Randomization of intervention-control pairs

This function provides random allocation into intervention or control arms of a trial for a paired/matched experimental design. Each subject will experience both intervention and control treatment at some stage during the trial, the paired randomization determines the treatment order.

Randomization reduces opportunities for bias and confounding in experimental designs, and leads to treatment groups which are random samples of the population sampled, thus helping to meet assumptions of subsequent statistical analysis (Bland, 2000). A particular bias in this design might be intervention having some carry-over effect on control treatment.

Example: randomization of 50 patients into treatment (intervention) and placebo (control) arms of a trial of a new drug. This would give 50 pairs of INTERVENTION - CONTROL or CONTROL - INTERVENTION. If this was a randomized crossover study then you would give drug first if the order was INTERVENTION - CONTROL and you would give placebo first if the order was CONTROL - INTERVENTION:

Randomized intervention-control pairs

Randomized with seed: 10, balanced allocation

1	Intervention - Control
2	Control - Intervention
3	Intervention - Control
4	Intervention - Control
5	Control - Intervention
6	Control - Intervention
7	Intervention - Control
8	Control - Intervention
9	Intervention - Control
10	Control - Intervention
11	Intervention - Control
12	Control - Intervention
13	Control - Intervention
14	Intervention - Control
15	Intervention - Control
16	Intervention - Control
17	Control - Intervention
18	Control - Intervention
19	Intervention - Control
20	Control - Intervention
21	Intervention - Control
22	Control - Intervention
23	Control - Intervention
24	Intervention - Control
25	Control - Intervention
26	Control - Intervention
27	Control - Intervention
28	Intervention - Control
29	Intervention - Control
30	Intervention - Control
31	Intervention - Control
32	Intervention - Control
33	Intervention - Control
34	Control - Intervention
35	Control - Intervention
36	Intervention - Control
37	Intervention - Control
38	Control - Intervention
39	Control - Intervention
40	Control - Intervention
41	Control - Intervention
42	Intervention - Control
43	Control - Intervention
44	Control - Intervention
45	Intervention - Control
46	Intervention - Control
47	Control - Intervention
48	Control - Intervention
49	Intervention - Control
50	Intervention - Control

Technical validation

Robust (pseudo-)random number generation is used, see random number generation.