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Incidence and Prognosis of Stroke in the Belluno Province, Italy

First-Year Results of a Community-Based Study
Originally publishedhttps://doi.org/10.1161/01.STR.26.10.1787Stroke. 1995;26:1787–1793

    Abstract

    Background and Purpose We sought to register the incidence rate, risk factors, and case-fatality rate of all the new cases of first-ever-in-a-lifetime stroke in the province of Belluno, Italy. This study aimed to provide an epidemiological survey of cerebrovascular disease that could supply investigative objectives and support information for regional healthcare facilities planning.

    Methods We undertook a prospective population-based study in the territory of the 1st, 2nd, 3rd, and 4th local health units in the province of Belluno, an area located in northeast Italy (population, 211 389).

    Results In the first year of the study (June 1, 1992, to May 31, 1993), 474 cases of first-ever stroke were registered. The crude annual incidence rate was 2.24/1000 (2.01/1000 for men and 2.45/1000 for women). After adjustment to the European population, the incidence rate for first stroke was 1.70/1000 per year. The pathological diagnosis was confirmed by a CT scan in 89.5% of cases. Cerebral infarction accounted for 319 cases, while 93 patients suffered a primary intracerebral hemorrhage, 12 patients a subarachnoid hemorrhage, and 50 patients a stroke of unknown origin. The overall 30-day case-fatality rate was 33%, and the mortality within the first week from stroke onset was 23%. The recurrence rate after 1 month was 1.9%. After 1 month, 46% of our patients were functionally independent in activities of daily living.

    Conclusions Our first-year results confirm the fairly high risk for stroke in central and northern Italy and support European findings regarding risk factors for stroke.

    Despite the various community-based studies adhering in terms of definition and design to the criteria proposed by Malmgren et al1 for an “ideal” stroke incidence study, concern is still expressed about the accuracy of the pathological diagnoses and the prognostic interpretation.23 We scheduled an epidemiological survey on cerebrovascular disease in the province of Belluno, Italy, which could either provide information for territorial healthcare facilities planning or, in view of recent therapeutic advances, support investigative aims for the prevention and the acute management of stroke. The health structures present in the study area, the active cooperation of all the health services of the territory, and public awareness of cerebrovascular disease allowed us to perform a prospective community-based study on stroke. These factors ensured either a case collection of all clinical events or an ascertainment by CT of the pathological diagnosis that was as complete as possible and provided reliable incidence and prognosis figures. The study started on June 1, 1992, and we report the results after 1 year.

    Subjects and Methods

    Area of Investigation

    The study population includes all the residents in the territory of the 1st, 2nd, 3rd, and 4th USLs in the province of Belluno in the Veneto region. This territory, located in northeast Italy, has an area of 3678 km2 (1.22% of the national territory) and lies at 45°53′ N and 12°45′ E. The majority of the area is mountainous, with altitudes ranging from 198 to 3343 m above sea level. The territory is divided into 69 communes (the smallest Italian political district). The study population was 211 389 (100 824 men and 110 565 women); 34 300 people (16.2%) were aged 65 years and older (12 404 men and 21 896 women). The proportions of men and women 65 years and older were 12.3% and 19.8%, respectively.

    All the residents are served by six general hospitals, with two wards of neurology (USLs 3 and 4), 168 general practitioners, and 14 first-aid stations. In every hospital without a neurology ward patients are admitted to internal medicine units and assisted by neurologists operating in the neurological divisions of the province with a weekly service. The local hospitals are also interconnected by a 24-hour helicopter service supplied by an emergency unit.

    Diagnostic Criteria

    The diagnosis of stroke was defined, according to World Health Organization criteria, as rapidly developing clinical symptoms and/or signs of focal, and at times global, loss of cerebral function, with symptoms lasting more than 24 hours or leading to death, with no apparent cause other than that of vascular origin.4

    Case Collection and Ascertainment

    One or more physicians of the wards of neurology, medicine, and geriatrics of Belluno General Hospital (USL 3), the wards of neurology and medicine of Feltre General Hospital (USL 4), and the wards of medicine of the Hospitals of Auronzo and Pieve di Cadore (USL 1), Agordo (USL 2), and Lamon (USL 4) participated in the study.

    All the participant physicians were provided and trained to fill a study protocol for recording data on all suspected patients with acute cerebrovascular disease who were either admitted to their division or were inpatients on other wards. The physicians of the various wards and some of the authors (G.L., M.G., G.F.) organized meetings once every 2 weeks to discuss the case ascertainment of each patient and to state the inclusion of all the new cases in the study. All discharge diagnoses were also reviewed. All general practitioners and first-aid station physicians were notified of the study and asked to refer all suspected cases. All the patients, including those who were treated at home, had a neurological assessment as soon as possible, within 12 hours after the event. This clinical evaluation was repeated 24 hours after the onset of the symptoms to identify the cases of TIA. Both the CT archives present in the study area (USLs 3 and 4) and the death certificates were systematically screened every month to obtain information regarding fatal/nonhospitalized cases or patients who were subsequently transferred to hospitals outside the province. All available medical documents and data were collected, and casebooks for the same patients, from the aforementioned sources, were compared and stored in a computerized database, so that the recruitment of all putative cases would be as complete as possible.

    A detailed family and personal history and a thorough neurological examination were conducted on each patient by a study neurologist. A quantitative evaluation that used the Canadian Neurological Scale5 and disability status, determined according to the modified Rankin6 scale78 used in the Oxfordshire Community Stroke Project,3 were assessed on admission, every other day during hospitalization, and after 1, 6, and 12 months during the follow-up. Furthermore, during the follow-up all deaths and recurrent strokes were registered.

