Background It has been suggested that vaccination against measles,mumps, and rubella (MMR) is a cause of autism.
Methods We conducted a retrospective cohort study of all childrenborn in Denmark from January 1991 through December 1998. Thecohort was selected on the basis of data from the Danish CivilRegistration System, which assigns a unique identification numberto every live-born infant and new resident in Denmark. MMR-vaccinationstatus was obtained from the Danish National Board of Health.Information on the children's autism status was obtained fromthe Danish Psychiatric Central Register, which contains informationon all diagnoses received by patients in psychiatric hospitalsand outpatient clinics in Denmark. We obtained information onpotential confounders from the Danish Medical Birth Registry,the National Hospital Registry, and Statistics Denmark.
Results Of the 537,303 children in the cohort (representing2,129,864 person-years), 440,655 (82.0 percent) had receivedthe MMR vaccine. We identified 316 children with a diagnosisof autistic disorder and 422 with a diagnosis of other autistic-spectrumdisorders. After adjustment for potential confounders, the relativerisk of autistic disorder in the group of vaccinated children,as compared with the unvaccinated group, was 0.92 (95 percentconfidence interval, 0.68 to 1.24), and the relative risk ofanother autistic-spectrum disorder was 0.83 (95 percent confidenceinterval, 0.65 to 1.07). There was no association between theage at the time of vaccination, the time since vaccination,or the date of vaccination and the development of autistic disorder.
Conclusions This study provides strong evidence against thehypothesis that MMR vaccination causes autism.
It has been suggested that the measles, mumps, and rubella (MMR)vaccine causes autism.1,2,3,4 The widespread use of the MMRvaccine has reportedly coincided with an increase in the incidenceof autism in California,5 and there are case reports of childrenin whom signs of both developmental regression and gastrointestinalsymptoms developed shortly after MMR vaccination.1 Measles virushas been found in the terminal ileum in children with developmentaldisorders and gastrointestinal symptoms but not in developmentallynormal children with gastrointestinal symptoms.6 The measlesvirus used in the MMR vaccine is a live attenuated virus thatnormally causes no symptoms or only very mild ones. However,wild-type measles can infect the central nervous system andeven cause postinfectious encephalomyelitis, probably as a resultof an immune-mediated response to myelin proteins.7,8,9
Studies designed to evaluate the suggested link between MMRvaccination and autism do not support an association, but theevidence is weak and based on case-series, cross-sectional,and ecologic studies. No studies have had sufficient statisticalpower to detect an association, and none had a population-basedcohort design.10,11,12,13,14,15,16 The World Health Organizationand other organizations have requested further investigationof the hypothetical association between the MMR vaccine andautism.2,17,18,19,20 We evaluated the hypothesis in a cohortstudy that included all children born in Denmark in 1991 through1998.
Methods
Study Design
We designed a retrospective follow-up study of all childrenborn in Denmark during the period from January 1, 1991, to December31, 1998. The cohort was established on the basis of data obtainedfrom the Danish Civil Registration System and five other nationalregistries.
All live-born children and new residents in Denmark are assigneda unique personal identification number (a civil-registry number),which is stored in the Danish Civil Registration System togetherwith information on vital status, emigration, disappearance,address, and family members (mother, father, and siblings).21The registry is updated once a week, and all changes in thestored information are reported to the registry according toestablished legal procedures. The civil-registry number is usedas the link to information at the individual level in all othernational registries. This system provides completely accuratelinkage of information between registries at the individuallevel.
We determined MMR-vaccination status on the basis of vaccinationdata reported to the National Board of Health by general practitioners,who administer all MMR vaccinations in Denmark. The generalpractitioners are reimbursed by the state on the basis of thesereports. We retrieved information on vaccinations from 1991through 1999. The MMR vaccine was introduced in Denmark in 1987,and the single-antigen measles vaccine has not been used. TheMMR vaccine used in Denmark during the study period was identicalto that used in the United States and contained the followingvaccine strains: Moraten (measles), Jeryl Lynn (mumps), andWistar RA 27/3 (rubella).
The national vaccination program recommends that children bevaccinated at 15 months of age and again at 12 years. No changewas made in the program during the study period. We obtainedinformation on MMR vaccination at 15 months of age, since onlythis exposure is relevant to the end point under study. Sincethe vaccination data are transferred to the National Board ofHealth once a week, we chose Wednesday as the day of vaccination.When the vaccination information was recorded with the child'sown civil-registry number, the information was directly linkedwith other registries. Before 1996, in most cases the vaccinationinformation and the age of the child were recorded with thecivil-registry number of the accompanying adult; we used informationfrom the Danish Civil Registration System to identify the linkfrom the accompanying adult to the child. Thus, 98.5 percentof the children were identified with the use of the child'scivil-registry number or the civil-registry number of the motheror father and the age of the child at vaccination. The remaining1.5 percent of children were identified on the basis of additionalinformation from the Danish Civil Registration System on otherrelatives and information on the address at the time of vaccination.
