Confidential inquiry into quality of care before admission to intensive care

OBJECTIVE

To examine the prevalence, nature, causes, and consequences of suboptimal care before admission to intensive care units, and to suggest possible solutions.

DESIGN

Prospective confidential inquiry on the basis of structured interviews and questionnaires.

SETTING

A large district general hospital and a teaching hospital.

SUBJECTS

A cohort of 100 consecutive adult emergency admissions, 50 in each centre.

MAIN OUTCOME MEASURES

Opinions of two external assessors on quality of care especially recognition, investigation, monitoring, and management of abnormalities of airway, breathing, and circulation, and oxygen therapy and monitoring.

RESULTS

Assessors agreed that 20 patients were well managed (group 1) and 54 patients received suboptimal care (group 2). Assessors disagreed on quality of management of 26 patients (group 3). The casemix and severity of illness, defined by the acute physiology and chronic health evaluation (APACHE II) score, were similar between centres and the three groups. In groups 1, 2, and 3 intensive care mortalities were 5 (25%), 26 (48%), and 6 (23%) respectively (P=0.04) (group 1 versus group 2, P=0.07). Hospital mortalities were 7 (35%), 30 (56%), and 8 (31%) (P=0.07) and standardised hospital mortality ratios (95% confidence intervals) were 1.23 (0.49 to 2.54), 1.4 (0.94 to 2.0), and 1.26 (0.54 to 2.48) respectively. Admission to intensive care was considered late in 37 (69%) patients in group 2. Overall, a minimum of 4.5% and a maximum of 41% of admissions were considered potentially avoidable. Suboptimal care contributed to morbidity or mortality in most instances. The main causes of suboptimal care were failure of organisation, lack of knowledge, failure to appreciate clinical urgency, lack of supervision, and failure to seek advice.

CONCLUSIONS

The management of airway, breathing, and circulation, and oxygen therapy and monitoring in severely ill patients before admission to intensive care units may frequently be suboptimal. Major consequences may include increased morbidity and mortality and requirement for intensive care. Possible solutions include improved teaching, establishment of medical emergency teams, and widespread debate on the structure and process of acute care.

Organization, distribution, and stability of endogenous ecotropic murine leukemia virus DNA sequences in chromosomes of Mus musculus

The endogenous ecotropic murine leukemia virus DNA content and integration sites were characterized for 54 inbred strains and substrains of mice by restriction enzyme digestion, Southern blotting, and hybridization with an ecotropic murine leukemia virus DNA-specific probe. More than 75% of these strains carried endogenous ecotropic proviruses which were located in at least 29 distinct integration sites in chromosomes of Mus musculus. Fourteen of these proviruses have been assigned specific locus designations. Most, but not all, of the endogenous ecotropic proviruses were structurally indistinguishable by this analysis from the prototype AKR ecotropic virus, and the distribution of these proviruses followed known relationships among the inbred strains and substrains of mice. These results suggest that, in general, viral DNA integration preceded the establishment of inbred mouse strains and that these integrations are relatively stable.

Lengths of chromosomal segments conserved since divergence of man and mouse

Linkage relationships of homologous loci in man and mouse were used to estimate the mean length of autosomal segments conserved during evolution. Comparison of the locations of greater than 83 homologous loci revealed 13 conserved segments. Map distances between the outermost markers of these 13 segments are known for the mouse and range from 1 to 24 centimorgans. Methods were developed for using this sample of conserved segments to estimate the mean length of all conserved autosomal segments in the genome. This mean length was estimated to be 8.1 +/- 1.6 centimorgans. Evidence is presented suggesting that chromosomal rearrangements that determine the lengths of these segments are randomly distributed within the genome. The estimated mean length of conserved segments was used to predict the probability that certain loci, such as peptidase-3 and renin, are linked in man given that homologous loci are chi centimorgans apart in the mouse. The mean length of conserved segments was also used to estimate the number of chromosomal rearrangements that have disrupted linkage since divergence of man and mouse. This estimate was shown to be 178 +/- 39 rearrangements.

