==== Front Patient Prefer AdherencePatient Prefer AdherencePatient Preference and AdherencePatient preference and adherence1177-889XDove Medical Press 10.2147/PPA.S162892ppa-12-1347Original ResearchHealth-related quality of life in elderly diabetic outpatients in Vietnam Nguyen Huong Thi Thu 12Moir Mackenzie PI 3Nguyen Thanh Xuan 24Vu Anh Phuong 5Luong Long Hoang 24Nguyen Tam Ngoc 12Nguyen Long Hoang 6Tran Bach Xuan 78Tran Tung Thanh 9Latkin Carl A 8Zhang Melvyn WB 10Ho Roger CM 11Vu Huyen Thanh Thi 12 1 Department of Gerontology, Hanoi Medical University, Hanoi, Vietnam, thuhuonglk@hmu.edu.vn 2 National Geriatric Hospital, Hanoi, Vietnam, thuhuonglk@hmu.edu.vn 3 School of Public Health, University of Alberta, Edmonton, AB, Canada 4 Dinh Tien Hoang Institute of Medicine, Hanoi, Vietnam 5 Hanoi Medical University, Hanoi, Vietnam 6 School of Medicine and Pharmacy, Vietnam National University, Hanoi, Vietnam 7 Institute for Preventive Medicine and Public Health, Hanoi Medical University, Hanoi, Vietnam 8 Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA 9 Institute for Global Health Innovations, Duy Tan University, Da Nang, Vietnam 10 Biomedical Global Institute of Healthcare Research & Technology (BIGHEART), National University of Singapore, Singapore 11 Department of Psychological Medicine, Yong Loo Lin School of Medicine, National University of Singapore, SingaporeCorrespondence: Huong Thi Thu Nguyen, Department of Gerontology, Hanoi Medical University, 01 Ton That Tung, Hanoi, 115000, Vietnam, Tel +84 9 7305 6334, Email thuhuonglk@hmu.edu.vn2018 27 7 2018 12 1347 1354 © 2018 Nguyen et al. This work is published and licensed by Dove Medical Press Limited2018The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution – Non Commercial (unported, v3.0) License (http://creativecommons.org/licenses/by-nc/3.0/). By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed.Background Health-related quality of life (HRQoL) is an important indicator for designing care and treatment services for patients with diabetes. This is especially true given its rapid increase among the elderly population in Vietnam. HRQoL data in elderly diabetic Vietnamese are currently limited. This study aimed to 1) measure the HRQoL of elderly patients with type 2 diabetes (T2DM) in Vietnam and 2) identify related factors and their relationship with HRQoL. Patients and methods A cross-sectional study was conducted. We recruited 171 patients aged ≥60 years with T2DM at the Outpatient Department, National Geriatric Hospital from June to November 2015. Patients were asked to evaluate their health status using the EuroQol Five Dimensions Three Levels (EQ-5D-3L) and the Visual Analog Scale (VAS). Sociodemographic, diabetic treatment, and management characteristics were collected. Multivariate Tobit regression was used to determine which factors were associated with HRQoL, and the strength of this relationship. Results Patients reported some problems in all areas of the EQ-5D: pain/discomfort (50.9%), mobility (33.3%), anxiety/depression (24.0%), usual activities (21.1%), and self-care (10.5%). The mean EQ-5D index score was 0.80 (SD=0.20), and the mean EQ-VAS was 57.5 (SD=14.4). Patients who were male, lived in an urban area, could afford treatment, were taking fewer medications, and monitored blood pressure often (1–4 times a week) had a higher EQ-5D index when compared to other groups. Meanwhile, a longer duration of diabetes and older age were negatively associated with the EQ-5D index. Patients with any comorbidity had lower VAS scores than their counterparts. Conclusion The presence of diabetes and comorbidity were responsible for a significant decrease in HRQoL. Screening and identifying health problems, providing prompt treatment, and facilitating self-management among patients have the potential to increase diabetic patients’ HRQoL. Keywords elderquality of lifediabetesVietnam ==== Body Introduction Population aging is an emerging problem of priority on the global health care policy agenda.1 The aging of the Vietnamese population has been accelerating in recent years, with substantial