Nationwide paediatric cohort study of a protective association between allergy and complicated appendicitis

BACKGROUND

In a nationwide cohort the potentially protective association between allergy and complicated appendicitis was analysed, and the influence of seasonal antigens, antihistamine treatment, and timing of allergy onset assessed.

METHODS

Some 1 112 571 children born between 2000 and 2010 were followed from birth until the end of 2014. A cross-sectional analysis of appendicitis cases, with comparison of allergic versus non-allergic children for absolute risk and odds of complicated appendicitis was first undertaken. This was followed by a longitudinal analysis of children with allergy and matched controls who had never had an allergy, for incidence rate and hazard of subsequent complicated or simple appendicitis.

RESULTS

Of all children, 20.4 per cent developed allergy and 0.6 per cent had appendicitis during follow-up. Among children with appendicitis, complicated appendicitis was more common among non-allergic children (18.9 per cent, 948 of 5016) than allergic children (12.8 per cent, 173 of 1351) (P < 0.001), and allergic children had a lower adjusted odds of complicated appendicitis (adjusted odds ratio (OR) 0.80, 95 per cent c.i. 0.67 to 0.96; P = 0.021). The risk of complicated appendicitis among children with manifest allergy was reduced by one-third in the longitudinal analysis (incidence rate 0.13 versus 0.20 per 1000 person-years; hazard ratio (HR) 0.68, 95 per cent c.i. 0.58 to 0.81; P < 0.001), whereas the risk of simple appendicitis remained unchanged (incidence rate 0.91 versus 0.91; HR 1.00, 0.94 to 1.07; P = 0.932). Seasonal antigen exposure was a protective factor (adjusted OR 0.82, 0.71 to 0.94; P = 0.004) and ongoing antihistamine medication a risk factor (adjusted OR 2.28, 1.21 to 4.28; P = 0.012).

CONCLUSION

Children with allergy have a lower risk of complicated appendicitis, but the same overall risk of simple appendicitis. Seasonal antigen exposure reduced, and antihistamine treatment increased, the risk of complicated disease.

Association between heavy metals and metalloids in topsoil and mental health in the adult population of Spain

BACKGROUND AND OBJECTIVES

Despite the biological plausibility of the association between heavy metal exposure and mental health disorders, epidemiological evidence remains scarce. The objective was to estimate the association between heavy metals and metalloids in soil and the prevalence of mental disorders in the adult population of Spain.

METHODS

Individual data came from the Spanish National Health Survey 2011-2012, 18,073 individuals residing in 1772 census sections. Mental health was measured with the 12-item General Health Questionnaire. The concentration estimates of heavy metal and metalloid levels in topsoil (upper soil horizon) came from the Geochemical Atlas of Spain based on 13,317 soil samples. Levels of lead (Pb), arsenic (As), cadmium (Cd) and manganese (Mn) were estimated in each census section by "ordinary Kriging". Odds ratios (OR) were calculated by multilevel logistic regression models.

RESULTS

Compared with the lowest Pb concentration levels quartile, the OR for the second quartile was 1.29 (95%CI: 1.11-1.50), increasing progressively to 1.37 (95%CI: 1.17-1.60) and 1.51 (95%CI: 1.27-1.79) in the third and fourth quartiles, respectively. For As, the association was observed in the third and fourth quartiles: 1.21 (95%CI: 1.04-1.41) and 1.42 (95% CI: 1.21-1.65), respectively. Cd was associated also following a gradient from the second quartile: 1.34 (95%CI: 1.15-1.57) through the fourth: 1.84 (95%CI: 1.56-2.15). In contrast, Mn only showed a positive association at the second quartile. Additionally, individuals consuming vegetables > once a day the OR for the fourth quartile of Pb concentration, vs. the first, increased to 2.93 (95%CI: 1.97-4.36); similarly for As: 3.00 (95%CI: 2.08-4.31), and for Cd: 3.49 (95%CI: 2.33-5.22).

CONCLUSIONS

Living in areas with a higher concentration of heavy metals and metalloids in soil was associated with an increased probability of having a mental disorder. These relationships were strengthened in individuals reporting consuming vegetables > once a day.

Long-term evaluation of the efficacy on the podalic support and postural control of a new elastic functional orthopaedic device for the correction of Class III malocclusion

AIM

Correlations between occlusion and posture are open to new perspectives, which include treatment of functional alterations traditionally approached separately. The aim of this study is to evaluate whether the treatment of Class III malocclusion, through an innovative elastic functional orthopaedic device, allows an overall improvement of the podalic support.

MATERIALS AND METHODS

A 5½-year-old patient with Angle Class III malocclusion and c anterior ross bite in deciduous dentition has been treated for 7 years with a functional orthopaedic device (MSB Class III). Assessment of frontal and lateral postural plumb line was performed with stabilo-baro-podometric platform analysis, in order to record the podalic support discrepancy between feet, both in static phase and in dynamic phase. The patient has been posturally re-evaluated at nine and twelve years old.

RESULTS

The functional device allowed the restoration of the correct intermaxillary relationship, favourably conditioning also the posture. In particular, the correction of the valgus flat foot and a significative reduction of the podalic support discrepancy between feet has been obtained.

CONCLUSIONS

A global approach to the patient can successfully address both malocclusion and postural alterations.

