Journal of Human Hypertension (2008) 22, 366–369 & 2008 Nature Publishing Group All rights reserved 0950-9240/08 $30.00 www.nature.com/jhh
RESEARCH LETTER
Factors associated with hypertension awareness, treatment and control in rural Chinese Journal of Human Hypertension (2008) 22, 366–369; doi:10.1038/sj.jhh.1002303; published online 15 November 2007
The factors associated with hypertension awareness, treatment and control were studied in 45 925 rural Chinese aged X35 years. Of all hypertensives (n ¼ 17 355), 29.5% were aware of their condition, 20.2% were receiving treatment and only 0.9% had their blood pressure (BP) adequately controlled, and most hypertensives in rural China did not comprehend the fatalness of high BP. Results indicate that more attention is needed in improving the cognitional level of hypertensive fatalness and more effort is also needed in promoting hypertension awareness, treatment and control among all hypertensives in rural China. Hypertension is one of the leading causes of cardiovascular disease and premature mortality in the world and its role is set to continue.1,2 Establishing factors associated with awareness and management is an essential starting point in preventing increasing burden of morbidity and mortality from hypertension-related cardiovascular diseases.3–5 However, in China, especially in rural China where resource setting is poorer than the urban, information on factors associated with awareness, treatment and control of hypertension is very scarce despite increasing prevalence of hypertension. The emerging data, mostly from the industrialised nations, indicate that factors such as age, sex, socioeconomic and body sizes are associated with hypertension awareness, treatment and control.3,5 It is unclear, however, whether these factors are applicable in very poor resource settings. We investigated 45 925 rural adult people from 2004 to 2006 in Liaoning province of China to examine factors associated with hypertension awareness, treatment and control. Overall, 37.8% (n ¼ 17 355) of the Chinese rural adult population age 35–85 years had hypertension. Only 29.5% of those with hypertension were aware of their diagnosis. Of all hypertensives, only 20.2% were taking prescribed medication to lower their blood pressure (BP), and 0.9% had controlled hypertension. Of those aware of their hypertension diagnosis, 68.5% (3507/5116) were treated, and 4.5% (159/3507) of those treated had an systolic BP/diastolic BP o140/90 mm Hg at their study visit.
Among all hypertensives, 61.9% (10 745/17 355) did not think that high BP would endanger their lives, which was higher in those unaware of their hypertension (69.8%; 8547/12 239) than that in those aware of their hypertension diagnosis (43.0%; 2198/ 5116). Among those non-compliant hypertensives who were aware their hypertension diagnosis but not taking prescribed medication to lower their BP, only 48.0% (772/1609) cognized the fatalness of hypertension, and 28.0% (450/1609) cited unaffordable drug prices as the reasons for non-compliance. After adjusted for age, sex and other factors, the odds ratio (OR) of hypertension awareness were higher among participants X55 years old; those who had a higher level of education, were former smokers, were overweight or obese, had a higher income and with family history of hypertension (Table 1). Among those aware of having hypertension, participants who were older than 45 years, were female, were former smokers and were overweight, had a higher education level, with family history of hypertension, and those whose BP had been measured termly were more likely to be receiving pharmacological treatment for their hypertension. In contrast, those with the highest income were significantly less likely to be receiving antihypertensive medication (OR ¼ 0.77; 95% CI: 0.66– 0.91). Among persons receiving treatment for their hypertension, the OR (95% CI) of hypertension control was 0.47 (0.22, 0.99) for those who