The main harm of hypertension lies in its complications. In the incidence spectrum of complications in hypertension patients, the constituent ratio from high to low was cerebrovascular diseases (49.61%), diabetes mellitus (34.94%), heart damage (13.93%), kidney diseases (1.04%), fundus damage (0.30%) and peripheral vascular diseases (0.04%). Cardiovascular and cerebrovascular diseases were the main complications in patients with hypertension in community [14]. In this study, the cumulative incidence rate of stroke in hypertensive patients was 6.62%, the male was 6.87% and the female was 6.37%.. The incidence rate of stroke in hypertensive patients was much higher than that incidence rate in general population [1, 3, 15]. Therefore, It‘s an important link in community stroke prevention and control that strengthen the blood pressure control of patients with hypertension and prevent the occurrence of stroke in patients with hypertension. What needs to be explained here again is that Jiading District government began to implement the free medication policy for hypertension patients with rural medical insurance as early as around 2000. Later, due to the cancellation of rural household registration and the implementation of urban population management policy in Shanghai, the free medication policy gradually faded out, but it is still open to poor households. The vast majority of patients were taking antihypertensive drugs in followed-up hypertension patients in Jiading Shanghai, only a few patients were not willing to accept drug treatment. Assuming these patients did not receive antihypertensive treatment, the incidence of stroke might be higher.
At present, there are many reports on the risk probability analysis or prediction of stroke with hypertension, and the methods used include Logistic Regression analysis, Framinghan evaluation method and ESRs score method [16–19]. The results of different methods are different. Kaplan-Meier method was used in this study, which is also called product limit method. It is not only suitable for small sample data, but also suitable for large sample data. In addition, this method can take into account the objects exiting the observation queue or incomplete censored data, so it is more applicable. Through the analysis of long-term observation data, it was found that with the extension of hypertension years, the cumulative risk probability of stroke in hypertension patients would continue to increase, and the increasing distance was not equidistant. The total cumulative occurred probability of stroke in hypertension patients was 0.789 (78.9%), and male was 0.910 (91.0%), female was 0.707 (70.7%). Male was higher than female. The observation results remind us that hypertension patients must control their blood pressure as soon as possible. With the extension of the course of disease, the risk of stroke will increase, and finally reach a very high risk probability, especially male patients.
The risk occurred probability of stroke in hypertension patients was not fixed during the whole hypertension years, but fluctuates. There were 4 onset peaks, which were in 8 years (peak value 0.042, 4.2%), 15 years (peak value 0.140, 14.0%), 22 years (peak value 0.060, 6.0%) and 26 years (peak value 0.139, 13.9%). Why did the risk probability of stroke in hypertension patients show four different peaks instead of one-way change, it might be the result of long-term conflict between antihypertensive treatment and vascular damage accumulation in hypertension patients, and it might be accompanied by other reasons, which needs further and more study. It is difficult to observe the dynamic changes of hypertension patients in the natural state in practical work based on medical ethics. The highest risk probability of male patients was in 26 years (peak value 0.231, 23.1%), and the second peak was in 15 years (peak value 0.156, 15.6%). The highest risk of female patients was in 15 years (peak value 0.129, 12.9%), and the second peak was in 26 years (peak value 0.087, 8.7%). If hypertensive patients did not receive antihypertensive treatment, the risk probability of stroke might be higher, and the peak time point might be more advanced.
Stroke is a group of cerebrovascular circulation disorders caused by various reasons, manifested as focal neurological deficit, and even accompanied by disturbance of consciousness. Because of its sudden onset, it is also called cerebrovascular accident. There were many risk factors for stroke, such as age, heredity, hypertension, heart disease, arrhythmia, diabetes, hyperlipidemia, smoking, drinking, obesity, high salt, high animal oil diet, excessive physical activity, etc. [9, 20–27]. The risk of stroke was higher in the hypertension and diabetes population. From the results of Cox regression analysis, these factors have different degrees of influence (p < 0.05). According to the results of the long-term observation of registered hypertension patient, the major influencing factors of stroke complications were age (RR = 2.917), body mass index (RR = 1.450), family history of stroke (RR = 1.386), blood pressure grad (RR = 1.148,), hypertension duration (RR = 1.071) and family history of hypertension (RR = 1.051). These results were consistent with the above literature reports. The influence of sex, smoking habit, drinking habit and physical activity on stroke complications was statistically significant, the lower limit value of RR of were less than 1. This also means that the direction of action of these factors was protective factors or opposite effect. The reason might be affected by the assignment of data classification, for example, male was assigned as 1 and female was assigned as 2 in sex classification, but the risk of male was actually high than that of female. It might also be caused by other factors. This needs further study, but it is undeniable that sex, smoking habit, drinking habit and physical activity are the influencing factors of stroke, which must be paid attention to in community prevention and control.
In short, hypertension patients were prone to stroke, and the risk probability would continue to disproportionately increase during observation, and the total cumulative risk probability could finally reach 78.9%. Male was higher than female. Age, BMI, family history (stroke and HP), blood pressure grad and duration of HP were related to the occurrence of stroke complications. Early control of patients' blood pressure and prevention and control of hypertension related risk factors is an important part and means of community stroke prevention and control.