Individual and collective bodies: using measures of variance and association in contextual epidemiology

BACKGROUND

Social epidemiology investigates both individuals and their collectives. Although the limits that define the individual bodies are very apparent, the collective body's geographical or cultural limits (eg "neighbourhood") are more difficult to discern. Also, epidemiologists normally investigate causation as changes in group means. However, many variables of interest in epidemiology may cause a change in the variance of the distribution of the dependent variable. In spite of that, variance is normally considered a measure of uncertainty or a nuisance rather than a source of substantive information. This reasoning is also true in many multilevel investigations, whereas understanding the distribution of variance across levels should be fundamental. This means-centric reductionism is mostly concerned with risk factors and creates a paradoxical situation, as social medicine is not only interested in increasing the (mean) health of the population, but also in understanding and decreasing inappropriate health and health care inequalities (variance).

METHODS

Critical essay and literature review.

RESULTS

The present study promotes (a) the application of measures of variance and clustering to evaluate the boundaries one uses in defining collective levels of analysis (eg neighbourhoods), (b) the combined use of measures of variance and means-centric measures of association, and (c) the investigation of causes of health variation (variance-altering causation).

CONCLUSIONS

Both measures of variance and means-centric measures of association need to be included when performing contextual analyses. The variance approach, a new aspect of contextual analysis that cannot be interpreted in means-centric terms, allows perspectives to be expanded.

Socioeconomic position, macroeconomic environment and overweight among adolescents in 35 countries

OBJECTIVE

It is important to understand levels and social inequalities in childhood overweight within and between countries. This study examined prevalence and social inequality in adolescent overweight in 35 countries, and associations with macroeconomic factors.

DESIGN

International cross-sectional survey in national samples of schools.

SUBJECTS

A total of 11-, 13- and 15-year-olds from 35 countries in Europe and North America in 2001-2002 (N=162 305).

MEASUREMENTS

The main outcome measure was overweight based on self-reported height and weight (body mass index cut-points corresponding to body mass index of 25 kg/m(2) at the age of 18 years). Measures included family and school affluence (within countries), and average country income and economic inequality (between countries).

RESULTS

There were large variations in adolescent overweight, from 3.5% in Lithuanian girls to 31.7% in boys from Malta. Prevalence of overweight was higher among children from less affluent families in 21 of 24 Western and 5 of 10 Central European countries. However, children from more affluent families were at higher risk of overweight in Croatia, Estonia and Latvia. In Poland, Lithuania, Macedonia and Finland, girls from less affluent families were more overweight whereas the opposite was found for boys. Average country income was associated with prevalence and inequality in overweight when considering all countries together. However, economic inequality as measured by the Gini coefficient was differentially associated with prevalence and socioeconomic inequality in overweight among the 23-high income and 10-middle income countries, with a positive relationship among the high income countries and a negative association among the middle income countries.

CONCLUSION

The direction and magnitude of social inequality in adolescent overweight shows large international variation, with negative social gradients in most countries, but positive social gradients, especially for boys, in some Central European countries. Macroeconomic factors are associated with the heterogeneity in prevalence and social inequality of adolescent overweight.

Neighbourhood social interactions and risk of acute myocardial infarction

STUDY OBJECTIVE

Previous studies of neighbourhood effects on ischaemic heart disease (IHD) have used census or administrative data to characterise the residential context, most commonly its socioeconomic level. Using the ecometric approach to define neighbourhood social interaction variables that may be relevant to IHD, neighbourhood social cohesion and safety were examined to see how they related to acute myocardial infarction (AMI) mortality, after adjustment for individual and neighbourhood confounders.

DESIGN

To construct social interaction variables, multilevel models were used to aggregate individual perceptions of safety and cohesion at the neighbourhood level. Linking data from the Health Survey in Scania, Sweden, and the Population, Hospital, and Mortality Registers, multilevel survival models were used to investigate determinants of AMI mortality over a three year and nine month period.

PARTICIPANTS

7791 Individuals aged 45 years and over.

MAIN RESULTS

The rate of AMI mortality increased with decreasing neighbourhood safety and cohesion. After adjustment for individual health and socioeconomic variables, low neighbourhood cohesion, and to a lesser extent low safety, were associated with higher AMI mortality. Neighbourhood cohesion effects persisted after adjustment for various neighbourhood confounding factors (income, population density, percentage of residents from low-income countries, residential stability) and distance to the hospital. There was some evidence that neighbourhood cohesion effects on AMI mortality were caused by effects on one-day case-fatality, rather than on incidence.

CONCLUSIONS

Beyond commonly evoked effects of the physical environment, neighbourhood social interaction patterns may have a decisive influence on IHD, with a particularly strong effect on survival after AMI.

Residual risk for acute stroke in patients with type 2 diabetes and hypertension in primary care: Skaraborg Hypertension and Diabetes Project

AIM

The aim of this study was to investigate the risk of acute stroke in subgroups of patients treated for hypertension and type 2 diabetes in primary care.

METHODS

Patients with hypertension only (n = 695), type 2 diabetes only (n = 181) or both (n = 240), who consecutively attended an annual control in primary care in Skara, Sweden during 1992-1993, were evaluated for cardiovascular disease risk factors and enrolled in this study. Subjects with neither hypertension nor type 2 diabetes (n = 824) who participated in a population survey in the same community served as controls. Possible events of acute stroke through 2002 were validated using hospital records and death certificates.

