In a paper describing the use of a new drug for the treatment of hypertension in pregnancy you read: ‘The mean fall in diastolic blood pressure in the treated group (n = 30) was 10 mmHg +/-3 (SD) and in the control group (n = 29) given placebo the mean fall was 4 mmHg + /-2.6 (SD). Using the t-test, p> 0.001.’ The following statements are correct:
20. Assuming a normal distribution, approximately 68% of the treated group would have shown a fall in the diastolic pressure of between 7 and 13 mmHg 21. The difference observed in the fall of blood pressure between the two groups did not reach a level of statistical significance 22. If the trial was properly conducted, the doctors involved should have known which patients were receiving the active drug and which the placebo 23. The most appropriate way to allocate patients to the drug and to the placebo group would have been to give the drug or placebo to alternate patients 24. It would be possible to calculate the value of x (Chi-squared) on the data given