Letters

After little change in prevalence from 2003 to 2006-2007,1 the drop in smoking among registered nurses was more than twice that of the 13% decrease in the population, and the proportion who have quit was higher than the general population estimate (53.62%). Continued smoking and diminished quitting among licensed practical nurses remains a serious concern. Health care professionals are expected to be well-informed about health issues, but nicotine is highly addictive. Although a nationally representative sample, the Current Population Survey3 may not be representative of each health care professional group. Although the weighted samples were large, the sample size of some cells was small. Smoking status was not biochemically verified, and time since quitting was not available for these cross-sectional data. Linda Sarna, PhD, RN Stella Aguinaga Bialous, DrPH, RN Karabi Nandy, PhD Anna Liza Malazarte Antonio, MS Qing Yang, MS Author Affiliations: School of Nursing, University of California, Los Angeles, California (Sarna, Nandy, Antonio); Tobacco Policy International, San Francisco, California (Bialous); RTI Health Solution, Triangle Park, North Carolina (Yang). Corresponding Author: Linda Sarna, PhD, RN, School of Nursing, University of California, Los Angeles, 700 Tiverton Ave, PO Box 956918, Los Angeles, CA 90095-6918 ([email protected]). Author Contributions: Dr Nandy and Ms Antonio had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: Sarna, Bialous, Nandy. Acquisition of data: Sarna, Nandy, Yang. Analysis and interpretation of data: Sarna, Bialous, Nandy, Antonio, Yang. Drafting of the manuscript: Sarna, Bialous, Nandy. Critical revision of the manuscript for important intellectual content: Sarna, Bialous, Nandy, Antonio, Yang. Statistical analysis: Nandy, Yang, Antonio. Administrative, technical or material support: Sarna, Nandy. Obtained funding: Sarna. Supervision: Sarna, Bialous. Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Sarna reports consulting for the International Society for Nurses in Cancer Care and receiving grant funding from Pfizer Independent Grants for Learning and Change. No other disclosures were reported. Funding/Support: This study was funded in part by the University of California, Los Angeles (UCLA) School of Nursing endowment to the lead author. Role of the Sponsor: The University of California, Los Angeles had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication. Additional Contributions: Marjorie Wells, PhD (UCLA School of Nursing), assisted with manuscript preparation but did not receive compensation. 1. Fiore MC, Jaén CR, Baker TB, et al. Treating tobacco use and dependence. http://www.ncbi.nlm.nih.gov/books/NBK63952/. Accessed December 4, 2013. 2. Sarna L, Bialous SA, Sinha K, Yang Q, Wewers ME. Are health care providers still smoking? Nicotine Tob Res. 2010;12(11):1167-1171. 3. US Department of Commerce. Tobacco Use Supplement to the Current Population Survey. http://appliedresearch.cancer.gov/studies/tus-cps/. Accessed December 4, 2013.

6. Sarna L, Bialous S, Barbeau E, McLellan D. Strategies to implement tobacco control policy and advocacy initiatives. Crit Care Nurs Clin North Am. 2006;18(1):113-122, xiii.

