Out-of-hospital cardiac arrest: Survival in children and young adults over 30 years, a nationwide registry-based cohort study

OBJECTIVES

We studied short-term (30-day) and long-term (up to ten-year) survival among children and young adults following out-of-hospital cardiac arrest (OHCA) in Sweden over the course of the past 30 years. We also studied the causes of OHCA in children and examined predictors of survival.

SETTING

This was a nationwide, registry-based cohort study, using the Swedish Registry of Cardiopulmonary Resuscitation. Our study comprised a cohort of 4,804 individuals aged 0 to 30 years who suffered OHCA between 1990 and 2020, in whom cardiopulmonary resuscitation (CPR) was initiated. We stratified the study cohort to distinct age groups and time periods.

RESULTS

We found an increase in 30-day survival from 7% to 20% over the span of 30 years. In those under 1 year of age, survival increased from 2% to 19%. Time to CPR decreased from 14 to 2 min. The 10-year survival was high among those who survived 30 days. The etiology of cardiac arrests exhibited significant variations across different age groups but remained relatively consistent over time. Causes linked to mental illness constituted a substantial percentage of these cases. Compared to the reference period (1990-1994), the odds of survival in 2015-2020 was 3.00 (95% CI: 1.43, 6.94; p = 0.006).

CONCLUSION

Survival rate after OHCA in children and young adults has increased three-fold over the past 30 years. Still overall mortality is high underscoring the need for continued efforts to mitigate risk factors and optimize survival.

The impact of iron status and smoking on blood divalent metal concentrations in Norwegian women in the HUNT2 Study

Low iron (Fe) stores may result in increased absorption of divalent metals, in particular cadmium (Cd). We have previously shown that in non-smoking women participating in the Norwegian HUNT2 cohort study this also included other divalent metals, e.g. manganese (Mn) and cobalt (Co). The diet is the main source of metals in non-smoking individuals, whereas in smoking individuals tobacco smoke contributes significant amounts of Cd and lead (Pb). The aim of the present study was to investigate the impact of smoking on the relationship between low iron status and divalent metals. Blood concentrations of the divalent metals Cd, Mn, Co, Pb, copper (Cu) and zinc (Zn), determined using an Element 2 sector field mass spectrometer (ICP-MS), were investigated in smoking women of fertile age (range 21-55 years) (n=267) from the HUNT2 cohort. Among these, 82 were iron-deplete (serum ferritin<12μg/L) and 28 had iron deficiency anaemia (serum ferritin<12μg/L & Hb<120g/L). 150 (56%) women smoked 10 or more cigarettes daily, 101 (38%) had smoked for more than 20 years, and 107 (40%) had smoked for 11-20 years. Results from the smoking population were compared with results from our previous study in non-smoking women (n=448) of which 132 were previous smokers, all from the same cohort. Increasing concentrations of Cd in blood were observed for previous smokers, low-to-moderate smokers and high intensity smokers in all subgroups compared to never smokers, and according to age groups, education level, BMI and serum ferritin. Smokers had higher Pb concentrations than non-smokers in all subgroups, but less pronounced than for Cd. Smoking was not associated with Mn and Co concentrations in blood. In multiple regression models, low ferritin was associated with increased blood concentrations of Cd, Pb, Mn and Co. Ferritin was strongly associated with Cd at low smoking intensity, but was not a significant factor in heavy smokers, where intensity and duration of smoking emerged as main determinants. Ferritin associations with Co and Pb varied with tertiles of blood Cd. Ferritin emerged as the main determinant of blood Co and Mn, while for blood Pb, age and smoking intensity had higher impact. Cu and Zn remained within reference values and no significant associations with ferritin were found. Strong positive associations between blood concentrations of Pb, Mn, Cd and Co were observed, also when controlled for their common association with ferritin. Apart from these associations, the models showed no significant interactions between the divalent metals studied. Mild anaemia (110<Hb<120g/L) did not seem to have any effect independent of low ferritin. The results indicate that low serum ferritin facilitates absorption of certain divalent metal ions in female smokers as well as the previously shown effect in non-smokers. Even if smoking provides Pb and Cd, the mutual associations between Cd and other divalent metals in blood persisted in medium and heavy smokers. This indicates that the interrelationship between Cd and divalent metals not only reflect effects on the absorption, but possibly also on kinetic processes such as transportation in blood and other compartments, including excretion.

Low 25-hydroxyvitamin D level is independently associated with non-alcoholic fatty liver disease

BACKGROUND AND AIMS

We sought to explore associations between serum 25-hydroxyvitamin D [25(OH)D] levels and non-alcoholic fatty liver disease [NAFLD] in an integrated healthcare delivery system in the U.S.

METHODS AND RESULTS

Six hundred and seven NAFLD cases were randomly matched 1:1 with controls for age, sex, race and season of measurement. Conditional logistic regression was used to evaluate if serum 25(OH)D levels were associated with increased odds of NAFLD (diagnosed by ultrasound) after adjusting for body mass index and history of diabetes, renal, peripheral vascular and liver diseases (model 1) and also for hypertension (model 2). Mean (SD) serum 25(OH)D level was significantly lower in the group with NAFLD as compared with that in the matched control group (75 ± 17 vs. 85 ± 20 nmol/L [30 ± 7 vs. 34 ± 8 ng/mL], P<0.001). Inadequate 25(OH)D status progressively increased the odds of NAFLD when classified categorically as sufficient (25(OH)D 75 nmol/L [>30 ng/mL], reference group), insufficient (37-75 nmol/L [15-30 ng/mL]; adjusted odds ratio [OR]: 2.40, 95% confidence interval [CI]: 0.90-6.34) or deficient (<37 nmol/L [<15 ng/mL]; adjusted OR: 2.56, 95% CI: 1.27-5.19). When modeled as a continuous variable, increased log10 25(OH)D was inversely associated with the risk of prevalent NAFLD (adjusted OR: 0.25, 95% CI: 0.064-0.96, P=0.02).

CONCLUSION

Compared with matched controls, patients with NAFLD have significantly decreased serum 25(OH)D levels, suggesting that low 25(OH)D status might play a role in the development and progression of NAFLD.

Trends in overweight and obesity over 22 years in a large adult population: the HUNT Study, Norway

Some reports indicate that the obesity epidemic may be slowing down or halting. We followed body mass index (BMI) and waist circumference (WC) in a large adult population in Norway (n = 90 000) from 1984-1986 (HUNT1) through 1995-1997 (HUNT2) to 2006-2008 (HUNT3) to study whether this is occurring in Norway. Height and weight were measured with standardized and identical methods in all three surveys; WC was also measured in HUNT2 and HUNT3. In the three surveys, mean BMI increased from 25.3 to 26.5 and 27.5 kg m-2 in men and from 25.1 to 26.2 and 26.9 kg m-2 in women. Increase in prevalence of obesity (BMI ≥ 30 kg m-2) was greater in men (from 7.7 to 14.4 and 22.1%) compared with women (from 13.3 to 18.3 and 23.1%). In contrast, women had a greater increase in abdominal obesity (WC ≥ 102 cm for men and WC ≥ 88 cm for women). There was a continuous shift in the distribution curve of BMI and WC to the right, demonstrating that the increase in body weight was occurring in all weight groups, but the increase of obesity was greatest in the youngest age groups. Our data showed no signs of a halt in the increase of obesity in this representative Norwegian population.

Cohort Profile: the HUNT Study, Norway

The HUNT Study includes large total population-based cohorts from the 1980ies, covering 125 000 Norwegian participants; HUNT1 (1984-86), HUNT2 (1995-97) and HUNT3 (2006-08). The study was primarily set up to address arterial hypertension, diabetes, screening of tuberculosis, and quality of life. However, the scope has expanded over time. In the latest survey a state of the art biobank was established, with availability of biomaterial for decades ahead. The three population based surveys now contribute to important knowledge regarding health related lifestyle, prevalence and incidence of somatic and mental illness and disease, health determinants, and associations between disease phenotypes and genotypes. Every citizen of Nord-Trøndelag County in Norway being 20 years or older, have been invited to all the surveys for adults. Participants may be linked in families and followed up longitudinally between the surveys and in several national health- and other registers covering the total population. The HUNT Study includes data from questionnaires, interviews, clinical measurements and biological samples (blood and urine). The questionnaires included questions on socioeconomic conditions, health related behaviours, symptoms, illnesses and diseases. Data from the HUNT Study are available for researchers who satisfy some basic requirements (www.ntnu.edu/hunt), whether affiliated in Norway or abroad.

