Risk of fatal stroke according to blood pressure level: an 18-year follow-up of the Oslo Study.

OBJECTIVE: To determine how blood pressure level predicts the incidence of fatal stroke. DESIGN: The Oslo Study is a prospective cohort study of preventive and epidemiological aspects of cardiovascular disorders in middle-aged men. Of 25,915 men invited, 16,209 aged 40-49 years attended the screening. A 7% random sample of men aged 20-39 years were also invited to attend. METHODS: The screening started in May 1972 and the analysis presented is an 18-year follow-up for fatal strokes. Men with a history of stroke were excluded from the analyses. RESULTS: Of 16,173 men with no history of stroke 85 died from stroke. Results from Cox proportional hazards regression analysis confirm diastolic (DBP) and systolic blood pressure (SBP) as strong independent risk factors of fatal stroke, with DBP being the stronger predictor. Analyses of risk of fatal stroke by quintile values show SBP to give significantly increased risk from the third quintile (136 mmHg), and DBP from the fifth quintile (95 mmHg) relative to the first quintile. No levelling off at highest levels can be seen when analysing decile values. No J-shape of the curve was evident. Men on drug treatment for hypertension with no stroke history (n = 440) had 4.7-fold (crude) and 2.8-fold (adjusted for age and DBP) the rate of stroke mortality of men not on drug treatment for hypertension. CONCLUSION: DBP was a stronger predictor than SBP, with increasing risk from the fifth quintile of DBP and the third quintile of SBP. Men on drug treatment for hypertension at screening were at increased risk during the follow-up period, indicating that their treatment did not sufficiently reduce their risk of stroke.

Smoking habits and risk of fatal stroke: 18 years follow up of the Oslo Study.

STUDY OBJECTIVE: To examine the risk of fatal stroke in relation to smoking habits in men screened for the Oslo study. DESIGN: The Oslo study is a prospective, cohort study of the epidemiology and preventive aspects of cardiovascular diseases in middle aged men. Screening started in May 1972 and results after 18 years of follow up are reported. PARTICIPANTS: There were 16209 men aged 40-49 years, of whom 16173 had no stroke history. Eighty five men died from stroke, of whom 48 were daily cigarettes smokers, 7 were pipe and cigar smokers, 15 smoked cigarettes and pipe or cigars daily, 11 were previous cigarette smokers, and 4 had never smoked cigarettes. MAIN RESULTS: Results of proportional hazards regression analysis adjusted for age, diastolic blood pressure, and glucose concentration showed the following rate ratios (RR) (95% confidence interval) of smoking groups compared with those who had never smoked or had previously smoked: combined cigarette and cigar or pipe smokers, RR = 6.1 (3.0, 12.5); cigarettes only, RR = 4.1 (2.3,7.4); and pipe and/or cigars only RR = 2.2 (0.9,5.5). The overall, age adjusted risk of smoking cigarettes daily was 3.5 and was found to increase with increasing cigarette consumption. Regardless of their smoking group, stroke cases had increased diastolic (DBP) and systolic blood pressure (SBP) when compared with men who had not had a stroke. The absolute differences in DBP and SBP between stroke cases and others for never and previous cigarette smokers versus daily smokers were twice as large: DBP, 12.1 mmHg versus 6.5 mmHg respectively and SBP, 16.0 mmHg versus 7.1 mmHg respectively. A high BMI increased the risk of fatal stroke of never and previous cigarette smokers. Men being treated for hypertension at the time of screening had three times the crude risk of fatal stroke of men who were not taking hypertensive treatment. CONCLUSIONS: Daily cigarette smoking increased the risk of fatal stroke three and a half times. Combined cigarette and pipe or cigar smoking had a higher risk than smoking cigarettes only. An increased risk was found in relation to increased daily cigarette consumption.

Accuracy and repeatability of prostate volume measurements by transrectal ultrasound.

We evaluated six alternative methods of prostate volume determination by transrectal ultrasound, three based on planimetry and three based on measurement of prostate diameters. Prostate volume measurements were made on an average of 6.5 occasions over a 3 y period on 41 patients with benign prostatic hyperplasia, using standard techniques. We defined the average of multiple planimetries as the prostate reference volume. Agreement with the reference volume and reproducibility at repeat testing was in the same range for single planimetry and volume determinations based on the formulas height (H) x width (W) x length (L) x pi/6 and W x W x H x pi/6, but was poorer using the formula W x W x W x pi/6. Using the average result of two successive planimetry measurements increased the reproducibility of planimetry, being statistically significantly better than for one single planimetry (P=0.024) or for the formula W x W x H x pi/6 (P=0.048). Our study suggests that the simple formula based methods of prostate volume determination provide results that are only marginally inferior to one single planimetry, but results are improved by performing two planimetry measurements.