increases in the elderly population (aged ≥60 years) in both relative and absolute numbers.1 It is estimated that the percentage of elder people will rise to over 30% in 2050 from 8.9% in 2009.1,2 Ensuring sufficient care and treatment provision as well as social supports for this population has become a major challenge to the Vietnam Government.3,4 Health-related quality of life (HRQoL) is considered an important indicator of health issues and health care needs in the elderly.5–7 Information about HRQoL can also be used to evaluate the performance of health care services, particularly when the availability of administrative data is limited.7,8 It can also be used to economically evaluate the effectiveness of health technologies and treatment.7,9 HRQoL data are therefore needed in order to develop interventions and conditions favorable to the promotion of HRQoL. Diabetes is increasingly common in low- and middle-income countries such as Vietnam. It is estimated that in 2015, over 3.5 million Vietnamese adults were living with diabetes.10 The prevalence of diabetes is especially high among the elderly. Pham and Eggleston showed that 12.8% of males and 10.9% of females living in Thai Nguyen over the age of 60 years had diabetes.11 Type 2 diabetes mellitus (T2DM) is the most common form of metabolic disorder in Vietnam, with a prevalence that has doubled in the previous decade (2.7% in 2002 to 5.4% 2012).12,13 T2DM is disproportionally prevalent in different geographic regions throughout Vietnam.14,15 For example, in 2008, the rate of diabetes was more than 11% in Ho Chi Minh City, which is the biggest city in Vietnam,16 but less than 1% in rural Vietnam.17 Most patients with T2DM in Vietnam receive care on an outpatient basis, with hospital visitation used for regular physical assessment and management of complications. Elderly T2DM patients often suffer from comorbidities and geriatric syndromes that contribute to the development of frailty, defined as the cumulative decline of multiple physiological functions (eg, muscle weakness, low gait speed, etc.).18,19 The combination of diabetes and comorbidity can increase the likelihood of adverse outcomes, such as falls, disability, death, and hospitalization,19,20 all of which can significantly impair a patient’s quality of life.21–23 Moreover, geriatric syndromes are a major obstacle when providing treatment and care to diabetic patients.18,22,24 Therefore, it is necessary to investigate the HRQoL of these patients, and associated factors, so that interventions designed to improve HRQoL can be developed and deployed. Evaluations of HRQoL in elderly diabetic populations have been conducted worldwide in Asia,25,26 Europe,27–30 and the USA.31 Determinants of HRQoL have been found to vary across studies. Most have found correlations between HRQoL and sex, age, capacity to pay for treatment, occupations, income, body mass index (BMI), comorbidities (cardiovascular diseases, neuropathy, etc.), and treatment modalities like insulin or exercise.25,27,28,30,32 However, few evaluations of HRQoL in diabetic populations have been completed in resource-scarce settings like Vietnam. Therefore, the objective of this study was to measure the HRQoL of elderly patients with T2DM in Vietnam and identify its covariates. Patients and methods Study design A cross-sectional study was conducted from July to November 2015 at the Outpatient Department, National Geriatric Hospital. A convenience sampling approach was used to recruit patients. To participate in the study, all subjects had to be 1) aged 60 years and older, 2) diagnosed with diabetes according to diagnostic criteria set out by the International Diabetes Federation in 2013, 3) undergoing treatment as an outpatient at the National Geriatric Hospital, and 4) able to communicate with the data collector. Patients were excluded if 1) they were unable to complete the questionnaire and 2) they refused to participate in the study. A sample of 171 patients was recruited. Measures and instruments A structured questionnaire was developed and used for 25-min face-to-face interviews. Data