Public health impact of large airports.

Large airports with the related infrastructure, businesses and industrial activities affect the health of the population living, travelling and working in the surroundings of or at the airport. The employment and contributions to economy from the airport and related operations are expected to have a beneficial effect, which, however, is difficult to quantify. More pertinent data are available on the, largely negative, health effects of environmental factors, such as air and soil pollution, noise, accident risk, and landscape changes. Information on the concurrent and cumulative impact of these factors is lacking, but is of primary relevance for public health policy. A committee of the Health Council of The Netherlands recently reviewed the data on the health impact of large airports. It was concluded that, generally, integrated health assessments are not available. Such assessments, as part of sustainable mobility policy, should accompany the further development of the global aviation system.

Risk indicators for out-of-hospital cardiac arrest in patients with coronary artery disease.

The objective of this study was to identify risk factors for sudden cardiac arrest (SCA) in patients with coronary artery disease (CAD). A retrospective case-control study was performed consisting of a group of unselected patients who had suffered SCA and had a clinical history of CAD, and a group of unselected age- and gender-matched CAD control patients living in the region of Maastricht. Information about previous myocardial infarction (MI), left ventricular ejection fraction (LVEF), hypertension, hypercholesterolemia, diabetes mellitus, smoking, and coffee and alcohol consumption was collected. A logistic regression model was fitted to all mentioned variables including age and genders. Included were 117 SCA cases (84% men, mean age 65 years [+/-7]) and 144 control patients (83% men, mean age 63 years [+/-8]). Previous MI (odds ratio [OR] 4.0, 95% confidence interval [CI] 1.7-9.3), hypertension (OR 2.9, 95% CI 1.5-6.1), heavy coffee consumption (>10 cups per day) (OR 55.7, 95% CI 6.4-483), and a LVEF <40% (OR 11.2, CI 4.4-28.5) were independent risk indicators for SCA in patients with CAD. Alcohol consumption (1-21 glasses per week) seemed to protect patients with CAD from SCA (OR 0.5, 95% CI 0.2-0.98). These observations suggest that changes in lifestyle factors can be of potential importance in protecting patients with CAD from dying suddenly.

The effect of smoking on influenza, influenza vaccination efficacy and on the antibody response to influenza vaccination.

We examined the relation between cigarette smoking and (1) the occurrence of influenza, (2) the efficacy of influenza vaccination and (3) the antibody response to influenza vaccination in fifteen family practices in South-Limburg, the Netherlands, during the influenza season 1991 1992. Data were used from a randomized double-blind placebo-controlled trial into the efficacy of influenza vaccination in which smoking status was measured 10 weeks after the start of the trial. A total of 1838 subjects aged 60 years or older, of whom 1531 subjects (321 smokers, 1152 non-smokers and 58 cigar/pipe smokers) who returned the smoking questionnaire and were not previously vaccinated, were used in the analyses. The main outcome measures were serological influenza (fourfold increase of antibody titre between 3 weeks and 5 months after vaccination); clinical influenza as determined by criteria of the Dutch Sentinel Stations from self reported symptoms in postal questionnaires 10 weeks and 5 months after vaccination; increases after vaccination and decreases after 5 months in logarithmic titres of antibody against the vaccine strains. No relation between smoking and either serological or clinical influenza was found, although the risk for serological influenza was slightly (not significantly) elevated in smokers compared to non-smokers. A statistical interaction was found between smoking and vaccination when serological influenza was the outcome measure indicating that the efficacy of vaccination was greater in smokers than in non-smokers (comparison of model with and without interaction; likelihood ratio test, p < 0.0001). This finding is supported by a greater titre rise 3 weeks after vaccination for two out of four strains, but not by the antibody response after vaccination in previous studies on influenza and other infectious diseases. Also, this possible difference of immunogenicity is not reflected in a better protection for clinical influenza. The rise in antibody titre 3 weeks after vaccination was higher in smokers for A/Singapore/6/86 and B/Beijing/11/87, but not for the other two strains. Decline in titres after 5 months was similar for smokers and non-smokers. We conclude that smoking has no clinical or preventive significance for risk of influenza in the elderly.