Information about diagnoses of autism was obtained from theDanish Psychiatric Central Register, which contains informationon all diagnoses received by patients in psychiatric hospitals,psychiatric departments, and outpatient clinics in Denmark.22In our cohort, 93.1 percent of the children were treated onlyas outpatients, and 6.9 percent were at some point treated asinpatients in a psychiatric department. All diagnoses were basedon the International Classification of Diseases, 10th Revision(ICD-10), which is similar to the 4th edition of the Diagnosticand Statistical Manual of Mental Disorders (DSM-IV) with regardto autism.23,24,25,26 In Denmark, children are referred to specialistsin child psychiatry by general practitioners, schools, and psychologistsif autism is suspected. Only specialists in child psychiatrydiagnose autism and assign a diagnostic code, and all diagnosesare recorded in the Danish Psychiatric Central Register. Weidentified all children given a diagnosis of autistic disorder(ICD-10 code F84.0 and DSM-IV code 299.00) or another autistic-spectrumdisorder (ICD-10 codes F84.1 through F84.9 and DSM-IV codes299.10 and 299.80). When a child was given diagnoses of bothautistic disorder and one or more other autistic-spectrum disorders,we classified the diagnosis as autistic disorder. Autism isassociated with the inherited genetic conditions tuberous sclerosis,Angelman's syndrome, and the fragile X syndrome and with congenitalrubella. To maximize the homogeneity of the study population,data for children with these conditions were censored when thediagnosis was made. We obtained information on these conditionsfrom the National Hospital Registry.
We performed an extensive record review for 40 children withautistic disorder (13 percent of all the children with autisticdisorder) to validate the diagnosis of autism. A consultantin child psychiatry with expertise in autism examined the medicalrecords. Thirty-seven of the children (92 percent) met the operationalcriteria for autistic disorder according to a systematic codingscheme developed by the Centers for Disease Control and Preventionfor surveillance of autism and used in a prevalence study inBrick Township, New Jersey.27 The three children who did notmeet the criteria for autistic disorder were all classifiedas having other autistic-spectrum disorders. For two of thechildren, the diagnosis of autistic disorder was questionablebecause of profound intellectual impairment. For the third child,we did not have information about the onset of symptoms beforethe age of three years, which is a prerequisite for the diagnosisof autistic disorder.
We obtained information on birth weight and gestational agefrom the Danish Medical Birth Registry and the National HospitalRegistry.28,29 Information on potential confounders, includingsocioeconomic status (as indicated by the employment statusof the head of the household) and mother's education was obtainedfrom Statistics Denmark from the time when the child was 15months of age.
Statistical Analysis
Follow-up for the diagnosis of autistic disorder or anotherautistic-spectrum disorder began for all children on the daythey reached one year of age and continued until the diagnosisof autism or an associated condition (the fragile X syndrome,Angelman's syndrome, tuberous sclerosis, or congenital rubella),emigration, death, or the end of follow-up, on December 31,1999, whichever occurred first. The incidence-rate ratios forautistic disorder and other autistic-spectrum disorders in thegroup of vaccinated children, as compared with the unvaccinatedgroup, were examined in a log-linear Poisson regression modelwith the use of PROC GENMOD (SAS, version 6.12).30 We treatedvaccination as a time-dependent covariate. The children wereassigned to the nonvaccinated group until they received theMMR vaccine. From that date, they were followed in the vaccinatedgroup. In additional analyses, the MMR-vaccinated children weregrouped according to their age at the time of vaccination, theinterval since vaccination, and the calendar period when vaccinationwas performed.
In reporting the results, we refer to the incidence-rate ratiosas relative risks. For all risk estimates, we considered possibleconfounding by age (1, 2, 3, 4, 5, 6, 7, or 8 to 9 years), sex,calendar period (1992 to 1993, 1994, 1995, 1996, 1997, 1998,or 1999; for other autistic-spectrum disorders, the years 1992,1993, and 1994 were grouped together), socioeconomic status(six groups), mother's education (five groups), gestationalage (36, 37 to 41, or 42 weeks), and birth weight (2499, 2500to 2999, 3000 to 3499, 3500 to 3999, or 4000 g).
Results
A total of 537,303 children were included in the cohort andfollowed for a total of 2,129,864 person-years. Follow-up of5811 children was stopped before December 31, 1999, becauseof a diagnosis of autistic disorder (in 316 children), otherautistic-spectrum disorders (in 422), tuberous sclerosis (in35), congenital rubella (in 2), or the fragile X or Angelman'ssyndrome (in 8), and because of death or emigration in the casesof 5028 children, whose data were censored. For children whoreceived MMR vaccine, there were 1,647,504 person-years of follow-up,and for children who did not receive the vaccine, there were482,360 person-years of follow-up.
Table 1 shows the distribution of the MMR cohort according tovaccination status, sex, birth weight, gestational age, socioeconomicstatus, mother's education, and age when autism was diagnosed.The mean age at diagnosis was four years and three months forautistic disorder and five years and three months for otherautistic-spectrum disorders. The mean age at the time of theMMR vaccination was 17 months, and 98.5 percent of the vaccinatedchildren were vaccinated before 3 years of age. The proportionof children who were vaccinated was the same among boys andgirls (82.0 percent).
