Long-term survival and causes of death after stroke.

BACKGROUND AND PURPOSE: As part of the Danish contribution to the World Health Organization (WHO) MONICA (Monitoring Trends and Determinants in Cardiovascular Disease) Project, a register of patients with stroke was established in 1982. The purpose of the present study was to analyze long-term survival and causes of death after a first stroke and to compare them with those of the background population. METHODS: The study population comprised all subjects aged 25 years or older who were resident in a geographically defined region in Copenhagen County. All stroke events in the study population during 1982-1991 were ascertained and validated according to standardized criteria outlined for the WHO MONICA Project. After completion of the stroke registry at the end of 1991, all patients were followed up by record linkage to official registries. Standardized mortality ratios were calculated for various causes of death and periods after the stroke. RESULTS: The estimated cumulative risks for death at 28 days, 1 year, and 5 years after onset were 28%, 41%, and 60%, respectively. Compared with the general population, nonfatal stroke was associated with an almost 5-fold increase in risk for death between 4 weeks and 1 year after a first stroke and a 2-fold increase in the risk for death subsequent to 1 year. The excess mortality rate in stroke patients was due mainly to cardiovascular diseases but also to cancer, other diseases, accidents, and suicide. The probability for long-term survival improved significantly during the observation period for patients with ischemic or ill-defined stroke. CONCLUSIONS: Stroke is a medical emergency associated with a very high risk for death in the acute and subacute phases and with a continuous excess risk of death. Better prevention and management of strokes may improve the long-term survival rate.

Stable stroke occurrence despite incidence reduction in an aging population: stroke trends in the danish monitoring trends and determinants in cardiovascular disease (MONICA) population.

BACKGROUND AND PURPOSE: A stroke register was established at the Glostrup Population Studies in 1982 with the objective to monitor stroke occurrence in the population continuously during a 10-year period and contribute data to the WHO Monitoring Trends and Determinants in Cardiovascular Disease (MONICA) Project. The purpose of the current analysis was to estimate temporal trends in stroke occurrence. METHODS: All stroke events in the study population were ascertained and validated according to standardized criteria outlined by the WHO MONICA Project. The study population comprised all subjects > or = 25 years of age. Stroke was defined by the clinical presentation. A total of 5262 stroke events in >2 million person-years were analyzed. Age-adjusted rates for first-ever stroke and for all stroke events were calculated and temporal trends estimated by means of Poisson regression. RESULTS: The overall annual stroke attack rate per 100,000 person-years in the age range > or = 25 years was 272 in men and 226 in women. Age-adjusted stroke attack rates decreased among men by 3.9% per year and by 4.1% among women. Age-adjusted stroke incidence rates declined by 2.9% in men and by 3. 1% in women. The trends were statistically significant in both sexes. However, the proportion of elderly people in the study population increased during the time period of the study. Hence the numbers of stroke victims in the population remained largely unaltered. CONCLUSIONS: Decreasing age-adjusted stroke incidence rates point to a reduction of stroke risk during the time period of the study. Cardiovascular prevention, in particular improved hypertension control, is believed to have contributed to the incidence reduction. However, the burden of stroke on the healthcare system did not substantially diminish. The gain likely achieved from reduction of preventable risk factors was almost counterbalanced by population aging.

Stroke incidence and mortality correlated to stroke risk factors in the WHO MONICA Project. An ecological study of 18 populations.