Are autoimmune thyroid dysfunction and depression related?

The objective of this study was to examine the relationship between autoimmune thyroid disease and depression in perimenopausal women. Thyroid function [TSH, free T4, and thyroid peroxidase antibodies (TPO-Ab)] and depression (using the Edinburgh Depression Scale) were assessed cross-sectionally together with other determinants of depression. The subjects were 583 randomly selected perimenopausal women (aged 47-54 yr) from a community cohort of 6846 women. The main outcome measures were the occurrence of thyroid dysfunction (abnormal free T4 and/or TSH or elevated levels of TPO-Ab) and the concomitant presence of depression according to the Edinburgh Depression Scale. Neither biochemical thyroid dysfunction nor menopausal status was related to depression. Apart from several psycho-social determinants (the occurrence of a major life event, a previous episode of depression, or financial problems), an elevated level of TPO-Ab (> or = 100 U/mL) was significantly associated with depression (odds ratio, 3.0, 95% confidence interval, 1.3-6.8). We conclude that women with elevated TPO-Ab levels are especially vulnerable to depression, whereas postmenopausal status does not increase the risk of depression.

The relation between morbidity and cognitive performance in a normal aging population.

BACKGROUND: Factors related to physical health have been implicated in both normal and pathological aging of cognitive abilities. To substantiate this notion, we studied existing morbidity, as diagnosed by the general practitioner according to well-defined criteria, as a potential predictor of cognitive test performance. METHODS: A sample of 1360 individuals, aged 24-81 years and living in the community, was stratified for age, sex, and general ability. Active and total morbidity in this group were classified according to the International Classification of Primary Care. Neurocognitive tests were used to assess the domains of verbal memory, sensorimotor speed, and cognitive flexibility. RESULTS: Multiple regression analyses with adjustment for age, sex, and educational level showed both insulin-dependent and noninsulin-dependent diabetes to be negatively associated with all cognitive measures. More specific negative associations were found for chronic bronchitis (performance speed) and presbyacusia (memory). Single or aggregated cardiovascular morbidity (including hypertension) was unrelated to test performance. CONCLUSIONS: Existing morbidity as a whole contributes only modestly (up to 3.5%) to total variance in cognitive function. However, some specific, relatively common diseases of the elderly, such as diabetes and chronic bronchitis, may aggravate the age-related decline in cognitive ability.

Occurrence of arrhythmias in general practice.

OBJECTIVE: To study the occurrence and distribution of arrhythmias in patients with symptoms possibly caused by arrhythmias, in order to support the diagnostic process in general practice. DESIGN: From 1989-1991 all patients who consulted their general practitioner with symptoms or signs possibly indicating an arrhythmia had a transtelephonic electrocardiogram, which was sent to the Department of Cardiology for interpretation. SETTING: 20 Dutch general practices, serving a population of nearly 50,000 inhabitants. SUBJECTS: A total of 868 patients were included in the study. RESULTS: An arrhythmia was documented by ECG in 32% of the patients. Of these, 31% clinically more relevant arrhythmias needed medical attention. An incidence of 2.6 arrhythmias per 1000 listed patients was calculated. There was a highly positive correlation between the occurrence of arrhythmias and age. Relatively more arrhythmias were seen in men, in patients with occasional findings, and when there were symptoms that possibly indicated haemodynamic imbalance. CONCLUSION: Clinically relevant arrhythmias can be detected in general practice with 12-lead ECG recording in a significant proportion of patients with symptoms and physical findings suggesting an arrhythmia. The distribution of arrhythmias described in this study can help general practitioners in their diagnostic management.

Why do patients consult the general practitioner? Determinants of their decision.

