Letters

Life expectancy in children with cerebral palsy

We did not use the wheelchair item in our papers because it did not discriminate between the degrees of immobility. Hutton and colleagues chose to ignore differences in the severity of disabilities, including levels of mobility and types of feeding, when they discussed the differences between our findings and theirs.

To prove our point we adopted their cruder definitions of mobility--that is, wheelchair required and help needed for propulsion--and a separate category for manual dexterity, defined as inability to feed and dress without help, as well as their years of birth and degree of learning disability (all had cerebral palsy). We used all ages of admission to the California system. We estimated survival over 11 years for 3792 people meeting the wheelchair criteria. The five and 10 year cumulative proportions surviving were almost identical with those in Hutton and colleagues' study. When we used the criterion "does not feed or dress self without help" our cumulative proportions surviving after five and after 10 more years were also similar to those of Hutton and colleagues. We also used period life tables for Hutton and colleagues' definitions of mobility and manual dexterity. We selected subjects who received services during 1987-90 and estimated their average remaining lifetime. The results again were similar to the median survival estimated by Hutton and colleagues. These findings merely confirm that the definitions used by Hutton and colleagues did not have the precision necessary to replicate our findings on who would and would not have a reasonable survival outcome.

Diagnoses such as cerebral palsy and learning disabilities are not determinative predictors in as much as most subjects with these diagnoses are not substantially disabled. The category "patients confined to wheelchairs" is too broad to be a definitive predictor.⁴

Professor School of Education, University of California, Riverside, CA 92521, USA

Professor of medicine University of Michigan Hospital, Ann Arbor, MI 48109-0800, USA

Programmer analyst Assistant clinical professor Lanterman Developmental Center, PO Box 100-R, Pomona, CA 91768, USA

Richard K Eyman, Herbert J Grossman, Thomas L Call, Robert H Chaney 

1. Hutton JL, Cooke T, Pharoah PO. Life expectancy in children with cerebral palsy. BMJ 1994;309:431-5. (13 August.) [Abstract/Free Full Text]
2. Eyman RK, Grossman HJ, Chaney RH, Call TL. The life expectancy of profoundly handicapped people with mental retardation. N Engl J Med 1990;323:584-9. [Abstract]
3. Eyman RK, Grossman HJ, Chaney RH, Call TL. Survival of profoundly disabled people with severe mental retardation. Am J Dis Child 1993;147:329-36. [Abstract]
4. Eyman RK, Borthwick-Duffy SA, Call TL, White JF. Prediction of mortality in community and institutional settings. Journal of Mental Deficiency Research 1988;32:203-13.