[The Body-Mass-Index (BMI) has no impact on the frequency of typical reflux symptoms -- results of a nationwide telephone-based informing campaign in Germany]

BACKGROUND AND AIM

The effects of obesity on the gastrooesophageal reflux disease (GERD) are controversial. The aim of the study was to assess the relationship between the BMI and the frequency of reflux symptoms in a population with typical GERD symptoms.

METHODS

Based upon a nationwide informing campaign up to 5,000 subjects contacted the informing calling center. Subjects were included if they had heartburn and acid regurgitation. Age, gender, height, weight and the frequency of reflux symptoms were assessed by telephone interviewing.

RESULTS

1,296 subjects (668 female) with mean age of 54 +/- 14 years and a mean BMI of 26 +/- 4 were included in the study. 41.2% of the subjects had a BMI up to 25, 41.4 % between 25 to 30, and 13 % greater than 30. 74.5 % of all subjects reported reflux episodes daily and several times a week. 74.6 % of the subjects had reflux symptoms for more than one year. Both the frequency and pattern of reflux symptoms did not differ significantly in the three BMI-classes (p > 0.05, table).

CONCLUSION

In the present population with typical and frequent GERD symptoms the BMI showed no impact on the frequency of reflux symptoms. A high BMI does not appear to be a risk indicator for GERD. Interventional studies are needed to assess whether a high BMI is also no risk factor for GERD.

The impact of maternal education on intrauterine growth: a comparison of former West and East Germany

BACKGROUND

Objective of this re-analysis of datasets from former East and West Germany was to examine the influence of maternal education on intrauterine growth in two different political and social systems.

METHODS

Information on socio-demographic or lifestyle factors and pregnancy outcome was available for 3374 liveborn singletons from West Germany (1987/88) and 3070 from East Germany (1990/91). Multiple logistic regression was used to estimate the association between maternal education and the risk of delivering a small-for-gestational-age (SGA) newborn below the 10th percentile of birthweight.

RESULTS

Women with the lowest education had a significantly elevated risk of SGA newborns compared to women with the highest education in West (odds ratio [OR] = 2.58, 95% CI : 1.17-5.67) and East Germany (OR = 2.77, 95% CI : 1.54- 5.00). The distribution of factors known to influence intrauterine growth varied with education in both states. After adjusting for these factors, women with the lowest educational level still had a higher risk of SGA birth: OR (West) = 2.02, 95% CI : 0.87-4.72; OR (East) = 1.95, 95% CI : 1.02-3.74.

CONCLUSIONS

Our findings support the assumption that in former socialist countries health inequalities as a result of social inequalities existed.

Expression analysis of multidrug resistance associated genes in neuroblastomas

In a series of 40 neuroblastomas we analyzed the relative mRNA levels of the MDR associated genes encoding MDR1/P-glycoprotein (MDR1), multidrug resistance associated protein (MRP), lung cancer resistance related protein (LRP) and topoisomerase IIalpha (TOPO IIalpha) by cDNA-PCR. Cyclin A (CYCA) was included to examine cellular proliferation activity. MYCN gene expression was analyzed as it was recently shown to be associated with enhanced MRP gene expression in neuroblastomas. We found that tumors with MYCN gene amplification exhibit significantly increased MYCN and MRP gene expression levels. Tumors with an allelic loss of the chromosomal 1p region showed significant (P<0.05) lower MDR1 gene expression (MDR1: 50+/-29, n=4) than tumors without (MDR1: 117+/-81, P<0.05, n=36). Moreover, significant positive correlations were found for MYCN/TOPO IIalpha (P<0.0001), MYCN/CYCA (P<0.05), TOPO IIalpha/CYCA (P<0.01), MRP/CYCA (P<0.0001) and MRP/LRP (P<0.05). Our results give evidence that MDR in neuroblastomas might be caused by multiple resistance factors and that a higher proliferation rate of neuroblastoma cells possibly based on altered MYCN gene expression is associated with enhanced MRP, CYCA and TOPO IIalpha gene expression.