Ocular retardation mouse caused by Chx10 homeobox null allele: impaired retinal progenitor proliferation and bipolar cell differentiation

Ocular retardation (or) is a murine eye mutation causing microphthalmia, a thin hypocellular retina and optic nerve aplasia. Here we show that mice carrying the OrJ allele have a premature stop codon in the homeobox of the Chx10 gene, a gene expressed at high levels in uncommitted retinal progenitor cells and mature bipolar cells. No CHX10 protein was detectable in the retinal neuroepithelium of orJ homozygotes. The loss of CHX10 leads both to reduced proliferation of retinal progenitors and to a specific absence of differentiated bipolar cells. Other major retinal cell types were present and correctly positioned in the mutant retina, although rod outer segments were short and retinal lamination was incomplete. These results indicate that Chx10 is an essential component in the network of genes required for the development of the mammalian eye, with profound effects on retinal progenitor proliferation and bipolar cell specification or differentiation. off

Autism and measles, mumps, and rubella vaccine: no epidemiological evidence for a causal association

BACKGROUND

We undertook an epidemiological study to investigate whether measles, mumps, and rubella (MMR) vaccine may be causally associated with autism.

METHODS

Children with autism born since 1979 were identified from special needs/disability registers and special schools in eight North Thames health districts, UK. Information from clinical records was linked to immunisation data held on the child health computing system. We looked for evidence of a change in trend in incidence or age at diagnosis associated with the introduction of MMR vaccination to the UK in 1988. Clustering of onsets within defined postvaccination periods was investigated by the case-series method.

FINDINGS

We identified 498 cases of autism (261 of core autism, 166 of atypical autism, and 71 of Asperger's syndrome). In 293 cases the diagnosis could be confirmed by the criteria of the International Classification of Diseases, tenth revision (ICD10: 214 [82%] core autism, 52 [31%] atypical autism, 27 [38%] Asperger's syndrome). There was a steady increase in cases by year of birth with no sudden "step-up" or change in the trend line after the introduction of MMR vaccination. There was no difference in age at diagnosis between the cases vaccinated before or after 18 months of age and those never vaccinated. There was no temporal association between onset of autism within 1 or 2 years after vaccination with MMR (relative incidence compared with control period 0.94 [95% CI 0.60-1.47] and 1.09 [0.79-1.52]). Developmental regression was not clustered in the months after vaccination (relative incidence within 2 months and 4 months after MMR vaccination 0.92 [0.38-2.21] and 1.00 [0.52-1.95]). No significant temporal clustering for age at onset of parental concern was seen for cases of core autism or atypical autism with the exception of a single interval within 6 months of MMR vaccination. This appeared to be an artifact related to the difficulty of defining precisely the onset of symptoms in this disorder.

INTERPRETATION

Our analyses do not support a causal association between MMR vaccine and autism. If such an association occurs, it is so rare that it could not be identified in this large regional sample.

Dilute (d) coat colour mutation of DBA/2J mice is associated with the site of integration of an ecotropic MuLV genome

The single endogenous DBA/2J ectropic provirus segregated concordantly with the dilute (d) coat colour mutation on chromosome 9 in 53/53 DBA/2J-derived recombinant inbred mouse strains and all seven inbred and mutant strains tested that carry the d allele. Analysis of DNA from a spontaneous DBA/2J d revertant (d+2J) showed that these mice lack ecotropic-specific MuLV DNA sequences and suggested that the dilute mutation resulted from integration of an ecotropic provirus into the mouse genome.

Changes in the reported prevalence of childhood eczema since the 1939-45 war

Rates of reported eczema during early childhood were studied in 3 national cohorts of children born in 1946, 1958, and 1970. Overall rates rose from 5.1% in children born in 1946, to 7.3% in those born in 1958, to 12.2% in the 1970 cohort. In the 1958 and 1970 cohorts there was a positive association between eczema and breastfeeding. This relationship remained significant after allowing for parental history of allergy and socioeconomic status. Social classes I and II children born in 1946 were less likely to be reported as having eczema, compared with children from lower social classes, whereas children born into higher social classes in 1958 and 1970 had higher rates. These findings may reflect secular changes in the diagnosis of eczema or may represent a real increase in the disorder. The positive association with breastfeeding in the more recent cohorts suggests a new environmental agent may be crossing in breast-milk. The agent(s) may well be in other infant foods, since the rate of reported eczema in non-breastfed children rose from 5.7% in the 1946 and 1958 cohorts to 11.1% of children born in 1970.

Homozygous inactivation of the NF1 gene in bone marrow cells from children with neurofibromatosis type 1 and malignant myeloid disorders

BACKGROUND

The risk of malignant myeloid disorders in young children with neurofibromatosis type 1 is 200 to 500 times the normal risk. The gene for neurofibromatosis type 1 (NF1) encodes neurofibromin, a protein that negatively regulates signals transduced by Ras proteins. Genetic and biochemical data support the hypothesis that NF1 functions as a tumor-suppressor gene in immature myeloid cells, but inactivation of both NF1 alleles has not been demonstrated in leukemic cells from patients with neurofibromatosis type 1.

