Table 1 Extracted variables
From: Impact of methodology on estrogens’ effects on cerebral ischemia in rats: an updated meta-analysis
Factor/outcome measure | Data type | Final categories/unit | Reference category for regression analyses |
|---|---|---|---|
Rat properties | |||
Strain | Category | I. Sprague Dawley | Sprague Dawley |
II. Wistar | |||
III. Other strains | |||
Sex | Category | I. Female | Female |
II. Male | |||
Diseases | Category | I. Healthy | Healthy |
II. Diabetes | |||
III. Hypertension | |||
Elderly rats | Category | [No] | [No] |
[Yes] | |||
Number of rats in estrogen treated and control groups | Continuous | Â | NA |
Estrogen administration | |||
Estrogen administration mode | Category | I. Slow-release pellets | Slow-release pellets |
II. Injections | |||
III. Silastic capsules | |||
Estrogen type | Category | I. 17β-estradiol | 17β-estradiol |
II. Estradiol valerate | |||
III. Premarin | |||
IV. Estrone | |||
Slow-release pellets: estrogen dose/pellet | Continuous | ÎĽg | NA |
Injections: Daily estrogen dose | Continuous | ÎĽg/kg body weight | NA |
Silastic capsules: estrogen dose/silastic capsule | Continuous | ÎĽg | NA |
Washout (Length of time between ovariectomy and estrogen administration) | Category | I. 0–14 days | 0-14 days |
II. >14Â days | |||
Length of time between initiation of estrogen administration and induction of the ischemic damage | Continuous | Hours | NA |
Focal ischemia procedure | |||
Type of middle cerebral artery occlusion procedure | Category | I. Intraluminal filament | Intraluminal filament |
II. Direct, mechanical | |||
III. Embolic | |||
IV. Photothrombotic | |||
V. Endothelin injection | |||
Occlusion duration | Category | I. Permanent | Permanent |
II. Short transient (up to 60Â minutes) | |||
III. Long transient (>60Â min) | |||
Laser-Doppler flowmetry during surgery | Category | [No] | [No] |
[Yes] | |||
Analysis procedure | |||
Length of time between ischemia and evaluation of damage Edema correction | Continuous | Hours | NA |
Edema correction | Category | I. No edema correction used | No edema correction used |
II. Correcting for edema in infarct | |||
III. Correcting for edema in entire hemisphere | |||
Outcome measures | |||
Infarct size ratio between estrogen treated and control rats – “EC-ratio” | Continuous | % | NA |