SAM MORGAN, PhD,. FAY F. RUSSELL, MN, and BEVERLY RICHARDSON, BS. This report compares developmental milestones and current intellectual and.
Early Intervention with Down Syndrome Children Follow-up Report BARBARA CONNOLLY, EdD, SAM MORGAN, PhD, FAY F. RUSSELL, MN, and BEVERLY RICHARDSON, BS
This report compares developmental milestones and current intellectual and adaptive functioning of 20 children with Down syndrome who participated in an early intervention program with those of 53 noninstitutionalized children with Down syndrome who did not experience such a program. The children in the former group generally showed earlier acquisition of motor and self-help skills and significantly higher intelligence quotients and social quotients at three to six years of age. Because of certain variables that could not be rigorously controlled in this type of program, the higher functioning cannot be clearly attributed to early intervention. These findings nevertheless are consistent with the hypothesis that early intervention has a beneficial effect and should provide encouragement for further studies. Key Words: Child development, Down syndrome, Parent-child relations, Patientcare team.
The 1970s may be recorded as the decade that early intervention became accepted as an appropriate way of helping potentially handicapped or developmentally delayed infants and toddlers and their families. Despite the increasing acceptance and use of such intervention by professionals in the area of mental retardation, studies are needed to demonstrate the validity of specific approaches over a span of time and to justify the significant investment of time and money in such programs. One purpose of this study
Dr. Connolly is Chief of Physical Therapy, Child Development Center, University of Tennessee, 711 Jefferson Ave, Memphis, TN 38105 (USA), and Assistant Professor of Physical Therapy, University of Tennessee Center for the Health Sciences, Memphis, TN 38163. Dr. Morgan is Professor and Director of Clinical Psychology, Memphis State University, Memphis, TN 38152. Mrs. Russell is Chief of Nursing, Child Development Center, University of Tennessee, and Associate Professor of Nursing and Child Development, University of Tennessee Center for the Health Sciences. Mrs. Richardson is Instructor, Baptist Memorial Hospital School of Nursing, Memphis, TN 38105. Address reprint requests to Dr. Connolly at the Child Development Center. This study was supported in part by US Public Health Service Grant No. 900. This article was submitted July 23, 1979, and accepted February 13, 1980.
Volume 60 / Number 11, November 1980
was to assess the development and current functioning of 20 children with Down syndrome who were studied in 1975 by Connolly and Russell and who have completed the Early Intervention Program at the Child Development Center of the University of Tennessee Center for the Health Sciences.1 The second purpose was to compare these children with noninstitutionalized children who have Down syndrome and who have not had early intervention. Studies demonstrate a general decline in intelligence quotients (IQ) and social quotients (SQ) in children with Down syndrome from infancy to late childhood.2-4 This decline, however, may be decelerated with intensive early intervention. Thus, as infants and toddlers, these children present a special challenge to professionals. Melyn and White, for example, studied 612 home-reared individuals with Down syndrome ranging in age from birth through 20 years and found a fairly consistent decline in IQ.4 The mean IQ at 6 months was 58.3, whereas the mean IQ at 13½ years was 37.74. In addition to the decline in IQ and SQ with age, children with Down syndrome typically show a high degree of variability in intellectual and adaptive functioning.4,5 Although all exhibit this decline with age, some children consistently function at a higher level 1405
than others, showing a slower rate of deceleration and a higher point of leveling off in late childhood or early adolescence. What factors contribute to this wide variability in abilities? Why does one six-yearold function at a mildly retarded level while another functions at a severely retarded level? Genetic factors could contribute to this variability because intelligence in any large sample of children with Down syndrome appears to have the same polygenetic distribution as found in other individuals. Even when early educational experiences for these children are similar, there is significant variance that might be attributed to genetic influences. LaVeck and Brehm, for example, found wide variability in intellectual abilities in 5- and 6-year-olds who had all undergone the same infant and preschool program.5 A related variable is parental education. Golden and Pashayan noted a correlation between parental educational level and intellectual functioning in a group of children with Down syndrome.6 Although well-educated parents might be more likely than poorly educated parents to provide a stimulating environment and better educational opportunities for their child, the authors point out that this correlation cannot be explained solely in terms of superior environment because it might represent an interaction between environmental influences and genetic potential. Parental educational level is therefore a factor that should be controlled in evaluating the effectiveness of early intervention programs. Even though genetic influences undoubtedly contribute to the variability in intellectual development in children with Down syndrome, early intervention programs might still have positive effects on such development. Within the range of a given child's genetic potential, such programs might decelerate the rate of decline and increase the chances of a higher level of eventual functioning. The child who might have functioned as severely retarded at 6 years of age might, with early intervention, function as moderately retarded at that age. The assumption of many professionals that early intervention has positive long-range effects on the child is basic to the program being studied.
