Buhari was named in the category of five African presidents who routinely travel abroad for medical treatment.
Others listed were Presidents Abdelaziz Bouteflika (Algeria), Robert Mugabe (Zimbabwe), Jose Eduardo dos Santos (Angola) and Patrice Talon (Benin).
Buhari was described as the “first among equals” in terms of time spent abroad getting medical help.
In the report, BBC quoted Naziru Mikailu, its Abuja editor, as saying the public health system in Nigeria is terrible because of poor funding.
Earlier in the year, Buhari spent 49 days in the United Kingdom.
He returned to the London on May 7 and has been there since.
“I feel I could go home, but the doctors are in charge. I’ve now learnt to obey orders, rather than be obeyed,” Femi Adesina, Buhari’s spokesman, quoted him as saying.
“I’ve learnt to obey my doctor’s orders, rather than be the one issuing the orders. Here, the doctor is absolutely in charge.”