FTO genotype and weight gain in obese and normal weight adults from a Norwegian population based cohort (the HUNT study)

The fat mass and obesity associated gene ( FTO) is associated with bodyweight and obesity. The aim of this study was to investigate if FTO genotype affects weight gain in adulthood. We investigated the weight development over a period of 11 years in a case-control study, consisting of 1,632 cases (BMI≥35 kg/m (2)) and 3,379 normal weight controls (BMI 20-24.9 kg/m (2)) from a Norwegian population based cohort, the HUNT study. Subjects were aged 20-80 at baseline, 25% men and 75% women. FTO genotype was assessed by genotyping of the SNP rs1421085. A strong association between FTO and obesity was found, consistent with an additive gene effect. Cases had an average weight gain of 11.1 kg, whereas controls had an average weight gain of 1.4 kg. Genotype was neither associated with weight gain in obese, nor controls. Cases had an average weight gain of 10.7 kg for individuals with zero risk alleles, 11.3 for one risk allele and 11.1 kg for two risk alleles. Controls had an average weight gain of 1.4 kg, 1.4 and 1.3 for the respective genotypes. In conclusion, FTO was associated with obesity, but not with weight gain in adults during 11 years of follow-up.

Comparison of genetic risk in three candidate genes (TCF7L2, PPARG, KCNJ11) with traditional risk factors for type 2 diabetes in a population-based study--the HUNT study

We studied the impact of genetic and traditional risk factors for type 2 diabetes in a large, population-based study from Nord-Trøndelag county in Norway (HUNT), in both cross-sectional and prospective design.

MATERIAL AND METHODS

65,905 individuals participated in the HUNT study. We studied a randomly selected group of 869 individuals with self-reported diabetes or non-fasting serum glucose >or=11.1 mmol/L and 2,080 non-diabetic control subjects with non-fasting serum glucose <5.5 mmol/L. Four candidate polymorphisms in the three genes TCF7L2 (rs12255372 and rs7903146), PPARG (rs1801282), KCNJ11 (rs5219) and traditional risk factors were studied.

RESULTS

Risk alleles of the TCF7L2 gene showed increased risk of diabetes even when controlled for traditional diabetes risk factors (diabetes in family, waist circumference, physical activity, BMI, SBP and total and HDL-cholesterol) in both a cross-sectional and prospective setting (cross-sectional: rs12255372 OR 1.61 (1.31-1.99), rs7903146 OR 1.48 (1.20-1.83) and prospective: rs12255372 OR 1.59 (1.22-2.07), rs7903146 OR 1.47 (1.11-1.93)). The risk alleles of TCF7L2 indicated impaired beta-cell function in patients and control subjects. The population attributable risks for diabetes with TCF7L2 risk alleles were 15 % and with diabetes in a first-degree relative 31 %.

CONCLUSION

The risk alleles of the TCF7L2 gene (rs12255372 and rs7903146) were strongly associated with type 2 diabetes, even after controlling for traditional risk factors in both a cross-sectional and prospective setting. These risk alleles were associated with indices of reduced beta-cell function.

Relation between drug utilization and morbidity pattern: antihypertensive drugs

Drug utilization studies are a valuable tool in health services research aiming to improve quality of health care and use of resources. We first present a simple model for drug utilization studies and then give practical examples from our studies in Norway, mainly dealing with the treatment of hypertension. There are marked differences in drug utilization between hospitals, counties, and the five Nordic countries. The medical consequences of these differences are probably small, but they have important economic implications. The marked regional differences in drug utilization argue for better organization of health care, for standardized treatment programs, and for continuing education of doctors.

Blood pressure and renal cancer risk: the HUNT Study in Norway

In a prospective study of 36,728 women and 35,688 men during 18 years of follow-up, compared to systolic pressure <130 mm Hg, levels of 130-149, 150-169 and >or=170 mm Hg in women were associated with relative risks of renal cell cancer of 1.7, 2.0 and 2.0, respectively (P for linear trend, 0.11). In men, there was no association with blood pressure.

Change in height, weight and body mass index: Longitudinal data from the HUNT Study in Norway

OBJECTIVE

The aim of this study was to analyse changes in body weight and height, and the changes in the prevalence of overweight and obesity.

DESIGN

Prospective population based study with 11-year follow-up.

SUBJECTS

Norwegian men (n=21565) and women (n=24337) aged 20 years or more who participated in two health surveys, the first in 1984-1986 and the other in 1995-1997.

MEASUREMENTS

Height and weight were measured by using standardised procedures at both surveys, and we computed body mass index (BMI) as weight in kilo divided by the squared value of height in meters.

RESULTS

Participants who were younger than 50 years at the first survey showed a large increase in body weight, and men and women aged 20-29 years increased their weight with an average of 7.9 kg and 7.3 kg, respectively. Contradictory, participants who were 70 years or older had on average a weight loss. The prevalence of overweight (BMI=25.0-29.9 kg/m(2)) and obesity (BMI>/=30 kg/m(2)) increased between the surveys, especially in the youngest age groups. Overall, the proportion classified as obese increased from 6.7 to 15.5% among men and from 11.0 to 21.0% among women. Some of this increase was due to a reduction in height, which was most pronounced in the oldest age groups.

CONCLUSION

During approximately 10 years, body weight increased in all age groups below 70 years, and the prevalence of overweight and obese persons was approximately 20% higher at the second survey compared with the first survey.

Change in body mass index and its impact on blood pressure: a prospective population study

BACKGROUND

Overweight and obesity increase the risk of elevated blood pressure, but the knowledge of the effect of weight change on blood pressure is sparse.

OBJECTIVE

To investigate the association between change in body mass index (BMI) and change in diastolic blood pressure (DBP), systolic blood pressure (SBP), and hypertension status.

DESIGN

Two population-based cross-sectional studies, one in 1984-86 and the other in 1995-97.

SETTING

The Nord-Trondelag Health Study (HUNT).

PARTICIPANTS

We included 15,971 women and 13,846 men who were 20 y or older at the first survey, without blood pressure medication at both surveys and without diabetes, cardiovascular disease or dysfunction in daily life at baseline.

MEASUREMENTS

Weight, height and blood pressure were measured standardised. Change in BMI was categorised as stable (initial BMI+/-0.1 kg/m2 each follow-up year), increased or decreased, and BMI was categorised by using World Health Organisation's categorisation (underweight BMI: <18.5 kg/m2, normal weight BMI: 18.5-24.9 kg/m2, overweight BMI: 25.0-29.9 kg/m2, obesity BMI> or =30 kg/m2).

RESULTS

An increase in BMI and a decrease in BMI were significantly associated with increased and decreased SBP and DBP, respectively, compared to a stable BMI in both genders and all age groups, although the strongest effect was found among those who were 50 y and older. The adjusted odds ratio for having hypertension at HUNT 2 was 1.8 (95% confidence interval (CI): 1.5, 2.2) among women and 1.6 (95% CI: 1.4,1.8) among men aged 20-49 y who increased their BMI compared to those who had stable BMI. A similar, but weaker association was found among women and men aged 50 y or more. The mean change in both SBP and DBP was higher for those who changed BMI category from first to the second survey than for those who were in the same BMI class at both surveys.

CONCLUSIONS

Our result supports an independent effect of change in BMI on change in SBP and DBP in both women and men, and that people who increase their BMI are at increased risk for hypertension.

Weight change and mortality: the Nord-Trøndelag Health Study

OBJECTIVES

The prevalence of obesity is increasing. Overweight and obese people have increased mortality compared with normal weight people. We investigated the effect of weight change on mortality.

DESIGN

Prospective population study.

SETTING

We utilized data from two large population-based health studies conducted in 1984-86 and 1995-97 respectively. Cox proportional hazards models were used to calculate mortality rate ratios (RRs) with 95% confidence intervals (CIs) between people with a stable weight and people who lost or gained weight. Subjects. Totally 20,542 men and 23,712 women aged 20 years or more, without cardiovascular disease or diabetes at the first survey and without a history of cancer at the second survey were followed up on all-cause mortality for 5 years after the second survey.