    We recorded clinical and anamnestic information from the patients or from their relatives about the following risk factors: hypertension (anamnestic, on admission, and assessed during the follow-up; >160 mm Hg systolic and >95 mm Hg diastolic on at least two occasions), atrial fibrillation, heart diseases (coronary, valvular, congestive failure), previous TIAs, alcohol abuse (>60 g/d for men and >40 g/d for women), diabetes mellitus, cigarette smoking (regular smoking at the onset of the stroke), hyperlipidemia, peripheral arteriopathies, therapy with anticoagulant drugs (warfarin, heparin), and use of oral contraceptives.

    Diagnosis was based on CT findings and cerebrospinal fluid examination (when subarachnoid hemorrhage was suspected). Most patients were submitted to standard blood and urine tests, luetic serology, electroencephalography, 12-lead electrocardiography, and chest roentgenography. Selected groups of patients underwent duplex scanning of cervical vessels, transcranial Doppler scanning of intracerebral arteries, two-dimensional and/or transesophageal echocardiography, 24-hour Holter monitoring, MRI, cerebral angiography, and single-photon emission CT. Other diagnostic studies were performed on an individual basis.

    Statistical Analysis

    We computed the 95% CIs assuming a Poisson distribution.9 We calculated the adjusted rates by the direct method using 10-year age groupings with the European population10 as a standard. Student’s t test was used to compare the differences between averages and the z test to compare two rates. Comparisons between frequencies were evaluated by the χ2 test.

    Survival curves were obtained by the Kaplan-Meier product limit method11 for the diagnostic groups of intracerebral hemorrhage and cerebral infarction in relation to the onset of stroke. Comparisons between subgroups were evaluated by the log-rank statistic.12 Using this technique, we assessed the effect on survival of stroke-related factors (location and impaired consciousness) and of some risk factors associated with cerebrovascular disease (age, hypertension, heart disease, diabetes mellitus). A multivariate analysis was performed with the use of Cox’s proportional hazards model.13

    Results

    During the first year of the study, 858 patients with suspected stroke were recruited. From those we excluded 11 patients because they were not residents of the study territory and 17 patients because they were suffering from a nonvascular cerebral pathology. Data from 271 patients suffering a TIA and from 85 patients suffering a recurrent stroke were not included in the present analysis. Thus, the total number of patients who had suffered a first-ever-in-a-lifetime stroke was 474 cases, including 12 cases of spontaneous subarachnoid hemorrhage.

    A CT scan was performed within 30 days from onset in 424 patients (89.5%) of the 474 who had suffered a first-ever stroke. Of these 474 patients, 434 (91.6%) were admitted to study area hospitals, 6 (1.3%) were admitted to hospitals outside the province, 29 (6.1%) were treated at home, and 5 (1%) died before admission. Four of these were recruited from information by general practitioners and emergency services files, and only 1 was detected from death certificates. A postmortem examination confirmed the diagnosis in all cases.

    The pathological diagnoses for first stroke were as follows: 319 cases of cerebral infarction (67.3%), 91% in the carotid and 9% in the vertebrobasilar territory; 93 cases of intracerebral hemorrhage (19.7%), 80.6% of which were supratentorial and 19.4% infratentorial; and 12 cases of subarachnoid hemorrhage (2.5%). In 50 patients (10.5%) this classification was not possible because neither the CT nor the necropsy data were available (stroke of unknown origin).

    The overall annual crude incidence rate for first stroke was 2.24/1000 inhabitants (95% CI, 1.76 to 2.33) (2.01/1000 for men [95% CI, 1.83 to 2.20] and 2.45/1000 for women [95% CI, 2.39 to 3.07]), a significant difference (z=2.14; P<.05). After adjustment by the direct method to the European population,10 the annual incidence rate was 1.70/1000 population. Table 1 shows the age-specific incidences for first stroke: the rates increase progressively with age, reaching a maximum at 85 years and older in both sexes. In all except the group aged 85 years and older, incidence rates were higher for men than for women; the difference was significant (z=2.90; P<.01) for those aged 65 to 74 years. The crude incidence rates according to pathological diagnosis, shown in Table 2, were 1.50/1000 population for cerebral infarction (95% CI, 1.33 to 1.68), 0.43/1000 for intracerebral hemorrhage (95% CI, 0.34 to 0.52), 0.05/1000 for subarachnoid hemorrhage (95% CI, 0.02 to 0.08), and 0.23/1000 for stroke of unknown origin (95% CI, 0.17 to 0.30). The incidence rates for cerebral infarction increased with age in both sexes and were higher for men than for women in each age group except those aged 85 years and older. When adjusted by the direct method to the European population,10 the rates decreased to 1.10/1000 for cerebral infarction, 0.33/1000 for intracerebral hemorrhage, 0.04/1000 for subarachnoid hemorrhage, and 0.17/1000 for stroke of unknown origin.

