PICO works best for quantitative questions related to interventions. If PICO isn't working for your question, one of these frameworks may be helpful:
In adults with bladder cancer, are PD-L1 inhibitors or monoclonal antibodies more effective for improving survival?
Are children who use chewing gum more likely to develop dental caries than children who do not use chewing gum?
In adults with insomnia, is melatonin or zolpidem more successful in helping patients increase their hours of sleep?