Long-term results of blunt suction lipectomy assessed by a patient questionnaire survey.

A questionnaire was sent to 1339 consecutive patients who had undergone blunt suction lipectomy during the period between April 1984 and April 1987. Seventy-four percent replied, thus providing information about the results of 1929 procedures. The overall reported rate of satisfaction was 76 percent, with no significant difference between males and females. Highest satisfaction referred to pseudogynecomastia, submental area, iliac crest, and lower extremities on females. The rate of dissatisfaction was 6 percent. Dissatisfaction was associated most frequently with lipectomy of the buttocks. Underresection was reported for 30 percent and over-resection for 2.2 percent of the procedures. The latter, in particular, seemed to lead to dissatisfied patients. Asymmetry was reported for 19 percent of the procedures. Recurrence ("return") of fatty tissue was reported for 29 percent at the resection site. Thirty percent of the patients reported compensatory increase ("came back elsewhere") in fat deposits in nontreated locations. Self-reported weight gain was found to be a significant risk factor for both types of "regrowth." Irregularities were the most frequently reported permanent changes to skin. There were twice as many negative as positive changes to skin. Most of the patients had benefited personally from the surgery and were willing to consider undergoing lipoplasty again. All in all, the long-term results of blunt suction lipectomy are satisfactory.

Transfusion vs. alternative treatment modalities in acute bleeding: a systematic review.

BACKGROUND AND METHODS: The practice of transfusion varies a great deal between countries and hospitals. Therefore, a systematic literature review was performed to evaluate the evidence underlying practice of transfusion and alternative treatment modalities in acute bleeding. After a stepwise evaluation, 79 out of 2438 abstracts were approved as the evidence base. RESULTS: Albumin for volume therapy is not better than artificial colloids or crystalloids and may be detrimental in trauma patients. No outcome difference has been proved between artificial colloids and crystalloids. Use of hypertonic solutions remains controversial, as do the concepts of delayed and hypotensive resuscitation. Healthy individuals tolerate acute, normovolaemic anaemia at 5 g haemoglobin/dl, but pre-operative haemoglobin < 6 g/dl gives increased mortality from surgical interventions. Keeping haemoglobin higher than 8-9 g/dl has not been associated with any positive effect on mortality or morbidity, even in patients with cardiovascular disease. The changes induced in erythrocytes by storage may be clinically insignificant. No alternative to erythrocyte transfusion was established. Evidence underlying the practice of thrombocyte and plasma transfusion is scarce. Available evidence on recombinant coagulation factor VIIa is insufficient to define its future role in acute bleedings. Antifibrinolytic drugs in general seem to reduce the need for transfusion. CONCLUSIONS: Intravenous volume replacement and transfusion policies seem largely based on local tradition and expert opinions. As a result of the difficulties in performing controlled studies in patients with acute bleeding and the large number of patients needed to prove effects, other scientific evidence should be sought to better define best practice in this important field.

Ethics of palliative surgery in patients with cancer.

BACKGROUND: Surgery is an important palliative method for patients with advanced malignant disease. In addition to concerns related to clinical decision making, various moral challenges are encountered in palliative surgery. Some of these relate to the patients and their illness, others to the surgeons, their attitudes, skills and knowledge base. METHOD AND RESULTS: Pertinent moral challenges are addressed and analysed with respect to prevailing perspectives in normative ethics. The vulnerability of patients with non-curable cancer calls for moral awareness. Demands regarding sensibility and precaution in this clinical setting represent substantial challenges with regard to the 'duty to help', benevolence, respect of autonomy and proper patient information. Moreover, variations in definition of palliative surgery as well as limited scientific evidence with respect to efficacy, effectiveness and efficiency pose methodological and moral problems. Therefore, a definition of palliative surgery that addresses these issues is provided. CONCLUSION: Both surgical skill and much moral sensibility are required to improve palliative care in surgical oncology. This should be taken into account not only in clinical practice but also in education and research.

[Validation of causes of death by age]. / Validering av dødsårsaker etter alder.