Prevalence and determinants of prone sleeping position in infants: results from two cross-sectional studies on risk factors for SIDS in Germany

The authors investigated whether there was a decline in infants sleeping prone and other modifiable risk factors for sudden infant death syndrome (SIDS) in Germany, where, as in some other countries, no nationwide intervention campaign against the prone sleeping position had been initiated. Data were obtained from parents by mailed questionnaires in two cross-sectional studies in 1991 (n = 3,330) and 1995 (n = 3,124). Prevalence of prone sleeping decreased from 37.6% to 8.7% (p < 0.05) in the German population and from 44.1% to 32.0% (p < 0.05) in the Turkish immigrant population. Parents who laid their infants prone in 1995 were less likely to follow advice from physicians, public media, and other parents (relative risks < 0.5, p < 0.05) and were more likely to have a low educational level, to be <20 years old, to be single parents, to have two or more children, to be raised in West Germany, or to be of Turkish ethnicity. Although the information on prone sleeping being a risk factor for SIDS became known among the population, these data suggest that subgroup-specific public intervention campaigns may be needed to reduce the prevalence of prone sleeping even further in those countries where no nationwide campaign has been initiated.

Body and head position, covering of the head by bedding and risk of sudden infant death (SID)

We examined the position of the body and head, and the covering of the head by bedding on discovery in cases of sudden infant death (SID) in Lower Saxony. Between 1.1.1986 and 31.12.1992 structured, questionnaire-based interviews were carried out with parents of 140 SID victims. Control data were taken from a population-based cross-sectional study on infant sleeping position performed by the German Health Office (BGA) in autumn 1991. Of the SID cases 86.4% were discovered in the prone position [odds ratio (OR) = 7.4, 95% confidence interval (CI) = 4.3, 12.7] and 41.4% were found with the head covered. These infants were significantly older than those where the head was uncovered (p < 0.001) and covering of the head showed a significant association with a risk of SID (OR = 20.8; 95% CI = 11.5-37.6). Of the SID cases 27.9% were discovered in the face-down position. These infants were significantly younger than the infants who were discovered with the head in a side or supine position (p < 0.001). This study confirms the increased risk of SID associated with the prone position and suggests that this association could be related to the development of hypoxaemia or hypercapnia. Together with other factors such as heat stress or an infection, hypoxaemia or hypercapnia could culminate in SID if the arousal from sleep and auto-resuscitation apparently fails.

Necrotising enterocolitis: is there a relationship to specific pathogens?

Outbreaks of necrotising enterocolitis (NEC) have often been related to specific pathogens such as Enterobacteriaceae. This relationship, however, remains uncertain because of the retrospective nature of the studies addressing this issue. We performed a prospective study to investigate whether there is indeed an association between NEC and specific pathogens. Between April 1993 and March 1997, stools of neonates of < 36 weeks admitted to our neonatal unit were investigated for bacteria in weekly intervals. Clinical and bacteriological data from each infant who developed NEC were compared with those from two control infants matched for gestational age and date of admission. Eighteen infants developed 19 episodes of NEC (clinical signs + air in portal vein); 8 of these had laparotomy; two died. Occurrences of NEC were homogeneously distributed over the 4-year study period. The only significant differences in the clinical course prior to NEC were a more severe stage of respiratory distress syndrome [median 2 (0-4) vs. 0 (0-3), P < 0.05] and a higher proportion of infants who had only been formula fed (63 vs. 32%, P < 0.05) in the cases. Within the last week prior to NEC, potentially pathogenic bacteria were identified in stools of all cases and 79% of controls (P < 0.05). However, there was no significant difference in the occurrence of specific pathogens or groups of pathogens in cases compared with controls.

CONCLUSION

Although gut colonisation with potential pathogens appeared to be a prerequisite for the development of NEC, there were no specific bacteria associated with this disease if data from infants with NEC were compared with those from time- and gestational age-matched controls.

Modern oral contraceptive use and benign liver tumors: the German Benign Liver Tumor Case-Control Study

OBJECTIVE

To analyze the association between oral contraceptive use and the risk of benign liver tumors.

