The prevalence of autism spectrum disorders: impact of diagnostic instrument and non-response bias

  • M. Posserud
  • Astri J. Lundervold
  • Stein Atle Lie
  • Christopher Gillberg
Original Paper

Abstract

Background

A large part of the variability in rates of autism spectrum disorders (ASD) across studies is non-aetiologic, and can be explained by differences in diagnostic criteria, case-finding method, and other issues of study design.

Aim

To investigate the effects on ASD prevalence of two methodological issues; non-response bias and case ascertainment. We compared the findings of using a semi-structured parent interview versus in-depth clinical assessment, including an ASD specific interview. We further explored whether including information on non-responders affected the ASD prevalence estimate.

Method

A total population of 7- to 9-year olds (N = 9,430) was screened for ASD with the autism spectrum screening questionnaire (ASSQ) in the Bergen Child Study (BCS). Children scoring above the 98th percentile on parent and/or teacher ASSQ were invited to participate in the second and subsequently in the third phase of the BCS where they were assessed for ASD using the Development and Well-Being Assessment (DAWBA), and the Diagnostic Interview for Social and Communication disorders (DISCO), respectively.

Results

Clinical assessment using DISCO confirmed all DAWBA ASD cases, but also diagnosed additional cases. DISCO-generated minimum prevalence for ASD was 0.21%, whereas estimated prevalence was 0.72%, increasing to 0.87% when adjusting for non-responders. The DAWBA estimate for the same population was 0.44%.

Conclusion

Large variances in prevalence rates across studies can be explained by methodological differences. Both information about assessment method and non-response are crucial when interpreting prevalence rates of ASD.

Keywords

Autism spectrum disorders Prevalence Non-response bias Diagnostic instrument Assessment method 