collectors were students who were enrolling in undergraduate medical doctor and nursing degrees at Hanoi Medical University. To avoid social desirability bias, we did not use physicians and nurses employed at the hospital research site for collecting data. We conducted several training sessions for data collectors to ensure that they asked questions consistently and obtained high-quality data. The questionnaire included the following variables. Primary outcomes HRQoL was measured using EuroQol Five Dimensions Three Levels (EQ-5D-3L),25 which consists of five dimensions: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Each dimension has three levels of responses: level 1; no problems; level 2: some problems; level 3: extreme problems. Health states were converted into a weighted index by applying scores from the UK utility tariffs set due to the unavailability of a Vietnamese tariff.33 The EQ-5D index score ranged from −0.594 to 1, with a higher index depicting better HRQoL.33 We also employed the EQ Visual Analog Scale (EQ-VAS) to record the participant’s self-rated health on a vertical scale that ranges from 0 to 100. Zero represents the worst health state a patient can imagine and 100 represents the best health state a patient can imagine. Covariates Sociodemographic and behavior characteristics included age, sex (male/female), education attainment that was classified into three categories (low education: lower high school; medium education: graduate high school; high education: tertiary education), living location (urban/rural), people living with family/relatives/others/alone, who their primary informal caregiver was (family/relatives/others/none), the ability to pay for treatment (yes/no), smoking status (yes/no), and if they were a current alcohol user (yes/no). We measured the weight and height of participants to calculate their BMI. We used three BMI categories: <18.50 kg/m2 (underweight), 18.5–24.99 kg/m2 (normal), and ≥25.00 kg/m2 (overweight/obesity). Moreover, information on comorbidities was given by patients’ self-reported data and confirmed by investigator based on medical records and medication utilization. We also collected data on patients’ diabetes treatment characteristics such as their disease duration, treatment modality (oral antidiabetic drug, insulin, both or doing exercise only), number of medicines, whether they forgot to take medicine in the last 4 weeks (yes/no), fasting plasma glucose (mmol/L), and HbA1c (%) level. Glycemic goals for adults with diabetes were achievement of fasting plasma glucose ≤7.2 mmol/L and HbA1c <7%.34 Other characteristics such as self-monitoring of blood glucose at home (yes/no), frequency of blood pressure monitoring and exercises, diet modification (yes/no), and if patients had ever delayed an examination were also collected. Data analysis Data analysis was performed using STATA 12.0 software (Stata Corp. LP, College Station, TX, USA). First, we described variables by using frequency and percentage for categorical variables, and mean and standard deviation for continuous variables. Multivariate regression was used to identify the factors associated with the EQ-5D index and EQ-VAS. Because the outcome data were censored data, we employed Tobit regression (or censored regression) model to have better estimation compared to typical linear regression. Stepwise forward selection strategies were used to produce the reduced model. These strategies selected variables into the final models using the threshold of p-value at 0.2 for the log-likelihood ratio test. Statistical significance was defined as any p-value less than 0.05. Ethics approval and informed consent The study was approved by the National Geriatric Hospital Research Ethics Committee (No 794 NGH IRB). Written informed consent, which was approved by the Research Ethics Committee of the National Geriatric Hospital, Hanoi, Vietnam, was obtained from all participants in this study prior to data collection. Results Among 171 patients, the mean age was 69.4 years (SD=6.8). The majority of the patients were females (58.5%), had a medium