METHODS

Using an in vitro transcription and translation system, we screened bone marrow samples from 18 children with neurofibromatosis type 1 and myeloid disorders for NF1 mutations that cause a truncated protein. Mutations were confirmed by direct sequencing of genomic DNA from the patients, and from their affected parents, in cases of familial neurofibromatosis type 1.

RESULTS

Specimens from 9 of the 18 children contained abnormal peptide fragments, and truncating mutations of the NF1 gene were found in specimens from 8 of these children. The normal NF1 allele was absent in bone marrow samples from five of the eight children. We detected the same mutation in DNA from the affected parent of each child with familial neurofibromatosis type 1.

CONCLUSIONS

Both alleles of the NF1 gene are inactivated in leukemic cells in some patients with neurofibromatosis type 1. NF1 appears to function as a tumor-suppressor gene in immature myeloid cells.

Randomised controlled trial of laparoscopic versus mini cholecystectomy. The McGill Gallstone Treatment Group

Laparoscopic cholecystectomy (LC) has gained wide acceptance for treatment of cholelithiasis in preference to open cholecystectomy, though it has not been formally compared with mini cholecystectomy (MC). We have compared these two techniques in a randomised trial. 70 patients with ultrasound-proven cholelithiasis were randomly allocated LC (38) or MC (32); 37 and 25, respectively, underwent the assigned procedure. The mean hospital stay (including 1 preoperative day) was significantly shorter in the LC than the MC group (median 3 [interquartile range 2-3] vs 4 [3-5], p = 0.001) as was duration of convalescence (mean 11.9 [SD 9.1] vs 20.2 [16.5] days, p = 0.04). The rate of return to normal activities was 1.77 times greater in the LC group than in the MC group (95% confidence interval 1.01-3.11, p = 0.03). In regression analysis, the type of cholecystectomy done was the only variable significantly associated with the duration of convalescence. Although there was significant postoperative improvement in all of three quality of life scores in both groups, LC patients improved more quickly than did MC patients. This randomised trial shows the superior effectiveness of LC over MC in treating cholelithiasis.

Body mass index and asthma severity in the National Asthma Survey

BACKGROUND

The association between obesity and asthma severity remains controversial and limited to small studies.

METHODS

We determined the association of body mass index (BMI) and asthma severity in the National Asthma Survey. We included adults (age > or = 18 years) who self-reported symptoms of asthma in the past 5 years. A total of 3095 patients were divided into the following BMI categories: 1080 (35%) non-overweight (BMI < 25), 993 (32%) overweight (BMI > or = 25 and < 30) and 1022 (33%) obese (BMI > or = 30). Asthma severity measures included respiratory symptoms, healthcare utilisation, medication use, missed work days and the Global Initiative for Asthma (GINA) severity classification. Models were adjusted for: gender, race, age, education, income, employment status, smoking status, family history of asthma, state of residence and residence in a metropolitan statistical area.

RESULTS

Compared with non-overweight subjects, obese subjects with asthma were more likely to report continuous symptoms (OR 1.66, 95% CI 1.09 to 2.54), miss more work days (OR 1.35, 95% CI 1.01 to 1.81), use short acting beta agonists (OR 1.36, 95% CI 1.06 to 1.75), use inhaled corticosteroids (OR 1.34, 95% CI 1.01 to 1.79) and use any controller medication according to GINA guidelines (OR 1.37, 95% CI 1.01 to 1.85). Also, obese respondents were less likely to be in asthma remission (OR 0.56, 95% CI 0.38 to 0.82) and were more likely to have severe persistent asthma (GINA IV) (OR 1.42, 95% CI 1.05 to 1.90).

CONCLUSIONS

In a large, diverse sample of adults with asthma, obesity was associated with measures of asthma severity after adjusting for potential confounders.

Prevention of eczema

In a prospective study of the development of reaginic allergy, infants of allergic parents were either subjected to an allergen-avoidance regimen from birth for six months or managed conventionally. The group on the allergen-avoidance regimen had less eczema at six months and one year than did the control group at six months. They also had a lower mean serum-total-IgE level at six weeks.