References

  1. 1.
    American Psychiatric Association (2000) Diagnostic and statistical manual of mental disorders, 4th edn (text revision). American Psychiatric Association, WashingtonCrossRefGoogle Scholar
  2. 2.
    Baird G, Simonoff E, Pickles A, Chandler S, Loucas T, Meldrum D et al (2006) Prevalence of disorders of the autism spectrum in a population cohort of children in South Thames: the special needs and autism project (SNAP). Lancet 368(9531):210–215CrossRefPubMedGoogle Scholar
  3. 3.
    Barbaresi WJ, Colligan RC, Weaver AL, Katusic SK (2008) The incidence of clinically diagnosed versus research-identified autism in olmsted county, Minnesota, 1976–1997: results from a retrospective, population-based study. J Autism Dev Disord Epub ahead of printGoogle Scholar
  4. 4.
    Brugha TS, Bebbington PE, Jenkins R, Meltzer R, Taub NA, Janas M et al (1999) Cross validation of a general population survey diagnostic interview: a comparison of CIS-R with SCAN ICD-10 diagnostic categories. Psychol Med 29(5):1029–1042CrossRefPubMedGoogle Scholar
  5. 5.
    Brugha TS, Bebbington PE, Jenkins R (1999) A difference that matters: comparisons of structured and semi-structured psychiatric diagnostic interviews in the general population. Psychol Med 29(5):1013–1020CrossRefPubMedGoogle Scholar
  6. 6.
    Fombonne E (2003) Epidemiological surveys of autism and other pervasive developmental disorders: an update. J Autism Dev Disord 33(4):365–382CrossRefPubMedGoogle Scholar
  7. 7.
    Fombonne E, Simmons H, Ford T, Meltzer H, Goodman R (2001) Prevalence of pervasive developmental disorders in the British nationwide survey of child mental health. J Am Acad Child Adolesc Psychiatry 40(7):820–827CrossRefPubMedGoogle Scholar
  8. 8.
    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(1):e139–e150CrossRefPubMedGoogle Scholar
  9. 9.
    Gerrits MH, van den Oord EJ, Voogt R (2001) An evaluation of nonresponse bias in peer, self, and teacher ratings of children’s psychosocial adjustment. J Child Psychol Psychiatr 42(5):593–602CrossRefGoogle Scholar
  10. 10.
    Gillberg C, Wing L (1999) Autism: not an extremely rare disorder. Acta Psychiatr Scand 99(6):399–406CrossRefPubMedGoogle Scholar
  11. 11.
    Goodman R (1997) The strengths and difficulties questionnaire: a research note. J Child Psychol Psychiatr 38(5):581–586CrossRefGoogle Scholar
  12. 12.
    Goodman R, Ford T, Richards H, Gatward R, Meltzer H (2000) The development and well-being assessment: description and initial validation of an integrated assessment of child and adolescent psychopathology. J Child Psychol Psychiatr 41(5):645–655CrossRefGoogle Scholar
  13. 13.
    Hansen V, Jacobsen BK, Arnesen E (2001) Prevalence of serious psychiatric morbidity in attenders and nonattenders to a health survey of a general population: the Tromso Health Study. Am J Epidemiol 154(10):891–894CrossRefPubMedGoogle Scholar
  14. 14.
    Haslam N (2006) Bias in psychopathology research. Curr Opin Psychiatry 19(6):625–630CrossRefPubMedGoogle Scholar
  15. 15.
    Heiervang E, Stormark KM, Lundervold AJ, Heimann M, Goodman R, Posserud MB et al (2007) Psychiatric disorders in Norwegian 8- to 10-year-olds: an epidemiological survey of prevalence, risk factors, and service use. J Am Acad Child Adolesc Psychiatry 46(4):438–447CrossRefPubMedGoogle Scholar
  16. 16.
    Honda H, Shimizu Y, Rutter M (2005) No effect of MMR withdrawal on the incidence of autism: a total population study. J Child Psychol Psychiatr 46(6):572–579CrossRefGoogle Scholar
  17. 17.
    Hysing M, Elgen I, Gillberg C, Lie SA, Lundervold AJ (2007) Chronic physical illness and mental health in children. Results from a large-scale population study. J Child Psychol Psychiatr 48(8):785–792CrossRefGoogle Scholar
  18. 18.
    Haapea M, Miettunen J, Veijola J, Lauronen E, Tanskanen P, Isohanni M (2007) Non-participation may bias the results of a psychiatric survey: an analysis from the survey including magnetic resonance imaging within the Northern Finland 1966 Birth Cohort. Soc Psychiatry Psychiatr Epidemiol 42(5):403–409CrossRefPubMedGoogle Scholar
  19. 19.
    Kaufman J, Birmaher B, Brent D, Rao U, Flynn C, Moreci P et al (1997) Schedule for affective disorders and schizophrenia for school-age children-present and lifetime version (K-SADS-PL): initial reliability and validity data. J Am Acad Child Adolesc Psychiatry 36(7):980–988CrossRefPubMedGoogle Scholar
  20. 20.
