Which one of the following tests should be applied to compare mean haemoglobin level of two groups of antenatal mothers?
Choosing the Right Test for Two Group Means
The goal is to compare the average (mean) haemoglobin level between two distinct groups of antenatal mothers.
Understanding the Unpaired t-Test
- The Unpaired t-Test (also known as the independent samples t-test) is specifically designed to compare the means of a continuous variable (like haemoglobin level) between two independent groups.
- This test is appropriate because the two groups of antenatal mothers are assumed to be separate and unrelated.
Evaluating Other Options
- Chi-square test: Used for categorical data (counts or frequencies), not for comparing means of continuous measurements like haemoglobin levels.
- Paired t-test: Used when the two sets of measurements come from the *same* group (e.g., before and after an intervention) or from matched pairs. It requires dependent samples, which is not the case here.
- Analysis of variance (ANOVA): Used to compare means across *three or more* independent groups. While it can technically work for two groups, the unpaired t-test is the more direct and conventional choice for exactly two groups.
Therefore, the unpaired t-test is the most suitable statistical test for this scenario.
Important Questions from Biostatistics
What is the specificity of sputum microscopy in detection of Pulmonary Tuberculosis (PTB) as per the information given below?
PTB Total Sputum microscopy Present Absent Positive 270 20 290 Negative 30 180 210 Total 300 200 500 In a cohort of 500 women attending antenatal clinic, 70 % had ultrasonography (USG). This cohort was followed up at delivery. Of the women who had USG, 70 delivered low birth weight (LBW) babies; whereas of the women, who did not undergo USG, 50 delivered LBW babies. The incidence of LBW babies among women who had USG is:
In a case-control study, 300 women aged 20-45 years suffering from breast cancer were compared with age-matched 300 women without breast cancer. It was observed that 120 women among cases and 60 women among controls were obese. The odds ratio of developing breast cancer among obese women is:
What is the relative risk of developing pulmonary embolism in users of oral contraceptives as per the information given below?
Women using OCs Pulmonary embolism Total Yes No Yes 120 80 200 No 10 70 80 Total 130 150 280 - The following table shows the mortality figures among hazardous industry workers :
Age group National death rate per 1000 Hazardous industry worker population Observed deaths 25-34 2.0 3000 8 35-44 3.5 2000 9 45-54 6.0 2000 13
What is the Standardized Mortality Ratio (SMR) for the hazardous industry workers (as compared to national popu-lation) ?