RESULTS

During a mean follow-up time of 8.4 years, 190 first events of acute stroke, fatal or non-fatal, were ascertained. Risk factor levels were generally higher in all patient categories than in controls. Stroke risk was significantly increased in all male patients: hazard ratio 4.2 (95% CI 2.1-8.4) in patients with both conditions, 3.3 (1.5-7.0) in those with type 2 diabetes alone and 2.8 (1.5-5.3) in those with hypertension alone (adjusted for age, total cholesterol, current smoking, BMI and physical activity). Corresponding findings in women were 2.9 (1.5-5.8) in patients with type 2 diabetes only and 2.4 (1.2-4.7) in those with both conditions. However, in women with hypertension only, a significant risk was seen first when subjects were truncated at 85 years of age. There were too few fatal stroke events for conclusive results on stroke mortality.

CONCLUSIONS

A considerable risk of acute stroke remains in patients with type 2 diabetes and hypertension. Strategies for stricter multiple risk factor interventions should be implemented in primary care.

Understanding adherence to official guidelines on statin prescribing in primary health care--a multi-level methodological approach

OBJECTIVE

The aim was to investigate the role that municipalities and out-patient health care centres (HCCs) have in understanding adherence to official guidelines on statin prescribing. Our hypothesis was that after guideline publication, adherence to recommended statin prescription would increase and variance among HCCs and municipalities would decrease. Since multi-level regression analysis (MLRA) is a relatively new methodology in pharmacoepidemiology, we also aimed to explore the application of MLRA in our investigation.

METHODS

We obtained data from the Swedish Corporation of Pharmacies record of sales regarding all initial prescriptions of statins issued between April and December 2003. We applied multi-level analysis on 34,514 individual prescriptions (level 1) nested within 226 HCCs (level 2), which in turn were nested within 33 municipalities (level 3). Temporal trends and gender differences were investigated by means of random slope analysis. Variance was expressed using median odds ratio (MOR) and interval odds ratio.

RESULTS

HCCs appeared to be more relevant than municipalities for understanding the physicians' propensity to prescribe a recommended statin (MOR(HCC) = 1.96 and MOR(Municipality) = 1.41). Overall prevalence of adherence was very low (about 20%). After publication of the guidelines, prescription of recommended statins increased, and variance among HCCs decreased but only during the first 4 months of the observation period.

CONCLUSION

The publication of official guidelines in the county of Scania exerted a positive influence on statin prescription but, at the end of the observation period, adherence was still low and practice variation high. These facts may reflect inefficient therapeutic traditions and suggest that more intensive interventions may be necessary to promote rational statin prescription.

Atrial fibrillation and its association with type 2 diabetes and hypertension in a Swedish community

AIM

To explore the prevalence of atrial fibrillation in patients with hypertension and type 2 diabetes and to identify possible mechanisms for the development of atrial fibrillation.

METHODS

A community-based, cross-sectional observational study was conducted in the primary health care in Skara, Sweden, and 1739 subjects (798 men, 941 women) were surveyed. Patients were categorized as those with hypertension only (n = 597); those with both hypertension and type 2 diabetes (n = 171), and those with type 2 diabetes only (n = 147). In the reference population, 824 normotensive subjects without diabetes were identified and used as controls. Participants were examined for cardiovascular risk factors including fasting blood glucose, serum insulin, blood pressure, lipids and anthropometric measures. Resting electrocardiogram (ECG) was recorded and Minnesota-coded. Insulin resistance was measured by the homeostasis model assessment (HOMA).

RESULTS

Age-adjusted prevalence of atrial fibrillation was 2% in patients with hypertension only, 6% in patients with both hypertension and type 2 diabetes, 4% in patients with type 2 diabetes only and 2% in controls, respectively. Age and sex adjusted odds ratios (OR) (95% CI) were; hypertension 0.7 (0.30-1.5), combined hypertension and type 2 diabetes 3.3 (1.6-6.7), and type 2 diabetes 2.0 (0.9-4.7). The association with combined hypertension and type 2 diabetes remained significant when adjusted for cardiovascular disease (CVD) risk factors and body mass index (BMI), was attenuated with adjustment for ischemic ECG; 2.4 (1.1-5.0) and lost significance with adjustment for insulin resistance; 1.3 (0.5-3.1).

CONCLUSIONS

Atrial fibrillation is associated with the combined occurrence of type 2 diabetes and hypertension. Insulin resistance may be a common underlying mechanism.

Country of birth, socioeconomic position, and healthcare expenditure: a multilevel analysis of Malmö, Sweden

STUDY OBJECTIVE

The principle of equity aims to guarantee allocation of healthcare resources on the basis of need. Therefore, people with a low income and persons living alone are expected to have higher healthcare expenditures. Besides these individual characteristics healthcare expenditure may be influenced by country of birth. This study therefore aimed to investigate the role of country of birth in explaining individual healthcare expenditure.

DESIGN

Multilevel regression model based on individuals (first level) and their country of birth (second level).

SETTING

The city of Malmö, Sweden.

PARTICIPANTS

All the 52 419 men aged 40-80 years from 130 different countries of birth, who were living in Malmö, Sweden, during 1999.

