A researcher compares the variability of systolic blood pressure (mean 130 mmHg, SD 13 mmHg) and fasting blood glucose (mean 100 mg/dL, SD 12 mg/dL) in the same population. The appropriate measure to compare relative variability between these two parameters is:
- A Standard deviation
- B Coefficient of variation ✓
- C Standard error of mean
- D Variance
Correct answer: B. Coefficient of variation
Explanation
Coefficient of variation (CV) equals SD divided by mean, expressed as a percentage. It allows comparison of variability across measurements with different units or vastly different means. Here CV for BP is 10% and for glucose is 12%, showing glucose has relatively more variability. SD and variance are absolute measures and cannot be compared across different scales.
Reference: Park's Textbook of Preventive and Social Medicine, 26th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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