TECHNICAL NOTES SOURCES OF DATA BIRTHS, DEATHS AND FETAL DEATHS: Birth, death and fetal death certificates were the source documents for data on vital events to Delaware residents. A copy of each certificate is included as Appendices F, G and H. The cut-off date for data in this report was October 31 after the close of the calendar year. Any data pertaining to an event for which a certificate was filed after this date, are not included in this report. It is possible that data obtained directly from the Delaware Health Statistics Center (DHSC) may differ slightly from that which appear in this report. If this should occur, it is the result of an update that was made after the cut-off date for this report. Births and deaths to Delaware residents which took place in other states are included in this report. The inclusion of these data is made possible by an agreement among all registration areas in the United States for the exchange of copies of resident certificates. MARRIAGES AND DIVORCES: Each of Delaware's three counties has a state office for the collection of marriage certificates. All of these certificates are processed and maintained by the Office of Vital Statistics in the Division of Public Health's central office in Dover. Copies of divorce certificates are forwarded to the Office of Vital Statistics from the Delaware Family Court system so that certain selected data items can be processed for statistical purposes. A copy of each of these certificates is included as Appendices I and J. INDUCED TERMINATIONS OF PREGNANCY: Beginning on January 1, 1997, all induced terminations of pregnancy (ITOP) were required to be reported to the Department. Reports of induced termination of pregnancy are filed directly with the DHSC. The reports are filed for statistical purposes only and are shredded and discarded when all reports for the data year have been coded. ITOP records are currently not being exchanged among the states, so events to Delaware residents occurring out-of-state are not included in this report. A copy of the reporting form is included as Appendix K. REPORTED PREGNANCIES: Reported pregnancies refer to live births, fetal deaths, and ITOP. When used in combination, these three events can yield a great deal of information regarding pregnancy and pregnancy outcomes that is not possible by looking at each individual event separately. For example, live birth rates can be calculated using live births in conjunction with population data. However, differences observed between live birth rates in two or more geographic areas or within the same area at different points in time may be due to differences in the rate of pregnancy, differences in pregnancy outcomes (i.e., live birth, fetal death, or ITOP), or a combination of these factors. Only pregnancy rates allow such questions to be thoroughly examined. It should be kept in mind that both births and fetal deaths of Delaware residents are reported regardless of state of occurrence, while induced terminations are reported for only those that occur in Delaware. POPULATION PROJECTIONS: The state, county and city population figures used in this report are estimates and projections produced by the Delaware Population Consortium (DPC). The DHSC is a member of the DPC and supplies birth and death data used in making the projections. Copies of the most recent projections for Delaware's population by age, race, sex, and geographic location are available at http://www.cadsr.udel.edu/demography/consortium.htm. DATA QUALITY QUERY AND FIELD PROGRAMS: The quality of vital statistics data presented in this report is directly related to the completeness and accuracy of the information contained on the certificates and forms. The DHSC works with the Office of Vital Statistics to ensure that the information received is as complete and accurate as possible. The Office of Vital Statistics operates two programs related to improving the quality of information received on vital records--the query and field programs. The query program is a system used to follow-back to hospital and clinic personnel, funeral directors and/or physicians concerning data quality problems. The follow-back contact is usually via mail and/or telephone. The field program attempts to improve vital statistics data quality by educating the participants in the vital registration system (i.e., hospital personnel, funeral directors, physicians, etc.) of the uses and importance of vital statistics data. The field program completes this mission by conducting seminars with various associations representing the individuals listed above. The National Center for Health Statistics (NCHS) monitors Delaware's coding of statistical data on death certificates. A 20 percent sample of death records coded and submitted monthly by the state are used as a quality control mechanism by NCHS. NCHS codes these sample records independently and then conducts an item-by-item computer match of codes entered by the state and NCHS. NCHS has established an upper limit of two percent for coding differences involving any one data item of these sample records, with the exception of cause of death. NCHS independently codes cause of death information. COMPUTER EDITS AND DATA PROCESSING: Another dimension of data quality is related to the procedures and methodologies used in preparing the data for presentation. Beginning with the 1991 Annual Vital Statistics Report, methodologies for editing and processing vital data were standardized to match the procedures used by NCHS in tabulating national vital statistics data. These procedures include checking for valid codes, computation of data items (e.g., age, live-birth order, weeks of gestation, duration of marriage, interval between divorce and remarriage), consistency checks between data items (e.g., age and education), and imputation of missing values. FETAL DEATHS: In terms of the completeness of the data, the reporting of deaths and live births is considered to be virtually complete. However, in Delaware, a spontaneous termination of pregnancy is not required to be reported when the fetus weighs less than 350 grams or, when weight is unattainable, if the duration of pregnancy is less than 20 weeks. National estimates (Ventura, Taffel and Mosher, 1985) indicate that over 90 percent of all spontaneous terminations of pregnancy may occur before this 20 week period and thus go unreported. In addition, the