Vertebral end-plate (Modic) changes on lumbar spine MRI: correlation with pain reproduction at lumbar discography

The vertebral end-plate has been identified as a possible source of discogenic low back pain. MRI demonstrates end-plate (Modic) changes in 20-50% of patients with low back pain. The aim of this study was to investigate the association between Modic changes on MRI and discogenic back pain on lumbar discography. The MRI studies and discograms of 58 patients with a clinical diagnosis of discogenic back pain were reviewed and the presence of a Modic change was correlated with pain reproduction at 152 disc levels. Twenty-three discs with adjacent Modic changes were injected, 21 of which were associated with pain reproduction. However, pain was also reproduced at 69 levels where no Modic change was seen. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for a Modic change as a marker of a painful disc were 23.3%, 96.8%, 91.3% and 46.5% respectively. Modic changes, therefore, appear to be a relatively specific but insensitive sign of a painful lumbar disc in patients with discogenic low back pain.

Adult outcomes of binge drinking in adolescence: findings from a UK national birth cohort

AIMS

The aim of the study was to determine outcomes in adult life of binge drinking in adolescence in a national birth cohort.

DESIGN AND SETTING

Longitudinal birth cohort: 1970 British Birth Cohort Study surveys at 16 years (1986) and 30 years (2000).

PARTICIPANTS

A total of 11 622 subjects participated at age 16 years and 11 261 subjects participated at age 30 years.

MEASUREMENTS

At the age of 16 years, data on binge drinking (defined as two or more episodes of drinking four or more drinks in a row in the previous 2 weeks) and frequency of habitual drinking in the previous year were collected. Thirty-year outcomes recorded were alcohol dependence/abuse (CAGE questionnaire), regular weekly alcohol consumption (number of units), illicit drug use, psychological morbidity (Malaise Inventory) and educational, vocational and social history.

FINDINGS

17.7% of participants reported binge drinking in the previous 2 weeks at the age of 16 years. Adolescent binge drinking predicted an increased risk of adult alcohol dependence (OR 1.6, 95% CI 1.3 to 2.0), excessive regular consumption (OR 1.7, 95% CI 1.4 to 2.1), illicit drug use (OR 1.4, 95% CI 1.1 to 1.8), psychiatric morbidity (OR 1.4, 95% CI 1.1 to 1.9), homelessness (OR 1.6, 95% CI 1.1 to 2.4), convictions (1.9, 95% CI 1.4 to 2.5), school exclusion (OR 3.9, 95% CI 1.9 to 8.2), lack of qualifications (OR 1.3, 95% CI 1.1 to 1.6), accidents (OR 1.4, 95% CI 1.1 to 1.6) and lower adult social class, after adjustment for adolescent socioeconomic status and adolescent baseline status of the outcome under study. These findings were largely unchanged in models including both adolescent binge drinking and habitual frequent drinking as main effects.

CONCLUSIONS

Adolescent binge drinking is a risk behaviour associated with significant later adversity and social exclusion. These associations appear to be distinct from those associated with habitual frequent alcohol use. Binge drinking may contribute to the development of health and social inequalities during the transition from adolescence to adulthood.

Reliability and construct validity of a structured technical skills assessment form

Current methods of evaluating technical competence of surgical residents are subjective and potentially unreliable. This study assesses the reliability and construct validity of a new format for the assessment of technical ability, the two part Structured Technical Skills Assessment Form (STSAF). Part I, which is completed while an operation is proceeding consists of approximately 120 essential components of the procedure. Part II, completed at the end of the operation, is a 10-point global rating form. Forty-one operations were evaluated using the STSAF, with multiple observers present at 26. Inter-rater reliability of both Parts I and II were high (.78 and .73, respectively). Statistically significant differences were noted between senior-resident and junior-resident performances, suggesting construct validity. The incorporation of structured guidelines to the assessment of technical skill leads to high inter-rater reliability and construct validity, which ultimately may result in improved and reproducible evaluations of surgical trainees.

TTF-2, a new forkhead protein, shows a temporal expression in the developing thyroid which is consistent with a role in controlling the onset of differentiation

Expression of thyroglobulin (Tg) and thyroperoxidase (TPO) genes in thyroid follicular cells occurs in the mouse at embryonic day (E)14.5. Two transcription factors, TTF-1 and Pax-8, have been implicated in transcriptional activation of Tg and TPO, even though the onset of their expression is at E9.5, suggesting that additional events are necessary for transcriptional activation of Tg and TPO genes. We report in this paper the cloning of TTF-2, a DNA binding protein that recognizes sites on both Tg and TPO promoters. TTF-2 is a new forkhead domain-containing protein whose expression is restricted to the endodermal lining of the foregut and to the ectoderm that will give rise to the anterior pituitary. TTF-2 shows transient expression in the developing thyroid and anterior pituitary. In the thyroid, TTF-2 expression is down-regulated just before the onset of Tg and TPO gene expression, suggesting that this transcription factor plays the role in development of a negative controller of thyroid-specific gene expression.