In Norway the percentage of autopsies has gradually decreased during the 1986 to 1994 period. As a consequence, the Cause of Death Registry has to rely to a greater extent on physicians' certificates only. The overall percent of autopsies was reduced from 13.8% in 1986 to 9.1% in 1994 (Haukeland Hospital, Bergen, not included). The frequency decreased with age, was lowest in women, and differed according to cause of death. In the examined age groups of 0 year, 1-59 years and 60 years and above the percentage changes were as follows in women: 69.9% to 48.9%, 35.8% to 27.2%; 11.5% to 5.7%. In men the changes were: 72.2% to 54.7%; 44.5% to 39.2%; 15.1% to 8.65%. Deaths due to cancer, congenital disorders and perinatal deaths were all validated if possible. About 40% of deaths due to accidents, poisoning and violence were validated. Myocardial infarctions were autopsied more frequently than stroke. The extent of validation of cause of death during this period is discussed.

Risk factors of stroke incidence and mortality. A 12-year follow-up of the Oslo Study.

BACKGROUND AND PURPOSE: The objective of this study was to determine the risk factors of stroke incidence and mortality. METHODS: Our data are based on a prospective cohort study of men aged 40 to 49 years after 12 years of follow-up. RESULTS: In age-adjusted Cox proportional-hazards regression analysis of 14,403 healthy men, diastolic blood pressure was a stronger predictor for stroke incidence and mortality than systolic blood pressure. Smoking was a stronger predictor of mortality than of incidence. However, there was no dose-response relation among smokers by increased cigarette consumption. Total serum cholesterol was a significant (P < .05) risk factor for stroke mortality and of borderline significance (P = .08) for stroke incidence. Increased physical activity at leisure was associated with reduced stroke incidence but not mortality. The myocardial infarction risk score comprising systolic blood pressure, total serum cholesterol, and daily cigarette smoking was a strong predictor of mortality and incidence. Body mass index, triglycerides, blood glucose, and physical activity at work were not found to be risk factors for stroke. CONCLUSIONS: Reduction of blood pressure, cessation of smoking, lowered cholesterol, and increased physical activity at leisure are individual measures to reduce the risk of stroke.

The predictability of risk factors with respect to incidence and mortality of myocardial infarction and total mortality. A 12-year follow-up of the Oslo Study, Norway.

OBJECTIVES: To study the prognostic value of several risk factors on incidence and mortality of myocardial infarction (MI) and total mortality in men. DESIGN: Prospective cohort study of 12 years' follow-up. SETTING: All men in Oslo aged 40-49 and a 7% sample of men aged 20-39 were invited for screening. SUBJECTS: Of all 30,025 invited men, of whom 25,015 were aged 40-49, a total of 16,209 men aged 40-49 attended the screening and risk factors were recorded for these men. MAIN OUTCOME MEASURES: Incidence of first MI (non-fatal and fatal), mortality of MI, total mortality. RESULTS: When examining the rate ratio of the fifth to the first quintile of risk factors we found that systolic and diastolic blood pressures were stronger predictors for mortality than incidence of MI. The rate ratios (95% confidence interval) of systolic blood pressure were 3.73 (2.56, 5.44) and 2.56 (2.01, 3.25) respectively. For diastolic blood pressure the corresponding rate ratios were 4.14 (2.84, 6.04) and 2.78 (2.18, 3.54). Small differences in the rate ratios for these end-points were found for total serum cholesterol and triglycerides. Daily cigarette smoking versus non-cigarette smoking was a stronger predictor for MI mortality than incidence, with rate ratios of 3.16 (2.45, 4.24) and 2.34 (2.00, 2.79) respectively. The Cox proportional hazards regression analysis confirmed the above results. CONCLUSIONS: Total serum cholesterol and triglycerides predicted incidence and mortality of MI equally well. Whereas blood pressure and daily cigarette smoking predicted mortality of MI more strongly.

Nonfasting serum glucose and the risk of fatal stroke in diabetic and nondiabetic subjects. 18-year follow-up of the Oslo Study.