    On admission, we found 235 hypertensive patients (50.8%), excluding the cases of subarachnoid hemorrhage. However, hypertension, anamnestic or assessed during the follow-up (>160 mm Hg systolic and >95 mm Hg diastolic on at least two occasions) was found in 172 patients (54%) with a diagnosis of ischemic stroke and in 36 patients (39%) with an intracerebral hemorrhage (χ2=6.068; P=.014), with an overall proportion of 45%. We noted that almost 50% of anamnestic hypertensive patients were not following the antihypertensive therapy with good compliance. The prevalence of atrial fibrillation was significantly higher (χ2=12.924; P<.0001) in cerebral infarction (77 patients; 24%) than in intracerebral hemorrhage (6 patients; 7%). A significantly higher prevalence (χ2=5.415; P=.02) of peripheral arteriopathies was also found in cerebral infarction (44 patients; 14%) than in intracerebral hemorrhage (4 patients; 4%). Fifty-seven patients with a diagnosis of cerebral infarction (18%) and 24 patients with a diagnosis of intracerebral hemorrhage (25%) were current cigarette smokers, a nonsignificant difference. Only 3 patients were oral contraceptive users. Table 3 shows the prevalence of the other risk factors.

    The overall 30-day case-fatality rate for patients who had suffered a first stroke was 33% (158 of 474 patients). A higher mortality was observed in patients with intracerebral hemorrhage (34.4%) than in those with cerebral infarction (26.4%); the difference was not statistically significant. The mortality rates found in both patients with cerebral infarction and those with intracerebral hemorrhage were higher than in those with subarachnoid hemorrhage (8.3%), with a significant difference (z=2.05, P<.05 and z=2.53, P<.05, respectively). The mortality within the first week from onset of symptoms for all the pathological groups of stroke was 23.2% (110 cases) and again was nonsignificantly higher in those with primary intracerebral hemorrhage (20.4%) than in those with cerebral infarction (17.2%). Finally, 82% of the patients with a stroke of unknown origin died within the first month and 60% during the first week from the onset of symptoms. These figures were significantly higher (P<.01) compared with all the other pathological groups for both periods used to calculate mortality rates. At 1 month after stroke, 145 patients (46%) were independent in activities of daily living (Rankin score, ≤2), and the recurrence rate was 1.9% (6 of 316).

    The cumulative probability of survival at 30 days (Figure) was higher after cerebral infarction than primary intracerebral hemorrhage (P<.05). In both patients with a diagnosis of cerebral hemorrhage and patients with a diagnosis of cerebral infarction, the probability of survival at 30 days was related to impaired consciousness on admission (P<.0001). In patients with cerebral infarction a further relation to atrial fibrillation was found (P<.001). Increasing age and infratentorial location adversely affected survival in both groups, but not significantly. We did not find any sex difference for 1-week and 30-day survival. Other risk factors, including hypertension, had no significant effect.

    Multivariate analysis confirmed that depressed consciousness on admission significantly adversely affected the prognosis in either primary intracerebral hemorrhage (RR, 10.288; 95% CI, 4.059 to 26.076) or cerebral infarction (RR, 5.737; 95% CI, 3.658 to 8.989). Patients with vertebrobasilar territory infarction had a probability of survival at 1 month that was significantly worse than those with carotid infarction (RR, 2.535; 95% CI, 1.234 to 5.207), while no significant difference in survival emerged between patients with supratentorial and infratentorial hemorrhage. Finally, advancing age was of slight statistical significance (RR, 1.045; 95% CI, 1.018 to 1.071) only in the group of patients with cerebral infarction, while atrial fibrillation lost statistical significance.

    Discussion

    In this study we adopted a complete enumeration approach by using all possible case collection searches available in the territory. In the prospective outline, incidence and case-fatality rates were computed considering only the cases of first-ever-in-a-lifetime stroke, while all recurrent events and TIAs were placed into a separate branch of the study.

    Diagnostic criteria were applied by a study neurologist as soon as possible, within 12 hours after the stroke. The clinical assessment of all the patients, including those who were cared for at home, was repeated after 24 hours from the onset of the symptoms. In this way we could distinguish between TIA and stroke, and we recruited nine “supposed” cases of TIA as stroke cases. Our collaboration with the wards participating in the study was as good as that with the primary care physicians, and our surveillance of all the mentioned sources was active. Moreover, in the present study the proportion of patients undergoing a CT scan within 30 days from stroke onset was high (89.5%). Similar CT rates were reported in the community-based stroke studies performed in northern Sweden14 (90%) and in Australasia15 (86%). Few stroke registries1617 used routine CT scanning, but only one, carried out in Dijon, France,1819 was population-based. In Akita, Japan,16 and in the Lehigh Valley, Pa,17 all the diagnoses were confirmed by CT scanning, but both of these studies were hospital-based. In most of the other population-based studies,320212223242526 diagnoses were confirmed by CT or necropsy in a more limited number of cases. All these factors as well as the large and well-defined denominator allowed us to meet almost all the criteria proposed by Malmgren et al1 for an ideal stroke incidence study and to provide reliable and comparable results.

    In the present study the proportion of nonhospitalized first-ever stroke cases was lower (6.1%) than that reported in other studies. In particular, in the study conducted in Aosta, Italy,22 18% of the patients suffering a first-ever stroke were cared for at home. Higher proportions of patients managed at home by their general practitioners were also reported in the communities of Auckland, New Zealand15 (27.6%); Perth, Australia15 (22%); Copenhagen, Denmark20 (25%); and Oxfordshire, England27 (59%). In contrast, in the first Italian population-based study performed in Umbria21 in 1986 to 1987, the proportion of nonhospitalized patients suffering a first-ever stroke was 8.3%, a figure only slightly higher than that we reported for Belluno. High admission rates were also registered in the studies conducted in Dijon18 (90%); Finland23 (92%); Warsaw, Poland24 (90%); and Malmö, Sweden26 (95%). The high proportion of inpatients registered in these various studies can reflect different admission policies and diverse degrees of public awareness of acute cerebrovascular diseases in addition to disparities in socioeconomic status and the age structure of the population among the various communities. In our experience, because of the easy accessibility of health services even for the people living farther away from hospital facilities, almost all acute stroke patients were referred to the emergency units of the territory or to their general practitioners. Possibly, the presence since 1984 of a section devoted to cerebrovascular diseases inside the Division of Neurology of Belluno General Hospital and the good working relations established over time with the general practitioners and with the physicians operating in the various hospitals of the province contributed to increase the admission rate of first-ever stroke patients.