education (35.1%), lived in an urban area (94.7%), and lived with family (93.6%). Most of them were taken care by their families (94.2%) and were able to pay for diabetes treatment (81.9%). In addition, 93% of patients had comorbidities. The mean EQ-5D index was 0.80 (SD=0.20), and the mean EQ-VAS was 57.5 (SD=14.4) (Table 1). Table 2 depicts that most of the patients had a diagnosis that was over 10 years old (49.1%). The most common treatment modality was oral medications (50.3%). More than five oral prescriptions were prescribed to 45.6% of patients for diabetes mellitus or other comorbidities. The average fasting plasma glucose was 7.8 mmol/L (SD=2.2) and HbA1c was 7.1% (SD=1.5%). Self-management of respondents is shown in Table 3. Most respondents performed self-monitoring blood glucose at home (69.0%), modified their diet (86.6%), and always did their exercises (77.8%), whereas 42.7% always monitored their blood pressure at home. Only 3.5% of patients delayed their examinations and 17.0% forgot to take their medication in the last 4 weeks (Table 3). Figure 1 shows the HRQoL status of participants described with the five dimensions of the EQ-5D-3L. One-third of the sample had some problems (level 2) in mobility (33.3%), whereas 50.9% and 24.0% had some problems in pain/discomfort and anxiety/depression, respectively. About 81.3% of individuals were able to do daily activities in the last 2 weeks and 81.3% patients felt tired in the last 7 days. Figure 2 shows the mean VAS score based on age group. The group aged 60–64 years had the highest mean VAS score: 60.1 (SD=13.2). Table 4 presents the factors associated with HRQoL among diabetic patients. In terms of EQ-5D index, patients who were male, living in an urban area, could afford treatment, were taking fewer medications, and often monitored their blood pressure (1–4 times/week) had a higher EQ-5D index compared to others. Meanwhile, higher duration of diabetes and older age were negatively associated with the EQ-5D index. Participants who had any comorbidities had lower VAS scores than their counterparts. Those living in urban areas and taking 3–5 drugs had higher VAS score than those living in rural settings and taking more than 5 drugs, respectively. Discussion Our study was among the first research offering needed insights about the HRQoL of elderly Vietnamese with T2DM. In this study, we found that elderly patients with T2DM had a lower EQ-5D index and VAS score when compared to the general elderly Vietnamese population.35 This result was also lower than HRQoL of elderly patients with diabetes in Korea36 and India,37 but higher than that in Saudi Arabia.38 Moreover, our elderly diabetic patients reported substantially high rates of having problems in pain/discomfort, mobility, and anxiety/depression, which align with other studies on Asian populations.21,36,39,40 After using multivariate regressions to adjust for sociodemographic characteristics, our results showed that those suffering from comorbidities were more likely to report lower HRQoL, being consistent with worldwide studies.26,27,30,41,42 In our cohort, we observed that hypertension and dyslipidemia were the most common comorbidities. Our results also demonstrated that polypharmacy was associated with lower HRQoL. Multiple drugs were often prescribed to patients to manage their T2DM (ie, insulin, anti-hypoglycemic drugs, etc.), comorbid conditions, and related complications. Over-prescription and polypharmacy pose increased risk of adverse drug reactions in the elderly due to physiological changes that result in impaired drug metabolism and excretion.43 In addition, we also found that higher duration of diabetes was found to have a significantly negative association with patients’ HRQoL, which is consistent with some previous studies.39,44 Geriatric syndromes, increasing age, and T2DM often require some forms of long-term management and treatment of sequelae, which may compound in those with a longer disease duration.45,46 In middle- to low-income countries like Vietnam, management of these chronic conditions places a heavy socioeconomic and