COMMENT & RESPONSE

Prevalence of Diabetes in Chinese Adults To the Editor Dr Xu and colleagues1 estimated the prevalence of diabetes among a representative sample of Chinese adults at 11.6% and the prevalence of prediabetes at 50.1%. According to the Chinese National Nutrition and Health Survey (CNNHS) in 2002,2 the prevalence of diabetes was 2.6% among Chinese adults. Although the difference in the prevalence of diabetes might be partly explained by an increase in diabetes during the 8 years between the studies, we question the current diabetes prevalence among Chinese adults. One of the criteria for the diagnosis of prediabetes in the study was the hemoglobin A1c (HbA1c). However, there is still debate about the use of HbA1c. Moreover, there is no convincing evidence or validation to support applying HbA1c values based on a Western population to the Chinese population. There are racial and ethnic differences in the relationship between HbA1c and blood glucose.3 The potential population differences in HbA1c between the Western and Chinese populations should be addressed. The sampling method in the study depended on the Chinese Center for Disease Control and Prevention National Disease Surveillance Point System,4 which used probability proportionate to population size sampling to select a city or county. The sampling was based on 1982 census data, although the distribution of sample points was updated in 2000. The percentage of people who lived in urban areas was 20.43% in 1982 and 49.68% in 2010.5 Nonresidents (migrant workers, college students, and military personnel) are an important population that was not included in the study. For example, there were 229.78 million migrant workers in China in 2009.5 These workers were more likely to be healthy young men with less diabetes. Such potential systemic selection bias could overestimate the prevalence of diabetes among young Chinese men. This could partly explain why men younger than 50 years had higher diabetes prevalence in the study. Chuanwen Lu, BSc Wenjie Sun, PhD Author Affiliations: Texas Tech University, Lubbock (Lu); Tulane University, New Orleans, Louisiana (Sun). Corresponding Author: Wenjie Sun, PhD, Tulane University, 1440 Canal St, New Orleans, LA 70112 ([email protected]). Conflict of Interest Disclosures: The authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest and none were reported. 1. Xu Y, Wang L, He J, et al; 2010 China Noncommunicable Disease Surveillance Group. Prevalence and control of diabetes in Chinese adults. JAMA. 2013;310(9):948-959. 2. Li LM, Rao KQ, Kong LZ, et al; Technical Working Group of China National Nutrition and Health Survey. A description on the Chinese national nutrition and health survey in 2002 [in Chinese]. Zhonghua Liu Xing Bing Xue Za Zhi. 2005;26(7):478-484.

4. Koh HK. Realizing the vision for tobacco control. Am J Prev Med. 2012;43(5)(suppl 3):S264-S265.

3. Herman WH, Cohen RM. Racial and ethnic differences in the relationship between HbA1c and blood glucose: implications for the diagnosis of diabetes. J Clin Endocrinol Metab. 2012;97(4):1067-1072.

5. Centers for Disease Control and Prevention. Quitting smoking among adults—United States, 2001-2010. MMWR Morb Mortal Wkly Rep. 2011;60(44):1513-1519.

4. Yang G, Hu J, Rao KQ, Ma J, Rao C, Lopez AD. Mortality registration and surveillance in China: history, current situation and challenges. Popul Health Metr. 2005;3(1):3.

jama.com

JAMA January 8, 2014 Volume 311, Number 2

Copyright 2014 American Medical Association. All rights reserved.

Downloaded From: http://jama.jamanetwork.com/ by a Ndsu Library Periodicals User on 06/03/2015

199

Letters

5. National Bureau of Statistics of China. National population census data [in Chinese]. http://www.stats.gov.cn/tjgb/rkpcgb/qgrkpcgb/t20110428 _402722232.htm. Accessibility verified December 4, 2013.

To the Editor In an observational study of almost 100 000 adults, Dr Xu and colleagues1 provided alarming estimates of the burden of diabetes and prediabetes in China. The authors estimated that in 2010, more than 113 million Chinese adults had diabetes and close to 500 million had prediabetes. When directly compared with Chinese prevalence data from 2007,2 there has been a 20% increase in the prevalence of diabetes (from 9.7% in 2007 to 11.6% in 2010) and a 223% increase in the prevalence of prediabetes (from 15.5% to 50.1%). However, in our opinion the observed increase in both the prevalence of diabetes and prediabetes from 2007 to 2010 is an artifact explained by (1) adding the HbA1c criterion to the diagnosis of diabetes and (2) using the lower diagnostic threshold for impaired fasting glucose of 100 mg/dL instead of 110 mg/dL. Using fasting and 2-hour glucose criteria only, a prevalence of undiagnosed diabetes of 9.7% was found in both 2007 and 2010.1,2 Hence, the use of HbA1c in combination with the fasting and 2-hour glucose criteria in 2010 classified an additional 1.9% of the population with diabetes. Similarly, adding the HbA1c to the glucose-based criteria for prediabetes classified an additional 19.1% of the population with prediabetes. The study from 2007 used the World Health Organization cut point of 110 mg/dL for impaired fasting glucose; the study from 2010 used the American Diabetes Association cut point of 100 mg/ dL. This shift has previously been shown to increase the prevalence of impaired fasting glucose by 126% (from 12.7% to 28.7%) in the Chinese population.3 Thus, under the assumption that the distribution of people with prediabetes based on glucose and HbA1c criteria was the same in 2007 as in 2010, the corresponding prevalence of prediabetes would have been close to 54% (15.5 + 19.1 + 1.26 × 15.5) had the HbA1c and the lower diagnostic criteria for impaired fasting glucose been used in 2007. When HbA1c was recommended as a diagnostic criterion in 2009, it was stated that mixing different methods (glucose and HbA1c) should be avoided.4 The different tests are not completely concordant in either diabetes or prediabetes,4,5 and they are not intended to be used simultaneously in the same person. The study by Xu et al1 underscores that combining the glucose and HbA1c criteria, instead of using only one of them, will inflate the burden of prediabetes and type 2 diabetes. Kristine Færch, MSc, PhD Dorte Vistisen, MSc, PhD Author Affiliations: Steno Diabetes Center, Gentofte, Denmark. Corresponding Author: Kristine Færch, MSc, PhD, Steno Diabetes Center, Niels Steensens Vej 2, DK-2820 Gentofte, Denmark ([email protected]). Conflict of Interest Disclosures: The authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Drs Færch and Vistisen reported being employed by Steno Diabetes Center A/S, a research hospital working in the Danish National Health Service and owned by Novo Nordisk A/S. The Steno Diabetes Center A/S receives part of its core funding from unrestricted grants from the Novo Nordisk Foundation and Novo Nordisk A/S. Drs Færch and Vitisen also reported owning shares in Novo Nordisk A/S. 1. Xu Y, Wang L, He J, et al; 2010 China Noncommunicable Disease Surveillance Group. Prevalence and control of diabetes in Chinese adults. JAMA. 2013;310(9):948-959. 200