    Our incidence for first-ever stroke was fairly high and supports the rates reported in the other two similar Italian studies. In Umbria, during the period 1986 to 1987 Ricci et al21 found a crude annual incidence rate for first-ever stroke of 2.20/1000 inhabitants, whereas in the survey of the Valle d’Aosta22 during 1989 the corresponding rate was 2.23/1000 population. Hence, our finding confirms no regional variations within central and northern Italy. Similar rates were also found in the community of Copenhagen20 (2.14/1000), Malmö26 (2.25/1000), and Finland23 (2.22/1000). The Oxfordshire Community Stroke Project28 reported an incidence of 1.60 cases of first-ever stroke per 1000 inhabitants, similar to those found in Dijon18 (1.63/1000), Warsaw24 (1.70/1000), and Rochester, Minn29 (1.54/1000; 1980 to 1984).

    Since strokes, chiefly cerebral infarction, are most common in those aged 65 years and older in both sexes, differences in incidence rates may reflect dissimilarities in the age structure of the population. In fact, Warsaw24 and Benghazy, Libya,30 where the proportion of people aged 65 years and older (7% and 6%, respectively) was far lower than that of most of the other study populations, had the lowest incidence rates for first-ever stroke. In these studies, only 40% and 62% of stroke patients, respectively, were aged 65 years and older. In contrast, we noted that as many as 75% of stroke cases were in the group aged 65 years and older, as described in other studies1821222829 that have identified cases of all ages.

    The incidence rates for cerebral infarction and primary intracerebral hemorrhage do not differ substantially from those reported in previous European community-based studies,182023262831 particularly from those performed in Italy.2122 We recorded a low proportion of subarachnoid hemorrhage patients, resulting in a rate of 0.05/1000 inhabitants per year. Similar rates were also noted in Umbria21 (0.08/1000), Valle d’Aosta22 (0.05/1000), Malmö26 (0.06/1000), and Oxfordshire28 (0.08/1000), whereas higher rates were reported in Finland23 (0.28/1000) and Akita16 (0.29/1000). The proportion of strokes of unknown origin (10.5%) was lower than that reported in Valle d’Aosta22 (17.7%), Warsaw24 (31%), and Malmö26 (38%), where CT, as in our study, was the only diagnostic criterion. This figure, however, was higher than that found in Umbria21 (7%) and in Oxfordshire28 (4.6%), where in addition to CT, which was performed on a more limited percentage of patients, a diagnostic score was applied. As already reported,3 there is evidence that both community and hospital-based studies that had not used CT extensively had underestimated the incidence of primary intracerebral hemorrhage, particularly of the milder cases. Hence, the 89.5% CT rate either satisfied the original aim of our study or provides reliable results regarding the accuracy of the pathological diagnoses and the interpretation of prognostic data.

    Table 4 compares the overall and age- and sex-specific incidence rates for first-ever stroke reported in other studies performed throughout the world. Our findings did not differ substantially from those reported in Oxfordshire28 and fell in the middle of the values previously reported in Italy.2122 We noted that the incidence of stroke increased with age in both sexes and was higher in men than in women in each age group younger than 85 years. Because the proportion of women was higher than that of men in the Belluno population, mostly in the group aged older than 65 years, the overall incidence rate for stroke was higher in women than in men, even though the difference was not significant. A similar difference was also described in Warsaw,24 Malmö,26 and Oxfordshire,28 whereas other authors1820222930 reported higher incidence rates for first-ever stroke in men than in women. However, when the same age groups for men and women were compared, higher incidence rates were found in men than in women in all except the extreme age group, in accordance with data previously published.1820222426282930

    Cerebrovascular disease still represents the most common cause of severe disability in the western world.33 Although epidemiological studies1429 have shown that stroke mortality has been declining over time, the proportion of people among age groups at higher risk is progressively increasing because of the changing demographic structure. As in most of the communities15182122262829 in which epidemiological studies were performed during recent years, we found that more than 75% of the patients were aged 65 years or older. This trend is likely to be strengthened in the future and will have important implications for both social and scientific organizations. Therefore, healthcare facilities should be planned to take into account the changes in the age structure of the population for both the acute treatment of stroke and its secondary complications (eg, aspiration pneumonia, pulmonary thromboembolism, sepsis) and the long-term management of disabilities resulting from stroke. Moreover, as Broderick et al29 emphasized, the potential impact of strict inclusion criteria by age on patient recruitment in stroke therapeutic trials, which are still focused on younger people, would lead to the exclusion of at least 50% of possible candidates.