BACKGROUND: The aim of the present study was to determine the extent to which the variation in conventional risk factors contributed to the variation in stroke incidence among these populations. METHODS: Within the WHO MONICA Project, stroke has been recorded in 18 populations in 11 countries. In population surveys, risk factors for cardiovascular diseases have been examined in the age group 35 to 64 years. Over a 3-year period, 12,224 acute strokes were registered in men and women within the same age range. RESULTS: The highest stroke attack rates were found in Novosibirsk in Siberia, Russia, and Finland, with a more than three-fold higher incidence than in Friuli, Italy. The mean diastolic blood pressure among the populations differed by 15 mm Hg between Novosibirsk (highest) and Denmark (lowest). In multiple regression analyses, the presence of conventional cardiovascular risk factors (smoking and elevated blood pressure) explained 21% of the variation in stroke incidence among the population in men and 42% in women. In Finland, in China, and in men in Lithuania, the stroke incidence rates were higher than expected from the population risk factor levels. CONCLUSION: Prevalence of smoking and elevated blood pressure explain a substantial proportion of the variation of stroke attack rates between populations. However, other risk factors for stroke that were not measured in the present study also contribute considerably to interpopulation differences in stroke rates.

Stroke trends in the WHO MONICA project.

BACKGROUND AND PURPOSE: Stroke registers were established as part of the international collaborative World Health Organization Monitoring of Trends and Determinants in Cardiovascular Disease (WHO MONICA) Project in 17 centers in 10 countries. The aim of the present analyses was to estimate and compare temporal stroke trends across the MONICA populations. METHODS: All stroke events in defined populations were ascertained and validated according to a common protocol and uniform criteria. Almost 25,000 stroke events in more than 15 million person-years were analyzed. Age-standardized rates for fatal stroke and for all stroke events were calculated for whole calendar years for each of the populations. Temporal stroke trends were estimated using annual rates for 5 to 6 years. RESULTS: Annual stroke attack rates decreased among men in 13 populations and among women in 15 of the 17 MONICA populations. Stroke mortality rates declined among men in 11 populations and among women in 14 of the populations studied. The estimated trends reached the level of statistical significance at the 5% level in only a small number of populations. The trends in official cerebrovascular death rates were in agreement with those estimated on the basis of MONICA data in the majority of the populations studied. CONCLUSIONS: Decreasing stroke mortality and attack rates in a large proportion of populations studied can be interpreted as an indication of declining stroke rates in most of the populations studied. The numbers of populations with statistically significant trends were small, and it is therefore not possible to determine with certainty in which of the populations were the changes real.

[Prevalence and sex distribution of different forms of migraine]. / Praevalens og kønsfordeling af de forskellige former for migraene.

The aim of this study was to provide prevalence and sex-ratio of subtypes of migraine diagnosed by neurological interview according to the criteria of the International Headache Society. In all, 3000 males and 1000 females aged 40 years were randomly selected from the Danish population. They received a mailed questionnaire regarding migraine. The questionnaire response rate was 87%. People with self-reported migraine and a random sample of those reporting no migraine were invited to a headache interview, and a physical and a neurological examination. Those not reacting to the invitation were interviewed by telephone. Participation in the interview was 87%. Kappa was 0.77 validating self-reported migraine in the questionnaire against the diagnosis of the clinical interview. Lifetime prevalences of migraine without aura, migraine with aura, migraine aura without headache, and migrainous disorder were 8%, 4%, 1% and 1% in males and 16%, 7%, 3% and 2% in females. Overall lifetime prevalence of any type of migraine was 18%, 12% in males and 24% in females. This is lower than the sum of the prevalences since migraine diagnoses are not mutually exclusive. The male:female ratios of migraine without aura, migraine with aura, migraine aura without headache, and migrainous disorder were approximately 1:2.

Prevalence and sex-ratio of the subtypes of migraine.