Table 1. Characteristics of the 537,303 Children in the Danish Cohort.
Table 2 shows the association between variables related to MMRvaccination and the risk of autism. We calculated the relativerisk with adjustment for age, calendar period, sex, birth weight,gestational age, mother's education, and socioeconomic status.Overall, there was no increase in the risk of autistic disorderor other autistic-spectrum disorders among vaccinated childrenas compared with unvaccinated children (adjusted relative riskof autistic disorder, 0.92; 95 percent confidence interval,0.68 to 1.24; adjusted relative risk of other autistic-spectrumdisorders, 0.83; 95 percent confidence interval, 0.65 to 1.07).Furthermore, we found no association between the developmentof autistic disorder and the age at vaccination (P=0.23), theinterval since vaccination (P=0.42), or the calendar periodat the time of vaccination (P=0.06).
Table 2. Adjusted Relative Risk of Autistic Disorder and of Other Autistic-Spectrum Disorders in Vaccinated and Unvaccinated Children.
Adjustment for potential confounders with the exception of ageresulted in similar estimates of risk. Changing the start offollow-up for autistic disorder and other autistic-spectrumdisorders to the date of birth or 16 months of age had littleeffect on the estimates (data not shown). Furthermore, includingchildren with the fragile X syndrome, tuberous sclerosis, congenitalrubella, or Angelman's syndrome in the analysis did not changethe estimates (data not shown).
Discussion
This study provides three strong arguments against a causalrelation between MMR vaccination and autism. First, the riskof autism was similar in vaccinated and unvaccinated children,in both age-adjusted and fully adjusted analyses. Second, therewas no temporal clustering of cases of autism at any time afterimmunization. Third, neither autistic disorder nor other autistic-spectrumdisorders were associated with MMR vaccination. Furthermore,the results were derived from a nationwide cohort study withnearly complete follow-up data.
All previous studies of an association between autism and MMRvaccination have been case series,1,14,15 ecologic studies,11,12or cross-sectional studies,10,13 and the majority have not usedoptimal data for risk assessment. In a well-conducted, cross-sectionalprevalence study, Taylor and colleagues10 found that there wasno sharp increase in the prevalence of autism after the introductionof the MMR vaccine. However, it could be argued that a moregradual increase would be expected, since autism is characterizedby an insidious onset and a delay in diagnosis. A case-seriesstudy by Peltola et al.15 also provides evidence against a causalconnection.
One of the main reasons for public concern has been that thewidespread use of the MMR vaccine in some regions appeared tocoincide with an increase in the incidence of autism. However,this is not a uniform finding. In Denmark, the prevalence ofautism (according to the criteria of the International Classificationof Diseases, 8th Revision) was less than 2.0 cases per 10,000children between the ages of five and nine years in the 1980sand the beginning of the 1990s. Since then, the rates have increasedin all age groups except for children younger than two yearsof age, and in 2000, the prevalence of autism (according tothe ICD-10 criteria) was higher than 10.0 cases per 10,000 childrenfive to nine years of age (unpublished data). Thus, the increasein autism both in California5 and in Denmark occurred well afterthe introduction of the MMR vaccine.
Our study was based on individual reports of vaccination anddiagnoses of autism in a well-defined geographic area. The exposuredata were collected prospectively, independently of parentalrecall and before the diagnosis of autism. Furthermore, thediagnosis was recorded independently of the recording of MMRvaccination. Thus, there was little possibility of differentialmisclassification of exposure or outcome measures. Furthermore,our analysis was based on complete follow-up data.
We assume that the data on MMR vaccination are almost complete,since general practitioners in Denmark are reimbursed only afterreporting immunization data to the National Board of Health.We had an unvaccinated reference group with almost 500,000 person-yearsof follow-up, even though the study was numerically imbalancedin favor of the vaccinated group. The power of the study isreflected in the narrow 95 percent confidence intervals.
We had no information on the presence or absence of a familyhistory of autism, which could explain our negative findingsonly if families with a history of autism avoided MMR vaccination.If so, we would expect to have found high relative risks atthe beginning of the study period, before the hypothetical linkbetween vaccination and autism was publicized. This was notthe case. We had no information on whether the children withautism had regression, and thus we could not perform a subgroupanalysis. However, the fact that the overall relative risk ofautism or an autistic-spectrum disorder was less than 1.0 doesnot support the possibility of a subgroup of vulnerable children.
The Danish vaccination program recommends that children receivethe MMR vaccine at 15 months of age and provides the vaccinationfree of charge. Among the children in our cohort who were bornin 1995, the rate of MMR vaccination was lower than the rateof vaccination with the first Haemophilus influenzae type Bvaccine (86.9 percent vs. 97.0 percent). However, the rate ofMMR vaccination in our study was similar to that in the UnitedStates (87.6 percent in 1995) and Belgium (83.0 percent in 1997).31,32Nevertheless, the main concern is the comparability of vaccinatedand nonvaccinated children in relation to the end point understudy. In all analyses, when risk estimates were calculated,we controlled for possible confounders (age, sex, calendar period,socioeconomic status, mother's education, gestational age, andbirth weight). Except for age, none of these possible confounderschanged the estimates. The confounding by age was a functionof the time available for follow-up, since much of the follow-upfor the unvaccinated group involved young children, in whomautism is often undiagnosed.