A linkage map of endogenous murine leukemia proviruses

Thirty endogenous proviruses belonging to the modified polytropic (Mpmv) class of murine leukemia virus (MLV) were identified by proviral-cellular DNA junction fragment segregation in several sets of recombinant inbred mice. Twenty-six Mpmv loci were mapped to chromosomal regions by matching proviral strain distribution patterns to those of previously assigned genes. Like other endogenous nonecotropic MLVs, Mpmv loci were present on several chromosomes in all strains examined. We pooled recombinant inbred strain linkage data from 110 MLV loci and selected marker genes in order to construct a chromosomal linkage map. Every mouse chromosome was found to harbor at least one proviral insertion, and several regions contained multiple integrations. However, the overall distribution of the 110 mapped proviruses did not deviate significantly from a random distribution. Because of their polymorphism in inbred strains of mice, and the ability to score as many as 57 proviruses per strain using only three hybridization probes, the nonecotropic MLVs mapped in common strains of mice offer a significant advantage over older methods (e.g., biochemical or individual restriction fragment polymorphisms) as genetic markers. These endogenous insertion elements should also be useful for assessing strain purity, and for studying the relatedness of common and not-so-common inbred strains.

Validating the GDS depression screen in the nursing home

OBJECTIVE

The GDS (Geriatric Depression Scale) has demonstrated validity among ambulatory elderly but is less useful in nursing home (NH) populations, probably because of high rates of cognitive impairment. We, therefore, sought the lowest level of Mini-Mental Status Exam (MMSE) score for which the GDS would remain valid.

DESIGN

Validation Study.

SETTING

Nursing Homes in New York City.

PARTICIPANTS

A total of 66 of 168 newly admitted residents to the NH were able to complete psychiatric assessment, undergo an MMSE, and complete the GDS. The psychiatrists and testers (all non-MDs) were blinded to each others' results. Using a cutoff of 10 or greater on the GDS to indicate depression, the GDS's validity (when compared with the psychiatric diagnoses) was sought at ever decreasing levels of cognitive function as measured by the MMSE.

RESULTS

The results of all participants (n = 66) revealed a sensitivity of 63% and a specificity of 83%. When only those with an MMSE score > or = 15 (the best cutoff score) were included, 44 (64%) participants were selected, with a sensitivity and specificity of 84% and 91%, respectively.

CONCLUSIONS

The two-step procedure of first selecting those with MMSE scores > or = 15 and then giving the GDS significantly increases the utility of the GDS in detecting depression in NH residents and should improve the diagnostic process for this widely underdetected problem.

Colonic mucin synthesis is increased by sodium butyrate

The effects of sodium butyrate and sodium bromo-octanoate (an inhibitor of beta oxidation) on colonic mucus glycoprotein (mucin) synthesis have been assessed using tissue from colonic resection samples. Epithelial biopsy specimens were incubated for 16 hours in RPMI 1640 with glutamine, supplemented with 10% fetal calf serum and N-acetyl-[3H]-glucosamine ([3H]-Glc NAc), and differing concentrations of sodium butyrate. Incorporation of [3H] Glc NAc into mucin by normal epithelium at least 10 cm distant from colonic cancer was increased in the presence of sodium butyrate in a dose dependent manner, with maximum effect (476%) at a concentration of 0.1 mM (number of specimens = 24 from six patients, p < 0.001). The increase in response to butyrate was not seen when specimens were incubated in the presence of the beta oxidation inhibitor sodium bromo-octanoate 0.05 M. The striking increase in mucin synthesis that results when butyrate is added to standard nutrient medium suggests that this may be an important mechanism affecting the rate of mucin synthesis in vivo and may also explain the therapeutic effect of butyrate in colitis.

