgroups | Trials/patients | OR (95% CI) | Test for overall effect | Heterogeneity |
|---|---|---|---|---|
| Type of contrast | ||||
| Low-osmolar | 14/2823 | 0.59 (0.37 to 0.93) | Z=2.26 (p=0.024) | χ²=26.61, df=13 (p=0.014), I²=51% |
| Iso-osmolar | 4/1189 | 0.76 (0.43 to 1.34) | Z=0.93 (p=0.351) | χ²=4.67, df=3 (p=0.198), I²=36% |
| Setting | ||||
| Elective | 18/4162 | 0.76 (0.54 to 1.06) | Z=1.62 (p=0.105) | χ²=29.54, df=17 (p=0.030), I²=43% |
| Emergency | 2/118 | 0.16 (0.05 to 0.51) | Z=3.11 (p=0.002) | χ²=0.07, df=1 (p=0.784), I²=0% |
| Using NAC or not | ||||
| Use | 1/219 | 0.17 (0.04 to 0.79) | Z=2.26 (p=0.024) | Not applicable |
| Non-use | 18/3741 | 0.71 (0.48 to 1.03) | Z=1.80 (p=0.071) | χ²=33.13, df=17 (p=0.011), I²=49% |
| Publication year | ||||
| Before 2008 | 4/573 | 0.19 (0.09 to 0.41) | Z=4.26 (p=0.000) | χ²=1.06, df=10 (p=0.788), I²=0% |
| After 2008 | 16/3707 | 0.85 (0.62 to 1.16) | Z=1.03 (p=0.302) | χ²=22.13, df=15 (p=0.105), I²=32% |
| Manner of administration | ||||
| Continuous | 18/4077 | 0.75 (0.53 to 1.05) | Z=1.69 (p=0.091) | χ²=30.21, df=17 (p=0.025), I²=44% |
| Bolus | 2/203 | 0.15 (0.04 to 0.54) | Z=2.90 (p=0.004) | χ²=0.23, df=1 (p=0.632), I²=0% |
NAC, N-acetylcysteine.