Definition and application of biostatistics MCQs With Answer

Introduction:

This quiz set on the definition and application of biostatistics is designed specifically for M.Pharm students to strengthen foundational concepts and their practical use in pharmaceutical research. It covers core definitions, data types, descriptive and inferential measures, probability distributions, hypothesis testing, sample size, and common statistical tests used in clinical and experimental studies. Each question emphasizes real research scenarios—choosing appropriate tests, interpreting p-values, understanding errors, and applying statistics in study design and analysis. Regular practice with these MCQs will improve your ability to select correct methods, critically appraise literature, and apply biostatistics confidently in dissertation work and evidence-based practice.

Q1. Which of the following best defines biostatistics?

• The branch of statistics dealing with the design and analysis of biological and medical research
• The use of computers to store biological data
• The mathematical modeling of pharmaceutical manufacturing processes
• The study of clinical pharmacology and drug interactions

Correct Answer: The branch of statistics dealing with the design and analysis of biological and medical research

Q2. Which level of measurement indicates both order and equal intervals but no true zero?

• Nominal
• Ordinal
• Interval
• Ratio

Correct Answer: Interval

Q3. Which measure of central tendency is most appropriate for a skewed continuous distribution?

• Mean
• Median
• Mode
• Geometric mean

Correct Answer: Median

Q4. Standard deviation primarily describes which aspect of a dataset?

• Central location of the data
• Spread or variability around the mean
• Skewness of the distribution
• Number of outliers

Correct Answer: Spread or variability around the mean

Q5. Which probability distribution is commonly used for modeling the number of rare events occurring in a fixed interval?

• Normal distribution
• Binomial distribution
• Poisson distribution
• Exponential distribution

Correct Answer: Poisson distribution

Q6. In hypothesis testing, a Type I error represents which situation?

• Failing to detect a true effect (false negative)
• Incorrectly rejecting a true null hypothesis (false positive)
• Using an inappropriate statistical test
• Collecting biased sample data

Correct Answer: Incorrectly rejecting a true null hypothesis (false positive)

Q7. Which test is most appropriate to compare mean systolic blood pressure among three independent treatment groups?

• Paired t-test
• Chi-square test
• One-way ANOVA
• Mann-Whitney U test

Correct Answer: One-way ANOVA

Q8. Which non-parametric test is the alternative to one-way ANOVA for comparing medians of three or more independent groups?

• Kruskal-Wallis test
• Wilcoxon signed-rank test
• Spearman correlation
• Friedman test

Correct Answer: Kruskal-Wallis test

Q9. The p-value in a statistical test represents:

• The probability that the alternative hypothesis is true
• The probability of observing data as extreme as the sample assuming the null hypothesis is true
• The effect size of the treatment
• The probability of committing a Type II error

Correct Answer: The probability of observing data as extreme as the sample assuming the null hypothesis is true

Q10. Which metric describes the probability that a diagnostic test correctly identifies patients with the disease?

• Specificity
• Positive predictive value
• Sensitivity
• Negative predictive value

Correct Answer: Sensitivity

Q11. In a clinical trial, randomization primarily serves to:

• Ensure statistically significant results
• Eliminate the need for blinding
• Balance known and unknown confounders between groups
• Reduce sample size requirements

Correct Answer: Balance known and unknown confounders between groups

Q12. Which statistic quantifies the linear relationship between two continuous variables?

• Spearman’s rho
• Chi-square statistic
• Pearson correlation coefficient
• Odds ratio

Correct Answer: Pearson correlation coefficient

Q13. For time-to-event data, which method is commonly used to estimate the survival function?

• Cox proportional hazards model
• Kaplan-Meier estimator
• Logistic regression
• Linear regression

Correct Answer: Kaplan-Meier estimator

Q14. Statistical power of a study is defined as:

• The probability of rejecting the null hypothesis when it is true
• The probability of correctly accepting the null hypothesis
• The probability of detecting a true effect (1 − Type II error)
• The probability of a Type I error

Correct Answer: The probability of detecting a true effect (1 − Type II error)

Q15. Which test would you use to assess whether categorical variables are associated in a contingency table?

• Independent samples t-test
• Chi-square test of independence
• Pearson correlation
• ANOVA

Correct Answer: Chi-square test of independence

Q16. Confidence interval width for a mean decreases when which of the following occurs?

• Sample size decreases
• Standard deviation increases
• Confidence level increases (e.g., from 95% to 99%)
• Sample size increases

Correct Answer: Sample size increases

Q17. Which concept distinguishes standard error (SE) from standard deviation (SD)?

• SE measures variability of individual observations; SD measures precision of the sample mean
• SD measures variability of individual observations; SE measures precision of the sample mean
• SE is always larger than SD
• SD applies only to normally distributed data while SE applies to all data

Correct Answer: SD measures variability of individual observations; SE measures precision of the sample mean

Q18. Which method is suitable to test normality of a continuous variable in a dataset?

• Kaplan-Meier plot
• Shapiro-Wilk test
• Cochran’s Q test
• McNemar’s test

Correct Answer: Shapiro-Wilk test

Q19. In regression analysis, multicollinearity refers to:

• High correlation among predictor variables that can distort coefficient estimates
• Correlation between outcome and predictor variables only
• A situation where residuals are normally distributed
• Non-linearity between predictors and outcome

Correct Answer: High correlation among predictor variables that can distort coefficient estimates

Q20. Receiver Operating Characteristic (ROC) curve analysis is used to:

• Compare means between two groups
• Evaluate diagnostic test accuracy across thresholds
• Estimate survival probabilities over time
• Assess agreement between two raters

Correct Answer: Evaluate diagnostic test accuracy across thresholds

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