title: Familial and sporadic schizophrenia. A simulation study of statistical power.
abstract: The importance of genetic factors in schizophrenia is clear but the mechanism involved remains obscure. Etiological heterogeneity may be responsible. Recently there has been interest in a putative distinction between genetic and environmental forms of the illness based on a positive or negative family history of the disorder. Those with a positive family history are classified as 'familial' and are considered to be more likely to have the genetic form of the illness. Those with a negative family history are classified as 'sporadic' and considered more likely to have an environmental form of the illness. This paper reports the results of a Monte Carlo simulation study with varying rates of misclassification to determine the statistical power of comparisons between familial and sporadic groups. For a large sample (n = 175) statistical power was moderate to good for effect sizes greater than or equal to 1.0 standard deviation unit and positive predictive value of 0.3 or greater.
authors.affiliation: Department of Psychology, Boston University, MA 02115.
authors.forename: M J
authors.initials: MJ
authors.lastname: Lyons
authors.forename: S V
authors.initials: SV
authors.lastname: Faraone
authors.forename: W S
authors.initials: WS
authors.lastname: Kremen
authors.forename: M T
authors.initials: MT
authors.lastname: Tsuang
mesh_terms: D006801:Humans; D008957:Models, Genetic; D009010:Monte Carlo Method; D012307:Risk Factors; D012559:Schizophrenia / Q000145:classification / Q000175:diagnosis / Q000235:genetics*; D012565:Schizophrenic Psychology; D012931:Social Environment