We assessed the validity of the diagnosis of autistic disorderin a subgroup of children and found it to be high. This wasto be expected, since only specialists in child and adolescentpsychiatry are authorized to code the diagnosis of autism inthe Danish Psychiatric Central Register. All schools have accessto health care personnel as well as psychologists. Because ofthe comprehensive health care surveillance for children in Denmark,all severe cases of autism are likely to be diagnosed and reportedto the registry at some point. Reporting of the other autistic-spectrumdisorders is less complete than that for autistic disorder,and some diagnoses are almost certainly missed. However, itis unlikely that this misclassification would be associatedwith vaccination status. It is very difficult to determine theonset of autism, and many cases are probably due to prenatalfactors. Our records did not contain information on when thefirst autistic symptoms were noted, and we could not adjustfor a differential delay in the diagnosis. Again, it is highlyunlikely that a delayed diagnosis was associated with MMR vaccinationin this study.
There are few published data on the incidence of autism, butthe prevalence rates reported in the literature vary widely,from 1.2 cases per 10,000 (according to the criteria of thethird edition of the Diagnostic and Statistical Manual of MentalDisorders) to 30.8 per 10,000 (according to the ICD-10 criteria).33,34The prevalence rates among eight-year-old children in our cohortwere 7.7 per 10,000 for autistic disorder and 22.2 per 10,000for other autistic-spectrum disorders. These rates are similarto the prevalence rates of 5.4 per 10,000 for autistic disorderand 16.3 per 10,000 for other autistic-spectrum disorders ina cohort of 325,347 French children (ICD-10 criteria), reportedby Fombonne et al.,35 and the rate of 11 per 10,000 for autisticdisorder in a cohort of U.S. children (DSM-IV criteria), reportedby Croen and colleagues.36 The DSM-IV classification systemused in the United States and the ICD-10 classification systemused in many European countries are almost identical with regardto the classification of autistic disorder.23,24,25,26 In ourvalidity substudy, we found that 93 percent of cases diagnosedaccording to the ICD-10 criteria met the DSM-IV operationalcriteria for the diagnosis of autistic disorder.
Supported by grants from the Danish National Research Foundation;the National Vaccine Program Office and National ImmunizationProgram, Centers for Disease Control and Prevention; and theNational Alliance for Autism Research.
We are indebted to Susanne Toft and Meta Jørgensen forthe abstraction and review of medical records and to CatherineRice and Nancy Dornberg for assistance with the validity substudy.
Source Information
From the Danish Epidemiology Science Center, Department of Epidemiology and Social Medicine, Århus, Denmark (K.M.M., M.V., P.T., J.O.); the Danish Epidemiology Science Center, Department of Epidemiology Research, Statens Serum Institute, Copenhagen, Denmark (A.H., J.W., M.M.); and the National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta (D.S.).
Address reprint requests to Dr. Madsen at the Danish Epidemiology Science Center, Department of Epidemiology and Social Medicine, Vennelyst Blvd. 6, DK-8000, Aarhus C, Denmark, or at kmm{at}dadlnet.dk.
References
Wakefield AJ, Murch SH, Anthony A, et al. Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children. Lancet 1998;351:637-641. [CrossRef][Web of Science][Medline]
Stratton K, Gable A, Shetty P, McCormick M, eds. Immunization safety review: measles-mumps-rubella vaccine and autism. Washington, D.C.: National Academy Press, 2001.
Wakefield AJ, Montgomery SM. Measles, mumps, rubella vaccine: through a glass, darkly. Adverse Drug React Toxicol Rev 2000;19:265-283. [Medline]
Autism: present challenges, future needs why the increased rates? Hearing before the Committee of Government Reform, U.S. House of Representatives, 106th Congress, second session, April 6, 2000. Washington, D.C.: Government Printing Office, 2000.
Department of Developmental Services. Changes in the population of persons with autism and pervasive developmental disorders in California's Developmental Services System: 1987 through 1998: a report to the Legislature. Sacramento: California Health and Human Services Agency, March 1999.
Uhlmann V, Martin CM, Sheils O, et al. Potential viral pathogenic mechanism for new variant inflammatory bowel disease. Mol Pathol 2002;55:84-90. [Free Full Text]
Griffin DE, Ward BJ, Jauregui E, Johnson RT, Vaisberg A. Immune activation in measles. N Engl J Med 1989;320:1667-1672. [Abstract]
Singh VK, Lin SX, Newell E, Nelson C. Abnormal measles-mumps-rubella antibodies and CNS autoimmunity in children with autism. J Biomed Sci 2002;9:359-364. [Web of Science][Medline]
Johnson RT, Griffin DE, Hirsch RL, et al. Measles encephalomyelitis -- clinical and immunologic studies. N Engl J Med 1984;310:137-141. [Abstract]
Taylor B, Miller E, Farrington CP, et al. Autism and measles, mumps, and rubella vaccine: no epidemiological evidence for a causal association. Lancet 1999;353:2026-2029. [CrossRef][Web of Science][Medline]
Kaye JA, del Mar Melero-Montes M, Jick H. Mumps, measles, and rubella vaccine and the incidence of autism recorded by general practitioners: a time trend analysis. BMJ 2001;322:460-463. [Free Full Text]
Dales L, Hammer SJ, Smith NJ. Time trends in autism and in MMR immunization coverage in California. JAMA 2001;285:1183-1185. [Free Full Text]
Fombonne E, Chakrabarti S. No evidence for a new variant of measles-mumps-rubella-induced autism. Pediatrics 2001;108:991-991. abstract.