METHODS

Two parallel case-control studies on hepatocellular adenoma and focal nodular hyperplasia. Collaborative study of 15 German liver centers. Cases defined by histology and compared with population controls.

RESULTS

Fifty-one hepatocellular adenoma and 143 focal nodular hyperplasia cases (women) were recruited between 1990 and 1997, and compared to 240 population controls with a recent abdominal imaging test. The frequency age-matched odds ratio was 1.25 (95% confidence interval (CI), 0.37-4.22) and 1.96 (95% CI, 0.85-4.57) for hepatocellular adenoma and focal nodular hyperplasia, respectively. For hepatocellular adenoma, there was neither a significantly increased risk with longer duration of oral contraceptive use, nor an association with time since first or last use. For focal nodular hyperplasia, however, a slightly increased odds ratio was found with longer duration of use and more recent last use.

CONCLUSION

There is little evidence for an increased risk for hepatocellular adenoma in women using modern oral contraceptives. If there is a risk not detected by the limited study size, hepatocellular adenoma is an extremely rare, and focal nodular hyperplasia a rare, adverse effect potentially associated with long-term oral contraceptive use and likely to be without public health importance.

[MORBUS: the Sentinel Practice Network. Report on a study in South Oldenbury]

There has been considerable public concern that emissions from intensive livestock farming may have hazardous effects on human health, particularly on the respiratory system. From October 1991 to September 1992, data on consultations of asthmatic children (up to 8 years) were obtained by a network of 25 GP and paediatric practices in South Oldenburg, a region with one of the highest livestock densities in Germany. Comparable data from a similar network of 75 practices in 3 adjacent regions (Brunswick, Hanover, Verden) with average livestock density served as a reference. In South Oldenberg, 2084 consultations of 542 asthmatic children were observed, with asthma being the reason for visit in 734 of the contacts (36%). The boy-girl ratio was 2.1:1 among index patients and 1.9:1 among consultations. Consultation rate was 25.2 contacts by asthmatic children per 1,000 total consultations of children up to 8 years in South Oldenburg, compared to 17.8 per 1,000 in Hanover, 15.7 per 1,000 in Brunswick and 13.6 per 1,000 in Verden. Consultations due to asthma scored 11.2/1,000 in South Oldenburg, 10.8/1,000 in Hanover, 7.2/1,000 in Brunswick and 6.5/1,000 in Verden. Asthmatic patients in South Oldenburg were younger (mean age 38 vs. 42 months) than those observed in the reference regions. There were no regional patterns in sex ratio, severity of asthma, respiratory allergies or atopic dermatitis. As this is an ecological study design, inferences concerning the cause of the observed regional differences can only be weak. We therefore propose a case-control study in order to obtain exposure and health data on an individual level.

Approaches to the denominator in practice-based epidemiology: a critical overview

OBJECTIVES

An accurate knowledge of the population at risk is a fundamental requirement for determining rates and making comparisons in epidemiological research. The major obstacle of studying the epidemiology of sentinel practice networks is the determination of population at risk, in this case, the reference population of medical practices. This article is intended to give a brief overview of major denominator approaches used in practice based epidemiology today, to discuss their underlying assumptions, their strengths and limitations.

DESIGN

The literature used in this paper was searched from Medline databases of 1970-1997 using the logical expression "denominator and practice". More literature was identified from the references cited in those articles and from research reports that were available to the authors.

MAIN RESULTS

There are various approaches to the denominator at different levels of complexity, which were presented akin to the well known "iceberg phenomenon": with only a small portion of the iceberg visible above the surface, inference as to the size of the invisible part may still be made under certain assumptions. Crude numbers of cases may still reflect trends in the true epidemiology of disease and may be useful for time-series analyses. Differences in the number of network participants over time and across region may be controlled for by using the number of sentinel practices as a denominator. The number of consultations is a first step towards a population-based denominator, reflecting characteristics of both patients and the network. The yearly or quarterly contact group is a true person-based denominator, yet disregarding the population not consulting. The population in practices' catchment areas can be either determined from patient lists or estimated using mathematical models. The ideal denominator is the total population in a geographically defined area, though this information can be directly related to medical practices only in very few countries.

