Improved disability population estimates of functional limitation among American children aged 5-17.

OBJECTIVES: This paper (a) creates and validates measures for population survey data to assess functional limitation in mobility, self-care, communication, and learning ability for school-age American children; (b) calculates rates of functional limitation using these measures, and provides population estimates of the number of children with limitations; and (c) examines these limitations as a function of socioeconomic factors. METHOD: The study is based on data for children aged 5-17 collected in the 1994 National Health Interview Survey on Disability. Ordinal values are assigned to survey items in the four functional areas and analyzed to produce scales of high reliability. These measures are used to identify within a 95% confidence interval the number of children with these limitations. Ordered logistic regression models measure the effects of functional limitations on disability and societal limitation. Socioeconomic differences are measured with an ordered logistic regression model that predicts severity and comorbidity. RESULTS: Limitations in learning ability (10.6%) and communication (5.5%) are the most common, with mobility (1.3%) and self-care (0.9%) occurring less often. Six percent of children have one serious functional limitation and 2.0% have two or more serious functional limitations. This corresponds to 4.0 million school-age American children with serious functional limitations. Functional limitation is strongly linked to socioeconomic disadvantage and to residence in single-mother households. CONCLUSIONS: Future population research should use multiple-item scales for four distinct areas of functional limitation, and a summary that takes into account both severity and comorbidity. The improved estimates of the number of school-age children with functional limitation in this paper may help contribute to a more informed scientific and policy discussion of functional limitation and disability among American school-age children. Future research on the disability process among children must consider the role of socioeconomic disadvantage and family structure.

Contraception and community in Egypt: a preliminary evaluation of the population/development mix.

Egypt's Population and Development Program (PDP) is an effort to combine family planning and development approaches at the grass roots level. Introduced as a pilot project in the late 1970s, it is now active in nearly three quarters of Egypt's villages. A 1980 Contraceptive Prevalence Survey of over 5,000 rural women stratified 124 villages according to their exposure to the program (from zero to two or more years). Comparison of women living in villages of varying exposure revealed no differences in fertility; but modest differences in knowledge, attitudes, and contraceptive practice were apparent, especially in Upper Egypt. A multivariate analysis with socioeconomic and demographic controls did not weaken these relationships. Moreover, program effects were most marked among those most in need of services--noncontracepting fecund women who were illiterate.

Comment on 'The random variation in rates based on total enumeration of events' by J. R. Udry, C. Teddlie, C. M. Suchindran.

This comment builds on the work of Udry et al., developing a model of random variation of vital rates in small geographical areas. The model is based on the division of the variance of vital rates into three parts; that which would occur in a homogenous population; that due to population heterogeneity; and that due to yearly fluctuations in the underlying basis for the mean value of the probability of the vital event in question. Contrary to Udry et al., this model demonstrates that population heterogeneity must decrease the overall vital rate variance. Using birth rates presented in Udry et al., a test of the new model demonstrates the importance of the third factor, yearly fluctuations, in determining year-to-year variation in birth rates.

Measuring potential fertility through null segments: an exploratory analysis.

PIP: The demographic effectiveness of a family planning program must measure the difference between actual fertility and the "gross" potential fertility, i.e., the natural fertility which would have been achieved without use of contraception. The various methods of measuring "gross" fertility which have been used are described. It is understood that users of contraception are never a random sampling of the general population; they tend to be higher in fecundability and lower in proportion of sterile. For this reason, the best strategm of measurement involves utilization of preacceptance fertility rates over some given period of time among those reporting no contraceptive usage during that period. A procedure of measurement is proposed whereby natural fecundability is estimated from null segments. Possible biases are taken into account. Application of the method is made to 2 sets of data collected in Taiwan. Results of the application of the method to the Taiwanese data are tabulated. Fecundability functions derived from unrestricted null segments are different from those constructed from restricted subsets of "closed" null segments. Choice of whether to use restricted or unrestricted null segments will depend on the nature of the data available.^ieng

Methodological issues underlying multiple decrement life table analysis.

In this paper, the actuarial method of multiple decrement life table analysis of censored, longitudinal data is examined. The discussion is organized in terms of the first segment of usage of an intrauterine device. Weaknesses of the actuarial approach are pointed out, and an alternative approach, based on the classical model of competing risks, is proposed. Finally, the actuarial and the alternative method of analyzing censored data are compared, using data from the Taichung Medical Study on Intrauterine Devices.