emotional burden on both patients and their families.47–49 It is likely that our decreased HRQoL in those with a longer disease duration is a combination of compounding comorbidity and complications along with the impact of socioeconomic and emotional burden. In this study, we found that people with insulin treatment had lower HRQoL compared to those not using any therapies; however, the association was insignificant. Lu et al found that both insulin and oral agent use were associated with lower EQ-5D index scores.44 In addition, Luk et al found that insulin use was associated with higher EQ-5D index, but with a lower VAS score,39 whereas other work has found that treatment therapies had no impact on HRQoL.21,40,50 The lower HRQoL in insulin-treated patients is likely explained by the suffering associated with a heavier burden in patients with more advanced disease, along with the diverse set of complications that come with it.41 The difference between our study and other previous studies may be due to the smaller sample size and more advanced age of our cohort. Moreover, Maatouk et al suggested that insulin injections might carry lower stigma in the elderly than in younger adults.30 In addition, the lower HRQoL could be caused by the pain of multiple daily insulin injections and the patients’ beliefs that taking insulin means the diabetes is worse and the patient has failed.51 Therefore, this finding points the need of educational counseling programs for insulin-treated patients from the health staff. Self-monitoring of blood glucose and hypertension are common home management practices among elderly patients. In this study, we found that frequent monitoring of blood pressure was positively associated with higher HRQoL. Hypertension is both a complication and risk factor of diabetes.13 This illness is also a risk factor of other diseases such as stroke and cardiovascular diseases.52 Self-monitoring is associated with improved self-care and better treatment compliance, leading to the improvement of health status and HRQoL in patients with chronic diseases.31,53 This study has several implications. First, providers of patients with longer disease duration are cognizant of the increased burden faced by those with advanced disease. Interventions focused on improving psychological and emotional wellbeing may improve the HRQoL of patients by addressing important illness and burden-related concerns more common to advanced disease. Second, health care providers should provide education to patients about the importance and effectiveness of self-management practices, such as regular blood pressure and blood glucose monitoring. Moreover, the role of the family in supporting patients in being successful in the self-management of their disease, thereby slowing its advancement, should also be emphasized. Finally, larger future studies should be conducted to fill in the gaps about the HRQoL impact of insulin-related complications among Vietnamese diabetic patients. There were several limitations to this study. First, its cross-sectional design restricts the drawing of causal relationships between HRQoL and potential associated factors. Second, our use of convenience sampling limits the generalizability of our study to other hospital settings. The effects of recall bias in our data, due to the use of mainly self-reported data, further limit our results. Conclusion Our study is the first examination of the HRQoL among elderly diabetic patients in Vietnam. Significant decreases in reported HRQoL were related to disease duration, comor-bidity, treatment modality, and self-management practices. Screening and identifying health problems in these patients, as well as providing prompt treatment and facilitating self-management, offer low-cost solutions to improving HRQoL in a resource-scarce setting. Acknowledgments The authors gratefully appreciate Ms Dinh Kim Dung and Ms Dao Thi Huyen for helping to recruit patients for this study. Disclosure The authors report no conflicts of interest in this work. Figure 1 HRQoL of participants described with the EQ-5D-3L instrument. Abbreviations: HRQoL, health-related quality of life; EQ-5D-3L, EuroQol Five Dimensions Three Levels. Figure 2 Mean EQ-VAS score for age groups. Abbreviation: EQ-VAS, EuroQol Visual Analog Scale. Table 1 Socioeconomic and behavior characteristics of respondents n Percentage Total 171 100.0 Sex, female 100 58.5 Education attainment  Low education 57 33.4  Medium education 60 35.1  High education 54 31.6 Living location  Urban area 162 94.7  Rural area 9 5.3 Living with  Family 160 93.6  Alone 7 4.1  Others 4 2.3 Being taken care by  Family 161 94.2  Other people 6 3.5  None 4 2.3 Able to pay diabetes treatment 140 81.9 Have health insurance 170 99.4 Smoking 38 22.2 Alcohol use 138 80.7 Comorbidities  Yes 159 93.0  No 12 7.0 Body mass index categories  Underweight 5 2.9  Normal 138 80.7  Overweight/obesity 28 16.4 Mean SD Age (years) 69.4 6.8 EQ-5D index 0.80 0.20 VAS 57.5 14.4 Abbreviations: EQ-5D, EuroQol Five Dimensions; VAS, Visual Analog Scale. Table 2 Treatment characteristics among respondents n Percentage Duration of diabetes  <1 year 7 4.1  1–5 years 35 20.5  6–10 years 45 26.3  >10 years 84 49.1 Treatment therapy  OAD 86 50.3  Insulin 25 14.6  OAD and insulin 56 32.7  None 4 2.4 Number of medicines  <3 28 16.4  3–5 65 38.0  >5 78 45.6 Mean SD Fasting plasma glucose (mmol/L) 7.7 2.2 HbA1c (%) 7.1 1.5 Abbreviation: OAD, oral anti-diabetic drug. Table 3 Diabetes self-management of respondents n Percentage Self-monitoring blood glucose at home  Yes 118 69.0  No 53 31.0 Frequency of blood pressure monitor  Always (5 times per week or more) 73 42.7  Often (1–4 times per week) 42 24.6  Rarely (1–3 times per month) 44 25.7  Never 12 7.0 Diet modification  Yes 148 86.6  No 23 13.5 Frequency of doing physical exercises  5 times per week or more 133 77.8  1–4 times per week 12 7.0  1–3 times per month 11 6.4  Never 15 8.8 Ever delayed examination  Yes 6 3.5  No 165 96.5 Forgot to take medicine  Yes 29 17.0  No 142 83.0 Table 4 Factors associated with HRQoL among diabetic patients EQ-5D index VAS Coef 95% CI Coef 95% CI Sex (male vs female) 0.22* 0.11; 0.34 4.80 −0.40; 10.01 Age −0.01* −0.02; −0.00 Living location (urban vs rural) 0.33* 0.13; 0.54 12.13* 1.28; 22.98 Afford diabetic treatment (yes vs no) 0.16* 0.01; 0.30 Duration of diabetes (vs <1 year)  6–10 years −0.14* −0.25; −0.02 Treatment modalities (vs none) Insulin −0.12 −0.26; 0.01 −6.71 −13.87; 0.45 Number of drugs used (vs >5 drugs)  <3 drugs 0.23* 0.08; 0.38 5.19 −2.22; 12.59  3–5 drugs 0.19* 0.07; 0.30 9.77* 4.14; 15.39 Self-monitoring blood glucose at home (yes vs no) 0.07 −0.04; 0.19 Having comorbidities (yes vs no) −10.16* −19.00; −1.33 Frequency of doing exercises (vs none)  1–4 times/week 0.14 −0.05; 0.33 Forgot to take medicine (no vs yes) 0.16 −0.07; 0.39 Frequency of monitoring blood pressure (vs none)  1–4 times/week 0.21* 0.07; 0.34 Note: * p<0.05. Abbreviations: HRQoL, health-related quality of life; EQ-5D, EuroQol Five Dimensions; VAS, Visual Analog Scale; CI, confidence interval. ==== Refs References 1 World Health Organization World Report on Ageing and Health 2015 Available form: http://www.who.int/ageing/events/world-report-2015-launch/en/ Accessed November 18, 2017 2 General Statistics Office of Vietnam Major findings: the 1/4/2015 time-point population change and family planning Hanoi General Statistics Office of Vietnam 2016 3 Bussarawan T Long GT Socioeconomic status and health among older adults in Vietnam, 2001–2011 XXVII IUSSP International Population Conference August 26–31, 2013 Busan, Republic of Korea 4 Huong NT Ha LTH Tien TQ Determinants of health-related quality of life among elderly: evidence from Chi Linh Town, Vietnam Asia Pac J Public Health 2017 29 5_suppl 84S 93S 28425322 5 George PP Heng BH De Castro Molina JA Wong LY Wei Lin NC Cheah JT Self-reported chronic diseases and health status and health service utilization – results from a community health survey in Singapore Int J Equity Health 2012 11 44 22894180 6 Toan NV Trong LN Höjer B Persson LA Public health services use in a mountainous area, Vietnam: implications for health for policy Scand J Public Health 2002 