HEALTH PROMOTION AND DISEASE PREVENTION (HPDP) INJURY CONTROL AND CHILD SAFETY AND HEALTH SUPPLEMENT (ICCSH) NOTES INTRODUCTION 1. The 1990 Injury Control and Child Safety and Health (ICCSH) file contains the portions of the 1990 National Health Interview Survey (NHIS) of Health Promotion and Disease Prevention (HPDP) that were related to child health and safety. It is similar to the 1985 Child Safety and Infant Feeding file that contains the portions of the 1985 NHIS- HPDP that were related to child health and safety. 2. The Injury Control and Child Safety and Health file consists of: a. The NHIS person record from the Core questionnaire (locations 1-200) b. Weight fields (locations 201-212) c. Dummy record field (location 336) d. Household safety information concerning poison control, collected from the HPDP sample person in households with children under age 10 (locations 337-339). e. Child-specific information on seat belt/car seat use and breast-feeding (locations 340-347) f. Household safety information, collected from the HPDP sample person in all households (locations 348-371) g. Respondent's relationship to the child (location 372) Note: The household safety information was collected from the HPDP sample person and applies to the entire family. The information in these two sections was copied to the records of all children in the HPDP sample person's family. These data are also contained in the 1990 HPDP Sample Person file. 3. Items a-e and g, described above, were contained on the 1985 Child Safety/Infant Feeding file. Item f (household safety), although collected from the sample person in 1985, was not included on the 1985 Child Safety and Infant Feeding file. 4. A record exists for every child 0-17 years of age in the NHIS sample. A responsible adult in the household (usually, but not always, the HPDP sample person) was asked information about all children under 17 years of age in the family. The relationship of the respondent to the child is entered in location 372. Children 17 years of age could (but usually did not) respond for themselves (see location 91). - 1 - When a child was identified in the family, based on the Core questionnaire, but child-specific and/or injury control information was not obtained, a dummy record was created for the child. Three types of dummy records were created: a. Dummy - Household data only: No information was collected from the HPDP sample person for the household items and therefore was not available for the child file. b. Dummy - Child specific data only: No child- specific information was collected but the HPDP (sample person) household information was available. c. Dummy - Entire special topic portion of the HPDP: Neither the household safety information nor the child-specific data were obtained. Dummy records were processed with the non-dummy records. Codes were assigned for "unknown", "not ascertained", and "blank" according to the edit specifications established for all records. Although dummy records lack some or all of the special topic information, they do contain all of the information that was obtained during the Core household interview. This information can be found in locations 1-200. 5. The response rate for the Injury Control and Child Safety and Health portion of the NHIS-HPDP was 82.7 percent. This response rate was calculated as follows: Household response rate from the basic health and demographic questionnaire (i.e., Core) (95.5 percent) multiplied by the ICCSH response rate (86.6 percent) = 82.7 percent The ICCSH non-response includes children for whom no information was collected for any of the items on the file (12.1 percent) and children for whom household safety information was collected from the HPDP sample person but for whom no child-specific information was collected (1.3 percent). Children for whom the child-specific information was obtained but household HPDP safety information was lacking, were considered respondents for purposes of calculating the ICCSH response rate. 6. Weights: Weights must be used to make accurate estimates based on data from the National Health Interview Survey. Two weights are included on the 1990 ICCSH file: - 2 - a. The Final Basic Weight (location 207-212), calculated for each child in the family, is the weight that will be used in most analyses of the ICCSH data. This weight is the functional equivalent of the Annual Final Basic Weight found on the NHIS Person Record of the Basic Health and Demographic component of the survey (i.e., the Core questionnaire). The ICCSH Final Basic Weight differs from that calculated for the Core data file in that the weight field on the Core data file is in binary format and the weight field on this file is in character format. b. The Interim Basic Weight (before age-sex-race adjustment), required by some software packages for variance estimation for surveys with complex sample designs, is also included on the file (loc. 201-206). 7. Estimating numbers of events or conditions a. To reduce respondent error, the recall period for questions about some events is limited to two weeks. These events are: bed days and other restricted activity days, work loss and school loss days, and doctor visits. The two-week variables are found in locations 98-107 and 120-121. Estimates of the total number of occurrences of these events in the population can be derived as follows: Number of events x 26 (number of two-week periods in a year) x Final Basic Weight = Total number of events occurring in the population during the data year, i.e., 1990. Example: Number of bed days (loc. 100-101) x 26 x Final Basic Weight (loc. 207-212) = total number of bed days reported for the population in 1990. b. The recall period for acute incidence conditions is also two weeks and an annual estimate of the total number of acute incidence conditions is calculated using the same procedures as for two-week events: Number of acute incidence conditions x 26 x Final Basic Weight = Total number of acute incidence conditions occurring in the population during 1990. Note: An acute incidence condition is an acute condition with onset during the two weeks preceding the date of interview. - 3 - c. The recall period for information on hospitalizations is 12 months. However, in calculating number of discharges and number of days in hospital (locations 132-141), only discharges occurring in the past 6 months are counted. Therefore, the weighted estimates for these events must be calculated as follows: (1) Number of discharges x 2 (number of 6-month periods in a year) x Final Basic Weight = Total number of discharges occurring in the population in one year. (2) Number of days in hospital associated with discharges occurring in the past 6 months x 2 (number of 6-month periods in a year) x Final Basic Weight = Total number of days of hospitalization occurring in the population in one year. Note: On this file, "population" refers to all children age 0-17 years. 8. Calculation of rates for events and conditions: The number of events or conditions estimated for the population, as described in item 7, above, can be used as the basis for calculating rates of occurrence of these events (or conditions) per person and per 100 persons for the total U. S. population and for various population subgroups. Note: Only rates can be estimated from these data. The percent of the population experiencing a particular type of event during the data year cannot be estimated. [The percent of the population experiencing the event in the reporting period (i.e., two weeks or 6 months) can be estimated but is generally not meaningful.] 9. Data on hospital episodes and days, based on a 12-month recall are locations 122-131. The Final Basic Weight is used for calculating estimates of these events in the same way it is used for all other person-based variables. These variables do permit estimating the percent of the population experiencing a hospital episode in the past year and the percent of the population having a specified number of hospital days. This description prepared by: Charlotte A. Schoenborn, IDSB August, 1991 Amended: Oct. 1991 - 4 -