Patja A, Davidkin I, Kurki T, Kallio MJ, Valle M, Peltola H. Serious adverse events after measles-mumps-rubella vaccination during a fourteen-year prospective follow-up. Pediatr Infect Dis J 2000;19:1127-1134. [Web of Science][Medline]
Peltola H, Patja A, Leinikki P, Valle M, Davidkin I, Paunio M. No evidence for measles, mumps, and rubella vaccine-associated inflammatory bowel disease or autism in a 14-year prospective study. Lancet 1998;351:1327-1328. [CrossRef][Web of Science][Medline]
Taylor B, Miller E, Lingram L, Andrews N, Simmons A, Stowe J. Measles, mumps, and rubella vaccination and bowel problems or developmental regression in children with autism: population study. BMJ 2002;324:393-396. [Free Full Text]
Causality assessment of adverse events following immunization. Wkly Epidemiol Rec 2001;76:85-89. [Medline]
Smeeth L, Hall AJ, Rodrigues LC, Huang X, Smith PG, Fombonne E. Measles, mumps, and rubella (MMR) vaccine and autism: ecological studies cannot answer main question. BMJ 2001;323:163-163. [Free Full Text]
Edwardes M, Baltzan M. MMR immunization and autism. JAMA 2001;285:2852-2853. [Free Full Text]
Malig C. The civil registration system in Denmark. IIVRS technical paper no. 66. Bethesda, Md.: International Institute for Vital Registration and Statistics, 1996.
Munk-Jorgensen P, Mortensen PB. The Danish Psychiatric Central Register. Dan Med Bull 1997;44:82-84. [Web of Science][Medline]
The ICD-10 classification of mental and behavioural disorders: diagnostic criteria for research. Geneva: World Health Organization, 1993.
Filipek PA, Accardo PJ, Baranek GT, et al. The screening and diagnosis of autistic spectrum disorders. J Autism Dev Disord 1999;29:439-484. [Erratum, J Autism Dev Disord 2000;30:81.] [CrossRef][Web of Science][Medline]
Volkmar FR, Klin A, Siegel B, et al. Field trial for autistic disorder in DSM-IV. Am J Psychiatry 1994;151:1361-1367. [Free Full Text]
Hill A, Bolte S, Petrova G, Beltcheva D, Tacheva S, Poustka F. Stability and interpersonal agreement of the interview-based diagnosis of autism. Psychopathology 2001;34:187-191. [CrossRef][Web of Science][Medline]
Bertrand J, Mars A, Boyle C, Bove F, Yeargin-Allsopp M, Decoufle P. Prevalence of autism in a United States population: the Brick Township, New Jersey, investigation. Pediatrics 2001;108:1155-1161. [Free Full Text]
Knudsen LB, Olsen J. The Danish Medical Birth Registry. Dan Med Bull 1998;45:320-323. [Web of Science][Medline]
Andersen TF, Madsen M, Jorgensen J, Mellemkjoer L, Olsen JH. The Danish National Hospital Register: a valuable source of data for modern health sciences. Dan Med Bull 1999;46:263-268. [Web of Science][Medline]
Clayton D, Hills M. Statistical models in epidemiology. Oxford, England: Oxford University Press, 1993.
Vellinga A, Depoorter AM, Van Damme P. Vaccination coverage estimates by EPI cluster sampling survey of children (18-24 months) in Flanders, Belgium. Acta Paediatr 2002;91:599-603. [CrossRef][Web of Science][Medline]
Epidemiology and prevention of vaccine-preventable diseases. 7th ed. Atlanta: Centers for Disease Control and Prevention, 2002.
Burd L, Fisher W, Kerbeshian J. A prevalence study of pervasive developmental disorders in North Dakota. J Am Acad Child Adolesc Psychiatry 1987;26:700-703. [Web of Science][Medline]
Baird G, Charman T, Baron-Cohen S, et al. A screening instrument for autism at 18 months of age: a 6-year follow-up study. J Am Acad Child Adolesc Psychiatry 2000;39:694-702. [CrossRef][Web of Science][Medline]
Fombonne E, Du Mazaubrun C, Cans C, Grandjean H. Autism and associated medical disorders in a French epidemiological survey. J Am Acad Child Adolesc Psychiatry 1997;36:1561-1569. [CrossRef][Web of Science][Medline]
Croen LA, Grether JK, Hoogstrate J, Selvin S. The changing prevalence of autism in California. J Autism Dev Disord 2002;32:207-215. [CrossRef][Web of Science][Medline]
Ashwell, G.