RESULTS

We found no association between weight gain and mortality. People who lost weight had a higher total mortality rate compared with those who were weight stable [RR was 1.6 (95% CI: 1.4-1.8) in men and 1.7 (95% CI: 1.5-2.0) in women]. Similar associations were found for cardiovascular and noncardiovascular mortality. Additional analysis showed a linear increase in mortality rates across categories of weight loss for both men and women (P < 0.001). There was a statistically significant interaction between weight change and initial BMI, but only amongst men (P = 0.001).

CONCLUSIONS

Weight loss, but not weight gain, was associated with increased mortality amongst men and women. Although underlying undiagnosed disease is the most plausible explanation for this finding, the similar associations found for total mortality, cardiovascular mortality, and noncardiovascular mortality makes the causal pathway somewhat enigmatic.

Analgesic overuse among subjects with headache, neck, and low-back pain

OBJECTIVES

To examine the prevalence of chronic headache (> or =15 days/month) associated with analgesic overuse in relation to age and gender and the association between analgesic overuse and chronic pain (i.e., migraine, nonmigrainous headache, neck and low-back pain).

METHODS

In the Nord-Trøndelag Health Study 1995 to 1997 (HUNT-2), a total of 51,383 subjects responded to headache questions (Head-HUNT), of which 51,050 completed questions related to musculoskeletal symptoms and 49,064 questions regarding the use of analgesics.

RESULTS

The prevalence of chronic headache associated with analgesic use daily or almost daily for > or =1 month was 1% (1.3% for women and 0.7% for men) and for analgesic overuse duration of > or =3 months 0.9% (1.2% for women and 0.6% for men). Chronic headache was more than seven times more likely among those with analgesic overuse (> or =1 month) than those without (odds ratio [OR] = 7.5, 95% CI: 6.6 to 8.5). Upon analysis of the different chronic pain subgroups separately, the association with analgesic overuse was strongest for chronic migraine (OR = 10.3, 95% CI: 8.1 to 13.0), intermediate for chronic nonmigrainous headache (OR = 6.2, 95% CI: 5.3 to 7.2), and weakest for chronic neck (OR = 2.6, 95% CI: 2.3 to 2.9) and chronic low-back (OR = 3.0, 95% CI: 2.7 to 3.3) pain. The association became stronger with increasing duration of analgesic use for all groups and was most evident among those with headache, especially those with migraine.

CONCLUSIONS

Chronic headache associated with analgesic overuse is prevalent and especially chronic migraine is more strongly associated with frequent intake of analgesics than other common pain conditions like chronic neck and chronic low-back pain.

BMI change and leisure time physical activity (LTPA): an 11-y follow-up study in apparently healthy men aged 20–69 y with normal weight at baseline

OBJECTIVE

To study the association between self-reported leisure time physical activity (LTPA) at baseline and change in body mass index (BMI).

DESIGN

Prospective observational study with a 11-y follow-up period.

SETTING

A total population-based health survey in one county was performed in 1984-1986 (HUNT 1) and repeated in 1995-1997 (HUNT 2).

PARTICIPANTS

In total, 21 685 men participated in both surveys. In the present study, we included only apparently healthy 20-69-y-old men participating in both surveys and who had a normal body weight (BMI 18.5-24.9 kg/m(2)) at baseline-leaving 8305 men for the analyses. In all, 6945 men answered all questions about LTPA and 6749 men had complete data in the multiple analyses.

MEASUREMENTS AND MAIN RESULTS

At HUNT 1, the participants answered questions (self-reported) about the intensity, frequency and duration of LTPA. The association between change in BMI and LTPA was investigated in multiple linear regression analyses. Adjusted for smoking, education, age and BMI at baseline, the physical active cohort gained less weight than the inactive cohort. Low, moderate and high levels of LTPA showed a U-shaped effect adjusted for smoking, education, age and BMI at baseline. Adjusted for BMI and age at baseline, the high-intensity part of the physically active cohort gained less weight than the low-intensity group.

CONCLUSION

This study has demonstrated a moderate BMI effect of LTPA at the population level; however, even a high level of LTPA did not prevent weight gain during the 11-y follow-up period.

Analgesic use: a predictor of chronic pain and medication overuse headache: the Head-HUNT Study

OBJECTIVE

To examine the relation between analgesic use at baseline and the subsequent risk of chronic pain (> or =15 days/month) and the risk of analgesic overuse.

METHODS

In total, 32, 067 adults reported the use of analgesics in 1984 to 1986 and at follow-up 11 years later (1995 to 1997). The risk ratios (RR) of chronic pain and RR of analgesic overuse in the different diagnostic groups (i.e., migraine, nonmigrainous headache, neck pain, and low-back pain) were estimated in relation to analgesic consumption at baseline.

RESULTS

Individuals who reported use of analgesics daily or weekly at baseline showed significant increased risk for having chronic pain at follow-up. The risk was most evident for chronic migraine (RR = 13.3, 95% CI: 9.3 to 19.1), intermediate for chronic nonmigrainous headaches (RR = 6.2, 95% CI: 5.0 to 7.7), and lowest for chronic neck (RR = 2.4, 95% CI: 2.0 to 2.8) or chronic low-back (RR = 2.3, 95% CI: 2.0 to 2.8) pain. Among subjects with chronic pain associated with analgesic overuse, the RR was 37.6 (95% CI: 21.3 to 66.4) for chronic migraine, 14.4 (95% CI: 10.4 to 19.9) for chronic nonmigrainous headaches, 7.1 for chronic neck pain (95% CI: 5.5 to 9.2), and 6.4 for chronic low-back pain (95% CI: 4.9 to 8.4). The RR for chronic headache (migraine and nonmigrainous headache combined) associated with analgesic overuse was 19.6 (95% CI: 14.8 to 25.9) compared with 3.1 (95% CI: 2.4 to 4.2) for those without overuse.

CONCLUSION

Overuse of analgesics strongly predicts chronic pain and chronic pain associated with analgesic overuse 11 years later, especially among those with chronic migraine.

Clinical relevance of microalbuminuria screening in self-reported non-diabetic/non-hypertensive persons identified in a large health screening--the Nord-Trøndelag Health Study (HUNT), Norway

AIM

The aim of this study was to investigate the clinical relevance and consequences of screening for microalbuminuria (MA) in a randomly selected, apparently healthy population sample.

MATERIAL AND METHODS

A total of 2,113 individuals (> or = 20 years) without known diabetes and treated hypertension, all identified in the large population-based Nord-Trøndelag Health Study (HUNT) 1995-1997, (n = 65,258), delivered 3 morning urine samples for MA analysis. Those with MA, defined as at least 2 out of 3 urine samples with albumin-to-creatinine ratio (ACR) > or = 2.5 mg/mmol, were invited to a second clinical examination.

RESULTS

In total, 54 men and 54 women had MA, and 42 men (84%) and 42 women (78%) attended the second examination. All with MA had 1 or more cardiovascular risk factors, like elevated cholesterol, c-peptides and blood pressure, and they were older than those without MA. Ten men (25%) and 19 women (46%), who were defined as MA-positive at the screening, had normal albumin excretion in the overnight collected urine sample in the second clinical examination. Five men (12%) and 2 women (5%) were still followed-up at the hospital out-patient clinic 3 years later.

CONCLUSIONS

Several individuals in the second examination had cardiovascular risk factors and other pathology, but the clinical benefit of discovering this was not obvious. Due to low positive predictive value and reduced reliability and validity, MA did not satisfy the criteria for a good screening test in this apparently healthy population.

Gender differences in the impact of adolescent smoking on lung function and respiratory symptoms. the Nord-Trøndelag Health Study, Norway, 1995-1997

Girls take up smoking at least as frequently as boys. Few studies have focused on gender differences in the impact of adolescent smoking. We evaluated the sex-specific effect of adolescent smoking on respiratory symptoms and lung function. All students in junior high and high schools in Nord-Trøndelag County Norway, 1995-97, were invited to participate in a cross-sectional study. Information on smoking habits and respiratory symptoms was obtained by self-administered questionnaires. Spirometry was performed in accordance with ATS standards. Eight-thousand-three-hundred and five students (83%) completed both questionnaire and spirometry. Among 6811 students aged 13-18 years (50.3% girls) with no history of asthma, 2993 (43.9%) reported never smoking, 665 (98%) reported occasional smoking, and 667 (9.9%) reported daily smoking (mean initiation age: 13.9 years). More boys than girls were heavy smokers. In all smoking categories, smokers reported a higher prevalence of respiratory symptoms than nonsmokers; symptoms increased with smoke burden. Girls reported more symptoms compared to boys with comparable smoke burden. A dose-response relation between smoking and reduced lung function was found only in girls. Girls were more vulnerable than boys to the impact of smoking on respiratory symptoms and lung function.