MAIN RESULTS

At the individual level, persons with a low income and persons living alone showed a higher healthcare expenditure, with regression coefficients (and 95% confidence intervals) being 0.358 (0.325 to 0.392) and 0.197 (0.165 to 0.230), respectively. Country of birth explained a considerable part (18% and 13%) of the individual differences in the probability of having a low income and living alone, respectively. However, this figure was only 3% for having some health expenditure, and barely 0.7% with regard to costs in the 74% of the population with some health expenditure.

CONCLUSIONS

Malmö is a socioeconomically segregated city, in which the country of birth seems to play only a minor part in explaining individual differences in total healthcare expenditure. These differences seem instead to be determined by individual low income and living alone.

Neighbourhood social participation and women's use of anxiolytic-hypnotic drugs: a multilevel analysis

STUDY OBJECTIVES

To identify and quantify a hypothesised collective effect of the neighbourhood on individual use of anxiolytic-hypnotic drugs (AHD). To analyse the general impact of neighbourhood social participation on use of AHD, adjusting for individual characteristics.

DESIGN

Cross sectional analysis performed by multilevel logistic regression with women at the first level and neighbourhoods at the second level.

SETTING

Malmö (250 000 inhabitants), Sweden.

PARTICIPANTS

15 456 women aged 45 to 73, residing in 95 neighbourhoods in Malmö, who took part in the Malmö diet and cancer study (1991-1996).

MAIN RESULTS

The prevalence of AHD use was 5.5% in the study sample. Overall, 1.7% of the total individual differences in the propensity for using AHD were explained by the neighbourhood level. This percentage, however, differed between different individuals. Low level of social participation in the neighbourhood was associated with higher probability of AHD use (OR = 3.10 (95% CI 1.51 to 6.41)), independently of individual age, low social participation, low educational level, and living alone. This association was reduced (OR = 2.01 (95% CI 0.97 to 4.14)) after the additional accounting for individual disability pension, low self rated health, stress, and medication for somatic disorders.

CONCLUSIONS

The neighbourhood level of social participation seems to affect individual use of AHD, possibly through individual characteristics. However, neighbourhood boundaries play a minor part in understanding individual AHD use in the city of Malmö.

Thermal response to submaximal exercise before, during and after pregnancy: a longitudinal study

BACKGROUND

Heat stress in early pregnancy is known to have a teratogenic effect. Exercise produces excess heat and during pregnancy might therefore present a theoretical risk of malformations. Our aim was to assess the thermal response to exercise of healthy pregnant women in a longitudinal study.

METHODS

Fourteen women were examined before pregnancy, and followed five times during, and twice after pregnancy, using a submaximal bicycle test with a target heart rate of 85% of the predicted age-adjusted maximum. The main aim was to present reference values.

RESULTS

The temperature at submaximal work load declined continuously from preconception to postpartum levels (37.8 degrees C vs. 36.9 degrees C, p = 0.04). The difference between peak and basal core temperature fell from 0.6 degrees C to 0.05 degrees C at 29 and 36 weeks of gestation, reaching preconception levels at 24 weeks after delivery (0.8 degrees C lower).

CONCLUSION

During submaximal exercise the temperature response seemed to provide thermal protection for the embryo and the fetus.

Social capital and leisure time physical activity: a population based multilevel analysis in Malmö, Sweden

OBJECTIVE

To investigate the influence of social capital and individual factors on the level of leisure time physical inactivity in the neighbourhoods.

METHODS

The public health survey in Malmö 1994 is a cross sectional study. A total of 5600 people aged 20-80 years were invited to answer a postal questionnaire. The participation rate was 71%. A multilevel logistic regression model, with individuals at the first level and neighbourhoods at the second, was performed. The effect (intra-area correlation, cross level modification, and odds ratios) was analysed of individual and neighbourhood (the 1993 migration out of an area as a proxy for social capital) factors on leisure time physical inactivity after adjustment for individual factors.

RESULTS

Neighbourhood factors accounted for 5.0% of the crude total variance in physical inactivity. This effect was significantly reduced when the individual factors, especially country of origin, education, and social participation, were included in the model. In contrast, it was not reduced by the introduction of the contextual social capital variable.

CONCLUSION

This study suggests that in the neighbourhoods of Malmö leisure time physical inactivity is mainly affected by individual factors.

The relation between self-rated health, socioeconomic status, body mass index and disability pension among middle-aged men

The aim of this study was to assess the relations between self-rated health (SRH), socioeconomic status (SES), body mass index (BMI) and disability pension. Five birth-year cohorts of middle-aged male residents in Malmö, Sweden, were invited and 5313 with complete data constituted the cohort in this study. Each subject was followed for approximately 11 years. Of all subjects, 73% perceived their health as perfect and among obese men and blue collar workers, the corresponding figures were 67 and 68% respectively. The adjusted odds ratios for SRH less than perfect was 1.3 (CI: 1.1-1.7) for obese subjects and 1.7 (CI: 1.5-1.9) for blue collar workers. The interaction between low SES and obesity was estimated to 11% which was not statistically significant. The adjusted relative risks (RR) of disability pension was 3.3 for subjects with SRH less than perfect, 2.2 for blue collar workers and 2.0 for obese subjects, all statistically significant and only marginally less than the crude RR. Thus, SRH among middle-aged men was associated with obesity as well as low SES, but no evidence of synergism between obesity and low SES in relation to SRH was found. Furthermore, poor SRH in particular, but also low SES and obesity, independently predicted disability pension.