CONCLUSIONS

Although a person, or ideally a population-based denominator is desirable, even "lower-level" denominators may be suitable for certain research topics. In countries without patient registration, the estimation of incidences and prevalences has many methodological uncertainties that limit the use of sentinel practice systems. Assuming representativeness, valid analytical or time-series studies, however, can still be carried out even if there is very little information on the population at risk covered by particular medical practices.

Contamination of human breast milk with organochlorine residues: a comparison between East and West Germany through sentinel practice networks

STUDY OBJECTIVE

The aim of the study was to assess and compare the contamination of human breast milk with organochlorine residues through two sentinel practice networks in Lower Saxony, a state of former West Germany, and Saxony-Anhalt, a state of former East Germany.

DESIGN

Eligible women were enrolled in this cross sectional study by a network of 51 paediatric practices in Lower Saxony and 44 in Saxony-Anhalt when bringing their babies for a regular screening examination four to six weeks after delivery. Sociodemographic, lifestyle, and exposure factors were determined by questionnaire. Milk samples were analysed for hexachlorocyclohexane (HCH), hexachlorbenzole (HCB), DDT, dieldrin, polychlorinated biphenyls (PCB), and heptachlorepoxid (HCE); half the samples were also analysed for dioxin. Analytic statistics were computed using multiple logistic regression.

SETTING

The study was conducted in Lower Saxony, Germany, from July 1992 to June 1993, and in Saxony-Anhalt, Germany, from January to June 1995.

PARTICIPANTS

156 primiparous, breast-feeding women from Lower Saxony and 113 from Saxony-Anhalt were studied, who either were born and raised in former West or East Germany, respectively.

MAIN RESULT

Mean age of mothers and children differed significantly between the two study groups. In Lower Saxony all but two milk samples were well below the tolerable concentrations established by the German Research Council (Deutsche Forschungsgemeinschaft (DFG)). In Saxony-Anhalt no participant had concentrations above those recommended by the DFG. After adjustment for age of mother and child, occupational and non-occupational pesticide contact, DDT and beta-HCH concentrations were significantly lower in Lower Saxony; HCE and dieldrin concentrations were lower in Saxony-Anhalt. No differences between the two states were found for PCB, HCB, gamma-HCH, and dioxin.

CONCLUSIONS

Breast milk contamination levels in former East German Saxony-Anhalt exceeded the contamination in Lower Saxony only for DDT and beta-HCH.

[Acceptance of breast feeding and public discussion--evaluation of health campaigns for breast feeding between 1991 and 1995]

In 1990 the Innocenti Declaration on promoting breastfeeding was proclaimed in Florence/Italy. It became the subject of resolution 45.34 of the World Health Assembly in 1992. In the Federal Republic of Germany there was no wide-scale mass-media campaign to promote breastfeeding as in other countries. But mother-to-mother support groups, medical services and the newly founded National Breastfeeding Committee supported prolonged breastfeeding in public. The effects of the joint effort could be estimated by comparing the results of two postal surveys in 1991 and 1995. The surveys were conducted in Lower Saxony, North-Rhine-Westphalia and Berlin. A tendency could be shown toward more exclusive breastfeeding. Breastfeeding with supplementary food increased by a factor of 1.3 after adjusting for the variables mother's age, sleeping in parents' room or bed and no-smoking household. In Lower Saxony the increase was by a factor of 1.5 starting from a lower base value. The baby sleeping in the parents' room or in their bed furthered breastfeeding by a factor of 1.5 to 4. Non smoking mothers are 4 times more willing to breastfeed their infants than smoking mothers. German mothers breastfeed their infants two to three times more often than turkish mothers.