Blood pressure, smoking and body mass in relation to mortality from stroke and coronary heart disease in the elderly. A 10-year follow-up in Norway

OBJECTIVES

To examine the association between blood pressure, smoking and body mass index (BMI) and cerebro- and cardiovascular mortality in a population of healthy elderly.

DESIGN

Ten-year mortality follow-up of elderly men and women who participated in the Nord-Trøndelag Health Study 1984-86.

SETTING

Nord-Trøndelag county, Norway.

SUBJECTS

3121 men and 3271 women aged 70 years and older, free from any diagnosed atherosclerotic diseases or diabetes at baseline.

MAIN OUTCOME MEASURES

Relative risk of cerebro- and cardiovascular mortality and all-cause mortality according to blood pressure, smoking and BMI.

RESULTS

There was a consistent, positive association between systolic and diastolic blood pressure and cerebro- and cardiovascular mortality. The association persisted after adjustment for potential confounding factors, and was strongest for cerebrovascular mortality; the adjusted relative risks for systolic blood pressure categories 160-179 mmHg and > or = 180 mmHg in men were 1.63 (95% confidence interval, CI 1.06-2.53) and 2.19 (95% CI 1.39-3.44) compared to blood pressure < 140 mmHg. In women, the corresponding relative risks were 1.54 (95% CI 0.93-2.56) and 2.12 (95% CI 1.29-3.50). For diastolic blood pressure the adjusted relative risks in categories 100-109 and > or = 110 mmHg in men were 1.88 (95% CI 1.19-2.95) and 3.06 (95% CI 1.79-5.21) compared to pressure <90 mmHg. The corresponding relative risks in women were 1.75 (95% CI 1.05-2.91) and 2.02 (95% CI 1.04-3.93). Current smoking increased cardiovascular mortality in both men and women, and among women, BMI was negatively associated with all-cause mortality.

CONCLUSIONS

These findings add to the growing evidence that hypertension is a major risk factor for mortality from stroke and coronary heart disease among the elderly and the very old.

Microalbuminuria, cardiovascular disease and risk factors in a nondiabetic/nonhypertensive population. The Nord-Trøndelag Health Study (HUNT, 1995-97), Norway

OBJECTIVE

Microalbuminuria (MA) as an independent marker of cardiovascular morbidity and mortality in nondiabetic/nonhypertensive individuals is under international debate. The aim of this study was to investigate the associations between MA and known cardiovascular risk factors/markers and disease in a randomly selected nondiabetic/nonhypertensive sample.

DESIGN

Cross-sectional study.

SETTING

Participants in the population-based Nord-Trøndelag Health Study (HUNT), Norway (n = 65 258).

SUBJECTS

A total of 2113 individuals (> or =20 years), randomly selected without diabetes and treated hypertension, delivered three morning urine samples for MA analysis.

MAIN OUTCOME MEASURES

MA expressed as albumin-to-creatinine ratio (ACR), cardiovascular risk factors and disease.

RESULTS

Increasing age, pulse pressure, systolic (SBP) and diastolic blood pressure (DBP) and coronary heart disease (CHD) significantly predicted MA in men and increasing pulse pressure, SBP and DBP were associated with MA in women, adjusted for other cardiovascular risk factors/markers. After excluding individuals with known CHD and untreated hypertension (SBP > or = 140 mmHg, DBP > or = 90 mmHg) and hence a high total risk of cardiovascular disease (CVD), only increasing age was associated with ACR in men and increasing SBP and pulse pressure in women. Smoking, elevated lipid and glucose levels were strongly associated with MA in individuals with a high total risk of CVD than in individuals with a low total risk.

CONCLUSION

MA was associated with increasing blood pressure in both genders, age and CHD in men. Other cardiovascular risk factors/markers might be more influential in predicting ACR variation in nondiabetic/nonhypertensive individuals with a high total risk of CVD than in individuals with a low total risk.

Blood pressure and risk of headache: a prospective study of 22 685 adults in Norway

OBJECTIVES

Prevalence studies of the association between blood pressure and headache have shown conflicting results. The aim was to analyse the relation between blood pressure and risk of headache in a prospective study.

METHODS

A total of 22 685 adults not likely to have headache, had their baseline blood pressure measured in 1984-6, and responded to a headache questionnaire at follow up 11 years later (1995-7). The relative risk of headache (migraine or non-migrainous headache) was estimated in relation to blood pressure at baseline.

RESULTS

Those with a systolic blood pressure of 150 mm Hg or higher had 30% lower risk (risk ratio (RR)=0.7, 95% CI 0.6-0.8) of having non-migrainous headache at follow up compared with those with systolic pressure lower than 140 mm Hg. For diastolic blood pressure, the risk of non-migrainous headache decreased with increasing values, and these findings were similar for both sexes, and were not influenced by use of antihypertensive medication. For migraine, there was no clear association with blood pressure.

CONCLUSION

In the first prospective study of blood pressure and the risk of headache, high systolic and diastolic pressures were associated with reduced risk of non-migrainous headache. One possible explanation may be the phenomenon of hypertension associated hypalgesia, which probably involves the baroreflex system influencing nociception in the brain stem or spinal cord.

Physical exercise, sports, and lung function in smoking versus nonsmoking adolescents

Associations between adolescent smoking habits and exercise, particularly participation in sports and lung function were studied. All students aged 13-19 yrs in Nord-Trøndelag County, Norway, 1995-1997, were invited to join a cross-sectional study. Information on smoking habits and exercise was obtained by self-administered questionnaire. Spirometry was performed in accordance with American Thoracic Society standards. Of the 6,811 students (aged 13-18 yrs, without asthma), 2,993 (44%) reported never-smoking, and 1,342 (20%) reported current smoking (90% daily). Frequency of physical exercise was inversely associated with smoking, but participants in individual sports with lesser endurance, especially body-building and fighting sports, were more likely to be daily smokers than nonparticipants. Both daily (53%) and occasional smokers (43%) were more likely to have quit sports than never-smokers (26%)). Never-smokers showed a positive dose-response between physical exercise and lung function (forced vital capacity and forced expiratory volume in one second, adjusted for age and height). No similar significant association was observed in daily smokers. These data suggest that smoking habits in different sports should be considered when promoting physical activity as smoking prevention, and sports organizations should include smoking prevention programmes. Adolescents with better lung function may self-select into sports; this possibility needs to be studied in a longitudinal design.

Cigarette smoking gives more respiratory symptoms among women than among men. The Nord-Trondelag Health Study (HUNT)

STUDY OBJECTIVE

Studies have indicated that women are more vulnerable to the effect of tobacco smoking compared with men. The aim of this study was to explore the prevalence of reported respiratory symptoms and diseases according to smoking burden, age and sex.

DESIGN

Questionnaire in a cross sectional population based study.

SETTING

The BONT (Bronchial obstruction in Nord-Trondelag) study is part of a comprehensive health survey of all inhabitants aged above 19 years in the county of Nord-Trondelag, Norway, which was carried out from 1995 to 1997.

PARTICIPANTS

A total of 65 717 subjects, 71.3% of the total population aged 20-100, answered the main questionnaire.

MAIN RESULTS

In all, 12.7% men and 12.1% women reported episodes of wheezing or breathlessness during the past 12 months, 8.8% men and 8.4% women reported that they had or had had asthma, 7.5% men and 8.2% women had ever used asthma medication, and 4.0% men and 3.0% women reported chronic bronchitis. Thirty per cent of men and 31% of women were smokers, and average pack years of smoking were 15.9 and 10.3, respectively. Among previous and current smokers, significant more women reported episodes of wheezing or breathlessness, current asthma and persistent coughing compared with men with the same smoke burden (pack years) and daily number of cigarettes.