2. Yang W, Lu J, Weng J, et al; China National Diabetes and Metabolic Disorders Study Group. Prevalence of diabetes among men and women in China. N Engl J Med. 2010;362(12):1090-1101. 3. Borch-Johnsen K, Colagiuri S, Balkau B, et al. Creating a pandemic of prediabetes: the proposed new diagnostic criteria for impaired fasting glycaemia. Diabetologia. 2004;47(8):1396-1402. 4. International Expert Committee. International Expert Committee report on the role of the A1C assay in the diagnosis of diabetes. Diabetes Care. 2009;32(7):1327-1334. 5. Faerch K, Borch-Johnsen K, Vaag A, Jørgensen T, Witte DR. Sex differences in glucose levels: a consequence of physiology or methodological convenience? the Inter99 study. Diabetologia. 2010;53(5):858-865.

In Reply The prevalence of diabetes cannot be compared directly between our study and the 2002 CNNHS due to different methods of data collection, diagnostic procedures, and statistical analyses. In the 2002 CNNHS, an oral glucose tolerance test was conducted only in those with a fasting plasma glucose level of 5.5 mmol/L or higher and HbA1c levels were not measured.1 In addition, the 2002 CNNHS used the 1999 World Health Organization criteria plus a self-reported history of diabetes treatment to define diabetes. In our study, the 2010 American Diabetes Association criteria, which include fasting plasma glucose, 2-hour plasma glucose, and HbA1c as well as selfreported diabetes, were used. Moreover, sampling weights, which should be used to account for complex survey designs, were not applied in the 2002 CNNHS. We agree with Mr Lu and Dr Sun that there are racial and ethnic differences in HbA1c. However, the diagnostic criteria should be consistent across racial and ethnic groups for comparison purposes. We used weighted coefficients derived from the 2010 China population census data to account for discrepancies in urbanization between study participants and the general adult population. To include nonresidents, we included persons who had been living in their current residence for more than 6 months rather than those who were permanent residents. Nevertheless, some migrant workers might have been missed because they move more frequently. However, those people were counted as rural for weighting because they were considered permanent rural residents in the China population census. They should not contribute to an overestimation of the diabetes prevalence because prevalence in rural areas was lower than in urban areas. We agree with Drs Færch and Vistisen that different diagnostic criteria contributed to the differences in prevalence findings between our study and the 2007 survey.2 As discussed in our article, use of all 3 indexes (fasting plasma glucose, 2-hour plasma glucose, and HbA1c) provided a comprehensive estimation of diabetes prevalence in the Chinese population. This approach was recommended by the American Diabetes Association in their 2010 guidelines.3 Furthermore, the goal of using HbA1c to diagnose diabetes is to identify persons at risk for diabetes complications, so that they can be treated. Similarly, the goal of diagnosing prediabetes is to indicate high risk of future diabetes development. The association of an HbA1c level of 6.5% or greater with increased risk of microvascular and macrovascular complications and an HbA1c level of 5.7% to 6.4% with high risk of progression to diabetes is supported by data from diverse populations, including Asian.4,5

JAMA January 8, 2014 Volume 311, Number 2

Copyright 2014 American Medical Association. All rights reserved.

