J Van der Heyden

Socio-economic differences in the utilisation of health services in Belgium.

OBJECTIVE To investigate socio-economic differences in the use of health services in Belgium and to explore to what extent eventual socio-economic inequalities are explained by differences in demographic determinants and health needs. DESIGN Data was obtained from the 1997 Belgian national Health Interview Survey. In this survey information was collected on the health status, the life style and the medical consumption of a representative sample of the Belgian non-institutionalised population consisting of 8560 Belgian inhabitants aged 15 years and over. RESULTS Lower socio-economic groups make more often use of the general practitioner and nursing care at home and are more often admitted to hospital than persons with a high socio-economical status. There is, however, no socio-economic gradient when the health status is taken into account. On the opposite, persons with a higher socio-economic status report more often a visit to a specialist, a physiotherapist or a dentist. For the health services for which this was investigated no association was found between socio-economic status and the volume of the use of health services. CONCLUSIONS There are in Belgium still important socio-economic gradients in the use of some health services. These differences may be due to socio-economic inequities but could also indicate that the existing health facilities are not always used in an optimal way. Patient factors may be more important than supply factors in explaining the differential use of health services. Further research needs to focus on socio-economic differences in the reasons, the outcome and the quality of the provided care.

Molecular basis of a high affinity murine interleukin-5 receptor.

The mouse interleukin‐5 receptor (mIL‐5R) consists of two components one of which, the mIL‐5R alpha‐chain, binds mIL‐5 with low affinity. Recently we demonstrated that monoclonal antibodies (Mabs) recognizing the second mIL‐5R beta‐chain, immunoprecipitate a p130–140 protein doublet which corresponds to the mIL‐3R and the mIL‐3R‐like protein, the latter chain for which so far no ligand has been identified. In this study we show that a high affinity mIL‐5R can be reconstituted on COS1 cells by co‐expression of the mIL‐5R alpha‐chain with the mIL‐3R‐like protein (beta‐chain). Cross‐linking of 125I‐labeled mIL‐5 to the COS1 cells co‐transfected with both cDNAs revealed the same pattern as in B13 cells, i.e. two proteins of 60 and 130 kd which correspond to the low affinity mIL‐5R alpha‐chain and the mIL‐3R‐like protein, respectively. The dissociation rate of mIL‐5 from this reconstituted high affinity site was lower than that of the low affinity site, whereas the association rate was unchanged. Nonetheless, the apparent dissociation constant (Kd) for this reconstituted receptor was still 10‐fold higher than the Kd observed for B13 cells. Although the mIL‐3R is greater than 90% homologous to the mIL‐3R‐like protein, no increase in affinity for mIL‐5 was detected on COS1 cells co‐transfected with the cDNAs for the mIL‐5R alpha‐chain and the mIL‐3R protein.

Socioeconomic inequalities in lung cancer mortality in 16 European populations

OBJECTIVES This paper aims to describe socioeconomic inequalities in lung cancer mortality in Europe and to get further insight into socioeconomic inequalities in lung cancer mortality in different European populations by relating these to socioeconomic inequalities in overall mortality and smoking within the same or reference populations. Particular attention is paid to inequalities in Eastern European and Baltic countries. METHODS Data were obtained from mortality registers, population censuses and health interview surveys in 16 European populations. Educational inequalities in lung cancer and total mortality were assessed by direct standardization and calculation of two indices of inequality: the Relative Index of Inequality (RII) and the Slope Index of Inequality (SII). SIIs were used to calculate the contribution of inequalities in lung cancer mortality to inequalities in total mortality. Indices of inequality in lung cancer mortality in the age group 40-59 years were compared with indices of inequalities in smoking taking into account a time lag of 20 years. RESULTS The pattern of inequalities in Eastern European and Baltic countries is more or less similar as the one observed in the Northern countries. Among men educational inequalities are largest in the Eastern European and Baltic countries. Among women they are largest in Northern European countries. Whereas among Southern European women lung cancer mortality rates are still higher among the high educated, we observe a negative association between smoking and education among young female adults. The contribution of lung cancer mortality inequalities to total mortality inequalities is in most male populations more than 10%. Important smoking inequalities are observed among young adults in all populations. In Sweden, Hungary and the Czech Republic smoking inequalities among young adult women are larger than lung cancer mortality inequalities among women aged 20 years older. CONCLUSIONS Important socioeconomic inequalities exist in lung cancer mortality in Europe. They are consistent with the geographical spread of the smoking epidemic. In the next decades socioeconomic inequalities in lung cancer mortality are likely to persist and even increase among women. In Southern European countries we may expect a reversal from a positive to a negative association between socioeconomic status and lung cancer mortality. Continuous efforts are necessary to tackle socioeconomic inequalities in lung cancer mortality in all European countries.