[Predictors of follow-up course of asthma complaints in early childhood--results of a follow-up study]

A follow-up study was undertaken to determine the predictors of the course of recurrent wheezing episodes in children (between 0 to 8 years). In 1991, 600 children with wheezing episodes had been recorded by physicians who participated in a sentinel practice network. On each consultation with the same physicians from October 1994 until June 1995, parents of these children were questioned again about the course of their respiratory symptoms (n = 218). Associations between the course of disease and predictors (recorded by physicians in 1991) were analysed using polytomous logistic regression. The following factors were significantly associated with the frequency of asthmatic episodes (odds ratio (OR) > 1 indicates an unfavourable course of disease in comparison with the reference category, [95% confidence interval]): indoor cigarette smoking: OR = 1.7; [1.0-3.0], older than 1 year of age (reference: < 1 year): OR = 3.0; [1.1-8.5], more than 5 asthmatic episodes during the year before the first registration: OR = 2.7; [1.3-5.6], infect-associated asthma: OR = 0.4 [0.2-1.0], paediatrician as recording physician (reference: general practitioner): OR = 0.4 (0.2-0.8). No significant association with the course of disease was found for sex, education of the parents, region, parental asthma, hospital admissions because of obstructive symptoms. In correspondence with other studies, the majority of children showed a favourable course of their obstructive respiratory symptoms: for only 7% the frequency of episodes increased during 3 years after the first contact. Indoor smoking and severity of asthma are known as predictors of the course of the disease. The better prognosis of infect-associated obstructive symptoms supports the thesis that the majority of infants with asthmatic symptoms have narrow, infect-mediated airways obstructions, but no increased risk for bronchial asthma in their later lives. An early identification of children at risk may allow a specific and intensified therapy to improve the course of disease.

Blood transfusion. Iron load and retinopathy of prematurity

To study the relationship between blood transfusion, iron load and retinopathy of prematurity (ROP), we performed a prospective observational cohort study in a level III neonatal intensive care unit. During a 24-month period, data on the volume of blood transfused during the first 6 weeks of life and on the incidence of ROP were collected in all surviving very low birth weight infants (n = 114; median birth weight 1130 g. range 520-1500 g). Associations between these data and values for serum iron, transferrin and ferritin measured at weekly intervals were analysed in a nested case-control design by logistic regression. There was a significant association between the volume of blood transfused and the incidence of ROP. After adjustment for gestational age at birth, duration of oxygen therapy (FiO2 > 0.3) and duration of mechanical ventilation, the relative risk of developing ROP was 6.4 (95% CI 1.2-33.4) for infants who had received 16-45 ml/kg, and 12.3 (1.6-92.5) for those who had received more than 45 ml/kg of blood (reference, 0-15 ml/kg). In contrast, there was no independent relationship between ROP and any of the parameters on iron metabolism analysed.

CONCLUSION

This study confirms the role of blood transfusions as an independent risk factor for ROP. This relationship, however, does not appear to be mediated via an increased iron load.

[NO2 concentration in outdoor air and ambulatory physician consultations by children with asthma. Collaboration with the Lower Saxony and Saxony-Anhalt district health offices]

In a representative sample of 72 sentinel practices in Lower Saxony and 61 sentinel practices in Saxony-Anhalt, physicians were requested to record all consultations of asthmatic children (aged up to 8 years) over a period of 6 and 3 months, respectively. Children were classified as asymptomatic or newly symptomatic at each separate contact. Asymptomatic contacts with respiratory tract infections were excluded. From measurements of fixed air monitoring stations, the exposure to air pollutants (NO2, NO, SO2, ozone, particulates) at the place of the physician's practice (Lower Saxony) or at the child's residence (Saxony-Anhalt) was estimated, using a specific interpolation method (inverse distance weighting). Associations between exposure to particular air pollutants and the presence of asthmatic symptoms at the time of the consultation were determined using logistic regression. Temperature, month of the consultation region, day of the week, first or repeated contact in the recording period were included as covariates in the multivariate analyses to adjust for potential confounding. NO2 exposure was significantly and positively associated with the occurrence of asthmatic symptoms (p = 0.007). Exposure to other air pollutants did not significantly differ between asymptomatic and symptomatic contacts. A possible causal relationship between NO2 exposure and the occurrence of asthmatic symptoms in children suffering from asthma is in accordance with other studies. Our study adds data from routine office based outpatient care to independent evidence on the association between NO2 exposure and asthma.

