This study was carried out from November 1982 to October 1984 on Chuncheon City and Chunseong County where the population is about 210,000.
The objective of the research was to study natural history of cerebrovascular diseases through stroke registry and to indentify risk factors of the disease by case control study in order to formulate strategy of stroke control program.
Stroke registry was encouraged for the patients by distributing circulars to the community leaders, professional associations, hospitals, clinics and public doctors in addition to the propaganda through mass media. Also the responsible community nurse visited villages, hospitals and clinics to make the stroke patients registered.
When stroke patients registered to the stroke clinic these patients were examined at the stroke clinic in every Tuesday and Thursday by utilizing postcard appoint system. At the same time they were interviewed and checked for height, weight, blood pressure, chest x-ray, electrocardiogram, and blood chemistry.
For the case-control study on risk factors relatively new patients were selected and matched with their neighbor controls of the same sex and the similar age.
Since the risk factors of stroke identified were found to be very similar to that of hypertension, other set of case-control study on hypertension risk factors was also carried out to examine confounding effects of these variables.
Stroke management pattern, social problems encountered by the families with stroke patient, and activity index of the patients at three months after the onset and at the time of the study were also surveyed by interview.
The results and conclusion obtained are as followings:
1) The total number of stroke patients registered were only 305 during the two-year study period. This number is estimated to be about 10% of patients existing in the communities according to the sample survey of one township within the study area. Thus the study on natural history of stroke was not able to be accomplished due to the lack of representativeness for the patients registered. The major reason of low registration was reported to be the difficulty of attending the clinic and that the registration was not accounted to be helpful for them by patients themselves and their family.
2) Among 154 cases who were subjected to the case-control study on the risk factors of cerebrovascular disease, about half of them were new patients and only a few cases were old cases over one year after the onset. Most patients(76%) were older than 50 years of age. Cerebral infacrtion was the predominant pathological type, and 13% of the patients had previous experience of stroke prior to this attack. At the time of onset 15% tof them had loss of consciousness, motor paralysis in 90% and speech disturbance in 63%.
3) Among the risk factors examined for the association with the stroke by case-control study, and analysed by paired marginal test(McNemar’s X2 test) and estimated relative risk ratio, hypertension, family history of stroke, overweight, duration of smoking, left ventricular hypertrophy, serum total cholesterol, and uric acid showed significant statistical association the hypertension revealing the most strong association. Stepwise multiple regression also showed the similar pattern. On the other hand when the hypertension was controlled, these variables did not show any association.
Furthermore when the result of case-control study on risk factors of hypertension was compared with that of stroke by means of estimated relative risk ratio, the association strength of almost all variables in both stroke and hypertension was quite identical. Therefore it was concluded that other variables beside the hypertension were not causally associated but secondarily associated with the occurrence of cerebrovascular diseases by the intervened third factor, the hypertension; the hypertension was the most confirmatory risk factor of the cerebrovascular diseases among the variables examined.
4) Management pattern of the stroke patiens showed that only 20% of them was attended medically within the day of onset, among whom over 60% utilized Chinese medicine and 29% utilized modern medical facilities. The patients treated continuously comprised only 35% and the rest of the patients were either stopped treatment or treated intermittently.
The functional ability measured by activity index showed that the proportion of the patients with high score(ability of self-care) was 28% at the three months from the onset but the proportion increased up to 68% at the time of the study.
5) The most serious social and family problem incurred by the stroke was economic difficulty due to the loss of job for the patients themselves, and the activity limitation of the family members to take care of the patient. Home visited nursing care system may be worth to intervene for a community based stroke control program.
(This study was supported by WHO Research Grant)