BACKGROUND AND PURPOSE: The association between nonfasting serum glucose and stroke mortality for diabetic and nondiabetic subjects is presented for participants of the Oslo Study. METHODS: The study started in 1972; of 16,209 men aged 40 to 49 years, 16,172 had no previous history of stroke and 151 were known to be diabetic. Five diabetic and 80 nondiabetic subjects died of stroke during the 18 years of follow-up, giving a rate ratio of 7.87 (95% confidence interval [CI], 2.48 to 19.14). The rate of mortality for all causes in diabetic subjects was more than five times that of those who were nondiabetic. RESULTS: Nonfasting serum glucose was a predictor of fatal stroke in all participants (diabetic subjects included) without a history of stroke in age-adjusted univariate analysis. The relative risk was 1.13 (CI, 1.03 to 1.25) by increase of 1 mmol/L of serum glucose according to results of proportional hazards regression analysis. Accordingly, relative risk for nondiabetic subjects was 1.02 (CI, 0.83 to 1.26) with no linear trend. The rate ratio of the fifth quintile to the rest was 1.57 (CI, 0.94 to 2.56) for all participants and 1.28 (CI, 0.72 to 2.18) for nondiabetics. CONCLUSIONS: There was an interaction between glucose level and body mass index versus stroke for all participants but not for nondiabetic subjects, with an increased risk for men with above-median values of glucose and body mass index. Analysis of nondiabetic subjects failed to show glucose as a definite predictor of fatal stroke.

[Biopsy in non-neoplastic skin diseases]. / Biopsi ved ikke-neoplastiske hudlidelser.

The Department of Dermatology at Ullevål Hospital wanted to reveal any diagnostical problems with skin biopsies taken from patients in the Out-patient Clinic. 200 non-tumour skin biopsies from 200 patients were studied retrospectively (100 biopsies from 1986 and 100 from 1995/96). The tentative diagnosis coincided with the pathological anatomical diagnosis in 57.5%(n = 115) of the cases. Of the 200 patients, 22%(n = 44) had still not been given a specific diagnosis after biopsy. This study indicates that skin biopsy is of diagnostical help, but that closer cooperation between the pathologist and the clinician is probably necessary in order to increase the proportion of specific dermatological diagnoses.

Factors associated with the duration of breastfeeding: analysis of the primary and secondary responders to a self-completed questionnaire.

A cohort of 1192 consecutive newborn infants was followed prospectively for factors possibly affecting the length of time they were breastfed. Following the procedure of a double-blind test, one-third of the cohort received Credé prophylaxis at age 2 h. The duration of breastfeeding (sole or partial) was recorded up to age 6 months and there was a 100% follow-up. Multivariate proportional hazards regression analysis (Cox) of the whole cohort showed that babies being delivered between 21.00 and 24.00 h were associated with a shorter duration of breastfeeding (rate ratio = 1.37, 99% confidence interval = 1.05-1.78). Mother's age (under 21 years), marital status (unmarried) and birthweight (inversely) were factors also independently associated with shorter breastfeeding duration. Boys were breastfed for a shorter time than girls (p < 0.05). In univariate analyses only, the first-born babies had a significantly shorter breastfeeding time, and purulent eyes in the first 24 h was a factor of borderline significance (p < 0.05). Educational level, socioeconomic status and smoking habits of the mothers were not investigated in this study. Owing to the lack of regulations in place at the time of the study (1981-82), it was possible to differentiate between the mothers who responded spontaneously to the self-completion questionnaire (primary responders, 68.5%) and those who required one or two reminders. Short breastfeeding time was the strongest predictor of being a secondary responder, followed by being very young or unmarried. Approaching the secondary responders reduced the prevalence of breastfeeding at 6 months by 5% (from 53.8% to 48.8%).

Stroke unit treatment. Long-term effects.

BACKGROUND AND PURPOSE: We have previously shown that treatment in our combined acute and rehabilitation Stroke Unit improves outcome during the first year after onset of stroke compared with stroke patients treated in general wards. The aim of the present trial was to examine the long-term effects of the stroke unit care. METHODS: In a randomized controlled trial, 110 patients with symptoms and signs of an acute stroke were allocated to the Stroke Unit and 110 to general wards. No significant differences existed in baseline characteristics between the two groups. The outcome after 5 years was measured by the proportion of patients at home, the proportion of patients in an institution, the mortality, and the functional state assessed by Barthel Index. RESULTS: After 5 years, 38 (34.5%) of the patients randomized to the Stroke Unit and 20 (18.2%) of the patients randomized to the general wards were at home (P = .006). Sixty-five (59.1%) of the patients from the Stroke Unit and 78 (70.9%) of the patients from the general wards were dead (P = .041), while 7 (6.4%) and 12 (10.9%), respectively, were in an institution (e.g., nursing home) (P = NS). Functional state was significantly better for patients treated in the Stroke Unit. CONCLUSIONS: For the first time it is shown that stroke unit care improves long-term survival and functional state and increases the proportion of patients able to live at home 5 years after the stroke. Combined acute and rehabilitation stroke units appear to be an effective way of organizing treatment for acute stroke patients.

