STRENGTHS AND LIMITATIONS OF THIS STUDY
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A native representative and relative comprehensive disease surveillance system was used to evaluate the prevalence of disease among community residents in Dongfang.
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Data were not based on a random sample of the entire population, and confounding factors may exist.
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The 2021 disease data were affected by Corona Virus Disease 2019.
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Data reported by disease surveillance system contained fewer research variables and did not allow for more comprehensive identification of disease-related risk factors.
Introduction
The prevalence and burden of disease are important indicators of population health status.1 International organisations regularly released the Global Burden of Diseases, Injuries and Risk Factors Study (GBD),2 which exposed the transition in disease patterns as a result of economy development, demographic changes and changes in the living environment, lifestyles and psychological structure of the population.3 4 In 2015, the United Nations (UN) proposed reducing premature mortality from chronic non-communicable diseases (NCDs) by one-third as one of the UN’s Sustainable Development Goals (SDGs).5 As the most populous developing country in the world, China recorded that the prevalence of NCDs has increased from 17.0% in 1993 to 34.3% in 2018 and the burden of disease resulting from NCDs as a percentage of the total disability-adjusted life years increased by 21.31%.6 In addition, the financial burden of NCDs in China has reached 70% of the total economic burden in 2013, making them an important cause for affecting the economic level of families and the communities.7 To achieve the UN’s SDGs, the prevention and control of NCDs is the main health task in China.
Identifying the risk factors associated with NCDs is the key to prevention and treatment. The social determinants have been noted to have a key role in the onset and course of NCDs, with three individual-level sociodemographic factors of gender, age and socioeconomic status receiving increased attention.8 Previous epidemiological studies have found significant disparities in the prevalence of NCDs between men and women, and that older adults are more susceptible to most NCDs than younger adults.9 10 It has also been found that different personnel categories, that is, different socioeconomic status, including income and occupation, may affect NCDs, with the unemployed and the poor having a higher risk of NCDs than the employed and the wealthy.11 Furthermore, the effect of socioeconomic status on NCDs may vary by some demographic characteristics. A growing body of evidence suggests that the interaction between socioeconomic status and age, gender, ethnicity and other factors has a more complex picture arose on predicting NCDs.12 13 However, the consequences of sociodemographic factors are complex and dynamic, and each may have a unique contribution to different diseases10 and exhibit regionalised characteristics in terms of disease associations.
China is a vast country, and there are large differences among different regions in the environment, ethnicity, seasonal climate, living customs and level of economic development, making the prevalence of NCDs and risk factors distinctly regional and leading to a characteristic ordering of the NCDs spectrum across regions. Dongfang, the third largest coastal city in Hainan Province, with a tropical climate, but with distinct dry and wet seasons and low rainfall, becomes one of the driest cities in Hainan Province. Dongfang has achieved great economic development and is an important energy and heavy chemical industry base in Hainan Province, but its industrialisation has brought many negative effects, such as ranking last in Hainan in terms of environmental quality. Meanwhile, the average life expectancy of Dongfang residents in 2020 was 73.5 years, lower than the national average, and the premature mortality due to NCDs more than 13%. Dongfang is mostly rural. There is evidence that the prevalence of NCDs is increasing more rapidly in rural areas than in urban areas.14 Additionally, the cluster of staple food risk factors and physical activity risk factors in Dongfang, located in South China, was also at the highest level in China.15 However, there is fewer studies supporting its epidemiologic transition. Based on the above heterogeneity of region, including climate, regional distribution characteristics, lifestyle and exposure to the living environment,16 the health resource allocation and prevention and control measures of NCDs in other regions of China and Western populations are not applicable to Dongfang population. Dongfang will not be one of the enablers of China’s achievement of the SDGs without pronounced acceleration of progress to discover major diseases, reduce risk exposure and improve essential health services. Therefore, there is an urgent need to establish a large, localised population-based disease spectrum database.
The purpose of this study was to provide an up-to-date statistics of disease spectrum among community residents in Dongfang, China in 2021. Towards this goal, we investigated the prevalence and burden of specific NCDs, moreover, we evaluated the associated sociodemographic factors of major NCDs in Dongfang to provide a scientific basis for decision-making in the health administration and development of health promotion planning.
