We have conducted a trial with 30 participants, each participant given different intervention (Intervention A, Intervention B and Intervention C). The aim of the study is to compare the effectiveness of three interventions.
At baseline (T0), 6 weeks (T1) and 12 weeks (T2) participants assessed their conditions using a 5 point likert scale (1. No pain; 2.Slight discomfort; 3.Slight pain, 4.moderate pain, 5.severe pain)
I have attempted to analysis the outcomes using Kruskal-Wallis and ANCOVA on different occasions however: (1) Kruskal-Wallis is not appropriate as it looks at the degree of change from baseline to follow-up within each group, rather than comparing the findings across the groups at follow-up, adjusting for any baseline differences; (2) ANCOVA considers for baseline differences however it also treats the data as continuous variable.
Any advice would be highly appreciated.