    Regarding prevention, hypertension and heart diseases were the most common risk factors for stroke, supporting data reported in previous studies.1522263034 Since stroke can affect blood pressure levels,35 we excluded from the analysis on risk factors the patients who were hypertensive only on admission. In effect, 5.7% of hypertensive patients on admission returned to normal and stable blood pressure levels during the follow-up. The prevalence (54%) of hypertension among the patients with cerebral infarction was similar to those reported in Valle d’Aosta22 (54%) and Oxfordshire36 (52%) but lower compared with that registered in the Framingham Study37 (70%). In contrast to the data found in these studies, hypertension was significantly more frequent in cerebral infarction patients than in cerebral hemorrhage patients. After hypertension, nonvalvular atrial fibrillation was the most common risk factor in patients with cerebral infarction, confirming the consistent association with an increased risk of ischemic stroke assessed in previous prospective studies.3839 Cigarette smoking is recognized as an important modifiable risk factor for stroke.40 In the present study, 18% of the patients with cerebral infarction and 25% of the patients with primary intracerebral hemorrhage were current smokers at the onset of the disease, resulting in an overall prevalence of 17.5%, a figure similar to those previously reported in other European analyses.2226 A heavy daily alcohol intake was reported by 15.8% of stroke patients, a proportion slightly lower than that reported in Valle d’Aosta.22 However, comparisons among the various studies are particularly difficult, primarily because of the different alcohol consumption habits in the various countries.

    The overall 30-day case-fatality rate (33%) for patients with a diagnosis of first-ever stroke was similar to that reported in Valle d’Aosta22 (31%), East Germany41 (34%), and Espoo-Kauniainen42 (34%) but was higher compared with 19% in Oxfordshire,3 23% in Auckland and Perth,15 21.5% in Dijon,18 18% in Umbria,21 15% in Malmö,26 and 17% in Rochester.29 As expected, the fatality rate in intracerebral hemorrhage patients (34%) was higher than that found in cerebral infarction patients (26%). Nevertheless, among the cases of intracerebral hemorrhage we found fewer deaths than those registered in Oxfordshire3 (50%), Valle d’Aosta22 (47%), and Malmö26 (37%). In contrast, compared with these studies we noted a higher case-fatality rate in patients with a diagnosis of cerebral infarction (26% versus 10%, 13%, and 10%, respectively). These features might represent, at least in part, the consequence of a wider use of CT for either elderly people or mild strokes, which allowed us to allocate cases to the different diagnostic categories with a greater degree of precision.

    Prognosis was related to coma on admission in all the pathological groups of stroke, indicating that level of consciousness represents the most important predictor of short-term survival, in agreement with previous studies.2242 Patients with vertebrobasilar territory infarction fared worse than those with carotid territory infarction in the first month after stroke. A similar finding was reported by Chambers et al43 in the first 10 days after stroke, but by 30 days the difference had disappeared. Furthermore, as already described,43 we found that hypertension had only a weak nonsignificant adverse influence on survival in contrast to data from the Framingham Study,44 which was conducted in the early years of hypertensive therapy.

    To summarize, our incidence rates confirm the fairly high risk for stroke in central and northern Italy and support data from other European surveys. Case-fatality rates were somewhat higher compared with other studies throughout the world. We detected that hypertension and heart diseases represent the most common risk factors for stroke, in accordance with other authors.3843 Finally, we emphasize again the usefulness of a stroke registry as an important tool for both research and epidemiological studies on cerebrovascular disease.

    Selected Abbreviations and Acronyms

    CI=confidence interval
    RR=relative risk
    TIA=transient ischemic attack
    USL=local health unit (in Italian initials)

    
          Figure 1.

    Figure 1. Line graph shows stroke survival time (days from onset) related to pathological diagnosis.

    Table 1. Age- and Sex-Specific Incidence Rates (per 1000) for First Stroke in the Province of Belluno, Italy, 1992-1993

    No. of CasesRateCI
    Men
    0-340/50 1730.000.00
    35-448/14 4260.550.23-1.08
    45-5416/12 8261.240.70-2.00
    55-6434/10 9953.092.14-4.32
    65-7480/85479.367.42-11.60
    75-8452/332915.6211.6-20.46
    ≥8513/52824.6213.09-42.1
    Total203/100 8242.011.76-2.33
    Women
    0-340/48 1870.000.00
    35-445/13 6000.360.11-0.83
    45-5414/13 5001.030.56-1.73
    55-6425/13 3821.861.20-2.75
    65-7474/12 8395.764.52-7.25
    75-8488/725512.129.72-14.90
    ≥8565/180236.0727.84-45.8
    Total271/110 5652.452.39-3.07
    Men and women
    0-340/98 5910.000.00
    35-4413/27 9220.460.24-0.78
    45-5430/26 1991.140.76-1.63
    55-6459/24 3772.421.84-3.12
    65-74154/21 3867.206.12-8.45
    75-84140/10 62913.1711.11-15.6
    ≥8578/228534.1326.9-42.66
    Total474/211 3892.24 (1.70)2.04-2.45

    Value in parentheses is adjusted to the European population.

    Table 2. Incidence Rates (per 1000) for Pathological Groups of First Stroke According to Sex and Age in the Province of Belluno, Italy, 1992-1993