Methods
Study design and data source
This population-based cross-sectional study was conducted in Dongfang, which has a population of about 444 500. We evaluated the medical records of community residents between 1 January 2021 and 31 December 2021. The electronic medical record data were collected from the regional disease surveillance system of Dongfang. This system integrates all inpatient and outpatient electronic medical records derived from district and county hospitals, clinics and health community centres of Dongfang, as well as the local medical insurance databases. Furthermore, the total population covered by the system accounted for 81.65% of the total population in Dongfang, which indicates that it is more authoritative, has wide coverage and good municipal representation. The inclusion criteria were residents who met the population criteria of Dongfang as defined by the census and sample survey. The exclusion criteria were repeated visits for the same disease and cases with incomplete and inaccurate information. A total of 362 677 medical records were exported for the present study, of which 165 916 medical records were incomplete, inaccurate and duplicates and were excluded. Ultimately, the data of 196 761 community residents could be analysed in the study (online supplemental figure 1) with a demographic composition similar to that of the citywide population.
Supplemental material
The disease surveillance system includes information on general demographic characteristics (eg, sex, age, personnel category and residential address), medical insurance information (eg, medical insurance reimbursement rate) and disease information (eg, disease diagnosis, medical category, time in and out of hospital and days in hospital). Data from these sources are interrelated by each individual’s unique personal identification number and name used by each resident throughout their lifetime in China.
Case definition
Disease diagnoses were coded according to the Tenth Revision of International Classification of Diseases (ICD-10). This study classified the diseases with reference to the list of leading causes of death coded in ICD-10, which helped to rank the diseases.17 At the same time, to study profile from different diseases category, the diseases were grouped into four categories on the basis of the classification criteria of the WHO: communicable diseases, maternal-infant diseases and nutritional deficiency diseases, NCDs, injury and other diseases.
Six relevant individual factors were considered in the analysis: gender (men and women), age, geographical location (northern vs non-northern), personnel category, payment method and medical insurance reimbursement rate. Age was divided into five groups: <5 years, 5–14 years, 15–44 years, 45–59 years and ≥60 years. Personnel category referred to the classification of a population according to an individual’s social and economic status and were divided into three types: employed (including civil servants, flexible employment, disabled soldiers and ordinary workers), unemployed (including students, retired civil servants, jobless residents, retired flexible workers, retired disabled soldiers, preschool children and ordinary retired workers) and poor household (per capita net income is lower than the national poverty alleviation standard).
Statistical analysis
The cause-specific prevalence and corresponding disability burden were calculated separately for the gender. Disability burden included two indicators: (1) years of life lived with disability (YLDs): number of people with disease or sequelae×corresponding GBD disability weights;2 18 and (2) YLDs rate: YLDs/corresponding population×105. The above indicators have been standardised to account for variations in the age structure, using the seventh population census of China in 2020 as a reference. The rank order was based on proportion of diseases. The χ2 test and Cochran-Armitage trend test were performed to compare the differences in the prevalence of major diseases by personnel category or age under different genders.
Logistic regression was employed to test the influence and moderation effects of gender, age and personal category on major NCDs. Unadjusted and multivariable adjusted OR with 95% CI and two-sided p values were calculated. In multivariable models, age, gender, geographical location (northern vs non-northern), personnel category, payment method and medical insurance reimbursement rate were adjusted.
All analyses were conducted with SPSS V.26.0 (IBM Corporation, Armonk, NY, USA) and R V.4.0.3 (R Foundation for Statistical Computing). Differences were judged significant based on two-sided tests if p values were less than 0.05.
Patient and public involvement statement
Patients and/or the public were not involved in the design, or conduct, or reporting or dissemination plans of this research.
Results
In 2021, a total of 196 761 community residents were reported to be suffering from diseases in Dongfang, with the prevalence being 44.27% (95% CI 44.12% to 44.42%) and the age-standardised prevalence being 46.44% (95% CI 46.30% to 46.59%). Among them, there were 91 621 male patients, with a prevalence of 38.59% (95% CI 38.39% to 38.78%) and an age-standardised prevalence of 41.43% (95% CI 41.24% to 41.63%). There were 105 140 female patients, with the prevalence of 50.79% (95% CI 50.57% to 51.00%) and an age-standardised prevalence of 52.17% (95% CI 51.96% to 52.39%). It can be seen from the folding graph of prevalence of different sexes and age groups (online supplemental figure 2) that in different sexes in Dongfang, the age distribution of prevalence was approximately V-shaped. The prevalence in the age group of 1–4 years was high, then the rate decreased rapidly and reached the lowest point in the 25–29 age group for men and the 15–19 age group for women, followed by a gradual increase to reach its highest point (in ≥65 years old group).