Enhanced soluble interleukin‐5 receptor alpha expression in nasal polyposis

Background: Alternative splicing of the interleukin‐5 receptor alpha (IL‐5Rα)‐subunit leads to the generation of a signalling, membrane‐anchored (TM) isoform, or a secreted [soluble (SOL)], antagonistic variant. Given the key role of IL‐5 in eosinophil function, we investigated SOL IL‐5Rα expression pattern in an eosinophil‐associated disease such as nasal polyposis (NP).

Detailed analysis of the IL-5-IL-5R alpha interaction: characterization of crucial residues on the ligand and the receptor.

The receptor for interleukin‐5 (IL‐5) is composed of two different subunits. The IL‐5 receptor alpha (IL‐5R alpha) is required for ligand‐specific binding while association with the beta‐chain results in increased binding affinity. Murine IL‐5 (mIL‐5) has similar activity on human and murine cells, whereas human IL‐5 (hIL‐5) has marginal activity on murine cells. We found that the combined substitution of K84 and N108 on hIL‐5 by their respective murine counterpart yields a molecule which is as potent as mIL‐5 for growth stimulation of a murine cell line. Since the unidirectional species specificity is due only to the interaction with the IL‐5R alpha subunit, we have used chimeric IL‐5R alpha molecules to define regions of hIL‐5R alpha involved in species‐specific hIL‐5 ligand binding. We found that this property is largely determined by the NH2‐terminal module of hIL‐5R alpha, and detailed analysis defined D56 and to a lesser extent E58 as important for binding. Moreover, two additional residues, D55 and Y57, were identified by alanine scanning mutagenesis within the same region. Based on the observed homology between the NH2‐terminal module and the membrane proximal (WSXWS‐containing) module of hIL‐5R alpha we located this stretch of four amino acid residues (D55, D56, Y57 and E58) in the loop region that connects the C and D beta‐strands on the proposed tertiary structure of the NH2‐terminal module.(ABSTRACT TRUNCATED AT 250 WORDS)

MAPPIT: a cytokine receptor-based two-hybrid method in mammalian cells.

Therapy of allergic disease currently relies on pharmacological manipulation of mediators or immunotherapy. Drugs have been developed to target specific mediators and their receptors: for example antihistamines blocking the H1 receptor have been refined to maximize antagonism and reduce central side‐effects or adverse effects of activity on other receptors such as muscarinic cholinergic receptors. Traditional pharmacological approaches identify new surface receptors against which chemists will then design or screen compounds for activity: examples are H3 or H4 histamine receptors.

Environmental and genomic factors as well as interventions influencing smoking cessation: a systematic review of reviews and a proposed working model.