    Cerebral InfarctionCerebral HemorrhageSubarachnoid HemorrhageUncertain Type
    No.RateCINo.RateCINo.RateCINo.RateCI
    Men
    0-3400.000.0000.000.0000.000.0000.000.00
    35-4430.200.04-0.5830.200.04-0.5820.130.01-0.4600.000.00
    45-5470.540.21-1.1170.540.21-1.1120.150.01-0.5400.000.00
    55-64222.001.25-3.02100.900.43-1.6500.000.0020.180.02-0.64
    65-74546.314.73-8.20182.101.24-3.3110.110.002-0.6170.810.32-1.66
    75-844212.619.09-17.0220.600.07-2.1610.300.007-1.6772.100.84-4.32
    ≥851120.8310.39-37.2800.000.0000.000.0023.780.45-13.64
    Total1391.371.15-1.62400.390.27-0.5360.050.01-0.10180.170.10-0.26
    Women
    0-3400.000.0000.000.0000.000.0000.000.00
    35-4410.070.001-0.3820.140.01-0.5020.140.01-0.5000.000.00
    45-5430.220.02-0.7980.590.25-1.1620.140.01-0.5010.070.001-0.38
    55-64100.740.35-1.36120.890.46-1.5510.070.001-0.3820.140.01-0.50
    65-74453.502.55-4.69221.711.05-2.5800.000.0090.700.32-1.33
    75-84699.517.39-12.0770.960.38-1.9710.130.003-0.72111.510.75-2.70
    ≥855228.8521.55-37.7942.210.60-5.6500.000.0094.992.28-9.48
    Total1801.621.39-1.87530.470.35-0.6160.050.01-0.10320.280.19-0.39
    Men and women
    0-3400.000.0000.000.0000.000.0000.000.00
    35-4440.140.03-0.3550.170.05-0.3940.140.03-0.3500.000.00
    45-54100.380.18-0.69150.570.31-0.9440.150.04-0.3810.03.0007-0.16
    55-64321.310.89-1.84220.900.56-1.3510.040.001-0.2240.160.04-0.40
    65-74994.623.75-5.63381.771.25-2.4210.040.001-0.22160.740.42-1.19
    75-8411110.448.62-12.6290.840.38-1.5920.180.02-0.64181.691.00-2.67
    ≥856327.5721.17-35.2841.750.47-4.4800.000.00114.812.40-8.60
    Total3191.50 (1.10)1.33-1.68930.43 (0.33)0.34-0.52120.05 (0.04)0.02-0.08500.23 (0.17)0.17-0.30

    Values in parentheses are adjusted to the European population.

    Table 3. Prevalence of Risk Factors for Cerebral Infarction and Cerebral Hemorrhage in the Province of Belluno, Italy, 1992-1993

    InfarctionHemorrhageP
    Hypertension5439.02
    Atrial fibrillation247<.001
    Coronary heart disease2112NS
    Alcohol abuse11914NS
    Diabetes mellitus1812NS
    Cigarette smoking1825NS
    Hypercholesterolemia910.5NS
    Hypertriglyceridemia3.54NS
    Hyperlipidemia71NS
    Peripheral arteriopathy144.014
    Previous TIA136NS
    Valvular heart disease31NS
    Anticoagulant drugs2.53NS

    Values are percentages.

    1>60 g/d for men and >40 g/d for women.

    Table 4. Overall and Sex- and Age-Specific Incidence Rates for First-Ever Stroke in Various Studies (per 1000)

    Years of StudyMenWomenTotal
    45-5455-6465-7475-84≥8545-5455-6465-7475-84≥85
    Copenhagen201976-19882.064.7810.3919.31NR0.912.344.529.65NR2.14
    Shibata321977NR5.5013.8022.1 (≥75)NRNR2.205.1015.3 (≥75)NR2.77
    OCSP281981-19860.173.478.1115.8718.420.162.355.8413.3920.361.60
    Dijon181985-19861.452.428.7013.9313.880.790.882.986.8710.331.63
    Umbria211986-19870.42 (<50)2.876.2512.1118.690.13 (<50)1.074.0912.3725.952.20
    Aosta2219890.25 (<50)2.712.0916.9448.540.22 (<50)2.006.6716.1326.782.23
    Malmö2619891.132.077.6812.7915.750.371.623.7810.0117.622.25
    Auckland151991-1992NR2.206.8017.0025.70NR1.903.4014.2023.701.90
    Warsaw241991-19920.984.087.618.1817.780.961.894.3510.1417.981.70
    Belluno1992-19931.243.099.3615.6224.621.031.865.7612.1236.072.24
    (<50)(50-59)(60-69)(>70)(<50)(50-59)(60-69)(>70)
    Benghazy3019840.263.173.905.54NR0.292.633.103.54NR0.63

    OCSP indicates Oxfordshire Community Stroke Project; NR, no rate given for subgroup.

    We wish to thank the health authorities, general practitioners, and colleagues at first-aid stations in USLs 1, 2, 3, and 4 of the Veneto region, without whose kind cooperation this study would not have been possible. We also wish to thank Dr Giuseppe Gilli, Servizio di Fisica Sanitaria, Arcispedale S Anna, Ferrara, for statistical analyses.

    Footnotes

    Correspondence to Giuseppe Lauria, MD, Clinica Neurologica, Università di Ferrara, via Della Giovecca, 203, 44100, Ferrara, Italy.

