Randomization
PTB
Random allocation of PTB patients either into the intervention arm (A) or into the control arm (B) was conducted by using permuted block randomization method. Block size of four, with six possible permutations coded from 1 to 6 was used. The six possible permutations were 1 = AABB, 2 = ABAB, 3 = ABBA, 4 = BAAB, 5 = BABA, 6 = BBAA. A random number sequence was used to generate a number to select the corresponding block to determine the allocations, until the number of sample size had achieved.