CONCLUSION

The prevalence of reported asthma and use of asthma medication was higher than reported in previous Scandinavian studies. Respiratory symptoms increased by smoking burden. Comparing the prevalence of symptoms and current asthma among women and men with the same smoke burden or daily cigarette consumption, women seemed to be more susceptible to the effect of tobacco smoking than men.

Cardiovascular disease and risk factors in persons with type 2 diabetes diagnosed in a large population screening: the Nord-Trøndelag Diabetes Study, Norway

OBJECTIVE

To study cardiovascular status and risk factors in persons with newly diagnosed type 2 diabetes and controls in a large population.

DESIGN

Case-control study.

SETTING

Population screening.

SUBJECTS

The screening of 74 499 individuals (88.1%), aged 20 years and older, in Nord-Trøndelag County, Norway, during 1984-86 detected 428 persons with undiagnosed diabetes according to the 1980 WHO criteria, of whom 205 attended a clinical follow-up examination assessing cardiovascular status and risk factors.

METHODS

For each of 205 cases, one control person matched by age and sex underwent the same clinical examination. Lipids, body mass index, waist/hip ratio, blood pressure, pulse rate, blood pressure medication, kidney function, cardiovascular disease, family history and lifestyle were recorded.

RESULTS

At the screening prior to the diagnosis of diabetes, those with diabetes reported poorer general health, less physical activity, more siblings with diabetes and more frequent use of antihypertensive medication. They had higher body mass index, systolic and diastolic blood pressure and pulse rate compared with controls. At the clinical evaluation, diabetics had higher urine albumin levels, increased waist/hip ratio, and higher total cholesterol/HDL cholesterol ratios than the controls. They also reported a greater incidence of angina pectoris and had more ECG changes.

CONCLUSIONS

Diabetics presented with more cardiovascular risk factors, angina pectoris and ECG changes than the controls, and they had an established metabolic syndrome more often than controls. These results suggest that prevention of cardiovascular disease in diabetics requires earlier diagnosis of the diabetes.

Adolescent occasional smokers, a target group for smoking cessation? the Nord-Trøndelag Health Study, Norway, 1995-1997

BACKGROUND

Adolescent smokers are often unsuccessful in quitting and difficult to retain in cessation programs. In health promotion, focusing on the right target groups is essential. Aim. The aim was to examine if adolescent occasional smokers differ from daily smokers, and if possible differences could be useful for targeted smoking cessation programs.

METHODS

Ninety-one percent of all teenagers attending junior high or high schools participated in a cross-sectional study, conducted in Nord-Trøndelag County, Norway, 1995-1997, including 8,460 students 13-18 years old. Information on smoking habits, education, after school activities, and parents was obtained by self-administered questionnaires.

RESULTS

Fifty-four percent of boys and 57% of girls had tried at least one cigarette. Of these, 36% of boys and 41% of girls were current smokers, half of whom reported occasional smoking. Students who had quit smoking had more often been occasional than daily smokers. Compared to daily smokers, occasional smokers participated in higher academic courses, were more engaged in organized activities and sports, had been drunk less often, and had better family role models.

CONCLUSION

Differences support potential utility of focusing on occasional smokers as a special target group in smoking cessation programs.

Prevalence of thyroid disease, thyroid dysfunction and thyroid peroxidase antibodies in a large, unselected population. The Health Study of Nord-Trondelag (HUNT)

OBJECTIVE

To examine the prevalence of thyroid disease and dysfunction including thyroid autoimmunity in Norway.

MATERIALS AND METHODS

All inhabitants 20 years and older (94009) in Nord-Trondelag were invited to participate in a health survey with a questionnaire and blood samples.

RESULTS

The prevalence of former diagnosed hyperthyroidism was 2.5% in females and 0.6% in males, hypothyroidism 4.8% and 0.9%, and goitre 2.9% and 0.4% respectively. In both sexes the prevalence increased with age. In individuals without a history of thyroid disease the median, 2.5 and 97.5 percentiles for TSH (mU/l) were 1.80 and 0.49-5.70 for females and 1. 50 and 0.56-4.60 for males. The TSH values increased with age. When excluding individuals with positive thyroid peroxidase antibodies (TPOAb) (>200U/ml), the 97.5 percentiles dropped to 3.60 mU/l and 3. 40 mU/l respectively. The prevalence of pathological TSH values in females and males were TSH >/=10mU/l 0.90% and 0.37%; TSH 4.1-9. 9mU/l 5.1% and 3.7%; and TSH</=0.05mU/l 0.45% and 0.20% respectively. The prevalence of positive TPOAb (>200U/ml) was 13.9% in females and 2.8% in males. In females the lowest percentage (7.9%) of positive TPOAb was seen with TSH 0.2-1.9mU/l and increased both with lower and higher levels of TSH. The percentage of males with positive TPOAb was lower than in females in all TSH groups except for those with TSH>10mU/l (85% TPOAb positive).

CONCLUSIONS

In spite of a high prevalence of recognised thyroid disease in the population a considerable number of inhabitants have undiagnosed thyroid dysfunction and also positive TPOAb.

[Pharmacological prevention of cardiovascular diseases in general practice]

BACKGROUND

In this paper the Norwegian College of General Practitioners, Working Group on Hypertension report recommendations for primary preventive drug treatment of elevated cardiovascular risk.

MATERIAL AND METHODS

Updated metaanalyses and randomised controlled trials are the main basis for the recommendations. The purpose of treating hypertension is prevention of cardiovascular diseases. Drug treatment with documented effect on morbidity and mortality is therefore recommended. We have also evaluated the cost effectiveness of drug treatment.

RESULTS

An estimate of the total risk of future cardiovascular disease is a necessary basis for treatment decisions. This paper presents tools for estimating total cardiovascular risk. Drug treatment is recommended if ten-year risk exceeds 20% or blood pressure equals or exceeds 170/100 mmHg. Drug treatments include antihypertensive, antithrombotic, antidiabetic and lipid-lowering drugs with documented effect on hard endpoints. Aspirin, thiazides, betablockers, metformin, calcium blockers, ACE inhibitors and statins are all drugs with documented effects on significant endpoints, but the costs of these treatments differ substantially.

INTERPRETATION

Drug treatment to prevent cardiovascular disease should be recommended for patients at significant risk of cardiovascular disease. Drugs with documented effect on morbidity and mortality should be used. Considerations of costs are important in treatment decisions.

[Life style advice provided by primary health care to prevent cardiovascular diseases]

BACKGROUND

The Working Group on Hypertension of the Norwegian College of General Practitioners reports in this paper on the documentation on behavioural advice in the prevention of cardiovascular disease. Emphasis is given to hypertension.

MATERIAL AND METHODS

The recommendations are mainly based on updated metaanalyses and randomised controlled trials. Hypertension is treated to prevent cardiovascular disease; that is why we put emphasis on documentation with significant end points. The validity of the documentation for general practice is assessed. We have also assessed whether certain methods or theories for behavioural change could be helpful to the general practitioner.

RESULTS

The value of advice against smoking, dietary advice (increased intake of grain products, vegetables, fruit, poultry and fish), and advice about exercise are well documented and applicable in general practice. Respect for the patient's autonomy and interest in the patients and their health-related habits seem to be important factors for improving doctor's chances of influencing patient behaviour.

INTERPRETATION

The value of life-style advice is well documented and should play an important role in clinical strategies to prevent cardiovascular disease in high-risk patients.

Implementing clinical guidelines in the treatment of diabetes mellitus in general practice. Evaluation of effort, process, and patient outcome related to implementation of a computer-based decision support system

OBJECTIVES

To evaluate the implementation of clinical guidelines for diabetes mellitus in general practice with a specific computer-based clinical decision support system (CDSS) as part of the intervention.

METHODS

Randomized study with health center as unit. General practice in Sør- and Nord-Trøndelag counties in Norway, 380,000 inhabitants. Seventeen health centers with 24 doctors and 499 patients with diabetes mellitus were in the intervention group and 12 health centers with 29 doctors and 535 patients were in the control group. Main outcome measures were group differences in fractions of patients without registrations (process evaluation) and mean group differences for the same variables (patient outcome evaluation).