Stroke unit treatment. 10-year follow-up.

BACKGROUND AND PURPOSE: We have previously shown that treatment in our combined acute and rehabilitation stroke unit (SU) improves the outcome during the first 5 years after onset of stroke compared with that for stroke patients treated in general wards (GW). The aim of the present trial was to examine the effects of SU care after 10 years of follow-up. METHODS: In a randomized controlled trial, 110 patients with symptoms and signs of an acute stroke were allocated to the SU and 110 to GW. No significant differences existed in baseline characteristics between the groups. The outcome after 10 years was measured by the proportion of patients at home, the proportion of patients in an institution, the mortality, and the functional state as assessed by the Barthel Index, in which a Barthel Index score of >/=60 was classified as independent or partly independent and a score of >/=95 was classified as independent. RESULTS: After 10 years, 21 (19.1%) of the patients randomized to the SU and 9 (8.2%) of the patients randomized to the GW were at home (P=0.0184). Eighty-three (75.5%) of the patients from the SU and 96 (87.3%) of the patients from the GW were dead (P=0.0082), and 6 (5.4%) and 5 (4.5%), respectively, were in an institution (eg, nursing home; NS). Twenty-two (20.0%) of the SU patients and 9 (8. 2%) of the GW patients had a Barthel Index score of >/=60 (P=0.0118), and 14 (12.7%) and 6 (5.4%), respectively, had a score of >/=95 (P=0.0606). CONCLUSIONS: For the first time it has been shown that SU care improves survival and functional state and increases the proportion of patients able to live at home 10 years after their stroke. Treatment in combined acute and rehabilitation SU seems to have important long-term effects on outcome for stroke patients.

Treatment in a combined acute and rehabilitation stroke unit: which aspects are most important?

BACKGROUND AND PURPOSE: We have previously shown that treatment of acute stroke patients in our stroke unit (SU) compared with treatment in general ward (GWs) improves short- and long-term survival and functional outcome and increases the possibility of earlier discharge to home. The aim of the present study was to identify the differences in treatment between the SU and the GW and to assess which aspects of the SU care which were most responsible for the better outcome. METHODS: Of the 220 patients included in our trial, only 206 were actually treated (SU, 102 patients; GW, 104 patients). For these patients, we identified the differences in the treatment and the consequences of the treatment. We analyzed the factors that we were able to measure and their association with the outcome, discharge to home within 6 weeks. RESULTS: Characteristic features in our SU were teamwork, staff education, functional training, and integrated physiotherapy and nursing. Other treatment factors significantly different in the SU from the GW were shorter time to start of the systematic mobilization/training and increased use of oxygen, heparin, intravenous saline solutions, and antipyretics. Consequences of the treatment seem to be less variation in diastolic and systolic blood pressure (BP), avoiding the lowest diastolic BP, and lowering the levels of glucose and temperature in the SU group compared with the GW group. Univariate analyses showed that all these factors except the level of glucose were significantly associated with discharge to home within 6 weeks. In the final multivariate Cox regression model, shorter time to start of the mobilization/training and stabilized diastolic BP were independent factors significantly associated with discharge to home within 6 weeks. CONCLUSIONS: Shorter time to start of mobilization/training was the most important factor associated with discharge to home, followed by stabilized diastolic BP, indicating that these factors probably were important in the SU treatment. The effects of characteristic features of an SU, such as a specially trained staff, teamwork, and involvement of relatives, were not possible to measure. Such factors might be more important than those actually measured.

Stroke unit treatment improves long-term quality of life: a randomized controlled trial.