(2009). Autism and Asperger's syndrome. InnovAiT
2: 651-656
[Abstract][Full Text]
Kilburn, K. H, Thrasher, J. D, Immers, N. B
(2009). Do terbutaline- and mold-associated impairments of the brain and lung relate to autism?. Toxicol Ind Health
25: 703-710
[Abstract]
Gilger, M. A., Redel, C. A.
(2009). Autism and the Gut. Pediatrics
124: 796-798
[Full Text]
Alverson, B.
(2009). Autism's False Prophets: Bad Science, Risky Medicine, and the Search for a Cure. Arch Pediatr Adolesc Med
163: 396-396
[Full Text]
Li, J., Vestergaard, M., Obel, C., Christensen, J., Precht, D. H., Lu, M., Olsen, J.
(2009). A Nationwide Study on the Risk of Autism After Prenatal Stress Exposure to Maternal Bereavement. Pediatrics
123: 1102-1107
[Abstract][Full Text]
Offit, P. A., Moser, C. A.
(2009). The Problem With Dr Bob's Alternative Vaccine Schedule. Pediatrics
123: e164-e169
[Abstract][Full Text]
Baird, G, Pickles, A, Simonoff, E, Charman, T, Sullivan, P, Chandler, S, Loucas, T, Meldrum, D, Afzal, M, Thomas, B, Jin, L, Brown, D
(2008). Measles vaccination and antibody response in autism spectrum disorders. Arch. Dis. Child.
93: 832-837
[Abstract][Full Text]
Clarke, C. E.
(2008). A Question of Balance: The Autism-Vaccine Controversy in the British and American Elite Press. Science Communication
30: 77-107
[Abstract]
Schultz, S. T., Klonoff-Cohen, H. S., Wingard, D. L., Akshoomoff, N. A., Macera, C. A., Ming Ji,
(2008). Acetaminophen (paracetamol) use, measles-mumps-rubella vaccination, and autistic disorder: The results of a parent survey. Autism
12: 293-307
[Abstract]
Montiel-Nava, C., Pena, J. A.
(2008). Epidemiological findings of pervasive developmental disorders in a Venezuelan study. Autism
12: 191-202
[Abstract]
Elliman, D., Bedford, H.
(2007). MMR: where are we now?. Arch. Dis. Child.
92: 1055-1057
[Full Text]
Duggan, C. P., Westra, S. J., Rosenberg, A. E.
(2007). Case 23-2007 -- A 9-Year-Old Boy with Bone Pain, Rash, and Gingival Hypertrophy. NEJM
357: 392-400
[Full Text]
Woo, E. J., Ball, R., Landa, R., Zimmerman, A. W., Braun, M. M., VAERS Working Group, Center for Biologics Evaluati,
(2007). Developmental regression and autism reported to the Vaccine Adverse Event Reporting System. Autism
11: 301-310
[Abstract]
Dover, C. J, Le Couteur, A.
(2007). How to diagnose autism. Arch. Dis. Child.
92: 540-545
[Abstract][Full Text]
Kolevzon, A., Gross, R., Reichenberg, A.
(2007). Prenatal and Perinatal Risk Factors for Autism: A Review and Integration of Findings. Arch Pediatr Adolesc Med
161: 326-333
[Abstract][Full Text]
MacDonald, P.F.
(2007). The MMR vaccine controversy winners, losers, impact and challenges. British Journal of Infection Control
8: 18-22
[Abstract]
Atladottir, H. O., Parner, E. T., Schendel, D., Dalsgaard, S., Thomsen, P. H., Thorsen, P.
(2007). Time Trends in Reported Diagnoses of Childhood Neuropsychiatric Disorders: A Danish Cohort Study. Arch Pediatr Adolesc Med
161: 193-198
[Abstract][Full Text]
State, M. W.
(2006). A surprising METamorphosis: Autism genetics finds a common functional variant. Proc. Natl. Acad. Sci. USA
103: 16621-16622
[Full Text]
Friedlander, A. H., Yagiela, J. A., Paterno, V. I., Mahler, M. E.
(2006). The neuropathology, medical management and dental implications of autism.. Journal of the American Dental Association
137: 1517-1527
[Abstract][Full Text]
Barbaresi, W. J., Katusic, S. K., Voigt, R. G.
(2006). Autism: A Review of the State of the Science for Pediatric Primary Health Care Clinicians.. Arch Pediatr Adolesc Med
160: 1167-1175
[Abstract][Full Text]
Marks, S., Ciliska, D., Jull, A.
(2006). Evaluation of studies of treatment harm. Evid. Based Nurs.
9: 100-104
[Full Text]
D'Souza, Y., Fombonne, E., Ward, B. J.
(2006). No Evidence of Persisting Measles Virus in Peripheral Blood Mononuclear Cells From Children With Autism Spectrum Disorder. Pediatrics
118: 1664-1675
[Abstract][Full Text]
Fombonne, E., Zakarian, R., Bennett, A., Meng, L., McLean-Heywood, D.