exchange agreement among states for resident fetal death records is problematic due to different reporting requirements; it is unknown whether complete exchange is taking place. The result is that a large number of spontaneous terminations may not be reported. GEOGRAPHY ALLOCATION In Delaware's registration program, as in other states, vital events are classified geographically in two ways. The first way is by place of occurrence (i.e., the actual state and county in which the birth or death took place). The second and more customary way is by place of residence (i.e., the state, county, and census tract) stated to be the usual residence of the decedent in the case of death, or of the mother in the case of a newborn. While occurrence statistics are accurate and have both administrative value and some statistical importance, residence statistics are by far the more useful tool in developing health indices for planning and evaluation purposes. The natality and mortality statistics provided in this report are based upon Delaware residence data. However, the marriage and divorce statistics are occurrence data. This is primarily due to the fact that two separate residences are usually involved in a marriage or a divorce, and there are no accepted standard procedures for classification of residence in these events. Allocation of vital events by place of residence is sometimes difficult because classification depends entirely on a statement of the usual place of residence furnished by the informant at the time the original certificate is completed. For various reasons, this statement may be incorrect or incomplete. However, in recent years, the DHSC has invested a great deal of effort into editing of address information leading to a significant improvement in data quality. In any case, geographical allocation is generally a problem only at the level of census tract. Resident counts at the State level are, for all practical purposes, complete. County resident figures are substantially correct and can be used with a high degree of confidence. Most of the data provided in this report are available at the census tract level. This information can be obtained by contacting the DHSC. BIRTH WEIGHT This report presents birth weight in grams in order to provide data comparable to that published for the United States and other countries. For those live birth certificates where birth weight is reported in pounds and ounces, DHSC converts the birth weight into grams. The equivalents of the gram intervals in pounds and ounces are as follows: 499 grams or less = 1 lb. 1 oz. or less 500 - 999 grams = 1 lb. 2 ozs. - 2 lbs. 3ozs. 1,000 - 1,499 grams = 2 lbs. 4 ozs. - 3 lbs. 4ozs. 1,500 - 1,999 grams = 3 lbs. 5 ozs. - 4 lbs. 6ozs. 2,000 - 2,499 grams = 4 lbs. 7 ozs. - 5 lbs. 8ozs. 2,500 - 2,999 grams = 5 lbs. 9 ozs. - 6 lbs. 9ozs. 3,000 - 3,499 grams = 6 lbs. 10 ozs. - 7 lbs. 11ozs. 3,500 - 3,999 grams = 7 lbs. 12 ozs. - 8 lbs. 12ozs. 4,000 - 4,499 grams = 8 lbs. 13 ozs. - 9 lbs. 14ozs. 4,500 - 4,999 grams = 9 lbs. 15 ozs. - 11 lbs. 0ozs. 5,000 grams or more = 11 lbs. 1 oz. or more RATES Absolute counts of births and deaths do not readily lend themselves to analysis and comparison between years and various geographic areas because of differences in population characteristics (e.g., age, sex, and race). In order to account for such differences, the absolute number of events is converted to a relative number such as a percentage, rate, ratio, or index. These conversions are made by relating the number of events to the population at risk in a particular area at a specified time. Precautions should always be taken when comparing any rates based on vital events. Both the number of events and the characteristics of the population are important to take into account when interpreting a rate. All statistics are subject to random variation.1 Rates based on a relatively small number of events tend to be subject to more random variation than rates based on a large number of events. In addition to the problem of small numbers, demographic characteristics of populations (i.e., age, race and sex) can affect the comparability of rates. Since mortality rates vary substantially by age, race and sex, comparisons between rates from populations that differ in these characteristics could be misleading. However, there are two methods that can be used separately or in combination to improve the comparability of mortality rates. The first method involves comparing rates for specific age, race, and/or sex groups in the populations of interest. With this method, the rates are easily calculated and very specific groups may be compared. However, when very specific groups are compared the numbers are often small, and relationships between the overall populations are difficult to determine. The second method is a more sophisticated technique that statistically "adjusts" for demographic differences between populations and allows direct comparisons between overall population rates. The major disadvantages of adjusted rates are that they can be cumbersome to calculate without the aid of a computer and they only have meaning when compared to other rates adjusted in the same manner. RACE All Delaware vital records contain an item(s) regarding race. Race is self-reported in all records except on death certificates where it is provided by an informant. Although the question allows for a free form response, all race data are grouped for purposes of data analysis into the following categories established by NCHS: White Black American Indian/Aleut/Eskimo Chinese Japanese Hawaiian Asian and Pacific Islander Other Filipino Other Asian or Pacific Islander Other The categories Chinese, Japanese, Hawaiian, Filipino, and Other Asian or Pacific Islander can be combined to form the category Asian or Pacific Islander. For purposes of this report, American Indian/Aleut/Eskimo, Chinese, Japanese, Hawaiian, Filipino, Other Asian or Pacific Islander, and Other have been combined to form the category Other. In the case of death, race of decedent from the death certificate is reported in all tables except in the birth cohort (see next paragraph). However, in the case of birth and fetal death, race is indicated on the birth and fetal death certificates for the mother and father only (i.e., race of the newborn is not given). Consequently, birth and fetal death data are reported by race of the