In order to obtain more information about the reasons why patients consult their general practitioner 1000 patients completed a questionnaire in the waiting rooms of eight general practices. After the consultation the patients received a second questionnaire. The aim of the study was to determine why people decide to consult their general practitioner about one complaint but not about a second complaint. Both questionnaires were based on the health belief model, augmented by three other factors: the perceptions patients have of their own abilities to cope with their condition (efficacy of self care), their knowledge about the complaint and their need for information. The results showed that two of the additional factors (efficacy of self care and need for information) as well as most of the factors of the health belief model (efficacy of general practitioner care, perceived severity of complaint and cues to consult) were important determinants of consulting the general practitioner. The results suggest that patients sometimes expect information from their general practitioner rather than medical treatment. Furthermore, as the perceived efficacy of general practitioner care is also an important determinant, unnecessary consultation or unnecessary delay in treatment could be prevented by offering patients information about the potential effectiveness of medical care or self care for specific conditions. Implications for general practitioners' daily practice and future research are discussed.

Worry: a particular determinant of consultation illuminated.

In this study, exploring the worry experienced by patients in the GP waiting room and the reasons for being worried, 791 patients completed a structured questionnaire just before they consulted their GP, and afterwards. The perceptions of the patients concerning the complaint and the need for more information about the complaint played an important role in the degree of worry. Patients who wanted more information about the complaint were more worried than the patients who did not feel they needed more information. Not surprisingly, the more serious the patients perceived the complaint to be and the greater the perceived chance of serious disease, the more worried they were. General health status and frequency of consultations per year were related to the degree of general worry. According to the patient self-reports, worry was almost never due to information from the mass media or from other persons, or to a concern for the consultation itself. Patients generally evaluated the consultation as positive with respect to the way their worry was discussed. The decrease in worry after consulting the GP, in patients who were positive about the consultation was significantly higher than that in patients who were less positive. The theoretical and practical implications of this study are discussed.

Leucocyte count as an alternative to ESR in general practice?

We investigated the ability of the leucocyte count to discriminate between "inflammatory diseases and malignancies" on the one hand and other, often harmless and self-limiting diseases on the other, and compared this ability with that of the erythrocyte sedimentation rate (ESR) in general practice. In cooperation with nine general practitioners (GP) we prospectively followed 151 patients who were seen by their GP because of a new complaint for which the GP wanted to know their ESR. ESR and one leucocyte count measurement (Technicon H6000) were performed at the local hospital laboratory. The patients were seen again after three months, to determine the follow-up diagnoses. By comparing the test results with the follow-up diagnoses, ESR was found to have a better discriminating ability than the leucocyte count test (ESR: sensitivity = 53%, specificity = 84%, positive predictive value = 29%, negative predictive value = 93%, Odds Ratio = 5.73). Using Receiver Operating Characteristic analysis, this conclusion could be shown to be independent of the chosen reference values. We conclude that the determination of the leucocyte count is not a clinically interesting alternative to ESR.

Peripheral arterial occlusive disease in general practice: the reproducibility of the ankle-arm systolic pressure ratio.

One of the non-invasive techniques used in the diagnosis of patients with peripheral arterial occlusive disease is the measurement of the Ankle-Arm Systolic Pressure Ratio ("AA-Ratio"). The magnitude of different sources of measurement variation, relevant to clinical practice as well as multi-observer studies, was estimated from a random effects analysis of variance model. Thirty-five GPs and 24 practice assistants performed 503 AA-Ratio measurements on nine patients over a period of nine weeks, using pocket Doppler devices. When the AA-Ratio is used for diagnostic purposes, a 95% prediction interval consisting of the measured value +/- 15-20% AA-Ratio has to be taken into account. Furthermore, when the AA-Ratio is used in the follow-up of a patient with vascular disease, the difference between two subsequent measurements has to be at least 15.6-19.0% AA-Ratio to have an 80% certainty that this difference is not due to (intra-observer) measurement error.