90 infants participating in the study will be subjected to continuous positive airway pressure treatment with RAM cannula (30 people), nasal mask (30 people) and nasal prongs (30 people) in three groups using block randomization method. Six are used. All blocks are the same size. Within each block of 6, two people are randomly assigned to group A, two people to group B, and two people to group C. 15 blocks of 6 are used for this study.
The software used for block allocation is R software. Blockrand Package is used in this software. Randomization of six permutation blocks, all possible blocks are arranged as follows
Block 1: ABCABC, Block 2: AABBCC, Block 3: ABCCBA, Block 4: CCBBAA, Block 5: CBACBA, Block 6: CBAABC
To select 90 people, we randomly select 15 blocks from numbers 1 to 6. Using R software, we choose a random number between 1 and 6. For example, if number 6 is selected as the sixth block and number 2 is selected as the second block, the people entering the study will be given CBAABCAABBCC respectively. Finally, group A received the intervention of short nose cannula, group B received the nasal mask intervention, and group C received the RAM cannula intervention through connection to the system.
After study completion, intervention data for each group can be added to the data frame for analysis. Each intervention is written on a card and the cards are sealed in envelopes, then when a new person enters the study, the next envelope is opened and the sample is assigned to the corresponding treatment.