RESULTS

Statistically significant group differences were experienced for fractions of patients without registration of cigarette smoking (intervention group, 82.6%; control group 94.5%), body mass index (78.2% vs. 93.0%), and sufficient registrations for calculation of risk score for myocardial infarction (91.1% vs. 98.3%); all during 18 months. Large center variations were shown for all variables. The only statistically significant group difference was -2.3 mm Hg (95% CI, -3.8, -0.8) in diastolic blood pressure in favor of the intervention group. Statistically insignificant differences in favor of the intervention group were HbA1c, -0.1% (95% CI, -0.4, 0.1), systolic blood pressure, -1.2 mm Hg (95% CI, -4.4, 2.0). Statistically insignificant differences in favor of the control group were fractions of smokers, +3.0% (95% CI, -4.0, 10.0), body mass index, +0.3 kg/m2 (95% CI, -0.8, 1.4), risk score in female +0.1 (95% CI, -5.1, 5.2), and risk score in male +2.6 (95% CI, -14.2, 19.5).

CONCLUSIONS

Implementation of clinical guidelines for diabetes mellitus in general practice, by means of a CDSS and several procedures for implementation, did not result in a clinically significant change in doctors' behavior or in patient outcome.

[Treatment of children with asthma--ideals and reality]

Children with bronchial asthma are the largest group of children with chronic disease in general practice. The aim of this study was to obtain information on morbidity, examination, and treatment in children with bronchial asthma. 102 children with current asthma, aged 7-15 years, participated in this study, which used a questionnaire, flow volume spirometry with beta2-agonist reversibility test, and two weeks of registrations of peak flow and symptom score. Most children had mild to moderate asthma; 60% had acceptable asthma control defined by a morbidity index. 64 children used either inhaled steroids or dinatriumcromoglycate prophylactic. 76 children had been examined by a paediatrician. Lung function measurements had been performed in 57 of 69 children with follow-up in general practice during the last 12 months. Allergy tests had been taken of 87 children. With respect to allergen exposure at home, only 30 children reported having an optimal home environment. Despite the extensive follow-up of children with asthma, our study indicates that the asthma control is not up to the standard set by current guidelines. By use of written treatment plans, and increasing knowledge of the disease, triggers and of the treatment of children and their parents, we probably would exploit the potential better. The recommendations and goals of the guidelines should, however, also be evaluated.

Health problems in teenage daily smokers versus nonsmokers, Norway, 1995-1997: the Nord-Trøndelag Health Study

Increased morbidity among teenage smokers has been reported, but specific current health problems and medication use other than of alcohol and narcotics have received less attention. The aim of this study was to examine the association between health problems and daily smoking in teenagers. Ninety percent of all teenagers attending junior high or high schools participated in a cross-sectional study conducted in Nord-Trøndelag County, Norway, 1995-1997; included were 8,040 students aged 13-18 years. Information on smoking habits, health problems, medication use, and use of health services was obtained in schools by self-administered questionnaire and by interview. Fifty-five percent of boys and 57% of girls had tried smoking, and 9% and 11%, respectively, reported current daily smoking. When compared with boys and girls who had never smoked, daily smoking among both sexes and all age groups was associated with significantly poorer perceived health, respiratory symptoms, headache, neck and shoulder pain, stomachache, nausea, frequent heartbeats, nervousness/restlessness, and sleep problems. Daily smokers used more medications and health services. Daily smoking by adolescents is already associated with multiple somatic health problems. Whether or not the association is causal, daily smoking identifies a group of adolescents with health problems for whom preventive strategies should also include medical and social support.

Physical activity and stroke mortality in women. Ten-year follow-up of the Nord-Trondelag health survey, 1984-1986

BACKGROUND AND PURPOSE

Few studies have reported a protective effect of physical activity on stroke in women, particularly among elderly women. This study was conducted to examine the association between different levels of leisure-time physical activity and stroke mortality in a large prospective study of middle-aged and elderly women.

METHODS

We conducted a 10-year mortality follow-up of women aged >/=50 years, free from stroke at baseline (n=14 101), who participated in the Nord-Trondelag Health Survey in Norway during 1984-1986. Main outcome measures were relative risk of stroke mortality according to increasing levels of physical activity, with the least active group used as reference.

RESULTS

In groups aged 50 to 69, 70 to 79, and 80 to 101 years, the relative risk of dying decreased with increasing physical activity, after adjustment for potentially confounding factors. In groups aged 50 to 69 and 70 to 79 years, the most active women had an adjusted relative risk of 0. 42 (95% CI, 0.24 to 0.75) and 0.56 (95% CI, 0.36 to 0.88), respectively. In the group aged 80 to 101 years, there was a consistent negative association with physical activity; the adjusted relative risk for the most active was 0.57 (95% CI, 0.30 to 1.09).

CONCLUSIONS

Physical activity was associated with reduced risk of death from stroke in middle-aged and elderly women. This association persisted after we excluded individuals with prevalent cardiovascular and cerebrovascular disease at baseline and women who died during the first 2 years of follow-up. These observations strengthen the evidence that physical activity should be part of a primary prevention strategy against stroke in women.

Rapid changes in the prevalence of obesity and known diabetes in an adult Norwegian population. The Nord-Trøndelag Health Surveys: 1984-1986 and 1995-1997

OBJECTIVE

To determine whether changes in mean BMI and the prevalence of obesity in a total adult population during a short (11-year) period were associated with changes in the prevalence of diabetes.

RESEARCH DESIGN AND METHODS

This study involved cross-sectional surveys of all inhabitants aged > or = 20 years of the county of Nord-Trøndelag from 1984 to 1986 (n = 85,100) and from 1995 to 1997 (n = 92,434). Attendance rates were 88.1 and 71.3%, respectively, and 90.0% in an additional survey of people aged 13-19 years from 1995 to 1997 (n = 9,593). Main outcome measures were age-specific mean BMI for the diabetic and nondiabetic subgroups and the prevalence of obesity and diabetes. For comparison, mean BMIs from 18 of 19 Norwegian counties for the group aged 40-42 years were examined.

RESULTS

Mean BMI increased from 27.2 to 29.0 kg/m2 in the diabetic population and from 25.1 to 26.3 kg/m2 in the nondiabetic population. The BMI distribution curve shifted to the right, but homogeneity was also reduced. A comparison with other Norwegian counties indicated that this increase occurred during the last 6 years between the surveys. The prevalence of obesity (BMI > or = 30 kg/m2) increased from 7.5 to 14% in nondiabetic men and from 13 to 18% in nondiabetic women. The increase was particularly great in men aged < 60 years and in women aged < 50 years. The overall prevalence of known diabetes increased between the two surveys (from 2.9 to 3.2%) but only in men. The largest increase was observed in the corresponding younger sex and age-groups.

CONCLUSIONS

A substantial increase in mean BMI and the prevalence of obesity occurred in the younger age-groups at the same time as an increase in the prevalence of diabetes. A greater increase in diabetes prevalence in this ethnically stable Western European population may follow if effective primary preventive strategies are not undertaken.

Implementing clinical guidelines in the treatment of hypertension in general practice. Evaluation of patient outcome related to implementation of a computer-based clinical decision support system

OBJECTIVE

To evaluate the implementation of clinical guidelines for hypertension in general practice by use of a computer-based clinical decision support system (CDSS) and a specific implementation strategy. Evaluation of patient outcome.

DESIGN

Randomised study with health centres as units. The intervention group had the CDSS installed and made ready for use, doctors and assistants were trained and received a user-manual, the doctors were offered telephone repetitions, a seminar in risk intervention and, at the same seminar, further demonstration of the CDSS. The doctors received baseline registrations with information of how they treated their own hypertensive patients, and use of the CDSS was checked repeatedly.

SETTING

General practice in Sør- and Nord-Trøndelag counties in Norway, 380,000 inhabitants.

PARTICIPANTS

Seventeen health centres with 24 doctors and 984 patients in the intervention group. Data from 879 patients used in the final analyses. Twelve health centres with 29 doctors and 1255 patients in the control group. Data from 1119 patients used in the final analyses.

MAIN OUTCOME MEASURES

After an intervention period of 18 months, group differences in level of systolic and diastolic blood pressure, serum cholesterol, body mass index, and risk score for myocardial infarction were calculated, as well as group differences in fractions of smokers.

