Limited Health Literacy: Risk Factor for Hypoglycemia in Diabetes?
Limited Health Literacy: Risk Factor for Hypoglycemia in Diabetes?
Sarkar U, Karter AJ, Liu JY, Moffet HH, Adler NE, Schillinger D
J Gen Intern Med. 2010 May 18. [Epub ahead of print]
Investigators from University of California San Francisco Center for Vulnerable Populations, and San Francisco General Hospital measured health literacy's impact on hypoglycemia in diabetic patients. The authors analyzed cross-sectional survey data collected as part of the large Diabetes Study of Northern California (known as DISTANCE), which includes 14,357 patients treated at Kaiser Permanente Northern California, a nonprofit, integrated healthcare delivery system.
All patients in this observational study were taking antidiabetic medications. More than half (59%) of the 11% reporting significant hypoglycemia (at least 1 hypoglycemic event of losing consciousness or needing outside help in the prior 12 months) were taking insulin. Patients commonly reported limited health literacy behaviors: problems learning about health (53%), needed help reading health materials (40%), or were not confident filling out medical forms by themselves (32%).
In 3 separate multivariate logistic regression analyses, investigators found that limited health literacy (HL) -- problems learning, needing help reading, or lacking confidence in filling forms -- was significantly associated with hypoglycemia. The association of HL with hypoglycemia did not change even when each of the multivariate analyses was adjusted for demographic (age, gender, race/ethnicity, English proficiency, income, social support), and clinical factors (medication type, diabetes duration, glycemic control based on hemoglobin A1c, renal function based on glomerular filtration rate, self-monitoring of blood glucose practice, dementia, and history of stroke). The significant association of HL with hypoglycemia was unchanged in added models that further controlled for body mass index, alcohol use, medication adherence, and neuropathy.
In type 2 diabetes management, a significant goal for providers, patients, and health systems is to balance ideal glycemic control over the long-term to reduce microvascular complications with low risk for hypoglycemia.Hypoglycemia is a common adverse drug event that results in poor diabetes outcomes; reduced medication adherence for fear of hypoglycemia recurrence; increased risk for dementia, hospitalizations, and emergency department visits; reduced quality-of- life; and increased likelihood of death.
Although, the incidence of hypoglycemia reported in trials of type 2 diabetes patients is low, information on hypoglycemic events in real-world practice is limited. Because hypoglycemia could go unnoticed by providers or may not be reported by patients to providers, the investigators expected it to be more frequent in real world practice than reported in previous clinical trials. In summary, the frequency of hypoglycemia in practice and association of HL with hypoglycemia are not clear.
The authors used a self-reported HL measure that was validated against other direct measures and had predictive validity to identify subgroups at risk for clinically important hypoglycemia. To make the self-report precise, the survey data included questions to patients about clinically significant hypoglycemia specifically related to loss of consciousness or requiring treatment aid. The patients' reports are valid for 2 reasons. First, there was a gradual increase in hypoglycemia based on risk for hypoglycemia from different medications (ie, highest in insulin-treated patients). Second, patients with a hypoglycemia self-report were more likely to have an emergency department visit or hospitalization for hypoglycemia during the year before the survey.
The investigators recognized study limitations. The hypoglycemic event rates found in the study's integrated managed-care settings may underestimate rates in other populations; the underinsured or uninsured, and those in nonintegrated health systems. Because of cross-sectional analysis, this study shows only the association, it cannot infer that limited HL was the cause of increased hypoglycemia risk as other reasons may affect both. Also, those with limited HL may have mistakenly reported more hypoglycemia for nonhypoglycemic events than those with satisfactory HL who manage themselves. However, this would still identify those with limited HL to be at greater risk for hypoglycemia.
This study has important implications for providers and health policy experts to improve cost and quality of care. Earlier studies reported hypoglycemia in the range of 0.7% to 5.1% while this largest observational study showed significant hypoglycemia in about 11% of ambulatory type 2 diabetes patients. Thus, applying clinical goals and performance measures from efficacy trials to real world practice may risk the safety of many patients with type 2 diabetes. Therefore, to lower hypoglycemic events and encourage patient safety, having traditional glycemic targets, and excluding most hypoglycemia-inducing medications are important. Besides, providers need to assess hypoglycemic symptoms, and tailor hypoglycemia prevention counseling, and self-management support to those with limited HL, and their family members and caregivers.