The proportion of the four categories of diseases are shown in figure 1. The proportion of community residents with NCDs was higher than that of other three types of diseases, at 49.04% (n=96 490), which indicated that NCDs were the main health problem of community residents in Dongfang. The prevalence, percentage and disability burden for the 10 leading NCDs are shown in online supplemental table 1. The top three diseases were cardiovascular diseases (2.91%, 95%CI 2.86% to 2.96%), chronic lower respiratory diseases (1.95%, 95% CI 1.91% to 2.00%) and other upper respiratory tract diseases (1.52%, 95%CI 1.49% to 1.56%), accounting for 26.49% of all NCDs (28.65% in men and 24.57% in women). The age-standardised prevalence of cardiovascular diseases and chronic lower respiratory diseases was higher in men than in women, 2.95% (95% CI 2.88% to 3.02%) versus 2.88% (95% CI 2.80% to 2.95%) and 1.99% (95% CI 1.93% to 2.04%) versus 1.94% (95% CI 1.88% to 1.99%), respectively, while the opposite was true for other upper respiratory tract diseases (1.43%, 95% CI 1.38% to 1.47% vs 1.63%, 95% CI 1.57% to 1.68%). The main diseases that contributed to YLDs in community residents were cardiovascular diseases, with 414.72 person-years (95% CI 374.82 to 454.62), which was 1.23 to 11.92 times that of other diseases.
Supplemental material
The proportion of the four categories of diseases among community residents in Dongfang.
The age-specific and personnel-specific prevalence for major NCDs by gender are shown in online supplemental table 2. The prevalence of cardiovascular diseases increased with age in both men and women (each p<0.001). The prevalence of chronic lower respiratory diseases and other upper respiratory tract diseases showed a decrease and then an increase with age in both men and women (each p<0.05). Moreover, there were differences in age-standardised prevalence of major NCDs between different personnel categories in men and women (each p<0.001).
The association between demographic characteristics and risks of major NCDs are presented in table 1 and online supplemental figure 3, in which we show unadjusted and multivariable adjusted ORs (95% CI). After adjusting for age, gender, geographical location (northern vs non-northern), personnel category, payment method and medical insurance reimbursement rate, men were associated with increased risk of cardiovascular diseases (OR=1.210, 95% CI 1.162 to 1.261) and chronic lower respiratory diseases (OR=1.128, 95% CI 1.079 to 1.180) than women. Older residents were associated with increased risk of cardiovascular diseases (OR=83.952, 95% CI 58.954 to 119.550) than younger residents, whereas was associated with decreased risk of chronic lower respiratory diseases (OR=0.442, 95% CI 0.415 to 0.471) and other upper respiratory tract diseases (OR=0.450, 95% CI 0.411 to 0.493). Compared with the employed, the unemployed and poor household were associated with decreased risk of cardiovascular diseases (OR=0.463, 95% CI 0.412 to 0.521 and OR=0.390, 95% CI 0.342 to 0.444, respectively), whereas were associated with increased risk of chronic lower respiratory diseases (OR=12.219, 95% CI 6.343 to 23.539 and OR=10.954, 95% CI 5.666 to 21.177, respectively) and other upper respiratory tract diseases (OR=2.246, 95% CI 1.719 to 2.936 and OR=3.035, 95% CI 2.308 to 3.991, respectively).
Unadjusted and multivariable adjusted ORs of major non-communicable chronic diseases among community residents in Dongfang
Tables 2 and 3 show the moderating effects of gender and age on the association between personal category and the risk of major NCDs. The respective simple slopes of these relationship at different gender and age groups are displayed in online supplemental figure 4 and figure 2. Based on the magnitude and steepness of the slope, men and older employed residents had significantly higher odds of cardiovascular diseases than women and younger employed residents, respectively. Younger unemployed residents had a significant increase in their likelihood of chronic lower respiratory diseases than older unemployed residents, while younger residents of poor households had less likelihood on chronic lower respiratory diseases than older residents of poor households. Younger unemployed residents were less likely to have other upper respiratory tract diseases than older unemployed residents, while younger residents of poor households were more likely to have other upper respiratory tract diseases than older residents of poor households.