Protein tyrosine phosphatases

The molecular mechanisms of signal transduction have been at the focus of increasingly intense scientific research. As a result, our understanding of protein tyrosine kinase-mediated signaling has advanced at an unprecedented pace during the past decade. In contrast, the study of protein tyrosine phosphatases has lagged behind, but is now gathering momentum and is predicted to become a "hot topic" in the field within the next few years. This review summarizes the current state-of-the art in our understanding of the structure, regulation and role of protein tyrosine phosphatases with emphasis on the lymphocyte system.

Diastolic blood pressure and area of residence: multilevel versus ecological analysis of social inequity

STUDY OBJECTIVES

To study geographical differences in diastolic blood pressure and the influence of the social environment (census percentage of people with low educational achievement) on individual diastolic blood pressure level, after controlling for individual age and educational achievement. To compare the results of multilevel and ecological analyses.

DESIGN

Cross sectional analysis performed by multilevel linear regression modelling, with women at the first level and urban areas at the second level, and by single level ecological regression using areas as the unit of analysis.

SETTING

Malmö, Sweden (population 250 000).

PARTICIPANTS

15 569 women aged 45 to 73, residing in 17 urban areas, who took part in the Malmö Diet and Cancer Study (1991-1996).

MAIN RESULTS

In the "fixed effects" multilevel analysis, low educational achievement at both individual (beta=1.093, SE=0.167) and area levels (beta=2.966, SE=1.250) were independently associated with blood pressure, although in the "random effects" multilevel analysis almost none of the total variability in blood pressure across persons was attributable to areas (intraclass correlation=0.3%). The ecological analysis also found an association between the area educational variable and mean diastolic blood pressure (beta=4.058, SE=1.345).

CONCLUSIONS

The small intraclass correlation found indicated very marginal geographical differences and almost no influence of the urban area on individual blood pressure. However, these slight differences were enough to detect an effect of the social environment on blood pressure. The ecological study overestimated the associations found in the "fixed" effects multilevel analysis, and neither distinguished individual from area levels nor provided information on the intraclass correlation. Ecological analyses are inadequate to evaluate geographical differences in health.

[Multilevel analysis of regional disparities in survival after heart failure: differences between county health services affect little patients' prognosis]

The prognosis for patients suffering from heart failure in Sweden differs from county to county, indicating a need for a comparative study in order to uncover the reasons. Conventional single-level analytical methods, however, underestimate the statistical uncertainty in such studies, leading to an inappropriate ranking of regions. Consequently, public opinion and decision-making may be misled. Conventional methods are also unable to disentangle the extent to which differences in prognosis may depend on individual or regional factors. Multilevel analysis, on the other hand, provides a better estimate of statistical uncertainty, and can both identify and quantify the extent to which differences in prognosis depend on either patient-related or regional factors. Using multilevel analysis, we examined the one-year mortality of 38,343 heart failure patients for the period 1992-1995 in every county in Sweden. Regional differences in one-year mortality were found to be very small, the most relevant factors being individual ones. The limited differences distinguishable at the county level may be explained in part by physician density: the more physicians in a county, the better an individual patient's prognosis.

The use of analgesics and hypnotics in relation to self-rated health and disability pension--a prospective study of middle-aged men

AIMS

This cohort study on urban middle-aged men investigates the association between the use of analgesics and hypnotics, self-rated health (SRH) and disability pension.

METHODS

Five birth-year cohorts of middle-aged, urban, Swedish men were invited to a screening programme and were followed for approximately 11 years.

RESULTS

Out of all the subjects (n = 5798), 12.4% received a disability pension during follow-up, 27.0% rated their health as less than perfect, 10.6% used analgesics and 2.9% used hypnotics. Compared with non-users of analgesics and hypnotics, the adjusted hazard ratio of disability pension for the simultaneous use of both drugs was 7.0 (95% CI: 4.3, 11.6) and the adjusted odds ratio of poor SRH was 16.5 (6.3, 43.5). Thus, the use of analgesics and hypnotics was positively related to poor SRH and predicted award of a disability pension within an 11-year follow-up. This may reflect that the use of analgesics and hypnotics is a proxy of disease but an independent negative effect on health cannot be excluded.

CONCLUSIONS

Information on the use of these drugs could be used to predict the award of a disability pension, such as in different geographical areas or population groups.

Survival after initial hospitalisation for heart failure: a multilevel analysis of patients in Swedish acute care hospitals

STUDY OBJECTIVE

Although national variation in short-term prognosis (that is, 30 day mortality) after a patient's first hospitalisation for heart failure may depend on individual differences between patients, dissimilarities in hospital practices may also influence prognosis. This study, therefore, sought to disentangle patient determinants from institutional factors that might explain such variation.

DESIGN

A multilevel logistic regression modelling was performed with patients (1st level) nested in hospitals (2nd level). Institutional effects (that is, 2nd level variance and intra-hospital correlation) were calculated unadjusted and adjusted for specific patient (that is, age and previous diseases) and institutional (that is, size of hospital) characteristics. Patients were followed up until death or 30 days from hospital admission.

SETTING

Hospitals in Sweden.

PATIENTS

The study identified all the 20420 men and 17923 women (ages 65 to 85) admitted to the 90 acute care hospitals in Sweden during the period 1992-1995 for their first hospitalisation attributable to heart failure.

