论文信息 - Independent samples t test

Independent samples t test

A new programme of goal oriented visits from a rheumatologist was devised for patients in primary care with osteoarthritis of the knee.1 The new programme was assessed using a randomised controlled trial to ascertain whether it provided benefits in terms of weight management and physical activity. The control treatment was usual care. A total of 154 patients were randomised to the new programme (three goal oriented standardised consultations) and 182 to usual care. At four months, the mean weight loss for patients who received standardised consultations was on average greater than for those receiving usual care (mean 1.11 (SD 2.49) kg v 0.37 (SD 2.39) kg; P=0.007). The two groups were statistically compared using a two sided, independent samples t test with a 0.05 (5%) critical level of significance ( t =2.77, degrees of freedom=334). Which of the following statements, if any, are true?

Philip Sedgwick | P. Sedgwick

[1] Philip Sedgwick,et al. Statistical hypothesis testing , 2010, BMJ : British Medical Journal.

[2] I. Boutron,et al. ARTIST (osteoarthritis intervention standardized) study of standardised consultation versus usual care for patients with osteoarthritis of the knee in primary care in France: pragmatic randomised controlled trial , 2009, BMJ : British Medical Journal.