Final answer:
Avoiding the stimulation of backrubs or warm drinks before bedtime is the intervention that can best promote sleep for the older adult patient with arthritis.
Step-by-step explanation:
The intervention that can best promote sleep for the older adult patient with arthritis is avoiding the stimulation of backrubs or warm drinks before bedtime. Backrubs and warm drinks can stimulate the body and make it harder for the patient to fall asleep. Instead, it is recommended to create a calm and relaxing environment before bedtime to promote sleep.