RESULTS

Significant group difference in favour of intervention group: diastolic blood pressure 1 mmHg (95% CI -1.89, -0.17). However, a significant baseline difference in systolic blood pressure in favour of control group of 2.7 mmHg (95% CI 1.0, 4.5) had been reduced to 1.2 mmHg (95% CI -0.6, 3.0) after intervention.

CONCLUSION

Implementation of clinical guidelines in the treatment of hypertensive patients in general practice by means of a CDSS and several other procedures for implementation did not affect patient outcome in any clinically significant way.

Case report: paraarticular soft-tissue osteoma of the hip

A case of paraarticular soft-tissue osteoma of the hip is presented. The patient is a 30-year-old white male with a two year history of progressive left hip pain. Plain film and cross-sectional imaging in conjunction with pathologic correlation are used to make the diagnosis. The lesion lacks the typical zoning pattern of myositis ossificans, shows no direct communication with native bone, and is extraarticular in location as opposed to synovial osteochondromatosis. Soft tissue osteomas most commonly occur around the knee, the foot, and the ankle. Soft tissue osteomas are rare tumors and this case is unusual in that it occurs around the hip.

Identification of incident stroke in Norway: hospital discharge data compared with a population-based stroke register

BACKGROUND AND PURPOSE

The validity of hospital discharge diagnoses is essential in improving stroke surveillance and estimating healthcare costs of stroke. The aim of this study was to assess sensitivity, positive predictive value, and accuracy of discharge diagnoses compared with a stroke register.

METHODS

A record linkage was made between a population-based stroke register and the discharge records of the hospital serving the population of the stroke register (n=70 000). The stroke register (including patients aged 15 and older and with no upper age limit), applied here as a "gold standard," was used to estimate sensitivity, positive predictive value, and accuracy of the discharge diagnoses classification. The length of stay in hospital by stroke patients was measured.

RESULTS

Identifying cerebrovascular diseases by hospital discharge diagnoses (International Classification of Diseases, 9th Revision [ICD-9], codes 430 to 438.9, first admission) lead to a substantial overestimation of stroke in the target population. Restricting the retrieval to acute stroke diagnoses (ICD-9 codes 430, 431, 434, and 436) gave an incidence estimate closer to the "true" incidence rate in the stroke register. Selecting ICD-9 codes 430 to 438 of cerebrovascular diseases gave the highest sensitivity (86%). The highest positive predictive value (68%) was achieved by selecting acute stroke diagnoses (ICD-9 codes 430, 431, 434, and 436), at the expense of a lower sensitivity (81%). Accuracy of ICD codes 430 to 438.9 (n=678) revealed the highest proportion of incident strokes identified by the acute stroke diagnoses (ICD-9 codes 430, 431, 434, and 436). Seventy-four percent of hospital discharge diagnoses classified as first-ever stroke kept the original diagnosis. Only 4.6% of the discharge diagnoses were classified as nonstroke diagnoses after validation. The estimation of length of stay in the hospital was improved by selection of acute stroke diagnoses from hospital discharge data (ICD-9 codes 430, 431, 434, and 436), which gave the same estimate of length of stay, a median of 8 days (2.5 percentile=0 and 97.5 percentile=56), compared with a median of 8 days (2.5 percentile=0 and 97.5 percentile=51) based on the stroke register.

CONCLUSIONS

Hospital discharge data may overestimate stroke incidence and underestimate the length of stay in the hospital, unless selection routines of hospital discharge diagnoses are restricted to acute stroke diagnoses (ICD-9 codes 430, 431, 434, and 436). If supplemented by a validation procedure, including estimates of sensitivity, positive predictive value, and accuracy, hospital discharge data may provide valid information on hospital-based stroke incidence and lead to better allocation of health resources. Distinguishing subtypes of stroke from hospital discharge diagnoses should not be performed unless coding practices are improved.

Implementing clinical guidelines in the treatment of hypertension in general practice

Discrepancies between clinical guidelines and clinical practice call for practical implementation strategies. This study evaluates the implementation of clinical guidelines for hypertension in general practice with a specific computer-based clinical decision support system (CDSS) as part of the intervention. We carried out a randomized study of general practice health centres in Sør- and Nord-Trøndelag counties in Norway (population 380000). A total of 17 health centres were included, with 24 doctors and 984 patients in the intervention group. Data from 887 patients was used in the analyses. There were 12 health centres with 29 doctors and 1255 patients in the control group. Data from 1127 control patients was used in the analyses. The main outcome measures were doctor's behaviour, measured by adherence to registration of recommended variables in the Norwegian clinical guidelines for hypertension. The aim of the intervention was to lower the fractions of patients without registrations. However, there were no clinically significant differences between the intervention group and the control group for fractions of patients without registration of blood pressure (intervention group 14.3%, control group 14.2%) or serum cholesterol (62.3% vs. 56.8%) during 12 months, nor, during 18 months, for fractions of patients without a registration of cigarette smoking (82.9% vs. 87.1%), cardiovascular inheritance (79.5% vs. 73.4%) and body mass index (81.5% vs. 89.2%). One or several variables necessary for calculation of risk score for myocardial infarction were missing in 91.7% of patients in the intervention group and 91.9% of patients in the control group. Large centre variations were shown for all variables. Implementation of clinical guidelines in the treatment of hypertensive patients in general practice, by means of a CDSS and several procedures for implementation did not result in clinically significant changes in the doctors' behaviour. Of importance are both the lack of user-friendliness of the specific CDSS and problems in performing time-consuming multidimensional procedures.

[Drugs in the treatment of asymptomatic risk conditions--better documentation is required]

This paper points to the dilemmas posed by the lack of longitudinal studies of morbidity and mortality, or of side-effects, of several drugs widely used in treatment of asymptomatic risk factors. New drugs and new indications make large groups eligible for treatment, i.e. for mildly elevated blood pressure or cholesterol levels, impaired glucose tolerance and risk of osteoporosis. The treatment of people with asymptomatic elevated risk factors differs in point of principle from the treatment of diseases, symptoms or complaints: The patient has no subjective feeling about his or her condition; the health risk is usually lower; there are no good evaluation measures for the treatment; and the risk that side-effects outweigh the benefits is greater. This makes high quality treatment and good information to patients even more important than in ordinary practice. More knowledge about effects with regard to morbidity and mortality and about long-term side-effects is necessary. Doctors should prefer drugs for which the effects are documented, and give patients with the highest health risk top priority.

Correlates of subjective well-being in stroke patients

BACKGROUND AND PURPOSE

Data on survival and functioning after stroke needs to be supplemented by measures emphasizing the patients' subjective perception. We studied (1) subjective well-being (SWB) as a latent variable in a common-factor model with four items, (2) the reliability of these four items, and (3) variables related to SWB in stroke patients.

METHODS

Data on all stroke patients (n=1417) and a random subsample of stroke-free individuals of similar age (n=1439) were collected from the Nord-Trøndelag Health Survey, a cross-sectional study of 74977 persons. Based on a two-sample factor analysis model, scores of SWB were calculated, and variables explaining SWB were studied in a regression model.

RESULTS

Four items were a priori believed to measure SWB as a latent variable ("satisfaction," "strength," "calmness," and "cheerfulness"). This was confirmed by factor analysis. The reliability of these items (the proportion of the variance of the items that can be explained by the common factor) was between .42 and .53. Regression analyses showed a significant effect of having had a stroke, gender (lower SWB in men), age (increasing SWB with increasing age), perceived general health, nervousness, loneliness, sleep problems, social support, and use of analgesics. There was no statistical interaction between these variables and having had a stroke.

CONCLUSIONS

Higher SWB after stroke relates to female gender, older age, good general and mental health, and a firm social network.

Treatment of diabetes mellitus--physicians' adherence to clinical guidelines in Norway

OBJECTIVE

To assess general practitioners' current adherence to the Norwegian clinical guidelines for the treatment of diabetes mellitus.

DESIGN

Descriptive, retrospective registration of information from patient records of one year; 7 November 1993 to 7 November 1994. In addition, mailed questionnaire to examine the representativeness of the participating doctors.

SETTING

General practice in Sør- and Nord-Trøndelag counties in Norway, 380,000 inhabitants.