BACKGROUND: The aim of this study was to provide the prevalence and sex-ratio of subtypes of migraine diagnosed by neurological interview according to the criteria of the International Headache Society. METHODS: In all, 3000 males and 1000 females aged 40 years were randomly selected from the Danish population. They received a mailed questionnaire regarding migraine. The questionnaire response rate was 87%. People with self-reported migraine and a random sample of those reporting no migraine were invited to a headache interview, and a physical and a neurological examination. Those not reacting to the invitation were interviewed by telephone. Participation at the interview was 87%. Kappa was 0.77 validating self-reported migraine in the questionnaire against the diagnosis of the clinical interview. RESULTS: Lifetime prevalences of migraine without aura, migraine with aura, migraine aura without headache, and migrainous disorder were 8%, 4%, 1% and 1% in males and 16%, 7%, 3% and 2% in females. Overall lifetime prevalence of any type of migraine was 18%; 12% in males and 24% in females. This is lower than the sum of the prevalences since migraine diagnoses are not mutually exclusive. The male:female ratios of migraine without aura, migraine with aura, migraine aura without headache, and migrainous disorder were approximately 1:2. CONCLUSIONS: Migraine is more prevalent than previously thought. There was a significant preponderance in females of all the subtypes of migraine except migrainous disorder.

Stroke incidence, case fatality, and mortality in the WHO MONICA project. World Health Organization Monitoring Trends and Determinants in Cardiovascular Disease.

BACKGROUND AND PURPOSE: This report compares stroke incidence, case fatality, and mortality rates during the first years of the WHO MONICA Project in 16 European and 2 Asian populations. METHODS: In the stroke component of the WHO MONICA Project, stroke registers were established with uniform and standardized rules for case ascertainment and validation of events. RESULTS: A total of 13,597 stroke events were registered from 1985 through 1987 in a total background population of 2.9 million people aged 35 to 64 years. Age-standardized stroke incidence rates per 100,000 varied from 101 to 285 in men and from 47 to 198 in women. The combined stroke attack rates for first and recurrent events were approximately 20% higher than incidence rates in most populations and varied to the same extent. Stroke incidence rates were very high among the population of Finnish men tested. The incidence of stroke was, in general, higher among populations in eastern than in western Europe. It was also relatively high in the Chinese population studied, particularly among women. The case-fatality rates at 28 days varied from 15% to 49% among men and from 18% to 57% among women. In half of the populations studied, there were only minor differences between official stroke mortality rates and rates measured on the basis of fatal events registered and validated for the WHO MONICA stroke study. CONCLUSIONS: The WHO MONICA Project provides a unique opportunity to perform cross-sectional and longitudinal comparisons of stroke epidemiology in many populations. The present data show how large differences in stroke incidence and case-fatality rates contribute to the more than threefold differences in stroke mortality rates among populations.

Multinational comparisons of stroke epidemiology. Evaluation of case ascertainment in the WHO MONICA Stroke Study. World Health Organization Monitoring Trends and Determinants in Cardiovascular Disease.

BACKGROUND AND PURPOSE: As part of the WHO MONICA Project (World Health Organization Monitoring Trends and Determinants in Cardiovascular Disease), mortality and incidence rates of acute stroke in 14 centers covering 21 populations from 11 countries were compared. METHODS: In this report, coverage and quality of the MONICA stroke registers were evaluated on five key indicators using data submitted to the MONICA Data Center. RESULTS: A low ratio of MONICA stroke register to routine statistics of stroke mortality and a low proportion of nonfatal out-of-hospital events were the most common biases; they indicate that identifications of fatal cases and/or case finding of nonfatal events occurring outside the hospital were inadequate in many MONICA centers. In 10 populations, the data quality analyses suggested that clarification of possible biases would be needed before these populations can be included in a comparative study. Data from the remaining 11 populations meet the data quality standards for multinational comparisons with respect to case ascertainment. CONCLUSIONS: These results show that multinational comparisons of stroke incidence involve considerable problems in developing and maintaining appropriate standards of data quality. However, after considerable efforts to ensure quality, comparisons of stroke data within the MONICA Project are possible among a large number of the MONICA populations. Our observations also indicate that results from multinational comparisons of stroke mortality based on routine statistics must be interpreted with caution.

Are autopsy studies reliable in assessing gallstone prevalence in the community?