METHOD Twenty of the original 40 children studied in 1975 by Connolly and Russell were again evaluated in terms of intellectual, social, motor, and adaptive functioning.1 All children had completed the early intervention program described in detail in the original report. 1406
The interdisciplinary program began in 1973. The program focused on the family, and the activities were directed toward encouraging a healthy parentchild relationship and maximizing the overall development of each child. For 10 weeks in the spring and fall families brought their children to the Center one morning each week to participate in group sessions. In each session professionals spent one hour teaching and demonstrating to parents varied developmental interventions for individualized home-use stimulation programs. The parents spent the next hour in group therapy discussing feelings, concerns, and problems while the children were receiving individualized treatment. The final half-hour was devoted to feedingskill development. During the winter and summer, the staff did periodic follow-ups that included assessing the child's developmental status and updating individual programs. A diagnostic team evaluation was done in the first year of the child's enrollment, and needs in other areas such as health, nutrition, and audiology were met. The Early Intervention (EI) group (n = 20) in this study consisted of those children who participated in the EI program described above until 3 years of age, the maximum age for participation. At the time of follow-up testing, these children ranged in chronological age from 3.2 years to 6.3 years. Inasmuch as chronological age and parental educational level affect functioning in children with Down syndrome, an attempt was made to control for these two variables when selecting the Comparison group. The Comparison group (n = 53) included all children with Down syndrome who, when tested at the Center, were within the same age range as the EI group and whose parents had a mean educational level within the same range as the parents of the EI group. None of these children were institutionalized and none had participated in an early intervention program. The children had been referred to the Center for a complete diagnostic evaluation. Children with mosaicism were not included in the study. Intelligence quotients of all subjects were tested with either the Stanford-Binet Intelligence Scale or the Cattell Infant Intelligence Scale; SQs were tested with the Vineland Social Maturity Scale. All testers were licensed psychological examiners not involved in the program. Parental educational levels were determined from the routine application forms completed by parents who apply for services at the Child Development Center. Statistical analysis of the data included the t test for differences between the means of two groups and chi-square. The level of significance used throughout the study was p < .05. PHYSICAL THERAPY
RESULTS
Table 1 summarizes characteristics of the EI and Comparison groups and the results of the t test for differences between the means for the two groups. The t test revealed no significant differences between the means for either chronological age or parental educational level, thus indicating that these two var iables had been effectively controlled. The mean IQ for the EI group was almost 12 points higher than that for the Comparison group, a significant differ ence (p < .005) in the predicted direction. Although the difference in mean SQ between the two groups was not as large, the EI group significantly (p < .05) exceeded the Comparison group by 9 points in the predicted direction. Table 2 shows the percentage of children from each group at each level of retardation. A chi-square test revealed a significant difference χ2 = 11.08, df= 4,p < .05) in the distribution of subjects across levels of mental retardation for each group (Tab. 2). Sixty-five percent of the EI subjects were at the Borderline and Mild levels, but only 24.5 percent of the Comparison subjects were at these higher levels. Further, none of the EI subjects were below the Moderate level, whereas 19 percent of Comparison subjects fell below this level. Developmental data on the Comparison group was largely from parental report and not by professional observation. Therefore, certain motor, self-help, and social milestones of the EI children were compared with the norms established for children with Down syndrome and with normal children.7,8 Table 3 reveals that EI children as a group attained skills earlier than other children with Down syndrome but generally later than normal children. Variables such as parental educational level could not be controlled and there fore might confound interpretation of differences. DISCUSSION
The results are consistent with the hypothesis that intervention during infancy has a positive effect upon development of adaptive and intellectual skills in children with Down syndrome. Further, the findings suggest that early intervention facilitates acquisition of early developmental skills. Although this evalua tion of one program provides support for the effec tiveness of early intervention, any conclusions must be drawn with caution and viewed as tentative for two reasons. First, the generally higher IQs and SQs in the EI group cannot be unequivocally attributed to the ef fects of early intervention. Although the two signifi cant variables of age and parental educational level Volume 60 / Number 11, November
1980
TABLE 1 Summary Data for Early Intervention (n = 20) and Comparison (n = 53) Groups Early Comparison Intervention Group Group
Difference Between Two Groups
(0 Chronological Age (yr) Range Parental Educational Level (yr)
4.5 3.2-6.3
4.6 3.2-6.3
NS
14.1 10-19
13.2 10-21
NS
54.7 38-78 12.2
42.9 13-77 12.2
3.688 a
64.4 41-95 15.7
55.5 18-95 16.2
2.113 b
Range Intelligence Quotient Range SD Social Quotient Range SD a b
p < .005. p