PARTICIPANTS

In one year 1119 patients were registered with the diagnosis of diabetes mellitus in the records of 56 general practitioners. The patients were 53% women and 47% men; 51% were 70 years or older.

MAIN OUTCOME MEASURES

Levels of HbA1c and blood pressure in accordance with the recommendations of the Norwegian clinical guidelines for diabetes mellitus. Fractions of patients with a measured HbA1c, blood pressure, and serum cholesterol in one year.

RESULTS

At least one HbA1c was recorded in 77% of the diabetic patients during the specified year. In patients under 70 years of age, 56% had HbA1c above the recommended treatment level of 7.5%. In patients 70 years of age or older, 36% were above the recommended limit of 8.5%. At least one blood pressure was recorded in 79% of the patients during the specified year. In patients under 70 years of age, 53% had a systolic blood pressure above the recommendations of 140 mmHg, and 22% had a diastolic blood pressure above the recommendations of 90 mmHg. Serum cholesterol was not recorded during the specified year in 75% of the patients.

CONCLUSION

There are still major discrepancies between current practice and the intentions laid down in the Norwegian clinical guidelines. A discussion of alternative methods for implementation and evaluation of the efficacy of clinical guidelines is needed.

Epidemiology of stroke in Innherred, Norway, 1994 to 1996. Incidence and 30-day case-fatality rate

BACKGROUND AND PURPOSE

In Norway, as well as other industrialized countries, mortality from stroke has declined over the past decades. Data on stroke morbidity are lacking. This study was conducted to determine the incidence, case fatality, and risk factors of stroke in a defined Norwegian population.

METHODS

During the period 1994 to 1996, a population-based stroke registry collected uniform information about all cases of first-ever and recurrent stroke occurring in people aged > or = 15 years in the region of Innherred in the central part of Norway (target population 70,000), where the prevalence of cardiovascular risk factors was screened in 1984 to 1986 and 1995 to 1997.

RESULTS

During the 2 years of registration (September 1, 1994, to August 31, 1996), 432 first-ever (72.8%) and 161 recurrent (27.2%) strokes were registered. The crude annual incidence rate was 3.12/1000 (2.85/1000 for males and 3.38/1000 for females). Adjusted to the European population, the annual incidence rate of first-ever stroke was 2.21/1000. The annual incidence rate of cerebral infarction was 2.32/1000, intracerebral hemorrhage 0.32/1000, subarachnoid hemorrhage 0.19/1000, and unspecified stroke 0.38/1000. The 30-day case-fatality rate was 10.9% for cerebral infarction, 37.8% for intracerebral hemorrhage, and 50.0% for unspecified stroke. Fourteen percent of the patients were found outside the hospital, and only 50% of the suspected stroke cases in the hospital (at admission or reviewed discharge diagnosis of ICD-9 codes 430 to 438) fitted the final inclusion criteria.

CONCLUSIONS

This first population-based stroke register in Norway revealed incidence rates of stroke similar to other Scandinavian countries, and comparison between other European countries did not indicate regional variations within Western Europe.

BRCA1 sequence analysis in women at high risk for susceptibility mutations. Risk factor analysis and implications for genetic testing

CONTEXT

A mutation in the BRCA1 gene may confer substantial risk for breast and/or ovarian cancer. However, knowledge regarding all possible mutations and the relationship between risk factors and mutations is incomplete.

OBJECTIVES

To identify BRCA1 mutations and to determine factors that best predict presence of a deleterious BRCA1 mutation in patients with breast and/or ovarian cancer.

DESIGN

A complete sequence analysis of the BRCA1 coding sequence and flanking intronic regions was performed in 798 women in a collaborative effort involving institutions from the United States, Italy, Germany, Finland, and Switzerland.

PARTICIPANTS

Institutions selected 798 persons representing families (1 person for each family) thought to be at elevated a priori risk of BRCA1 mutation due to potential risk factors, such as multiple cases of breast cancer, early age of breast cancer diagnosis, and cases of ovarian cancer. No participant was from a family in which genetic markers showed linkage to the BRCA1 locus.

MAJOR OUTCOME MEASURES

Sequence variants detected in this sample are presented along with analyses designed to determine predictive characteristics of those testing positive for BRCA1 mutations.

RESULTS

In 102 women (12.8%), clearly deleterious mutations were detected. Fifty new genetic alterations were found including 24 deleterious mutations, 24 variants of unknown significance, and 2 rare polymorphisms. In a subset of 71 Ashkenazi Jewish women, only 2 distinct deleterious mutations were found: 185delAG in 17 cases and 5382insC in 7 cases. A bias in prior reports for mutations in exon 11 was revealed. Characteristics of a patient's specific diagnosis (unilateral or bilateral breast cancer, with or without ovarian cancer), early age at diagnosis, Ashkenazi Jewish ethnicity, and family history of cancer were positively associated with the probability of her carrying a deleterious BRCA1 mutation.

CONCLUSIONS

Using logistic regression analysis, we provide a method for evaluating the probability of a woman's carrying a deleterious BRCA1 mutation for a wide range of cases, which can be an important tool for clinicians as they incorporate genetic susceptibility testing into their medical practice.

Fifteen years with clinical guidelines in the treatment of hypertension--still discrepancies between intentions and practice

OBJECTIVE

To assess physicians' current adherence to the Norwegian clinical guidelines for the treatment of hypertension.

DESIGN

Descriptive, retrospective registration of information from patient records of one specified year. In addition, mailed questionnaire to examine the representativeness of the participating doctors.

SETTING

General practice in Sør- and Nord-Trøndelag counties in Norway, 380,000 inhabitants.

PATIENTS

In one year 2468 patients were registered with the diagnosis of hypertension in the records of 56 general practitioners. The patients were 57% women and 43% men; 41% were 70 years or older.

MAIN OUTCOME MEASURES

Levels of blood pressure in accordance with the recommendations of the Norwegian clinical guidelines for hypertension. Fractions of patients with a measured blood pressure and serum cholesterol in one year.

RESULTS

At least one blood pressure was recorded in 95% of the hypertensive patients during the specified year. The systolic blood pressure was 140 mmHg or less in 25% and 160 mmHg or less in 65%, while the diastolic blood pressure was 90 mmHg or less in 61%. According to the Norwegian clinical guidelines for systolic blood pressure, 29% of the women and 21% of the men were above recommended levels for treatment. With respect to the diastolic blood pressure, the figures were 38% for women and 40% for men. Patients under 60 years of age were often not treated according to the recommendations. Serum cholesterol was not recorded during the specified year in 68% of the total group, nor in 55% of patients aged 65 years or younger.

CONCLUSION

There are still major discrepancies between current practice and the intentions laid down in the Norwegian clinical guidelines. A discussion of alternative methods for implementation and for evaluation of the efficacy of clinical guidelines is needed.

Prevalence of known and previously unknown diabetes mellitus and impaired glucose tolerance in an adult Norwegian population. Indications of an increasing diabetes prevalence. The Nord-Trøndelag Diabetes Study

OBJECTIVE

To establish the prevalence of known and undiagnosed diabetes mellitus and impaired glucose tolerance in a representative Norwegian adult population according to the 1980 World Health Organization Expert Committee diagnostic criteria.

DESIGN

Screening survey applying questionnaire and non-fasting blood glucose followed by a fasting and an oral glucose tolerance test.

SETTING

The county of Nord-Trøndelag, Norway, 1984-86.

SUBJECTS

All inhabitants aged > or = 20 years (85,100); 90.3% participated. For previously unknown diabetes: all inhabitants > or = 40 years (53,001)--participation rate 84.7%.

MAIN OUTCOME MEASURE

Prevalence.

RESULTS

The prevalence of previously known diabetes was 2.6% in men and 3.2% in women. Total diabetes prevalence > or = 40 years was 4.8% in men and 5.6% in women. The prevalence increased continuously with age until 90 years. One patient in five was previously undiagnosed. Impaired glucose tolerance in those with an abnormal non-fasting value was rare; only 0.9% in men and 0.2% in women. The prevalence of known diabetes was three times higher than 20-30 years ago and four times higher than 50 years ago. Except for known diabetes in the very old the prevalence corresponded well with recent Nordic studies.

IMPLICATIONS

The present diabetes prevalence was so high that interested general practitioners will get sufficient experience in follow-up of diabetic patients to facilitate a good quality of the care.