(2006). Pervasive Developmental Disorders in Montreal, Quebec, Canada: Prevalence and Links With Immunizations. Pediatrics
118: e139-e150
[Abstract][Full Text]
Wright, J. A., Polack, C.
(2006). Understanding variation in measles-mumps-rubella immunization coverage--a population-based study. Eur J Public Health
16: 137-142
[Abstract][Full Text]
Shattuck, P. T.
(2006). The Contribution of Diagnostic Substitution to the Growing Administrative Prevalence of Autism in US Special Education. Pediatrics
117: 1028-1037
[Abstract][Full Text]
Hanley, J. A., Csizmadi, I., Collet, J.-P.
(2005). Two-Stage Case-Control Studies: Precision of Parameter Estimates and Considerations in Selecting Sample Size. Am J Epidemiol
162: 1225-1234
[Abstract][Full Text]
Steiner, J. F.
(2005). The Use of Stories in Clinical Research and Health Policy. JAMA
294: 2901-2904
[Full Text]
Ozonoff, S., Williams, B. J., Landa, R.
(2005). Parental report of the early development of children with regressive autism: The delays-plus-regression phenotype. Autism
9: 461-486
[Abstract]
Baley, J. E., Leonard, E. G.
(2005). The Immunologic Basis for Neonatal Immunizations. NeoReviews
6: e463-e470
[Full Text]
Bauch, C. T
(2005). Imitation dynamics predict vaccinating behaviour. Proc R Soc B
272: 1669-1675
[Abstract][Full Text]
Hviid, A., Wohlfahrt, J., Stellfeld, M., Melbye, M.
(2005). Childhood Vaccination and Nontargeted Infectious Disease Hospitalization. JAMA
294: 699-705
[Abstract][Full Text]
Larsson, H. J., Eaton, W. W., Madsen, K. M., Vestergaard, M., Olesen, A. V., Agerbo, E., Schendel, D., Thorsen, P., Mortensen, P. B.
(2005). Risk Factors for Autism: Perinatal Factors, Parental Psychiatric History, and Socioeconomic Status. Am J Epidemiol
161: 916-925
[Abstract][Full Text]
McGreevy, D.
(2005). Risks and benefits of the single versus the triple MMR vaccine: how can health professionals reassure parents?. The Journal of the Royal Society for the Promotion of Health
125: 84-86
[Abstract]
Steuernagel, T.
(2005). Increases in Identified Cases of Autism Spectrum Disorders: Policy Implications. Journal of Disability Policy Studies
16: 138-146
[Abstract]
Goin-Kochel, R. P., Myers, B. J.
(2005). Congenital Versus Regressive Onset of Autism Spectrum Disorders: Parents' Beliefs About Causes. Focus Autism Other Dev Disabl
20: 169-179
[Abstract]
Barbaresi, W. J., Katusic, S. K., Colligan, R. C., Weaver, A. L., Jacobsen, S. J.
(2005). The Incidence of Autism in Olmsted County, Minnesota, 1976-1997: Results From a Population-Based Study. Arch Pediatr Adolesc Med
159: 37-44
[Abstract][Full Text]
Folb, P. I., Bernatowska, E., Chen, R., Clemens, J., Dodoo, A. N. O., Ellenberg, S. S., Farrington, C. P., John, T. J., Lambert, P.-H., MacDonald, N. E., Miller, E., Salisbury, D., Schmitt, H.-J., Siegrist, C.-A., Wimalaratne, O.
(2004). A Global Perspective on Vaccine Safety and Public Health: The Global Advisory Committee on Vaccine Safety. AJPH
94: 1926-1931
[Abstract][Full Text]
Dubik, M., Offit, P. A.
(2004). Measles Virus RNA and Autism Revisited. AAP Grand Rounds
12: 56-57
[Full Text]
Meissner, H. C., Strebel, P. M., Orenstein, W. A.
(2004). Measles Vaccines and the Potential for Worldwide Eradication of Measles. Pediatrics
114: 1065-1069
[Abstract][Full Text]
Parker, S. K., Schwartz, B., Todd, J., Pickering, L. K.
(2004). Thimerosal-Containing Vaccines and Autistic Spectrum Disorder: A Critical Review of Published Original Data. Pediatrics
114: 793-804
[Abstract][Full Text]
VERDOUX, H., BEGAUD, B.
(2004). Pharmaco-epidemiology: what do (and don't) we know about utilisation and impact of psychotropic medications in real-life conditions?. Br. J. Psychiatry
185: 93-94
[Full Text]
Vestergaard, M., Hviid, A., Madsen, K. M., Wohlfahrt, J., Thorsen, P., Schendel, D., Melbye, M., Olsen, J.
(2004). MMR Vaccination and Febrile Seizures: Evaluation of Susceptible Subgroups and Long-term Prognosis. JAMA
292: 351-357
[Abstract][Full Text]
Klein, K. C, Diehl, E. B
(2004). Relationship Between MMR Vaccine and Autism. The Annals of Pharmacotherapy
38: 1297-1300
[Abstract][Full Text]
Jick, H., Kaye, J. A.