MAIN RESULTS

Patient age and previous diseases (particularly senile dementia) were major determinants of impaired prognosis. Institutional factors explained only 1.6% and 2.3% of the total variation in 30 day mortality in men and women, respectively. These modest institutional effects remained after adjusting for patient age and previous diseases, but were in part explained by hospital size.

CONCLUSIONS

National variation in short-term prognosis after an initial hospitalisation for heart failure was mainly explained by differences between patients, with hospital factors playing a minor part. Of the latter, hospital size seemed to emerge as one determinant (that is, the greater the number of patients, the better the individual prognosis).

Association of outpatient utilisation of non-steroidal anti-inflammatory drugs and hospitalised heart failure in the entire Swedish population

OBJECTIVE

Individual-based studies on restricted geographical settings have suggested that non-steroidal anti-inflammatory drugs (NSAIDs) may precipitate congestive heart failure. As NSAID use is very extensive, it might increase the occurrence of symptomatic heart failure in the general population. Therefore, in order to study the impact of NSAID utilisation (prescribed and over the counter) on hospitalised heart failure in an entire country (Sweden), we performed an ecological analysis, a design appropriate for studying large geographical areas.

METHODS

We employed weighted (population size) ecological linear regression to study the association between outpatient utilisation of NSAIDs during 1989-1993 and hospitalised heart failure in 1993 in 283 of Sweden's 288 municipalities. Data were adjusted for age and gender proportions, socio-economic factors, latitude and utilisation of cardiovascular drugs, aspirin, low-dose aspirin and paracetamol.

RESULTS

The unadjusted relative risk of hospitalised heart failure for each increase of one standard deviation of NSAID utilisation (5.8 defined daily doses/1000 inhabitants/day) was 1.23 [95% confidence interval (CI) 1.18, 1.27]. After adjustments, the relative risk was 1.08 (95% CI 1.04, 1.12); the corresponding values if aspirin (non-low-dose) was included as an NSAID were 1.26 (95% CI 1.23, 1.28) and 1.07 (95% CI 1.04, 1.10). There was no such adjusted association with the utilisation of paracetamol-0.95 (95% CI 0.92, 0.98).

CONCLUSION

The NSAID--heart failure association already established by individual-based studies on restricted geographical settings was corroborated in the present ecological study based on the whole population of an entire country (Sweden). Efforts should be made to promote a rational use of NSAIDs in the general population.

Mortality in elderly men with low psychosocial coping resources using anxiolytic-hypnotic drugs

OBJECTIVE

Insufficient coping with stress may lead to increased susceptibility for disease and death. Use of anxiolytic-hypnotic drugs has been suggested as a coping strategy, and some opinions have proposed their use as preventive medication. The aim of this study was to estimate if use of anxiolytic-hypnotic drugs counters the increased mortality observed in individuals lacking other coping strategies such as emotional support and social participation.

METHODS

A population based cohort study with 10-year (1982/83-1993) survival analysis was performed in 491 men born in 1914, living in the Swedish city of Malmö.

RESULTS

Compared with men with a high level of psychosocial coping resources who did not use anxiolytic-hypnotic drugs, men with a low level of psychosocial coping resources had a higher risk of death irrespective whether they used anxiolytic-hypnotic drugs, RR = 1.7 (95% CI 1.1-2.6) or not RR = 1.8 (95%: 1.3-2.5).

CONCLUSION

Anxiolytic-hypnotic drugs do not seem to counter increased mortality in elderly men with low psychosocial coping resources.

Self-administered questionnaire compared with a personal diary for assessment of current use of hormone therapy: an analysis of 16,060 women

A personal diary may be more appropriate than a questionnaire for assessing self-reported current use of hormone therapy (estrogens, progestagens, or their combination); however, use of a questionnaire is more feasible and less expensive. The authors compared both methods for 16,060 Swedish women aged 45-73 years from the Malmo Diet and Cancer Study (baseline, 1991-1996). In a reliability analysis, the authors investigated the agreement (kappa value) between the questionnaire and the diary regarding current hormone therapy use (yes vs. no), studying the ability to replicate results whether or not they were correct. They also explored associations between discrepancy and individual characteristics. A validity analysis was conducted to determine whether use of the questionnaire achieved an outcome without systematic error (i.e., high specificity and sensitivity); the personal diary was considered the "gold standard." Agreement between both methods was high: 95.5% (kappa = 0.840). The sensitivity was 84.9% and the specificity 97.7%. Higher body mass index and being a widow were associated with agreement, whereas age (50-59 years), use of anxiolytics/hypnotics or opiates, high alcohol consumption, past smoking, and higher educational level were associated with discrepancy. Compared with a personal diary, a simple self-administered questionnaire is a valid method for assessing current use of hormone therapy.

Distribution and determinants of ischaemic heart disease in an urban population. A study from the myocardial infarction register in Malmö, Sweden

OBJECTIVE

Age adjusted incidence of myocardial infarction has been found to vary substantially between the residential areas of the city of Malmö. The objective of this study was to assess the extent to which major biological risk factors and socio-economic circumstances account for the differences in incidence of and mortality from myocardial infarction.

DESIGN

Ecological study of risk factor prevalence and incidence and mortality from myocardial infarction.

SETTING

Seventeen administrative areas in Malmö, Sweden.