Smoking during pregnancy and poor antenatal care: two major preventable risk factors for sudden infant death syndrome

BACKGROUND

In this case-control study on sudden infant death syndrome (SIDS), the magnitude of the risk factors 'maternal smoking during pregnancy' and 'poor antenatal care' was assessed and the attributable proportions of SIDS incidence estimated.

METHODS

Perinatal data from 190 SIDS cases, who died between 1986 and 1990 at age > 7 days and had a diagnosis of SIDS confirmed by autopsy, were compared to 5920 controls. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were computed by unconditional logistic regression. The attributable risk per cent among the exposed (AR%) and the population attributable risk per cent (PAR%) were calculated.

RESULTS

Maternal smoking during pregnancy was associated with a more than twofold risk of SIDS (OR = 2.4; 95% CI: 1.7-3.4) and showed a significant dose-response. Low numbers of antenatal care visits were also associated with an increased risk of SIDS: OR = 1.6 (95% CI: 1.1-2.3) for 4.8 consultations and 2.9 (95% CI: 1.4-5.8) for 0-3 consultations; reference: > 8 consultations. Maternal smoking during pregnancy yielded an AR% of 58% (95% CI: 42-70) and a PAR% of 28% (95% CI: 16-40). The AR% for < or = 8 antenatal care visits versus > 8 consultations was 41% (95% CI: 16-59); the PAR% 10% (95% CI: 3-17).

CONCLUSIONS

Assuming causality, our data suggest that a reduction of the prevalence of either risk factor by population-based interventions may yield a worthwhile public health impact in terms of a substantially lower SIDS incidence.

Hyperthermia in sudden infant death

To determine whether preterminal hyperthermia is significantly associated with sudden infant death (SID), 140 structured interviews with parents of SID victims were compared with questionnaires filled in by a control group of parents living in the same area. All SID autopsies were performed between 1986 and 1992 at the Institute of Legal Medicine of Hannover Medical School according to the same protocol. Signs of profuse sweating (i.e. moist head, damp clothing or bedding) were present at the scene of death in 35.7% of cases. SID victims with signs of profuse sweating were more frequently found under their bedding (p < 0.001), were older (178 vs. 130 days) and the time period between when they were last seen alive and when they were found dead was longer (6.5 vs. 4.5 hours p < 0.01) compared to cases without sweating. Sweat on the head [odds ratio (OR) = 1.9; 95% confidence interval (CI) = 1.0, 3.6], and sweaty clothing and bedding (OR = 17.9; 95% CI = 8.7; 37.1) showed a significant association with the risk for SID. The pathophysiological basis for hyperthermia is SID remains to be determined. Hyperthermia could result from infection, overinsulation from excessive clothing with high environmental temperatures, covering of the infant's head or immature central thermoregulatory centres. The influence on the fatal outcome and the role in the pathogenesis of these deaths requires further research.

Organochlorine residues in human breast milk: analysis through a sentinel practice network

STUDY OBJECTIVE

The study aimed to assess through a sentinel practice network the validity of data on levels of organochlorine residues in human milk along with personal, lifestyle, and exposure variables of breastfeeding women; to compare the results of this new approach with those of the Lower Saxony breast milk surveillance programme; and to test hypotheses on potential determinants of contamination levels.

DESIGN

Eligible women were enrolled into this cross sectional study by a network of 51 paediatric practices when bringing their babies for a U3 infant screening examination (4th to 6th week after delivery). Lifestyle and exposure factors were obtained by questionnaire. All milk samples were analysed for hexachlorocyclohexane, hexachlorbenzole, DDT, dieldrin, polychlorinated biphenyls (PCB) and heptachlor; half the samples were also analysed for dioxin. Analytic statistics were computed using polychotomous logistic regression (PLR).

SETTING

The study was conducted in Lower Saxony, Germany, from summer 1992 to summer 1993.

PARTICIPANTS

Altogether 156 primiparous, breast feeding German women, aged 25-35 years, who had been born and had grown up in West Germany, were studied.