Downloaded From: http://jama.jamanetwork.com/ by a Ndsu Library Periodicals User on 06/03/2015

jama.com

Letters

In addition, to optimize the sensitivity and specificity for predicting future diabetes, the American Diabetes Association lowered the fasting glucose cut point from 110 mg/dL to 100 mg/dL for the diagnosis of impaired fasting glucose in their 2003 guidelines.6 This criterion has been widely accepted and used. Yufang Bi, MD, PhD Yu Xu, PhD Guang Ning, MD, PhD Author Affiliations: Key Laboratory for Endocrine and Metabolic Diseases of Ministry of Health, Rui-Jin Hospital, Shanghai, China. Corresponding Author: Guang Ning, MD, PhD, Rui-Jin Hospital, 197 Rui-Jin 2nd Rd, Shanghai 200025, China ([email protected]). Conflict of Interest Disclosures: The authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest and none were reported. 1. Li LM, Rao KQ, Kong LZ, et al; Technical Working Group of China National Nutrition and Health Survey. A description on the Chinese national nutrition and health survey in 2002 [in Chinese]. Zhonghua Liu Xing Bing Xue Za Zhi. 2005;26(7):478-484.

of headache less likely to be subarachnoid hemorrhage in their sample, resulting in an estimated sensitivity that may be higher than what would be expected in a routine clinic. They recommended use of the OSHR be restricted to patients with similar characteristics.1 However, this spectrum effect may also be related to lower reliability. Specifically, a homogeneous sample of patients would have less variability, and as variability decreases so does the ability to use the OSHR in different patient groups over time (ie, reliability).3 Although developing and restricting clinical decision rule use for patients with a narrow spectrum of disease is appealing because it may lead to improved sensitivity, repeated application of the OSHR may reveal poorer performance over time. One would expect that the risk of misclassification of important characteristics such as thunderclap headache would be high in this OSHR, and thus, even if applied precisely,4 the rule may not perform as well as expected at different centers.5 Development of formal training criteria may be necessary before its widespread use.

2. Yang W, Lu J, Weng J, et al; China National Diabetes and Metabolic Disorders Study Group. Prevalence of diabetes among men and women in China. N Engl J Med. 2010;362(12):1090-1101.

Adrian V. Specogna, MSc, PhD

3. American Diabetes Association. Diagnosis and classification of diabetes mellitus. Diabetes Care. 2010;33(suppl 1):S62-S69.

Author Affiliation: Department of Community Health Sciences, University of Calgary, Calgary, Alberta, Canada.

4. Sabanayagam C, Liew G, Tai ES, et al. Relationship between glycated haemoglobin and microvascular complications: is there a natural cut-off point for the diagnosis of diabetes? Diabetologia. 2009;52(7):1279-1289.

Corresponding Author: Adrian V. Specogna, MSc, PhD, University of Calgary, 3280 Hospital Dr NW, Calgary, AB T2N 4Z6, Canada ([email protected]).

5. Heianza Y, Hara S, Arase Y, et al. HbA1c 5·7-6·4% and impaired fasting plasma glucose for diagnosis of prediabetes and risk of progression to diabetes in Japan (TOPICS 3): a longitudinal cohort study. Lancet. 2011;378(9786):147-155. 6. Genuth S, Alberti KG, Bennett P, et al; Expert Committee on the Diagnosis and Classification of Diabetes Mellitus. Follow-up report on the diagnosis of diabetes mellitus. Diabetes Care. 2003;26(11):3160-3167.

Subarachnoid Hemorrhage Diagnosis To the Editor In their recent study, Dr Perry and colleagues1 addressed the challenging problem of misdiagnosis of subarachnoid hemorrhage. Perry et al1 reported 100% sensitivity for detecting subarachnoid hemorrhage, using the new Ottawa subarachnoid hemorrhage rule (OSHR). Despite this finding, 3 of the 6 characteristics in the rule showed only modest reliability (κ

Prevalence of diabetes in Chinese adults--reply.

Prevalence of diabetes in Chinese adults--reply. - PDF Download Free
67KB Sizes 0 Downloads 0 Views