Doctors reluctant to reduce medication even when blood sugar may be dangerously low

Older patients with diabetes whose blood sugar or blood pressure (BP) may be dangerously low are being overtreated because clinicians are reluctant to change medication in this group of patients, according to the results of two studies published in JAMA Internal Medicine
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Both studies focused on patients aged over 70 years with type 1 or type 2 diabetes whose blood sugar and BP were controlled with medication.

In the first study, researchers from the University of Michigan, Ann Arbor, analysed the records of 211,667 patients. They found that treatment was “deintensified” in 18.8% of patients identified with very low BP (defined as less than 120/65mmHg) and 16.0% of patients with moderately low BP (systolic BP 120-129mmHg or diastolic BP less than 65mmHg). In patients with very low BP whose medication remained the same, only 0.2% had raised BP at a follow-up check.

Some 20.9% of patients whose HbA_1c levels were moderately low had their treatment changed or stopped, as did 27.0% of those who were categorised as having very low HbA_1c levels (defined as between 6.0% and 6.4% and less than 6.0%, respectively). Of those patients who had very low levels but whose medication was not changed or stopped, less than 0.8% had raised levels at follow up.

The researchers describe their findings as a “lost opportunity to reduce overtreatment”, and say that practice guidelines and performance measures should place more focus on reducing overtreatment through deintensification.

Victoria Ruszala, specialist pharmacist in diabetes and endocrinology at North Bristol NHS Trust, who was not involved in the research, says the paper highlights the need to treat older patients in the same way as younger patients.

“This is an important point to make,” says Ruszala. “This is about being pragmatic and saying there is nothing wrong with taking away their medicines to make them safer.”

Ruszala adds that the paper is useful because it delivers hard data. “Working in secondary care we see [overtreatment] all the time and now they have come up with the figures,” she says. “What that does is give people the confidence to deintensify treatment – that that is a valid treatment choice.”

The second study^[2]
aimed to shed light on why overtreatment happens.

Another team of researchers, also from the University of Michigan, Ann Arbor, sent a survey to 1,222 primary care health professionals including doctors, nurse practitioners and physician assistants, of whom 594 responded.

The clinicians were presented with the hypothetical case study of a 77-year-old patient with chronic type 2 diabetes at high risk for hypoglycaemia (HbA_1c level 6.5%; severe kidney disease; and receiving glipizide 10mg twice daily). They were asked a series of questions to determine whether they would consider lowering or abolishing the patient’s medication. Participants were also asked to rate the level of difficulty they would face in following the recommendation to “avoid using medications other than metformin to achieve HbA1c less than 7.5% in most older adults”.

Almost half the participants (44.9%) said they would not worry about potential harm from tight control for an older patient with an HbA_1c level of 6.5% who is at high risk for hypoglycaemia. A similar proportion (42.1%) were concerned about missing performance measures if they reduced the glipizide dosage. Nearly one quarter (23.5%) were worried about future liability claims resulting from deintensification of hypoglycaemic medications.

The authors of the first study propose several reasons why a low BP or low HbA_1c level had a weak association with deintensification of treatment in this group of patients: stopping a drug requires a shift in how treatment is understood by patients and explained by healthcare professionals. “It requires a transition from a simplistic focus on ‘one size fits all’ to the more nuanced balancing of risks and benefits,” they say.

Clinical uncertainty about the reliability of a single BP and HbA_1c measurement and unwillingness to risk under-treatment may also influence decisions around deintensification.

“Until guidelines and performance measures specifically call for deintensification for patients who are at risk of being harmed by overtreatment, rates are likely to remain low,” the researchers conclude.