    Leekam SR, Libby SJ, Wing L, Gould J, Taylor C (2002) The diagnostic interview for social and communication disorders: algorithms for ICD-10 childhood autism and wing and gould autistic spectrum disorder. J Child Psychol Psychiatr 43(3):327–342CrossRefGoogle Scholar
  21. 21.
    Lord C, Risi S, Lambrecht L, Cook EH Jr, Leventhal BL, DiLavore PC et al (2000) The autism diagnostic observation schedule-generic: a standard measure of social and communication deficits associated with the spectrum of autism. J Autism Dev Disord 30(3):205–223CrossRefPubMedGoogle Scholar
  22. 22.
    Lord C, Rutter M, Le Couteur A (1994) Autism diagnostic interview-revised: a revised version of a diagnostic interview for caregivers of individuals with possible pervasive developmental disorders. J Autism Dev Disord 24(5):659–685CrossRefPubMedGoogle Scholar
  23. 23.
    Lundberg I, Damstrom Thakker K, Hallstrom T, Forsell Y (2005) Determinants of non-participation, and the effects of non-participation on potential cause–effect relationships, in the PART study on mental disorders. Soc Psychiatry Psychiatr Epidemiol 40(6):475–483CrossRefPubMedGoogle Scholar
  24. 24.
    Madsen KM, Hviid A, Vestergaard M, Schendel D, Wohlfahrt J, Thorsen P et al (2002) A population-based study of measles, mumps, and rubella vaccination and autism. N Engl J Med 347(19):1477–1482CrossRefPubMedGoogle Scholar
  25. 25.
    Mullick MS, Goodman R (2005) The prevalence of psychiatric disorders among 5–10 year olds in rural, urban and slum areas in Bangladesh: an exploratory study. Soc Psychiatry Psychiatr Epidemiol 40(8):663–671CrossRefPubMedGoogle Scholar
  26. 26.
    Posserud MB, Lundervold AJ, Gillberg C (2006) Autistic features in a total population of 7–9-year-old children assessed by the ASSQ (autism spectrum screening questionnaire). J Child Psychol Psychiatr 47(2):167–175CrossRefGoogle Scholar
  27. 27.
    Posserud M, Lundervold AJ, Gillberg C (2008) Validation of the autism spectrum screening questionnaire in a total population sample. J Autism Dev Disord Epub ahead of printGoogle Scholar
  28. 28.
    Rutter M, Cox A, Tupling C, Berger M, Yule W (1975) Attainment and adjustment in two geographical areas. I—the prevalence of psychiatric disorder. B J Psychiatry 126:493–509CrossRefGoogle Scholar
  29. 29.
    Sponheim E, Skjeldal O (1998) Autism and related disorders: epidemiological findings in a Norwegian study using ICD-10 diagnostic criteria. J Autism Dev Disord 28(3):217–227CrossRefPubMedGoogle Scholar
  30. 30.
    Stang A (2003) Nonresponse research—an underdeveloped field in epidemiology. Eur J Epidemiol 18(10):929–931CrossRefPubMedGoogle Scholar
  31. 31.
    Stormark KM, Heiervang E, Heimann M, Lundervold A, Gillberg C (2008) Predicting nonresponse bias from teacher ratings of mental health problems in primary school children. J Abnorm Child Psychol 36(3):411–419CrossRefPubMedGoogle Scholar
  32. 32.
    Volkmar FR, Lord C, Bailey A, Schultz RT, Klin A (2004) Autism and pervasive developmental disorders. J Child Psychol Psychiatr 45(1):135–170CrossRefGoogle Scholar
  33. 33.
    Wakefield AJ, Murch SH, Anthony A, Linnell J, Casson DM, Malik M et al (1998) Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children. Lancet 351(9103):637–641CrossRefPubMedGoogle Scholar
  34. 34.
    Williams JG, Higgins JP, Brayne CE (2006) Systematic review of prevalence studies of autism spectrum disorders. Arch Dis Child 91(1):8–15CrossRefPubMedGoogle Scholar
  35. 35.
    Wing L, Leekam SR, Libby SJ, Gould J, Larcombe M (2002) The diagnostic interview for social and communication disorders: background, inter-rater reliability and clinical use. J Child Psychol Psychiatr 43(3):307–325CrossRefGoogle Scholar
  36. 36.
    Wing L, Potter D (2002) The epidemiology of autistic spectrum disorders: is the prevalence rising? Ment Retard Dev Disabil Res Rev 8(3):151–161CrossRefPubMedGoogle Scholar

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  • M. Posserud
    • 1
  • Astri J. Lundervold
    • 2
  • Stein Atle Lie
    • 3
  • Christopher Gillberg
    • 4
  1. 1.Centre for Child and Adolescent Mental HealthUnifob HealthBergenNorway
  2. 2.Department of Biological and Medical Psychology, Faculty of PsychologyUniversity of BergenBergenNorway
  3. 3.Centre for Child and Adolescent Mental HealthUnifob HealthBergenNorway
  4. 4.Child and Adolescent PsychiatryUniversity of GothenburgGöteborgSweden

Personalised recommendations