Background: Smoking behaviour is a major public health problem worldwide. Several sources have confirmed the implication of genomic factors in smoking behaviour. These factors interact both with environmental factors and interventions to develop a certain behaviour. Objectives: Describing the environmental and genomic factors as well as the interventions influencing smoking cessation (SC) and developing a working model incorporating the different factors influencing SC were our main objectives. Methods: Two systematic reviews were conducted using articles in English from the Cochrane library, PubMed and HuGENet from January 2000 to September 2012: (1) a systematic review of systematic reviews and meta-analyses and (2) a systematic review of original research for genomic factors. The proposed working model was developed by making use of previous models of SC and applying an iterative process of discussion and re-examination by the authors. Results: We confirmed the importance of the 4 main factors influencing SC: (1) environmental factors, (2) genomic factors, (3) gene-environment interactions, and (4) evidence-based interventions. The model demonstrates the complex network of factors influencing SC. Conclusion: The working model of SC proposed a global view of factors influencing SC, warranting future research in this area. Future testing of the model will consolidate the understanding of the different factors affecting SC and will help to improve interventions in this field.

Comparison of self-rated health and the global activity limitation indicator as predictors of mortality in the older population

Background Self-rated health (SRH) is a widely used and validated health measure and an excellent predictor of mortality, morbidity, functional status, disability and health consumption. The global activity limitation indicator (GALI), which identifies subjects with longstanding (at least 6 months) limitations due to a health problem by severity level, has been developed more recently and is increasingly used to calculate healthy life expectancies. Both instruments are included in the European Survey of Income and Living Conditions and the European Health Interview Survey. In …

P1-411 Using multiple measures of social inequalities to study time trends in smoking inequalities

Introduction Trends in social inequalities in smoking have been examined in a number of international publications; however these studies have rarely used multiple measures of health inequalities and did not compare simultaneously results in terms of relative vs absolute inequalities and measures of total impact vs measure of effect. Methods Data from four successive waves of the Belgian Health Interview Survey (1997, 2001, 2004, 2008) were used to study trends in educational inequalities in daily smoking and calculate 4 measures of inequalities: the slope index of inequality (SII), the relative index of inequality (RII), both accounting for the size of each educational group, the population attributable risk (PAR), and the OR comparing the two extreme education groups. Results All examined measures pointed towards significant inequalities in smoking. Time trends in social inequalities in smoking differed according to the indicator used. Looking at the relative measures of inequality, we found a significant increase between 1997 and 2008 especially for females for the OR (test of trend =+5% p=0.02 for females and trend=+8% p=0.08 for males) and a weaker slope for the RII (test of trend =+1% p=0.08 for females and trend=+1% p=0.07 for males). Looking at the absolute measures (PAR and SII), we found no significant increase. Conclusion These results could be explained by the reduced prevalence of tobacco smoking in the country and the increase in the overall educational level of the population.

P2-311 Consistency between the measurements of chronic morbidity in a health interview survey and a population census

Introduction The mode of data collection may affect the outcome of a health indicator. This study aimed to examine the consistency between answers to an identical question on chronic morbidity obtained through a face-to-face interview in a health interview survey (HIS) and a self-administered questionnaire from a population census. Methods During the last quarter of 2001, 2710 people aged 15 years and older participated both to a census and a HIS in Belgium. An individual linkage was performed between the two data sources by using the National Population Registry ID number. Consistency of answers to the question on chronic morbidity was assessed by the κ-statistic. Results The prevalence of chronic morbidity was 29.4% (HIS) and 26.6% (census). Consistency was relatively poor, with a κ-statistic of 0.56 (95% CI 0.52 to 0.60). The κ-statistic did not differ by gender, but was substantially lower among persons aged 75 years and older (0.44; 95% CI 0.41 to 0.48) than among younger individuals (0.55; 95% CI 0.51 to 0.59). The κ-statistic was also lower for non-Belgians (0.43; 95% CI 0.40 to 0.47) than for Belgians (0.57; 95% CI 0.54 to 0.61). Consistency differed further among educational groups, although no real educational gradient was observed. Conclusion There was no satisfactory correlation between self-reported chronic morbidity data in the HIS and the population census. The consistency also differed across population subgroups. The mode of data collection appears to impact the estimates. Estimates and sociodemographic determinants of self-reported chronic morbidity should be interpreted cautiously.