30 2 86 93 12028857 7 Kruk ME Freedman LP Assessing health system performance in developing countries: a review of the literature Health Policy 2008 85 3 263 276 17931736 8 Giang KB Allebeck P Self-reported illness and use of health services in a rural district of Vietnam: findings from an epidemiological field laboratory Scand J Public Health Suppl 2003 62 52 58 14649642 9 Ravens-Sieberer U Measuring and monitoring quality-of-life in population surveys: still a challenge for public health research Soz Praventivmed 2002 47 4 203 204 12415920 10 International Diabetes Federation IDF Diabetes Atlas Seventh Edition 2015 Available from: http://www.diabetesatlas.org/component/attachments/?task=download&id=116 Accessed September 23, 2017 11 Pham NM Eggleston K Prevalence and determinants of diabetes and pre-diabetes among Vietnamese adults Diabetes Res Clin Pract 2016 113 116 124 26795973 12 Khue NT Diabetes in Vietnam Ann Glob Health 2015 81 6 870 873 27108154 13 Nguyen CT Pham NM Lee AH Binns CW Prevalence of and risk factors for type 2 diabetes mellitus in Vietnam: a systematic review Asia Pac J Public Health 2015 27 6 588 600 26187848 14 Duc Son le NT Hanh TT Kusama K Anthropometric characteristics, dietary patterns and risk of type 2 diabetes mellitus in Vietnam J Am Coll Nutr 2005 24 4 229 234 16093399 15 Khan NC Khoi HH Double burden of malnutrition: the Vietnamese perspective Asia Pac J Clin Nutr 2008 17 Suppl 1 116 118 16 Ta MT Nguyen KT Nguyen ND Campbell LV Nguyen TV Identification of undiagnosed type 2 diabetes by systolic blood pressure and waist-to-hip ratio Diabetologia 2010 53 10 2139 2146 20596691 17 Mwangi J Kulane A Van Hoi L Chronic diseases among the elderly in a rural Vietnam: prevalence, associated socio-demographic factors and healthcare expenditures Int J Equity Health 2015 14 134 26578189 18 Paolisso G Pathophysiology of diabetes in elderly people Acta Biomed 2010 81 Suppl 1 47 53 19 Kesavadev JD Short KR Nair KS Diabetes in old age: an emerging epidemic J Assoc Physicians India 2003 51 1083 1094 15260395 20 Croxson SC Price DE Burden M Jagger C Burden AC The mortality of elderly people with diabetes Diabet Med 1994 11 3 250 252 8033522 21 Choi YJ Lee MS An SY The relationship between diabetes mellitus and health-related quality of life in Korean adults: the Fourth Korea National Health and Nutrition Examination Survey (2007–2009) Diabetes Metab J 2011 35 6 587 594 22247901 22 Kanauchi M Kubo A Kanauchi K Saito Y Frailty, health-related quality of life and mental well-being in older adults with cardiometabolic risk factors Int J Clin Pract 2008 62 9 1447 1451 18643932 23 Lin CC Li CI Chang CK Reduced health-related quality of life in elders with frailty: a cross-sectional study of community-dwelling elders in Taiwan PLoS One 2011 6 7 e21841 21747961 24 Nezu S Okamoto N Morikawa M Health-related quality of life (HRQOL) decreases independently of chronic conditions and geriatric syndromes in older adults with diabetes: the Fujiwara-kyo Study J Epidemiol 2014 24 4 259 266 24814506 25 Tang WL Wang YM Du WM Cheng NN Chen BY Assessment of quality of life and relevant factors in elderly diabetic patients in the Shanghai community Pharmacoepidemiol Drug Saf 2006 15 2 123 130 16294368 26 Ghassemzadeh R Nasseh H Arastoo AA Kamali M Rahimi Foroushani A Arzaghi M Quality of life in elderly diabetic: comparison between home and nursing home Acta Med Iran 2013 51 4 254 259 23690106 27 Trief PM Wade MJ Pine D Weinstock RS A comparison of health-related quality of life of elderly and younger insulin-treated adults with diabetes Age Ageing 2003 32 6 613 618 14600002 28 Ausili D Bulgheroni M Ballatore P Self-care, quality of life and clinical outcomes of type 2 diabetes patients: an observational cross-sectional study Acta Diabetol 2017 54 11 1001 1008 28852863 29 Trikkalinou A Papazafiropoulou AK Melidonis A Type 2 diabetes and quality of life World J Diabetes 2017 8 4 120 129 28465788 30 Maatouk I Wild B Wesche D Temporal predictors of health-related quality of life in elderly people with diabetes: results of a German cohort study PLoS One 2012 7 1 