(2004). Autism and DPT Vaccination in the United Kingdom. NEJM
350: 2722-2723
[Full Text]
Woo, E. J., Ball, R., Bostrom, A., Shadomy, S. V., Ball, L. K., Evans, G., Braun, M.
(2004). Vaccine Risk Perception Among Reporters of Autism After Vaccination: Vaccine Adverse Event Reporting System 1990-2001. AJPH
94: 990-995
[Abstract][Full Text]
Serajee, F. J., Nabi, R., Hailang Zhong, , Mahbubul Huq, A.H.M.
(2004). Polymorphisms in Xenobiotic Metabolism Genes and Autism. J Child Neurol
19: 413-417
[Abstract]
Fitzpatrick, M.
(2004). MMR: risk, choice, chance. Br Med Bull
69: 143-153
[Abstract][Full Text]
Bardenheier, B., Yusuf, H., Schwartz, B., Gust, D., Barker, L., Rodewald, L.
(2004). Are Parental Vaccine Safety Concerns Associated With Receipt of Measles-Mumps-Rubella, Diphtheria and Tetanus Toxoids With Acellular Pertussis, or Hepatitis B Vaccines by Children?. Arch Pediatr Adolesc Med
158: 569-575
[Abstract][Full Text]
Muhle, R., Trentacoste, S. V., Rapin, I.
(2004). The Genetics of Autism. Pediatrics
113: e472-e486
[Abstract][Full Text]
DeStefano, F., Bhasin, T. K., Thompson, W. W., Yeargin-Allsopp, M., Boyle, C.
(2004). Age at First Measles-Mumps-Rubella Vaccination in Children With Autism and School-Matched Control Subjects: A Population-Based Study in Metropolitan Atlanta. Pediatrics
113: 259-266
[Abstract][Full Text]
Hviid, A., Stellfeld, M., Wohlfahrt, J., Melbye, M.
(2003). Association Between Thimerosal-Containing Vaccine and Autism. JAMA
290: 1763-1766
[Abstract][Full Text]
Wright, S.
(2003). Measles, mumps, and rubella vaccine was not associated with autism in children. Evid. Based Nurs.
6: 89-89
[Full Text]
Gurney, J. G., Fritz, M. S., Ness, K. K., Sievers, P., Newschaffer, C. J., Shapiro, E. G.
(2003). Analysis of Prevalence Trends of Autism Spectrum Disorder in Minnesota. Arch Pediatr Adolesc Med
157: 622-627
[Abstract][Full Text]
Wilson, K., Mills, E., Ross, C., McGowan, J., Jadad, A.
(2003). Association of Autistic Spectrum Disorder and the Measles, Mumps, and Rubella Vaccine: A Systematic Review of Current Epidemiological Evidence. Arch Pediatr Adolesc Med
157: 628-634
[Abstract][Full Text]
Mullins, M. E.
(2003). Measles-Mumps-Rubella Vaccine and Autism. Pediatrics
112: 206-206
[Full Text]
Frid, P. J
(2003). The measles, mumps, and rubella vaccine was not associated with autism in children. Evid. Based Med.
8: 93-93
[Full Text]
Tidmarsh, L.
(2003). There is little evidence that combined vaccination against measles, mumps, and rubella is associated with autism. Evid. Based Ment. Health
6: 62-62
[Full Text]
(2003). MMR vaccine - how effective and how safe?. DTB
41: 25-29
[Abstract][Full Text]
(2003). Measles-Mumps-Rubella Vaccine and Autism: No Link Found. JWatch Neurology
2003: 9-9
[Full Text]
Spitzer, W. O., Mullins, M. E., Wakefield, A. J., Noble, K. K., Miyasaka, K., Madsen, K. M., Campion, E. W.
(2003). Measles, Mumps, and Rubella Vaccination and Autism. NEJM
348: 951-954
[Full Text]
Rathore, M. H., Barton, L. L.
(2003). MMR Vaccine and Autism: A Population-based Study. AAP Grand Rounds
9: 16-17
[Full Text]
Fombonne, E.
(2003). The Prevalence of Autism. JAMA
289: 87-89
[Full Text]
(2002). No Link Between MMR Vaccine and Autism. Journal Watch Dermatology
2002: 8-8
[Full Text]
(2002). Autism and the MMR Vaccine: No Connection Found. JWatch Psychiatry
2002: 5-5
[Full Text]
Newschaffer, C. J., Fallin, D., Lee, N. L.
(2002). Heritable and Nonheritable Risk Factors for Autism Spectrum Disorders. Epidemiol Rev
24: 137-153
[Full Text]
(2002). No Link Between MMR Vaccine and Autism. JWatch Pediatrics
2002: 1-1
[Full Text]
(2002). No Link Between MMR Vaccine and Autism. JWatch General
2002: 6-6
[Full Text]
Tanne, J. H.
(2002). MMR vaccine is not linked with autism, says Danish study. BMJ
325: 1134-1134
[Full Text]
Risher, J. F, Murray, H E., Prince, G. R
(2002). Organic mercury compounds: human exposure and its relevance to public health. Toxicol Ind Health
18: 109-160
[Abstract]