SUBJECTS

Assessment of risk factor prevalence was based on 28 466 men and women, ranging from 45 to 73 years old, who were recruited as participants in the Malmö Diet and Cancer study. Information on serum lipids was available in a random subsample of 5362 subjects. Information about socio-economic level of the residential area was based on statistics from the Malmö City Council and Statistics Sweden.

MAIN OUTCOME MEASURES

Weighted least square regressions between prevalence of risk factors (i.e. smoking, hypertension, obesity, diabetes, hypercholesterolemia and hypertriglyceridemia), a myocardial infarction risk score, a socio-economic score and incidence and mortality from myocardial infarction.

RESULTS

The risk factor prevalence and myocardial infarction incidence was highest in areas with low socio-economic level. Prevalence of smoking, obesity and hypertension was significantly associated with myocardial infarction incidence and mortality rates amongst men (all r > 0.60). Prevalence of smoking was significantly associated with incidence and mortality from myocardial infarction amongst women (r = 0.66 and r = 0.61, respectively). A myocardial infarction risk score based on four biological risk factors explained 40-60% of the intra-urban geographical variation in myocardial infarction incidence and mortality. The socio-economic score added a further 2-16% to the explained variance.

CONCLUSION

In an urban population with similar access to medical care, well-known biological cardiovascular risk factors account for a substantial proportion of the intra-urban geographical variation of incidence of and mortality from myocardial infarction. The socio-economic circumstances further contribute to the intra-urban variation in disease.

Comparison of different procedures to identify probable cases of myocardial infarction and stroke in two Swedish prospective cohort studies using local and national routine registers

In prospective cohort studies, person-time time is calculated from baseline until the first definite event occurs or until censoring. A way to correctly identify and date definite events when only routine registers are available is to retrieve all hospital discharge notes and death certificates with a diagnosis of probable event and perform a consecutive revision. It is important to detect all possible hospital stays as they may contain useful information for the revision study. Furthermore, loss to follow-up can be avoided by extending the retrieval outside the specific geographical area where the cohort was defined. The aims of this study were (i) to describe a comprehensive retrieval of probable myocardial infarctions (diagnosis with International Classification of Diseases 8th and 9th revisions codes 410-414) or stroke (codes 430-438), (ii) to quantify the relative efficiency of different local and national routine registers or their combination compared with the use of all available registers together, and (iii) to audit local and national registers by comparing their outcome at the county level. The study was performed in two prospective cohorts studies i.e., 'Men-born-1914' (n = 500) from Skåne (period 1982-1993), and Skara-1 (n = 683) from Skaraborg (period 1988-1994.). All available routine registers were linked to the cohorts. The use of all available routine registers improved retrieval of both individual and hospital stays with a discharge diagnosis of probable event and gave an enhanced basis for a future validation study. Local registers were not completely covered by the national register, but the accessible combination of national inpatient and mortality registers was an efficient alternative.

Overcoming the barriers to cross-continuum information integration

Due to the lack of a single information system solution that can meet all of the data management requirements of an integrated delivery system (IDS), IDSs must pursue various strategies to ensure that they manage their data as efficiently as possible. An IDS can identify which strategies will work best for its circumstances by evaluating the chief factors that contribute to inefficient data management across its organization. The IDS then should adopt a written plan, with a clear mission and vision, that describes the strategies to be pursued to improve data management.

Utilization of cardiovascular drugs (blood pressure lowering drugs, lipid lowering drugs and nitrates) and mortality from ischaemic heart disease and stroke. An ecological analysis based on Sweden's municipalities

OBJECTIVE

To perform an ecological study in an effort to generate questions concerning the preventive impact of various cardiovascular drugs on mortality from stroke and ischaemic heart disease (IHD) in the community, and to explore the association between sales of nitrates and mortality from stroke and IHD.

METHODS

Out-patient drug utilization (sales) of blood pressure lowering drugs, lipid lowering drugs and nitrates were categorized in four groups of equal size by quartiles and compared with mortality from IHD and stroke, using the group of municipalities with the lowest utilization as reference, from 1989 to 1993 in 283 of Sweden's 288 municipalities, by Poisson regression. Adjustments were made for population size, age and gender proportions, the utilization rate of cardiovascular drugs other than the tested drug group and location of the municipality.

RESULTS

Compared with the group of municipalities with the lowest sales and adjusting only for population size, mortality from IHD and stroke increased with the extent of utilization of blood pressure lowering drugs and nitrates. In contrast, mortality decreased with increased utilization of lipid lowering drugs. After further adjustments by percentage of men, age structure, geographical location (mid-points) of the municipalities, and, as a proxy for cardiovascular disease, the sales of cardiovascular drugs other than the tested drug group, the increased risk associated with blood pressure lowering drugs disappeared, and there was a dose-response association between sales of diuretics and old antihypertensives and decreasing mortality, sales of nitrates continued to be associated with an increased risk, and the low mortality risk associated with sales of lipid lowering drugs persisted.

CONCLUSION

Lipid lowering drugs may have a preventive impact in the general population, but the preventive impact of blood pressure lowering drugs, with the exception of diuretics and old antihypertensives, may be low in many municipalities. The safety of nitrates needs more investigation at the individual level.

Incidence of myocardial infarction in elderly men being treated with antihypertensive drugs: population based cohort study

OBJECTIVE

To analyse the association between use of antihypertensive treatment, diastolic blood pressure, and long term incidence of ischaemic cardiac events in elderly men.