measure their BP termly within 3–6 months. This study presents several important findings regarding awareness, treatment and control of hypertension in rural China where information is especially lacking. Overall, the proportion of hypertensives aware, treated and controlled was low. At the same time, the results also showed that most hypertensives both unaware and aware of their hypertension diagnosis did not think that high BP would endanger their lives, and among those non-compliant hypertensives who were not taking prescribed medication to lower their BP, only 48.0% cognized the fatalness of hypertension. A total of 27.4% of the hypertensives never measured their BP after a diagnosis of hypertension. Like other economically developing countries, the health care system in China, especially in rural China, faces a financial challenge. Although national guidelines require BP to be measured
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Table 1 Prevalence (%) and adjusted OR (95% CI) of factors associated with hypertension awareness, treatment and control in rural a
adults, Liaoning province, China
Awareness (n ¼ 5116)
Characteristic
Treatment (n ¼ 3507)
Control (n ¼ 159)
P
OR (95% CI)
P
OR (95% CI)
P
OR (95% CI)
Age group (year) 35–44 45–54 55–64 X65
19.5 27.0 35.6 34.1
1.00 1.58 (1.42, 1.76) 2.64 (2.37, 2.94) 3.00 (2.66, 3.38)
62.8 67.2 70.1 70.7
1.00 1.22 (1.00, 1.49) 1.43 (1.17, 1.74) 1.68 (1.35, 2.09)
5.5 5.0 4.7 3.5
1.00 0.84 (0.50, 1.41) 0.75 (0.45, 1.24) 0.54 (0.30, 0.97)
Sex Male Female
25.9 32.8
1.00 1.32 (1.21, 1.43)
64.7 71.4
1.00 1.39 (1.19, 2.22)
3.8 5.0
1.00 1.30 (0.86, 1.97)
Marital status No Married
21.3 33.0
1.00 1.52 (0.80, 2.90)
84.6 60.2
1.00 0.28 (0.06, 1.34)
1.2 5.1
1.00 1.31 (0.47, 2.61)
Educational level No school Primary school XHigh school
31.5 28.8 34.0
1.00 1.23 (1.10, 1.37) 1.57 (1.32, 1.87)
68.4 68.1 73.9
1.00 1.17 (0.96, 1.42) 1.63 (1.19, 2.22)
4.2 4.5 5.6
1.00 0.97 (0.57, 1.67) 1.31 (0.61, 2.80)
Body weight Normal weight Overweight Obese
26.3 36.1 43.1
1.00 1.66 (1.54, 1.79) 2.04 (1.71, 2.43)
67.3 70.2 72.9
1.00 1.14 (1.00, 1.30) 1.16 (0.86, 1.55)
4.9 4.1 3.2
1.00 0.71 (0.50, 1.02) 0.51 (0.22, 1.20)
Income Quartile Quartile Quartile Quartile
28.5 28.4 27.9 33.9
1.00 1.04 (0.95, 1.14) 1.02 (0.93, 1.12) 1.28 (1.17, 1.41)
69.8 69.4 69.9 64.8
1.00 1.01 (0.86, 1.19) 1.04 (0.87, 1.25) 0.77 (0.66, 0.91)
3.8 5.4 4.2 4.9
1.00 1.45 (0.95, 2.22) 1.09 (0.67, 1.77) 1.31 (0.83, 2.07)
Cigarette smoking Never Current Former
30.9 26.2 49.8
1.00 1.01 (0.93, 1.10) 2.58 (2.10, 3.18)
69.5 65.9 77.6
1.00 1.04 (0.89, 1.20) 1.47 (1.04, 2.09)
4.8 3.8 6.8
1.00 0.94 (0.63, 1.41) 1.89 (0.96, 3.73)
Alcohol consumption o2 drinks per day X2 drinks per day
31.1 23.9
1.00 0.82 (0.74, 0.91)
69.6 63.9
1.00 0.90 (0.75, 1.08)
4.8 3.3
1.00 0.73 (0.42, 1.27)
Family history of hypertension No 26.2 Yes 43.6
1.00 2.43 (2.24, 2.64)
69.7 68.1
1.00 1.10 (0.96, 1.26)
4.7 4.2
1.00 0.86 (0.60, 1.24)
Periodicity of BP measurement Never 27.4b 46 months 15.9b 3–6 months 10.2b o3 months 46.5b
— — — —
53.4 67.2 68.3 78.0
1.00 1.79 (1.48, 2.13) 1.87 (1.51, 2.32) 3.05 (2.64, 3.52)
5.1 4.8 2.5 4.6
1.00 0.92 (0.55, 1.53) 0.47 (0.22, 0.99) 0.88 (0.59, 1.31)
1 (lowest) 2 3 4 (highest)
Abbreviations: BP, blood pressure; CI, confidence interval; OR, odds ratio. a Adjusted for age, sex, education level, marital status, former and current smoking, overweight, obesity, income, alcohol consumption, family history of hypertension and periodicity of BP measurement. b Represents the percentage of the participants aware of their hypertension diagnosis.
during all outpatient visits, it is still very common that no BP check-up is performed, especially in rural China. In addition, community-based BP screening and education programmes are uncommon in rural China. Our findings highlight the need for developing a national high BP education programme to coordinate the effort of detection, prevention and treatment of hypertension in rural China.