Abstract
Hypoglycemia Is More Common Among Type 2 Diabetes Patients With Limited Health Literacy: The Diabetes Study of Northern California (DISTANCE)
Sarkar U, Karter AJ, Liu JY, Moffet HH, Adler NE, Schillinger D
J Gen Intern Med. 2010 May 18. [Epub ahead of print]
Study Summary
Investigators from University of California San Francisco Center for Vulnerable Populations, and San Francisco General Hospital measured health literacy's impact on hypoglycemia in diabetic patients. The authors analyzed cross-sectional survey data collected as part of the large Diabetes Study of Northern California (known as DISTANCE), which includes 14,357 patients treated at Kaiser Permanente Northern California, a nonprofit, integrated healthcare delivery system.
All patients in this observational study were taking antidiabetic medications. More than half (59%) of the 11% reporting significant hypoglycemia (at least 1 hypoglycemic event of losing consciousness or needing outside help in the prior 12 months) were taking insulin. Patients commonly reported limited health literacy behaviors: problems learning about health (53%), needed help reading health materials (40%), or were not confident filling out medical forms by themselves (32%).
In 3 separate multivariate logistic regression analyses, investigators found that limited health literacy (HL) -- problems learning, needing help reading, or lacking confidence in filling forms -- was significantly associated with hypoglycemia. The association of HL with hypoglycemia did not change even when each of the multivariate analyses was adjusted for demographic (age, gender, race/ethnicity, English proficiency, income, social support), and clinical factors (medication type, diabetes duration, glycemic control based on hemoglobin A1c, renal function based on glomerular filtration rate, self-monitoring of blood glucose practice, dementia, and history of stroke). The significant association of HL with hypoglycemia was unchanged in added models that further controlled for body mass index, alcohol use, medication adherence, and neuropathy.
Viewpoint
In type 2 diabetes management, a significant goal for providers, patients, and health systems is to balance ideal glycemic control over the long-term to reduce microvascular complications with low risk for hypoglycemia.Hypoglycemia is a common adverse drug event that results in poor diabetes outcomes; reduced medication adherence for fear of hypoglycemia recurrence; increased risk for dementia, hospitalizations, and emergency department visits; reduced quality-of- life; and increased likelihood of death.
Although, the incidence of hypoglycemia reported in trials of type 2 diabetes patients is low, information on hypoglycemic events in real-world practice is limited. Because hypoglycemia could go unnoticed by providers or may not be reported by patients to providers, the investigators expected it to be more frequent in real world practice than reported in previous clinical trials. In summary, the frequency of hypoglycemia in practice and association of HL with hypoglycemia are not clear.
The authors used a self-reported HL measure that was validated against other direct measures and had predictive validity to identify subgroups at risk for clinically important hypoglycemia. To make the self-report precise, the survey data included questions to patients about clinically significant hypoglycemia specifically related to loss of consciousness or requiring treatment aid. The patients' reports are valid for 2 reasons. First, there was a gradual increase in hypoglycemia based on risk for hypoglycemia from different medications (ie, highest in insulin-treated patients). Second, patients with a hypoglycemia self-report were more likely to have an emergency department visit or hospitalization for hypoglycemia during the year before the survey.
The investigators recognized study limitations. The hypoglycemic event rates found in the study's integrated managed-care settings may underestimate rates in other populations; the underinsured or uninsured, and those in nonintegrated health systems. Because of cross-sectional analysis, this study shows only the association, it cannot infer that limited HL was the cause of increased hypoglycemia risk as other reasons may affect both. Also, those with limited HL may have mistakenly reported more hypoglycemia for nonhypoglycemic events than those with satisfactory HL who manage themselves. However, this would still identify those with limited HL to be at greater risk for hypoglycemia.
This study has important implications for providers and health policy experts to improve cost and quality of care. Earlier studies reported hypoglycemia in the range of 0.7% to 5.1% while this largest observational study showed significant hypoglycemia in about 11% of ambulatory type 2 diabetes patients. Thus, applying clinical goals and performance measures from efficacy trials to real world practice may risk the safety of many patients with type 2 diabetes. Therefore, to lower hypoglycemic events and encourage patient safety, having traditional glycemic targets, and excluding most hypoglycemia-inducing medications are important. Besides, providers need to assess hypoglycemic symptoms, and tailor hypoglycemia prevention counseling, and self-management support to those with limited HL, and their family members and caregivers.
Abstract
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