BACKGROUND AND PURPOSE: We have previously shown that treatment of acute stroke patients in the combined acute and rehabilitation stroke unit in our hospital improves survival and functional outcome compared with treatment in general wards. The primary aim of the present trial was to examine whether the treatment in our stroke unit had an effect on different aspects of quality of life (QoL) for stroke patients 5 years after the onset of stroke. METHODS: In a randomized controlled trial, 110 patients with symptoms and signs of an acute stroke were allocated to the stroke unit and 110 to general wards. No significant differences existed in baseline characteristics between the two groups. The patients alive after 5 years were assessed by the Nottingham Health Profile (NHP) and the Frenchay Activities Index (FAI), which were the scales used as primary outcome measures for QoL. As secondary outcome measures we used a global score for the NHP and a simple visual analogue scale (VAS). RESULTS: After 5 years, 45 of the patients treated in the stroke unit and 32 of those treated in general wards were alive. All surviving patients were assessed by the FAI. Thirty-seven (82.2%) of the stroke unit patients and 25 (78.1%) of the general wards patients were assessed by the NHP; 38 (84.4%) and 28 (87.5%), respectively, were assessed by the VAS. Patients treated in the stroke unit had a higher score on the FAI (P=0.0142). Assessment with the NHP showed better results in the stroke unit group for the dimensions of energy (P=0.0323), physical mobility (P=0.0415), emotional reactions (P=0.0290), social isolation (P=0.0089), and sleep (P=0.0436), although there was no difference in pain (P=0.3186). The global NHP score and VAS score also showed significantly better results in the stroke unit group (NHP, P<0.01; VAS, P<0.001). Patients who were independent in activities of daily living had significantly better QoL assessed by these scales than patients who were dependent. CONCLUSIONS: Our study shows for the first time that stroke unit care improves different aspects of long-term QoL for stroke patients.

Occurrence and clinical presentation of systemic pneumococcal infections in an unselected population in Oslo, Norway, between 1993 and 1997.

In order to describe the clinical and microbiological manifestations of systemic pneumococcal infection in an unselected urban population, 147 cases that occurred in the period 1993-1997 were retrospectively reviewed. An unexpected finding was that gastrointestinal symptoms were remarkably common. All pneumococcal isolates were fully susceptible to penicillin. The 7-valent conjugated vaccine covered 71% of those under 2 years of age, but only 21% of those 15-65 years of age were covered. Although the case fatality rate was 17%, the rate of early fatality due to systemic pneumococcal infection was unchanged compared with data published in the era before antibiotics. This study emphasizes the importance of continuing efforts to prevent systemic pneumococcal infections.

Lung cancer and air pollution: a 27 year follow up of 16 209 Norwegian men.

BACKGROUND: The well documented urban/rural difference in lung cancer incidence and the detection of known carcinogens in the atmosphere have produced the hypothesis that long term air pollution may have an effect on lung cancer. The association between incidence of lung cancer and long term air pollution exposure was investigated in a cohort of Oslo men followed from 1972/73 to 1998. METHODS: Data from a follow up study on cardiovascular risk factors among 16 209 40 to 49 year old Oslo men in 1972/73 were linked to data from the Norwegian cancer register, the Norwegian death register, and estimates of average yearly air pollution levels at the participants' home address in 1974 to 1998. Survival analyses, including Cox proportional hazards regression, were used to estimate associations between exposure and the incidence of lung cancer. RESULTS: During the follow up period, 418 men developed lung cancer. Controlling for age, smoking habits, and length of education, the adjusted risk ratio for developing lung cancer was 1.08 (95% confidence interval, 1.02 to 1.15) for a 10 micro g/m(3) increase in average home address nitrogen oxide (NO(x)) exposure between 1974 and 1978. Corresponding figures for a 10 micro g/m(3) increase in sulphur dioxide (SO(2)) were 1.01 (0.94 to 1.08). CONCLUSIONS: Urban air pollution may increase the risk of developing lung cancer.

Low frequency of complications in imported falciparum malaria: a review of 222 cases in south-eastern Norway.

We performed a retrospective study of 222 cases of falciparum malaria diagnosed in Oslo and Akerhus counties, Norway, from January 1988 to December 1997. Except for 12 cases, all had acquired the disease in sub-Saharan Africa. Sixty-four (28.8%) cases occurred in assumed non-immune individuals; of these, 41 (64.1%) were compliant to recommended antimalarial chemoprophylaxis. The mean time lag from first symptom to diagnosis (total diagnosis delay) was 4.6 d (median 3 d, range 0-30 d) and the mean time from presentation to diagnosis (doctor's delay) was 1.3 d (median 0 d, range 0-25 d). There were no fatal cases, and only 8 (3.6%) had a complicated course. The following factors were significantly associated with development of complicated disease: higher age, non-immunity combined with chemoprophylaxis non-compliance, prolonged doctor's delay and prolonged total diagnosis delay (p < or = 0.05). Our data suggest that complicated disease in imported falciparum malaria may largely be prevented by high chemoprophylaxis compliance rates in non-immune travellers and a high index of suspicion in physicians evaluating febrile travellers.