    References

    • 1 Malmgren R, Warlow C, Bamford J, Sandercock P. Geographical and secular trends in stroke incidence. Lancet.1987; 2:1196-1200. CrossrefMedlineGoogle Scholar
    • 2 Suzuki K, Kutsuzawa T, Takita K, Ito M, Sakamoto T, Hirayama A, Ito T, Ishida T, Ooishi H, Kawalami K, Hirota K, Ogasawara T, Yoshida J, Tamura T, Hattori S, Iwabuchi S, Karouji Y, Waga T, Oosato Y, Yazaki K, Saito T, Oouchi T, Kojima S. Clinico-epidemiologic study of stroke in Akita, Japan. Stroke.1987; 18:402-406. CrossrefMedlineGoogle Scholar
    • 3 Bamford J, Sandercock P, Dennis M, Burn J, Warlow C. A prospective study of acute cerebrovascular disease in the community: the Oxfordshire Community Stroke Project: 1981-86, II: incidence, case fatality rates and overall outcome at one year of cerebral infarction, primary intracerebral and subarachnoid haemorrhage. J Neurol Neurosurg Psychiatry.1990; 53:16-22. CrossrefMedlineGoogle Scholar
    • 4 Hatano S. Experience from a multicentre stroke register: a preliminary report. Bull World Health Organ.1976; 54:541-553. MedlineGoogle Scholar
    • 5 Cotè R, Hachinsky VC, Shurvell BL, Norris JW, Wolfson C. The Canadian Neurological Scale: a preliminary study in acute stroke. Stroke.1986; 17:731-737. CrossrefMedlineGoogle Scholar
    • 6 Rankin J. Cerebrovascular accidents in patients over 65 years of age, II: prognosis. Scott Med J.1957; 2:200-205. CrossrefMedlineGoogle Scholar
    • 7 van Swieten JC, Koudstaal PJ, Visser MC, Scouten HJA, van Gijn J. Interobserver agreement for the assessment of handicap in stroke patients. Stroke.1988; 19:604-607. CrossrefMedlineGoogle Scholar
    • 8 Bamford J, Sandercock P, Warlow C. Interobserver agreement for the assessment of handicap in stroke patients. Stroke.1989; 20:828. Letter. CrossrefMedlineGoogle Scholar
    • 9 Schoenberg BS. Calculating confidence intervals for rates and ratios. Neuroepidemiology.1983; 2:257-265. CrossrefGoogle Scholar
    • 10 Waterhouse J, Muir C, Shanmugaratham K, Powell J. Cancer incidence in five continents. IARC Sci Publ.1982; 4:673. Google Scholar
    • 11 Kaplan EL, Meier P. Nonparametric estimation from incomplete observations. J Am Stat Assoc.1958; 53:457-481. CrossrefGoogle Scholar
    • 12 Peto R, Pike MC, Armitage P, Breslow NE, Cox DR, Mantel N, McPherson K, Peto J, Smith PG. Design and analysis of randomized clinical trials requiring prolonged observation of each patient, II: analysis and examples. Br J Cancer.1977; 35:1-39. CrossrefMedlineGoogle Scholar
    • 13 Cox DR. Regression models and life tables. J R Stat Soc B.1972; 34:187-220. Google Scholar
    • 14 Stegmayr B, Asplund K, Wester PO. Trends in incidence, case-fatality rate and severity of stroke in northern Sweden, 1985-1991. Stroke.1994; 25:1738-1745. CrossrefMedlineGoogle Scholar
    • 15 Bonita R, Anderson C, Broad JB, Jamrozik KD, Steward-Wynne EG, Anderson NE. Stroke incidence and case fatality in Australasia: a comparison of the Auckland and Perth population-based stroke registers. Stroke.1994; 25:552-557. CrossrefMedlineGoogle Scholar
    • 16 Suzuki K, Kutsuzawa A, Takita K, Ito M, Sakamoto T, Hirayama A, Ito T, Ishida T, Ooishi H, Kawakami K, Hirota K, Ogasawara T, Yoshida J, Tamura T, Hattori S, Iwabuchi S, Karouji Y, Waga T, Oosato Y, Yazaki K, Saito T, Oouchi T, Kojima S. Clinico-epidemiologic study of stroke in Akita, Japan. Stroke.1987; 18:402-406. CrossrefMedlineGoogle Scholar
    • 17 Sobel E, Zhang ZX, Alter M, Lai S, Davaipour Z, Friday G, McCoy R, Isack T, Levitt L. Stroke in the Lehigh Valley: seasonal variation in incidence rates. Stroke.1987; 18:38-42. CrossrefMedlineGoogle Scholar
    • 18 Giroud M, Beuriat P, D’Athis PH, Dusserre L, Dumas R. Stroke in a French prospective population study. Neuroepidemiology.1989; 8:97-104. CrossrefMedlineGoogle Scholar
    • 19 Giroud M, Gras P, Chadan N, Beuriat P, Milan C, Arveux P, Dumas R. Cerebral haemorrhage in a French prospective population study. J Neurol Neurosurg Psychiatry.1991; 54:595-598. CrossrefMedlineGoogle Scholar
    • 20 Lindenstrom E, Boysen G, Nyboe J, Appleyard M. Stroke incidence in Copenhagen, 1976-1988. Stroke.1992; 23:28-32. CrossrefMedlineGoogle Scholar
    • 21 Ricci S, Celani MG, Guercini G, Rucireta P, Vitali R, La Rosa F, Duca E, Ferraguzzi R, Paolotti M, Seppoloni D, Caputo N, Chiurulla C, Scaroni R, Signorini E. First-year results of a community-based study of stroke incidence in Umbria, Italy. Stroke.1989; 20:853-857. CrossrefMedlineGoogle Scholar
    • 22 D’Alessandro G, Di Giovanni M, Roveyaz L, Iannizzi L, Pesenti Compagnoni M, Blanc S, Bottacchi E. Incidence and prognosis of stroke in the Valle d’Aosta, Italy: first-year results of a community-based study. Stroke.1992; 23:1712-1715. CrossrefMedlineGoogle Scholar
