Table 2 A simulated trial in asthma. Twelve patients have been randomised in three cycles to treatment A followed by B or B followed by A. The table gives the periods in which the patients received A or B and the FEV₁ in mL below. For example, patient 1 received treatment A in periods 1, 3, and 6 and treatment B in periods 2, 4, and 5

1

1

2

3

4

6

5

2394

2686

2515

2675

2583

2802

2

2

1

3

4

6

5

2746

2726

2592

2867

2743

2742

3

1

2

3

4

6

5

2668

2560

2542

2584

2491

2737

4

1

2

3

4

6

5

2397

2696

2411

2895

2499

2760

5

2

1

3

4

5

6

3179

3221

2952

3096

2600

3192

6

1

2

4

3

5

6

2643

2496

2759

2847

2651

2860

7

1

2

3

4

5

6

2678

2843

2492

2763

2801

2890

8

2

1

3

4

5

6

2887

2862

2875

3083

2689

2967

9

2

1

3

4

6

5

2490

2841

2648

3044

2688

2914

10

2

1

3

4

6

5

2268

2576

2413

2493

2344

2699

11

2

1

4

3

6

5

2617

2923

2629

2832

12

1

2

4

3

5

6

2627

2759