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SAMPLE, DESIGN, & INTERVENTIONACHIEVEMENTMEASUREOUTCOMElower family income. Univariate predictors of achievement scores weresimilar, except for school days missed for illness.A simultaneous regression model was used to predict the presence orabsence of attainment problems with hematocrit, days of illness, cognitiveability scores, parent education, and family income as the predictors. Theoverall model was statistically significant, F(5, 44) =4.00, p < .01, R2 = .31. Beta weights indicated that cognitive ability, β = –.40, t = −2.77,p < .01, and days of illness, β = –.24, t = 2.07, p < .05, were uniquepredictors of attainment problems.A parallel regression model was used to evaluate mean academicachievement scores. The overall model was significant, F(5,44) = 11.12, p< .01, R2 = .56. Cognitive ability was the only significant unique predictorof achievement scores, β = 0.65, t = 5.64, p < .01.Swift (1989)Sample: N = 42 children (21 with sickle cell anemia and21 sibling controls) selected from the pediatric clinic ofthe Comprehensive Sickle Cell Center, Medical Collegeof Georgia, Augusta, who ranged from 7 to 16 years ofage.Sickle Cell Anemia Measure: Hemoglobinconcentration, percentage of Hb S, percentage of Hb F,and history of vaso-occlusive episodes andhospitalizations all taken from clinic recordsStudy Design: Case-controlSpecial educationplacement, schoolprogress and attendancetaken school recordsWISC-R, Kaufman,Detroit Test ofLearning Aptitude-2,Beery, Woodcock-JohnsonPsychoeducationalBatteryOn the Wechsler Intelligence Scale for Children-Revised, the sickle cellgroup had a mean Full Scale IQ of 77.7 (SD 12.4) compared with 94.3 (SD11.0) for the control group.The profile test of scores was similar for the two groups, with the sicklecell group scoring significantly lower than the control group on almost allcognitive measures.Among all the sickle cell anemia measures, only sequestration and vasoocclusivecrisis showed a significant association with cognitive outcome.Both groups showed academic achievement to be commensurate with theirmeasured intellectual ability.Wang (2001)Sample: N = 373 pediatric patients aged 6 to 18 yearsoldbetween September 1989 and August 1999Sickle Cell Anemia Measure: MRI for infarctionStudy Design: Cross-sectionalWechsler IntelligenceScale for Children(WISC-R or WISC III)Woodcock-JohnsonMath and ReadingAchievement TestsPatients with hemoglobin SS and silent infarcts had significantly lowerscores for math and reading achievement, Full-Scale IQ, Verbal IQ, andPerformance IQ, when compared with those with normal MRI findings.In children with hemoglobin SS and normal MRI findings, the scores forVerbal IQ, math achievement, and coding (a subscale of Performance IQ)declined with increasing age.Wasserman(1991)Sample: N = 73 children 8 to 16 years old (43 patientswith Hb SS, Hb SC, or Hb Sß thalassemia who had nothad a clinically apparent cerebrovascular accident; 30sibling controls who had sickle cell trait or normalLNNB-Children’sRevision (LNNB-C) forchildren 8 to 12; LNNBfor those 13+Controlled for number of subjects, proportion of females, and age.The average number of school days missed within the past year wassignificantly greater for patients (p