“As people get older and see doctors more often, they’re more likely to get these tests,” said Dr.
Caleb Alexander, co-director of the Johns Hopkins Center for Drug Safety and Effectiveness.
readings over 10 milli-international units per liter of blood,
and who have low levels of other thyroid hormones, generally get a prescription for levothyroxine — and need one.
Usually, doctors order a blood test to measure the hormone when patients complain of symptoms suggestive
of a failing thyroid — fatigue, constipation, weight gain, muscle weakness or cold sensitivity.
“We were very aware the practices we adopt weren’t really based on good evidence,” said Dr. David Stott, a geriatrician at the University
of Glasgow who led the new study, conducted with 737 adults over age 65 in Scotland, Ireland, the Netherlands and Switzerland.