This question is based on Effectiveness and economic evaluation of a nurse delivered home exercise programme to prevent falls. 1: Randomised controlled trial (Robertson et al. (2001) British Medical Journal 322, 697-701.) Read the paper and answer the questions.
Question 1. The 'mean (SD)' of the number of current prescribed drugs were 3.1 (2.4) and 2.9 (2.3) for the two groups. What does this mean? What does it tell us about the shape of the distribution of the number of prescribed drugs taken?
Check suggested answer 1.
Question 2. The authors report 'We found a 46% reduction in the number of falls during the trial for the exercise group compared with the control group (incidence rate ratio 0.54, 95% confidence interval 0.32 to 0.90).' What is a 95% confidence interval? What does this tell us about the difference in incidence of falls?
Check suggested answer 2.
Question 3. What might be the effect on the interpretation of the results of some subjects not completing the trial?
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Question 4. There were 9 serious falls in the control group and 2 in the exercise group, P=0.033. What is meant by 'P=0.033'? What does it tell us about the effect of exercise on falls?
Check suggested answer 4.
Question 5. In Table 2, P values are only given when the difference is statistically significant. The difference for injurious falls is therefore not statistically significant. What can we conclude from this?
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Question 6. The main conclusion of the paper is 'An individually tailored exercise programme delivered at home can prevent falls.' Do the data support this?
Check suggested answer 6.
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