e31088 22292092 31 Gilden JL Casia C Hendryx M Singh SP Effects of self-monitoring of blood glucose on quality of life in elderly diabetic patients J Am Geriatr Soc 1990 38 5 511 515 2332571 32 Brown DW Balluz LS Giles WH Behavioral Risk Factor Surveillance System (BRFSS) Diabetes mellitus and health-related quality of life among older adults. Findings from the behavioral risk factor surveillance system (BRFSS) Diabetes Res Clin Pract 2004 65 2 105 115 15223222 33 Group E EQ-5D-3L User Guide: Basic information on how to use the EQ-5D-3L instrument 2015 Available from: https://euroqol.org/wp-content/uploads/2016/09/EQ-5D-3L_UserGuide_2015.pdf Accessed January 6, 2017 34 American Diabetes Association Standards of medical care in diabetes – 2017 Diabetes Care 2017 40 1 48 57 35 Bang KS Tak SH Oh J Yi J Yu SY Trung TQ Health status and the demand for healthcare among the elderly in the rural Quoc-Oai District of Hanoi in Vietnam Biomed Res Int 2017 2017 4830968 29147653 36 Lee WJ Song KH Noh JH Choi YJ Jo MW Health-related quality of life using the EuroQol 5D questionnaire in Korean patients with type 2 diabetes J Korean Med Sci 2012 27 3 255 260 22379335 37 Singh K Kondal D Shivashankar R Health-related quality of life variations by sociodemographic factors and chronic conditions in three metropolitan cities of South Asia: the CARRS study BMJ Open 2017 7 10 e018424 38 Al-Aboudi IS Hassali MA Shafie AA Knowledge, attitudes, and quality of life of type 2 diabetes patients in Riyadh, Saudi Arabia J Pharm Bioallied Sci 2016 8 3 195 202 27413347 39 Luk AOY Zhang Y Ko GTC Health-related quality of life in Chinese patients with type 2 diabetes: an analysis of the Joint Asia Diabetes Evaluation (JADE) Program J Diabetes Metab 2014 5 333 40 Sakamaki H Ikeda S Ikegami N Measurement of HRQL using EQ-5D in patients with type 2 diabetes mellitus in Japan Value Health 2006 9 1 47 53 16441524 41 Wändell PE Tovi J The quality of life of elderly diabetic patients J Diabetes Complications 2000 14 1 25 30 10925063 42 Sakurai T Iimuro S Sakamaki K Japanese Elderly Diabetes Intervention Trial Study Group Risk factors for a 6-year decline in physical disability and functional limitations among elderly people with type 2 diabetes in the Japanese Elderly Diabetes Intervention Trial Geriatr Gerontol Int 2012 12 Suppl 1 117 126 22435947 43 Milton JC Hill-Smith I Jackson SH Prescribing for older people BMJ 2008 336 7644 606 609 18340075 44 Lu Y Wang N Chen Y Health-related quality of life in type-2 diabetes patients: a cross-sectional study in East China BMC Endocr Disord 2017 17 1 38 28683734 45 Li MZ Ji LN Meng ZL Management status of type 2 diabetes mellitus in tertiary hospitals in Beijing: gap between guideline and reality Chin Med J (Engl) 2012 125 23 4185 4189 23217384 46 Stolar MW Hoogwerf BJ Gorshow SM Boyle PJ Wales DO Managing type 2 diabetes: going beyond glycemic control J Manag Care Pharm 2008 14 5 Suppl B s2 s19 47 Gallacher K May CR Montori VM Mair FS Understanding patients’ experiences of treatment burden in chronic heart failure using normalization process theory Ann Fam Med 2011 9 3 235 243 21555751 48 Sav A Salehi A Mair FS McMillan SS Measuring the burden of treatment for chronic disease: implications of a scoping review of the literature BMC Med Res Methodol 2017 17 1 140 28899342 49 Sav A King MA Whitty JA Burden of treatment for chronic illness: a concept analysis and review of the literature Health Expect 2015 18 3 312 324 23363080 50 Mayberry LS Osborn CY Family support, medication adherence, and glycemic control among adults with type 2 diabetes Diabetes Care 2012 35 6 1239 1245 22538012 51 Fremantle N Blonde L Duhot D Availability of inhaled insulin promotes greater perceived acceptance of insulin therapy in patients with type 2 diabetes Diabetes Care 2005 28 2 427 428 15677807 52 World Health Organization Hypertension 2017 Available from: http://www.who.int/topics/hypertension/en/ Accessed November 18, 2017 53 Watts FN Behavioural aspects of the management of diabetes mellitus: education, self-care and metabolic control Behav Res Ther 1980 18 3 171 180 7417205