Current estimates from the health interview survey, United States - 1968

Data in this report for calendar year 1968 were obtained from a split sample, as were the data in the previous Current Estimates report (Series 10, No. 52). From January to June 1968; one-half the sample was interviewed using the "condition approach" and the other one-half was interviewed using. the "person approach." Beginning in July 1968, the person approach was used for the entire sample. For details of the split-sample methodology, see appendix III, Series 10, No, 52. Since variations in the estimates from the two versions of the questionnaire were found to be within the limits of sampling error, the data from the two approaches were combined to produce the estimates shown in this report.