DESIGN

Population based cohort study. Baseline examination in 1982-3 and follow up for up to 10 years.

SETTING

Malmŏ, Sweden.

SUBJECTS

484 randomly selected men born in 1914 and living in Malmŏ during 1982.

MAIN OUTCOME MEASURES

Observational comparisons of incidence rates and rate and hazard ratios of ischaemic cardiac events (myocardial infarction or death due to chronic ischaemic cardiac disease).

RESULTS

The crude incidence rate of ischaemic cardiac events was higher in those subjects who were taking antihypertensive drugs than in those who were not (rate ratio 2.6 (95% confidence interval 1.7 to 3.9)). After adjustment for potential confounders (differences in baseline smoking habits, blood pressure, time since diagnosis of hypertension, ischaemic or other cardiovascular disease, hypercholesterolaemia, hypertriglyceridaemia, diabetes mellitus, obesity, and raised serum creatinine concentration) this rate was reduced but still raised (hazard ratio 1.9 (1.0 to 3.7)). In men with diastolic blood pressure > 90 mm Hg, antihypertensive treatment was associated with a twofold increase in the incidence of ischaemic cardiac events (rate ratio 2.0 (1.1 to 3.6)), which vanished after adjustment for potential confounders (hazard ratio 1.1 (0.5 to 2.6)). In those subjects with diastolic blood pressure < or = 90 mm Hg, antihypertensive treatment was associated with fourfold increase in incidence (rate ratio 3.9 (2.1 to 7.1)), which remained after adjustment for potential confounders (hazard ratio 3.8 (1.3 to 11.0)).

CONCLUSION

Antihypertensive treatment may increase the risk of myocardial infarction in elderly men with treated diastolic blood pressures < or = 90 mm Hg.

Comparison of dose standard units for drug utilisation studies

OBJECTIVE

As employment of different dose standards would be impractical and confusing, the aim of this article is to compare the define daily dose (DDD) with some more recently proposed standards, namely, the minimum marketed dose (MMD), the equipotential dose (ED), the average daily dose (ADD), and the non-standard prescribed daily dose (PDD).

METHODS

Literature review, critical comparative analysis.

RESULTS

The DDD, defined by an independent scientific committee assisting the WHO Collaborating Centre for Drugs Statistics Methodology, has been employed in a large number of national and international comparative studies at the population level, usually as number of DDDs per 1000 inhabitants per day. However, the DDD can also be used at the individual level. The PDD, not being a standard unit, can be appropriately used in a second step to explain differences detected by the DDD methodology.

CONCLUSIONS

A globally accepted dose standard unit is important in drug utilisation studies, particularly if different investigations are to be compared. None of the alternatives seemed to offer any advantage over the DDD. Hence there is reason to advocate use of the DDD as the sole standard dose unit in all pharmacoepidemiologic studies.

Increased risk of ischaemic heart disease mortality in elderly men using anxiolytics-hypnotics and analgesics. Results of the 10-year follow-up of the prospective population study "Men born in 1914", Malmo, Sweden

OBJECTIVES

An increased risk of all-cause and cardiovascular mortality in users of anxiolytic-hypnotic drugs (AHD) has been reported, and use of analgesics may be an additional factor. Therefore, we examined the association of AHD and analgesic use, alone and in combination, with all-cause and ischaemic heart disease (IHD) mortality.

METHODS

Multivariate 10-year survival analysis in a population based cohort of 500 men born in 1914. Relative risks (RR) were adjusted by relevant confounders (blood pressure, serum cholesterol, diabetes mellitus, smoking habit, high alcohol consumption, history of previous IHD, cancer, and other diseases).

RESULTS

The RR of both all-cause and IHD mortality were significantly increased among those using both AHD and analgesics compared to those who took neither of these drugs: RR = 1.8 for all-cause mortality, and RR = 2.7 for IHD mortality.

CONCLUSION

Although the number of cases was small, warranting interpretative caution, the current study suggests that the combined use of AHD (mainly benzodiazepines) and analgesics seems to be associated with an increase in all-cause and IHD mortality in elderly men.

Age standardisation of drug utilisation: comparisons of different methods using cardiovascular drug data from Sweden and Spain

In drug utilisation studies, the units of defined daily doses (DDD) and DDD/1000 inhabitants per day standardise for differences in dosage and population size, but not for age-related differences in drug utilisation. There is no consensus as to how age standardisation of DDD data should be carried out. Using cardiovascular drug utilisation data from Sweden and Spain, the current study compared the outcome of different methods of age standardisation. Both indirect methods (based on a comparison of observed and expected drug usage) and direct methods (using different weighting for the age categories) were used. The largest impact of standardisation was seen for diuretics. The crude rate for men and women combined was 26 DDD/1000 inhabitants per day in Costa de Ponent and 98 DDD/1000 inhabitants per day in Värmland. The corresponding figures when standardising the Costa de Ponent population were 26 and 58, respectively. Using the equivalent average rate (EAR) method, the rate for Värmland was 129 DDD/1000 inhabitants per day. Lesser but still important differences were found for beta-adrenoceptor and antihypertensives. Thus, the results of standardisation differ depending on which method is used and which drugs are evaluated. EAR is recommended for direct standardisation because of its ease of use and because it does not require the choice of a standard population.