Studies from several countries have investigated factors associated with hypertension awareness, treatment and control.6–9 Our study findings are consistent with several previous reports. Studies conducted in developing countries have consistently indicated that compared to their counterparts with a lower income, persons with a higher income have better access to health care and higher rates of awareness, treatment and control of hypertension. Journal of Human Hypertension
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However, contrast to these studies, our investigation showed that among those aware of their hypertension, treatment was less common among those with the highest income (OR ¼ 0.77; 95% CI: 0.66–0.91). Among these rural Chinese with a higher income, 15.7% cited often forgetting to take medication for busy work as the reasons for non-compliance that was higher than their counterparts with a lower income (9.2%). So, it may suggest that the association of the highest income and less treatment among rural Chinese could be explained by persons with more income spending much more time on their busy work and forgetting to take medication. Also, there may be other potential factors, and we will continue to study for the reason that remained unclear. The associations between education level and hypertension awareness, treatment and control have remained inconsistent. In the SUNSET study,9 there were no associations between education level and hypertension awareness, treatment and control in the ethnic groups of the Indian and the African, but in the white Dutch hypertensives. In Nieto et al.’s10 study, lower education level was associated with poor BP control. On the contrary, others have found lower control rates among those with higher education levels.11 The results of this study showed that education is a strong socioeconomic predictor of awareness and treatment, but not of control. Family history of hypertension is a well-established risk factor for hypertension. However, very little is known about the associations between family history of hypertension and awareness, treatment and control of hypertension. One study that had assessed family history of hypertension and BP control found no association.12 In the SUNSET study,9 however, family history of hypertension was a strong predictor of hypertension awareness and treatment in the Dutch ethnic groups and was also associated with better BP control in African subjects. In the present study, however, we found that the family history of hypertension was associated only with awareness and treatment of hypertension. These findings may imply that the presence of family history of hypertension may positively influence individuals to check their BP and seek medication intervention. It may also be well that physicians pay more attention to patients with a family history of hypertension, as they are at greater risk of cardiovascular disease. In conclusion, the findings of this study have important public health implications. First, more attention is needed in improving the cognitional level of the fatalness of hypertension in rural adults of China. Second, more effort is also need in promoting hypertension awareness, treatment and control among those not only with higher hypertension risk but also with lower hypertension risk. Finally, control of hypertension was lower among former smokers and among persons who consume o2 drinks of alcohol per day, although the Journal of Human Hypertension
difference was not significant. Smoking cessation and reduced alcohol consumption may not be the sole reason for controlled hypertension among these patients but may occur concurrently with other lifestyle modifications that benefit persons making these changes. Contribution of this paper to the understanding of hypertension in rural Chinese from Liaoning province What is known on this topic K In rural China, hypertension, once rare, is rapidly becoming a major public health burden. At the same time hypertension awareness, treatment and control, which are central to prevention, are unacceptably low. What this paper adds Most hypertensives in rural China did not comprehend the fatalness of high BP. K Old age, overweight, obesity, high income, former smokers and persons with family history of hypertension are associated with higher awareness of hypertension. K Old age, female sex, high educational level and former smokers are associated with higher, whereas male sex and high income are associated with lower treatment of hypertension in rural Chinese. K Old age and BP measured termly are associated with poor BP control in rural Chinese. K
Abbreviation: BP, blood pressure.
G Dong1, Z Sun2, L Zheng2, J Li3, X Zhang2, C Xu2, D Hu3 and Y Sun2 1 Department of Biostatistics, School of Public Health, China Medical University, Shenyang, People’s Republic of China; 2 Division of Cardiology, The Second Affiliated Hospital of China Medical University, Shenyang, People’s Republic of China and 3 Heart, Lung and Blood Vessel Center, Tongji University, Shanghai, People’s Republic of China E-mails:
[email protected] or
[email protected] Published online 15 November 2007
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