MAIN RESULTS

Compared with the regular programme, participants in this study had their milk analysed sooner after delivery and were more likely to have grown up in rural areas, less likely to have been exposed to hazardous substances, less likely to have a diet of health food, and slightly less likely to be a smoker at the time of the study. Breast milk contamination levels were comparable in both studies, and in all but two cases well below the tolerable concentrations established by the Deutsche Forschungsgemeinschaft (German Research Fellowship). After adjustment for potential confounders using polychotomous logistic regression, there were statistically significant positive associations between breast milk contamination and age (PCB, test for trend: p = 0.006), average dietary fat intake per week (dioxin, p = 0.01), and proximity of residence to hazardous sites (dioxin, p < 0.05), and negative associations between residue levels and relative body weight at the time of the study (PCB; p < 0.0001) and difference in body weight (weight minus weight before the pregnancy; PCB, p = 0.0002), respectively.

CONCLUSIONS

Sentinel practice networks are a feasible and low-biased approach to population based breast milk studies. The contamination levels and associations found are biologically plausible and comparable with the results of other studies. To reduce organochlorine residue levels in human milk in the short term, breast-feeding women should be advised not to try to reduce their weight until after lactation. Public promotion of a lower dietary fat intake may reduce the lifetime accumulation of organochlorine compounds in the human body fat tissue in the long term, resulting in lower concentrations in breast milk as well.

Sudden infant death and maternal cigarette smoking: results from the Lower Saxony Perinatal Working Group

Maternal smoking has long been identified as a risk factor for sudden infant death (SID). However, only few studies analysed the biological plausibility of the relationship between maternal smoking and SID. In Lower Saxony (North Germany), detailed information concerning the perinatal period is routinely obtained for almost all infants born in this region. The perinatal data sets from 190 SID cases who had died between 1986 and 1990 and in whom a full autopsy had been performed were identified and compared to data sets from 5920 random controls, frequency matched to cases on year of birth. After adjusting for potential confounders (socio-economic status, birth weight, maternal age and nationality), smoking during pregnancy was still associated with a significantly increased risk of SID (odds ratio (OR) 2.7, 95% confidence interval (CI) 1.7-4.5). There was a clear dose-effect relationship between the number of cigarettes smoked and the risk of SID: adjusted ORs were 2.6 (1.5-4.4) for 1-10 cigarettes/day, 2.8 (1.8-6.0) for 11-20 cigarettes/day, and 6.9 (1.9-25.5) for > 20 cigarettes/day. There also appeared to be an interaction between smoking during pregnancy and maternal anaemia: the risk of SID almost doubled if mothers not only smoked, but were also anaemic (haemoglobin < 100 g/l). These results support the concept that smoking during pregnancy has direct biological effects on the fetus which are associated with an increased risk of SID later in life. The exact mechanism(s) whereby smoking increases the risk of SID, however, remains to be determined.(ABSTRACT TRUNCATED AT 250 WORDS)

[Data quality in the MORBUS Sentinel Project--expiratory wheezing in infants]

Since 1991 the MORBUS project is being conducted to establish and run a sentinel network of 100 general and paediatric practices in three regions of Germany. A number of health conditions have been and will be monitored consecutively with special emphasis on environmentally determined health problems. From March to June, 1991, 1054 contacts of 1- and 2-year-old children with expiratory wheezing were reported. Quality of these event data was assessed by means of internal completeness. Important clinical information was missing in about 10% of all cases without evidence for regional differentiations. Data quality by this criterion was better in first contact than in re-contact cases (9.7% vs 18.1% missing). Questions concerning the parents (allergies, smoking, education) were less frequently answered (up to 24% missing) than questions of obvious medical relevance to the child. Completeness of parental information varied considerably between regions. There was no association between the medical specialty of the doctors and the quality of their data. In a longitudinal view, there was a slightly positive trend over time in the proportion of clinically incomplete case reports at borderline statistical significance (p = 0.057). Apart from these minor findings then, there was an overall good consistency of completeness in the MORBUS data on expiratory wheezing. By optimizing questionnaires and data transmission, it should be possible to increase the data quality even further.