BACKGROUND: Autopsy studies have been used for many years to estimate gallstone prevalence in the population, although this has been questioned because of the risk of selection bias. METHODS: Gallstone prevalence measured by ultrasonographic screening of a random population was compared with gallstone prevalence assessed by routinely collected autopsy data in the same area during the same time period. To assess whether recording of gallstones detected in routinely performed autopsies was valid, a prospective investigation of gallstone prevalence in consecutive autopsies was performed. RESULTS: The age-standardized gallstone prevalences were 9.5 in the population and 9.2 in the autopsy study among males, whereas the corresponding figures were 16.1 and 15.9 among females. These figures were not significantly different. Gallstone prevalence in the prospective study was significantly higher than in the retrospective autopsy study (odds ratio [OR] = 1.54, 95% confidence interval [CI]: 1.08-2.19), suggesting inadequate recording of gallstones in routinely performed autopsies. The proportions of small stones were equal in the prospective autopsy study and the screening study, indicating that autopsy is not superior to ultrasonography in detecting gallstones. CONCLUSION: Routinely collected autopsy data may be a good estimate of gallstone prevalence in the community, but this could be coincidental and due to bias acting in opposite directions, with higher true prevalence balanced by inadequate detection of gallstones in routine autopsy studies.

Persisting pain after cholecystectomy. A prospective investigation.

A prospective survey of the short-term outcome after cholecystectomy was carried out under circumstances in which the study itself did not influence preoperative decision making or surgical procedures. Of 122 consecutive patients, 115 were evaluable. In all cases gallstones were verified preoperatively either by oral cholecystography or by ultrasonography. Follow-up study was 6-12 months postoperatively. Ninety-one patients (79.1%) reported satisfactory outcome in terms of complete relief of preoperative symptoms. Age, sex, preoperative pain characteristics, history of disease, type of surgery, histology, and complications did not predict the surgical outcome. A test for psychic vulnerability was included among preoperative data items. Psychic vulnerability was significantly associated with persisting pain irrespective of the above-mentioned factors. This suggests that psychologic factors influence the outcome after cholecystectomy with regard to pain relief.

Psychological vulnerability as a predictor for short-term outcome in lumbar spine surgery. A prospective study (Part II).

A prospective survey of the outcome following lumbar spine surgery was carried out during a period of six months. Of a consecutive series of 144 patients 130 cases (90%) could be evaluated. Postoperative follow-up was for six months. A test of psychological vulnerability was included with the preoperative data. Outcome was determined as unsatisfactory in case of re-operation (9%) before follow-up or if pain persisted unchanged or became worse (30%). Psychological vulnerability was significantly associated with poor outcome irrespective of age, sex, pre-operative somatic health, and surgical findings. The relative risk ratio of persisting pain attributable to psychological vulnerability was 1.8. The finding support the contention that psychogenic factors independently and significantly contribute to the multiple factor interaction that determines short-term outcome. The social consequences were strongly associated with psychological vulnerability. Among patients pre-operatively on sick-leave the relative risk ratio of unemployment attributable to psychological vulnerability was 6.0.

Short-term outcome in lumbar spine surgery. A prospective study (Part I).

A prospective survey of the outcome of lumbar surgery was carried out under conditions where all intervention was according to routine procedures. Of a consecutive series of patients 132 cases (92%) could be evaluated. The aim was to investigate possible predictive factors among self-reported data and clinical data readily available under routine circumstances. Follow-up was for six months post-operatively. Surgical findings were: herniated disc (62%), osteochondrosis (21%), other pathology (7%), and negative findings (10%). Unsatisfactory outcome was either relapse, operation before follow-up (9%) or persisting pain (30%). The surgical finding of a disc herniation predicted a significantly better outcome than any other finding. Cases previously operated upon (20%) fared equal with those operated upon for the first time irrespective of surgical findings. Self-reported weighting of preoperative pain and its location showed that predominant sciatica was significantly associated with the finding of a disc herniation, but also with satisfactory outcome irrespective of the operative finding. Factors without predictive value included sex, age, number of prior back surgeries, duration and impact of symptoms, and clinical findings. The social consequences were associated with the duration of low back disease.