"Low-value" glycemic outcomes among older adults with diabetes cared for by primary care nurse practitioners or physicians: A retrospective cohort study

Abstract

Background: "Low-value" healthcare is care without benefit to patients. Overly intensive glycemic control (i.e., HgbA₁C < 7 %) can cause harm to patients at high risk of hypoglycemia, particularly among older adults with co-morbidities. It is unknown whether overly intensive glycemic control differs among patients with diabetes and at high-risk of hypoglycemia cared for by primary care nurse practitioners versus physicians.

Objective: This study examined patients with diabetes at high risk of hypoglycemia receiving primary care between Jan 2010 and Jan 2012, comparing patients reassigned to nurse practitioners to those reassigned to physicians after their previous physician separated from practice in an integrated United States health system.

Design: This was a retrospective cohort study. Study outcomes were collected at two years after reassignment to a new primary care provider. Outcomes were predicted probabilities of HgbA₁C < 7 % using two-stage residual inclusion instrumental variable models, controlling for baseline confounders.

Setting: Primary care clinics within the United States Veterans Health Administration.

Participants: 38,543 patients with diabetes at increased risk for hypoglycemia (age ≥ 65 years with renal disease, dementia, or cognitive impairment), who had their primary care physician leave the Veterans Health Administration and who were reassigned to a new primary care provider in the following year.

Results: Cohort patients were on average 76 years and 99 % men. Of these, 33,700 were reassigned to physicians and 4843 to nurse practitioners. After two years with their new provider, in adjusted models, patients reassigned to nurse practitioners had a -20.4 percentage-point [95 % CI -37.9 to -2.8] lower probability of two-year HgbA₁C < 7 %.

Conclusions: Aligned with prior studies on care quality, rates of overly intensive glycemic control may be appropriately lower among older patients with diabetes at high-risk of hypoglycemia, cared for by nurse practitioners than physicians.

Tweetable abstract: Primary care nurse practitioners deliver equivalent or better rates of low-value diabetes care for older patients, compared to physicians.

Keywords: Diabetes mellitus; Health workforce; Low-value care; Nurse practitioners; Primary health care.