Detection of obesity QTLs on mouse chromosomes 1 and 7 by selective DNA pooling

The inheritance of obesity has been analyzed in an intercross between the lean 129/Sv mouse strain and the obesity-prone EL/Suz mouse strain. The weights of three major fat pads were determined on 4-month-old mice, and the sum of these weights, divided by body weight, was used as an adiposity index. The strategy of selective DNA pooling was used as a primary screen to identify putative quantitative trait loci (QTLs) affecting adiposity index. DNA pools representing the leanest 15% and fattest 15% of the F2 progeny were compared for differential allelic enrichment using widely dispersed microsatellite variants. To evaluate putative QTLs, individual genotyping and interval mapping were employed to estimate QTL effects and assess statistical significance. One QTL affecting adiposity index, which accounted for 12.3% of phenotypic variance in gender-merged data, was mapped to the central region of Chromosome (Chr) 7. The QTL allele inherited from EL conferred increased adiposity. A second QTL that accounts for 6.3% of phenotypic variance was identified on Chr 1 near D1Mit211. At both QTLs, the data are consistent with dominant inheritance of the allele contributing to obesity. The possible relationships between these QTLs and previously described obesity QTLs, major obesity mutations, and candidate genes are discussed.

Mouse DNA 'fingerprints': analysis of chromosome localization and germ-line stability of hypervariable loci in recombinant inbred strains

Human minisatellite probes cross-hybridize to mouse DNA and detect multiple variable loci. The resulting DNA "fingerprints" vary substantially between inbred strains but relatively little within an inbred strain. By studying the segregation of variable DNA fragments in BXD recombinant inbred strains of mice, at least 13 hypervariable loci were defined, 8 of which could be regionally assigned to mouse chromosomes. The assigned loci are autosomal, dispersed and not preferentially associated with centromeres or telomeres. One of these minisatellites is complex, with alleles 90 kb or more long and with internal restriction endonuclease cleavage sites which produce a minisatellite "haplotype" of multiple cosegregating fragments. In addition, one locus shows extreme germ-line instability and should provide a useful system for studying more directly the rates and processes of allelic variation of minisatellites.

Outcome in the second year of life after in-vitro fertilisation by intracytoplasmic sperm injection: a UK case-control study

BACKGROUND

There have been reports suggesting that children born after in-vitro fertilisation by intracytoplasmic sperm injection (ICSI) are at increased risk of neurodevelopmental delay. We have undertaken a case-control study of this issue.

METHODS

We studied 208 singleton children conceived by ICSI and a control group of 221 normally conceived singleton children. Children were recruited from 22 fertility centres and local nurseries throughout the UK. Controls were selected to match cases as closely as possible for social class, maternal educational attainment, region, sex, and race. The primary outcome measure was neurodevelopmental scoring; secondary measures were perinatal outcomes, postnatal health, and congenital abnormalities. A single examiner assessed all the children.

FINDINGS

A follow-up rate of 90% for the ICSI group was achieved at a mean age of 17 months. No difference between the study children and controls was found in mean neurodevelopmental scores (98.08 [SD 10.93] vs 98.69 [9.99]) or any subscales on the Griffiths' scales of mental development. Perinatal outcome was similar apart from a higher rate of caesarean section (73 [35.1%] vs 53 [24.0%], p=0.015) and a lower mean birthweight (3163 [SD 642] vs 3341 [606] g, p=0.013) in the study group. Rates of major congenital abnormality were also similar overall (ten [4.8%] study vs ten [4.5%] control), although there were significantly more congenital anomalies among children born to fathers with oligozoospermia than in other children.

INTERPRETATION

This population study did not show any significant difference between children conceived after ICSI and their naturally conceived peers in terms of physical health and development.

MMR and autism: further evidence against a causal association

The hypothesis that MMR vaccines cause autism was first raised by reports of cases in which developmental regression occurred soon after MMR vaccination. A previous study found no evidence to support this hypothesis. It has recently been suggested that MMR vaccine might cause autism, but that the induction interval need not be short. The data from the earlier study were reanalysed to test this second hypothesis. Our results do not support this hypothesis, and provide further evidence against a causal association between MMR vaccination and autism.

Maternal smoking during pregnancy and lower respiratory tract illness in early life

In a national study of 12,743 children maternal, but not paternal, smoking was confirmed as having a significant influence on the reported incidence of bronchitis and admission to hospital for lower respiratory tract illness during the first five years of life. Reported rates of admissions to hospital for lower respiratory tract diseases were found to be as high in children born to mothers who stopped smoking during pregnancy as in those whose mothers smoked continuously both during and after pregnancy. Rates of admissions to hospital for lower respiratory tract diseases in children whose mothers started smoking only postnatally were no higher than in those whose mothers remained non-smokers. Postnatal smoking seemed to exert a significant influence on the reported incidence of bronchitis, but less than smoking during pregnancy. These findings suggest that maternal smoking influences the incidence of respiratory illnesses in children mainly through a congenital effect, and only to a lesser extent through passive exposure after birth.