PERCENTAGE OF FAMILIES WITH VOLUNTARY Annual Family Income Percentage of Families with Some Coverage under $3,000 $3,000-$4,999 $5,000 and over HEALTH INFORMATION FOUNDATION PERCENTAGE OF FAMILIES WITH VOLUNTARY HEALTH INFORMATION FOUNDATION SURVEY OF MEDICAL COSTS AND VOLUNTARY HEALTH INSURANCE How the families were selected for the NORC survey A sample of area-probability type was used in this study. It was drawn by the same methods as those used by the United States Bureau of the Census in the current population survey. Estimates derived from it are, therefore, reliable within calculable, and generally small, margins of error. That the sample yields highly reliable estimates for characteristics of the population for which independent data are available is indicated by the following comparisons: TABLE A.-Percentage of males and females in the sample population and in the United States civilian noninstitutional population Adapted from U. S. Bureau of the Census, Current Population Reports, Population Characteristics, Series P-20, No. 47, p. 9; Current Population Reports, Population Estimates, Series P-25, No. 73, p. 4; and United States Census of Population: 1950, Vol. IV, Special Reports, pt. 2, chapter C, Institutional Population, p. 13. TABLE B.-Percentage distribution by age and sex of the sample population and United States civilian noninstitutional population Adapted from U. S. Bureau of the Census, Current Population Reports, Population Characteristics, Series P-20, No. 47, p. 9; Current Population' Reports, Population Estimates, Series P-25, No. 73, p. 4; and United States Census of Population: 1950. Vol. IV, Special Reports, Pt. 2, Chapter C, Institutional Population, p. 13. |