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PRACTICAL POINTERS

Clinical Use of A1c to Improve Management

Alan M. Delamater, PhD, ABPP

or more than 25 years, the hemo- one recent study conducted in Norway6 A1C values. Only 14% of the youths globin A1c (A1C) test has been revealed that the majority (82.6%) of were able to accurately describe the A1C Fthe most widely accepted out- 201 adult patients with test. Just 11, 7.8, and 7.8% correctly come measure for evaluating glycemic knew what their last A1C was, and most identified the A1C ranges for good, fair, control in individuals with diabetes. patients (90%) knew what a satisfactory and poor glycemic control, respectively. The test provides an index of a patient’s A1C value would be. But a significant Very few youths (1.6–3.2%) knew the average level during the number of patients (42%) reported they blood glucose values corresponding to past 2–3 months1 and is considered to had low knowledge of A1C testing in specific A1C results. Only a small num- be the most objective and reliable general. Furthermore, 25% of patients ber of youths correctly estimated the measure of long-term metabolic con- did not think that treatment intensifica- short- and long-term risks associated trol.2,3 The Diabetes Control and tion should occur at an A1C value of with A1C values of 7 and 12%. In this Complications Trial established that 10%. sample, there was a significant lack of maintaining A1C levels as close as pos- A recent cross-sectional study knowledge concerning the meaning and sible to the normal range results in con- examined the relationship between implications of the A1C test. siderable reductions in long-term health patients’ knowledge of their recent A1C complications.4 Thus, as the “gold stan- values and diabetes self-management.7 A1C to Patients dard” measure of diabetes control, this In this study, an ethnically diverse sam- The most frequently used assay to meas- test provides important feedback to ple of 663 patients with ure A1C is high-performance liquid health care professionals and patients. It in the United States completed the sur- chromatography. Although this is the follows that patients’ understanding of vey. Results showed that 66% of standard reference method, the disad- this test and its implications for long- patients did not know their last A1C vantage of it is that the results are not term health risk is essential. results, with only 25% able to accurate- available at the time of the patient visit, ly report the value. Knowledge of A1C and patients are typically told about RESEARCH FINDINGS results was associated with higher edu- their test results days later with either a Research has shown that regular meas- cational levels and ratings of good letter or follow-up phone call. With this urement of A1C over the long term can provider communication, as well as bet- delay in communicating health feed- identify patients with poor glycemic ter understanding of diabetes care, but back, opportunities in the clinical control and facilitate their improve- not with diabetes management attitudes encounter for decision-making and ment.5 The established relationship or self-management behaviors. These changes in regimen prescriptions may be between A1C measurements and long- findings are consistent with another missed. term complications,4 as well as the study8 in which just 24% of patients With recent technological advances, association between regular A1C test- who reported having a recent A1C test immediately available accurate and reli- ing and improved metabolic control,5 actually knew the result when compared able A1C results can be obtained during underscore the importance of determin- with the medical chart. the clinical encounter with a benchtop ing the extent of patients’ understanding One study9 examined knowledge analyzer (DCA 2000; Bayer, Elkhart, of this important test and how its results about A1C in youths with type 1 dia- Ind.). A controlled study was conducted are used in the clinical setting. betes. Sixty-four low-income minority to evaluate the effects on subsequent youths (11–16 years of age) with type 1 glycemic control of immediate feedback Patient Knowledge of A1C diabetes were recruited from a specialty of A1C levels.10 In this randomized study Relatively few studies have examined clinic. Youths were interviewed concern- of 201 patients (both type 1 and type 2 diabetic patients’ knowledge and under- ing their knowledge of the A1C test and diabetic patients with treatment), standing of A1C testing. Findings from the health risks associated with particular one group received immediate feedback,