ORs of interaction terms for logistic regression models of moderation by gender and age of the employed on major non-communicable chronic diseases
ORs of interaction terms for logistic regression models of moderation by gender and age of the unemployed and poor household on major non-communicable chronic diseases
The moderation graph of age on personal category and major chronic non-communicable diseases. (A) The moderation graph of age on the employed and cardiovascular diseases; (B) the moderation graph of age on the unemployed and cardiovascular diseases; (C) the moderation graph of age on poor household and cardiovascular diseases; (D) the moderation graph of age on the employed and chronic lower respiratory diseases; (E) the moderation graph of age on the unemployed and chronic lower respiratory diseases; (F) the moderation graph of age on poor household and chronic lower respiratory diseases; (G) the moderation graph of age on the unemployed on other upper respiratory diseases and (H) the moderation graph of age on poor household on other upper respiratory diseases.
Discussion
The current study documented that the age-standardised prevalence of community residents in Dongfang was close to 50%, with the diseases predominantly occurring in the male and female populations aged≥65 years, indicating that the health status in Dongfang was poor, especially among the elderly. Therefore, identifying major diseases and some prominent problems, focusing on key groups in the region allow an effective way for the government, society and public work together to promote health. We found that NCDs accounted for 49.04% of all diseases, and although their proportion is still much lower than that in developed regions of China,19 they have become a major public health challenge in Dongfang. It is worth nothing that the proportion of the population aged 65 years or older in 2020 has increased by 2.99% compared with 2010, while the proportion of the population aged 15–59 years has decreased by 2.66%. The ageing population likely contributed to an overall increase in NCDs. Primary healthcare was considered an appropriate strategy to address such challenges. Our study found that the composition of NCDs mainly consisted of cardiovascular diseases, chronic lower respiratory diseases and other upper respiratory tract diseases, which differed from the national disease composition of cardiovascular and cerebrovascular diseases, tumours and chronic obstructive pulmonary diseases.20 This suggests that residents in Dongfang may be more sensitive to respiratory symptoms and that there have disparities in medical focus between policy makers, programme planners, clinicians and researchers in Dongfang and elsewhere, who mostly focused on respiratory diseases rather than cardiovascular-metabolic diseases and cancer.
Cardiovascular diseases are the leading cause of death in China.21 In this study, we estimated the age-standardised prevalence of cardiovascular diseases in Dongfang to be 2.91%, which contributed to the highest YLDs. There were indications that the smoking rate in Hainan was high and disease detection, awareness and control rates were low, which implied the inadequate risk factor prevention and control measures in this region and the poor self-care awareness of the population, thus leading to the occurrence of cardiovascular diseases.22 However, the disease burden of cardiovascular diseases in Dongfang was relatively lower than in Henan, China.23 National study reported that the standardised rates of populations with high risk of cardiovascular diseases were lower in south China (8.0%) than in north China (11.4%) and central China (10.7%).24 The reasons for this phenomenon may be manifold. It has to do with the high fresh fruit consumption of the residents in Dongfang. Previous survey has shown that a higher level of fruit consumption was significantly associated with lower risks of major cardiovascular diseases.25 Moreover, the climate in Dongfang is warm and hot all year round. Previous studies have found that cold temperatures had a greater correlation with cardiovascular diseases than high ambient temperature.26 27
Multivariable adjusted logistic regression analysis showed that cardiovascular diseases were 1.210 times more common in men than in women, but both men and women had a higher prevalence in older age groups (≥60 years). A growing body of research suggests that advanced age and men are strongly associated with a clustered risk of cardiovascular risk factors and results in a greater likelihood to diseases.28 29 Conversely, some studies showed that the risk of cardiovascular diseases for older men (aged≥65 years) was lower than that for young people in better-off areas of China.30 31 The reason for these reported differences might be related to the imperfection of basic public services in Dongfang, where the surveillance of cardiovascular disease risk factors in the elderly were carried out later, such as free screening and physical examination for hypertension and dyslipidaemia, which improving control rates for elderly at risk.32 In addition, employment had a greater impact on cardiovascular diseases in men and older population in our study. Dongfang still has social constraints and influences governed by traditional norms such as patriarchy and Confucianism, where men are considered the external breadwinners and decision-makers of the family. A scholar found that job strain was a risk factor for heart diseases in those men aged 50 years and older.33 Therefore, focusing on further strengthening the primary prevention of cardiovascular diseases, and developing the health promotion for key populations in Dongfang, especially elderly men, as well as behavioural and psychological screening, assessment and monitoring.