    • 23 Tuomilehto J, Sarti C, Narva E, Salmi K, Sivenius J, Kaarsalo E, Salomaa V, Torppa J. The FINMONICA stroke register: description of the community-based stroke register and analysis of stroke incidence during 1983 to 1985 in Finland. Am J Epidemiol.1992; 135:1259-1270. CrossrefMedlineGoogle Scholar
    • 24 Czlonkowska A, Danuta R, Weissbein T, Baranska-Gieruszczak M, Hier DB. A prospective community-based study of stroke in Warsaw, Poland. Stroke.1994; 25:547-551. CrossrefMedlineGoogle Scholar
    • 25 Sarti C, Tuomilehto J, Sivenius J, Kaarsalo E, Narva EV, Salmi K, Salomaa V, Torppa J. Stroke mortality and case-fatality rates in three geographic areas of Finland from 1983 to 1986. Stroke.1993; 24:1140-1147. CrossrefMedlineGoogle Scholar
    • 26 Jentorp P, Berglund G. Stroke registry in Malmö, Sweden. Stroke.1992; 23:357-361. CrossrefMedlineGoogle Scholar
    • 27 Bamford J, Sandercock P, Warlow C, Gray M. Why are patients with acute stroke admitted to hospital? The experience of the Oxfordshire Community Stroke Project. Br Med J.1986; 292:1369-1372. CrossrefMedlineGoogle Scholar
    • 28 Bamford J, Sandercock P, Dennis M, Warlow C, Jones L, McPherson K, Vessey M, Fowler G, Molyneux A, Hughes T, Burn J, Wade D. A prospective study of acute cerebrovascular disease in the community: the Oxfordshire Community Stroke Project 1981-86, I: methodology, demography and incident cases of first-ever stroke. J Neurol Neurosurg Psychiatry.1988; 51:1373-1380. CrossrefMedlineGoogle Scholar
    • 29 Broderick JP, Phillips SJ, Whisnant JP, O’Fallon WM, Bergstralh EJ. Incidence rates of stroke in the eighties: the end of decline in stroke? Stroke.1989; 20:577-582. CrossrefMedlineGoogle Scholar
    • 30 Ashok PP, Radhakrishnan K, Sridharan R, El-Mangoush MA. Incidence and pattern of cerebrovascular diseases in Benghazy, Libya. J Neurol Neurosurg Psychiatry.1986; 49:519-523. CrossrefMedlineGoogle Scholar
    • 31 Hansen SE, Marquadsen J. Incidence of stroke in Fredriksberg, Denmark. Stroke.1977; 6:663-665. Google Scholar
    • 32 Tanaka H, Ueda Y, Date C, Baba T, Yamashita H, Hayashi M, Shoji H, Owada K, Baba KI, Shibuya M, Kon T, Detels R. Incidence of stroke in Shibata, Japan: 1976-1978. Stroke.1981; 12:460-466. CrossrefMedlineGoogle Scholar
    • 33 Humphrey P. Stroke and transient ischaemic attacks. J Neurol Neurosurg Psychiatry.1994; 57:534-543. CrossrefMedlineGoogle Scholar
    • 34 Meissner I, Whisnant JP, Garraway WM. Hypertension and stroke recurrence in a community (Rochester, Minnesota, 1950-1979). Stroke.1988; 19:459-463. CrossrefMedlineGoogle Scholar
    • 35 Marshall J, Kaesar AC. Survival after non-hemorrhagic cerebrovascular accidents: a prospective study. Br Med J.1961; 2:72-77. Google Scholar
    • 36 Sandercock PAG, Warlow CP, Jones LN, Starkey IR. Predisposing factors for cerebral infarction: the Oxfordshire Community Stroke Study. Br Med J.1989; 298:75-78. CrossrefMedlineGoogle Scholar
    • 37 Wolf PA, Kannel WB, McGee DL. Prevention of ischemic stroke: risk factors. In: Barnett HJM, Mohr JP, Stein BM, Yatsu FM, eds. Stroke: Pathophysiology, Diagnosis and Management. New York, NY: Churchill Livingstone, Inc; 1986:967-978. Google Scholar
    • 38 Davis PH, Dambrosia JM, Schoenberg BS, Schoenberg DG, Pritchard DA, Lilienfeld AM, Whisnant JP. Risk factors for ischemic stroke: a prospective study in Rochester, Minnesota. Ann Neurol.1987; 22:319-327. CrossrefMedlineGoogle Scholar
    • 39 Albers GW, Sherman DG, Gress DR, Paulseth JE, Petersen P. Stroke prevention in non valvular atrial fibrillation: a review of prospective randomized trials. Ann Neurol.1991; 30:511-518. CrossrefMedlineGoogle Scholar
    • 40 Shinton R, Beevers G. Meta-analysis of relation between cigarette smoking and stroke. Br Med J.1989; 298:789-794. CrossrefMedlineGoogle Scholar
    • 41 Eisenblatter D, Classen E, Schadlich H, Heinemann L. Incidence and prognosis of stroke episodes in the East German population: results from a stroke register 1985-1988. Nervenarzt.1994; 65:95-100. MedlineGoogle Scholar
    • 42 Aho K, Fogelholm R. Incidence and early prognosis of stroke in Espoo-Kauniainen area, Finland, in 1972. Stroke.1974; 5:658-661. CrossrefGoogle Scholar
    • 43 Chambers BR, Norris JW, Shurvell BL, Hachinski VC. Prognosis of acute stroke. Neurology.1987; 37:221-225. CrossrefMedlineGoogle Scholar
    • 44 Sacco RL, Wolf PA, Kannel WB, McNamara PM. Survival and recurrence following stroke: the Framingham Study. Stroke.1982; 13:290-295.CrossrefMedlineGoogle Scholar

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