6 Volume 24, Number 1, 2006 • CLINICAL DIABETES PRACTICAL POINTERS

while the other group received delayed cal decisions, intensification of treat- ship with their patients, encourage their feedback via phone call or letter. Patients ment regimens, and better subsequent active engagement in the decision-mak- were followed for 1 year. Results indi- glycemic control. ing process, and explore with them their cated that immediate A1C feedback Based on these findings, it is clear goals for diabetes management, the bar- helped to improve subsequent glycemic that clinicians should actively discuss riers they perceive, and the confidence control at 6 and 12 months, although this A1C results with their patients. This they feel in order to enhance their self- study did not identify any specific means taking the time to explain the efficacy and improve their motivation for changes in behavior that were responsi- importance of the test and then provide effective self-management of diabetes. ble for the improved glycemic control. graphic illustrations of what the numbers Another more recent randomized mean in terms of average blood glucose CONCLUSIONS prospective study11 examined the effects levels. It is important for patients to The A1C test provides crucial informa- of rapid A1C feedback on clinical deci- understand the concept that the test aver- tion about glycemic control in patients sion making and subsequent glycemic ages all the daily blood glucose excur- with diabetes, but it often is not used control in patients with type 2 diabetes sions during the previous 2–3 months. skillfully in clinical practice. Most recruited from an urban primary care set- Examples should be provided that show patients do not understand the test and ting. The study focused on whether rapid what specific A1C values would corre- are not aware of their recent A1C A1C feedback would lead to improved spond to specific average blood glucose results. Clinicians have the opportunity intensification of treatment regimens as values. Clinicians should discuss indi- to use the A1C test as part of the clinical well as improved A1C results at follow- vidual patients’ glycemic goals, not just encounter to engage their patients, dis- up. Of 597 patients initially recruited for on a long-term, but also on a daily basis. cuss their glycemic goals, and work col- a baseline evaluation, 440 had one fol- Patients should clearly understand the laboratively with them to improve dia- low-up visit, and 275 had two follow-up relationship between high A1C results betes self-management. visits over the course of the study period. and health risks, but this should be Results showed that rapid availability of explained in the context of the impor- REFERENCES A1C values resulted in more frequent tance of having good daily glycemic pro- 1Gonen B, Rachman H, Rubenstein AH, intensification of therapy when A1C was files, which can be so important to quali- Tanega SP, Horwitz DL: Hemoglobin A1c as an > 7%. In addition, for patients with two ty of life by reducing the variability of indicator of the degree of glucose intolerance in diabetics. Lancet 2:734–737, 1977 follow-up visits, A1C decreased signifi- blood glucose during the day. 2Nathan DM, Singer DE, Hurxthal K, Good- cantly in the rapid feedback group but Providing A1C results to patients son JD: The clinical information value of the gly- not in the control group. gives clinicians an opportunity to moti- cosylated hemoglobin assay. N Engl J Med These findings are similar to a previ- vate patients to more effectively manage 310:341–346, 1984 ous report12 that showed that immediate their diabetes, as well as to positively 3Singer DE, Coley CM, Samet JH, Nathan DM: Tests of glycemia in diabetes mellitus: their availability of A1C results enhanced reinforce those who are already effec- use in establishing a diagnosis and treatment. Ann clinical decision making in an urban tively managing their diabetes. Ideally, Intern Med 110:125–137, 1989 sample of African-American patients. this should be done at the time of the 4The DCCT Research Group: The effect of 13,14 intensive treatment of diabetes on the develop- Other recent studies have shown that clinical encounter. If immediate A1C ment and progression of long-term complications presenting A1C results graphically to testing is not available, then having the in insulin dependent diabetes mellitus. N Engl J patients may not only help them under- test conducted before the patient Med 329:977–986, 1993 stand what the results mean, but also encounter would be preferable so the 5Larsen ML, Horder M, Mogensen EF: Effect of long-term monitoring of glycosylated hemo- improve their glycemic control. results could be discussed and utilized globin levels in insulin-dependent diabetes melli- during the patient visit. tus. N Engl J Med 323:1021–1025, 1990 CLINICAL IMPLICATIONS It is important to remember that 6Skeie S, Thue G, Sandberg S: Interpretation of hemoglobin A1c (HbA1c) values among diabet- These research findings indicate that knowledge of A1C test results is an ic patients: implications for quality specifications health care providers should not assume important prerequisite for effective dia- for HbA1c. Clin Chem 47:1212–1217, 2001 their patients understand the A1C test betes self-management but is not suffi- 7Heilser M, Piette J, Spencer M, Kieffer E, because several studies have indicated cient to achieve good diabetes self-man- Vijan S: The relationship between knowledge of recent HbA1c values and diabetes care under- that most patients do not know their agement behaviors and good glycemic standing and self-management. Diabetes Care most recent A1C values or the meaning control. Providing information can help 28:816–822, 2005 of those values. The research has also increase knowledge, but it does not nec- 8Harwell TS, Dettori N, McDowall JM, Que- senberry K, Priest L, Butcher MK, Flook BN, demonstrated that it is better to have essarily lead to the behavior changes Helgerson SD, Gohdes D: Do persons with dia- immediate feedback of A1C results dur- required for effective diabetes manage- betes know their A1c number? Diabetes Educ ing the clinical encounter because this ment. Studies15–17 indicate that clinicians 28:99–105, 2002 gives the opportunity for enhanced clini- should establish a collaborative relation- 9Delamater AM, Patino AM, Schnieder K,

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Luna-Pinto C, Eidson M: The glycosylated ability of rapid HbA1c measurements enhances ment aspects of the Improving Chronic Illness hemoglobin A1c test: what do youths really know clinical decision making. Diabetes Care Care Breakthrough Series: implementation with about it? [Abstract] Diabetes 50 (Suppl. 2):A390, 22:1415–1421, 1999 diabetes and heart failure teams. Ann Behav Med 2001 24:80–87, 2002 13Levetan CS, Dawn KR, Robbins DC, Rat- 10Cagliero E, Levina EV, Nathan DM: Imme- tner RE: Impact of computer-generated personal- 17Holman H, Lorig K: Patients as partners in diate feedback of HbA1c levels improves ized goals on HbA1c. Diabetes Care 25:2–8, 2002 managing chronic disease: partnership is a pre- glycemic control in type 1 and insulin treated 14 requisite for effective and efficient health care. type 2 diabetic patients. Diabetes Care Chapin RB, Williams DC, Adair RF: Dia- BMJ 320:526–527, 2000 22:1785–1789, 1999 betes control improved when inner-city patients received graphic feedback about glycosylated 11Miller CD, Barnes CS, Phillips LS, Ziemer hemoglobin levels. J Gen Intern Med DC, Gallina DL, Cook CB, Maryman CD, El- 18:120–124, 2003 Alan M. Delamater, PhD, ABPP, is Kebbi IM: Rapid A1c availability improves clini- 15 director of clinical psychology and a cal decision-making in an urban primary care Anderson RM, Funnell MM, Butler PM, Arnold MS, Fitzgerald JT, Feste CC: Patient professor in the department of pediatrics clinic. Diabetes Care 26:1158–1163, 2003 empowerment: results of a randomized controlled at the University of Miami School of 12Thaler LM, Ziemer DC, Gallina DL, Cook trial. Diabetes Care 18:943–949, 1995 CB, Dunbar VG, Phillips LS, El-Kebbi IM: Dia- 16Glasgow RE, Funnell MM, Bonomi AE, Medicine in Florida. He is an associate betes in urban African-Americans. XVII. Avail- Davis C, Beckham V, Wagner EH: Self-manage- editor of Clinical Diabetes.

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