Chronic lower respiratory diseases represent a substantial healthcare burden in China.34 In our study, the age-standardised prevalence of chronic lower respiratory diseases was 1.95%, which was the second most prevalent disease affecting community residents in Dongfang, with a relatively higher prevalence than in other parts of China.35 The secondary sector, which has developed strongly in the Dongfang in recent years, has caused serious air pollution problems. Many studies have shown that ambient pollutants may cause and exacerbate various lung and respiratory diseases.36 37 Men were associated with a higher risk of chronic lower respiratory diseases, which is consistent with the findings in Shanxi, China.38 Previous studies have demonstrated that men are more likely to have occupational exposures and to display poor behaviours such as smoking, drinking and unhealthy diets.39 40 The medical management has a greater impact on men due to the fact that mortality from chronic obstructive pulmonary disease is initially higher in men than in women, resulting in higher diagnostic rate in men.41 Children were associated with high risk of chronic lower respiratory diseases in our study. A study of mostly Western populations showed that asthma and bronchitis were the most commonly reported respiratory conditions in children, which places them at increased risk of future all-cause mortality.42 However, elderly people in developed regions are more likely than children to be the mainstay of chronic lower respiratory diseases.43 44 Children in Dongfang experienced more frequent, severe and recurrent respiratory infections, the consequences of which led to the development of chronic respiratory diseases. This would suggest, then, it is important and necessary for health sector in Dongfang to improve healthcare for children and add measures to improve knowledge of child carers about disease prevention and treatment. Meanwhile, our study also found that the unemployed and poor household were at a greater risk of chronic lower respiratory diseases than the employed, and that this association was moderated by age, that is, the negative effect of unemployed on chronic lower respiratory diseases was greater among younger residents and the enabling effect of poor household was greater among children. Young unemployed people were at high risk of difficulties in emotion regulation, leading to depression and other mental health problems45 and people with chronic mental illness were highly vulnerable to chronic respiratory problems.46 Therefore, counselling and treatment for abnormal psychological manifestations should be considered into respiratory diseases intervention for younger residents to achieve better intervention effects overall. In contrast, the chronic lower respiratory diseases of children from poor families in Dongfang were not affected by economic status, which is inconsistent with the previous conclusions.47
Other upper respiratory tract diseases contained a series of chronic inflammation of the upper respiratory tract including chronic nasopharyngitis, chronic tonsillitis and chronic laryngitis. Notably, we estimated the age-standardised prevalence of other upper respiratory diseases to be 1.52%, accounting for 7.03% of overall NCDs, making it the third most important health problem for the population in Dongfang, which showed a significant difference in the composition of NCDs from other regions (the third most common disease was diabetes).48 Contrary to findings in chronic lower respiratory diseases, young unemployed found to be less likely to suffer from other upper respiratory diseases and children in poor household were associated with high risk of diseases. It has been proven that young people and children are at high risk for upper respiratory tract diseases.49 As the most common diseases in primary medical care, Dongfang Municipal Healthcare gives adequate attention to these diseases, resulting in better access to healthcare services for young people who are not in employment. However, lower socioeconomic status due to poor household can expose children to higher air pollution, which causes and increases the severity of upper respiratory diseases.50
Limitations
The principal strength of our study is large, native representative sample. However, some limitations exist in our study that need to be further improved. First, since the data were based on the disease surveillance system rather than a random sample of the entire population, there may be confounding factors such as disease diagnostic conditions that affect the results of the study. Second, there were only data from the 2021 investigation and required keeping close attention to disease surveillance in Dongfang for a long time. Third, although we examined the association between sociodemography factors and diseases, the lack of research on factors such as behavioural and biochemical indicators have made the exploration of disease risk factors incomplete, and the association of some sociodemography factors with NCDs has not emerged as much of a new phenomenon. In addition, the findings of this study were influenced by Corona Virus Disease 2019, and the disease spectrum for the current year is not fully representative of the non-epidemic period. Therefore, in the future, we will collect more continuous data and conduct a large-sample prospective follow-up study, which includes physical examination and behavioural monitoring to identify disease trends and risk factors to address these limitations.
Conclusions
NCDs were a serious threat to the health of the population in Dongfang and made up a large proportion of overall diseases. Cardiovascular diseases, chronic lower respiratory diseases and other upper respiratory diseases were major diseases and showed different associations with demographic factors. The findings of this study may be of great value for preventing and controlling the occurrence and development of key NCDs in Dongfang, as well as for improving the health of residents. Furthermore, our study results may aid decision-makers in formulating more reasonable and effective resource allocation and preventive and sustained health policies.
Data availability statement
Data may be obtained from a third party and are not publicly available. The data were only permitted for use in this study and are not publicly available.
Ethics statements
Patient consent for publication
Ethics approval
This study was approved by Dongfang People’s Hospital Ethics Committee (ethics approval number: 2022-001).
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