mother in most tables throughout this report. However, some tables containing historical birth data prior to 1989 are reported by race of child. For these tables, race of child was imputed using criteria established by NCHS. In the birth cohort section of this report, birth certificate data for infants dying in the first year of life are combined with information from their death certificates. Therefore, data are available for race of the mother and race of the deceased infant for each case. In the vast majority of these cases, the race listed for the mother and infant are the same. However, in a small number of cases the race of the mother and infant differ. In order to maintain consistency with data in the natality section, race of the mother is used for all tables in the birth cohort section. HISPANIC ORIGIN Beginning in 1989, a specific question regarding Hispanic origin was added to the birth and death certificates. This question is considered to be separate from the Race question. Therefore, a person may report Hispanic origin in combination with any race category. The Hispanic question has two parts. The first simply asks whether the person is of Hispanic origin (Yes or No). The second part is a free-form item that asks for the specific origin (e.g., Cuban, Mexican, Puerto Rican, etc.). MISSING INFORMATION REGARDING FATHERS The Delaware vital statistics law specifies that information regarding the father should not be entered on the birth certificate if the mother is single. As such, there is no information regarding the father for the vast majority of births to single mothers. However, in a few cases, information about the father was entered on the certificate when the mother was single. Some tables in the natality section (e.g., births to parents of Hispanic origin) may contain information regarding the father that includes such cases. Beginning on January 1, 1995, a new program was instituted to allow fathers to acknowledge paternity through completion of a simple form in cases where the mother and father are not married. This form can be completed at any time up to the child’s eighteenth birthday. When such acknowledgments are completed at the hospital at the time of birth, the DHSC is able to add father information to its electronic data base. SOURCE OF PAYMENT FOR DELIVERY Beginning with the 1991 data year, the Center began obtaining information regarding the source of payment for delivery on birth certificates (private insurance, Medicaid, and self pay). However, this information was not available for Delaware resident mothers giving birth in other states (approximately 5 percent of all resident births). For purposes of this report, all such mothers were assigned to the private insurance category. This assignment was based on detailed analyses of the characteristics of these mothers. These analyses indicated that the demographic characteristics of these mothers very closely matched the characteristics of Delaware resident mothers who gave birth within the State and had private insurance listed as their source of payment. Furthermore, an examination of Medicaid data indicated that it is extremely rare for Medicaid mothers to give birth out-of-state. METHOD OF DELIVERY The number of cases reported for the category “Vaginal birth after previous C-section” (VBAC) of the METHOD OF DELIVERY question on the birth certificate may represent an undercount. Due to way that the question was worded (see Appendix F), persons completing the form may have sometimes reported VBACs in the “Vaginal” category. The DHSC staff has been working to improve the data quality of this question in two ways. The question has been reworded so that it is much clearer on the Electronic Birth Certificate (EBC). Over 95 percent of all birth certificates were filed through the EBC. For those records that were not filed using the EBC, efforts were made to train the staff about the proper way to complete the question. 2000 POPULATION STANDARD Beginning with the 1999 report, all mortality rates were age-adjusted using the projected 2000 U.S. population standard. All previous versions of the vital statistics report used the 1940 U.S. population standard from the census of the same year. All historical mortality data have been adjusted to the new standard to allow comparisons over time. Comparisons between rates using the old standard and the new standard are not valid and should not be made. A more detailed explanation of the rationale for updating the population standard can be found in a special report from NCHS (Anderson and Rosenberg, 1998). APPENDICES APPENDIX A RANDOM VARIATION In this report, the number of vital events represent complete counts for the U.S., Delaware and county populations. Therefore, they are not subject to sampling error, although they are subject to certain errors in the registration process such as age misreporting. However, the number of events and the corresponding rates are subject to random variation. That is, the rates that actually occurred may be considered as one of a large number of possible outcomes that could have arisen under the same circumstances (National Office of Vital Statistics, 1961). As a result, rates in a given population may tend to fluctuate from year to year even when the health of the population is unchanged. Random variation in rates based on a relatively small number of events, tends to be larger than for rates based upon events that occur more frequently. Delaware rates for some events (e.g., infant deaths) are particularly subject to such variations due to the small number of events that occur by definition in a relatively small population. Therefore, caution should be exercised when drawing conclusions about rates based on small numbers. The issue of random variation was handled in two ways in this report. First, multi-year average rates were reported instead of annual rates. This tended to reduce the effects of random variation since the number of events in a three or five-year period was much larger. Second, tests of statistical significance were used to make comparisons between rates when appropriate. These statistical tests were used to determine the chance that the observed differences would occur in populations with equal rates by random variation alone. The methods used to calculate infant mortality rates are described in Appendix B. APPENDIX B METHODS FOR CALCULATION AND STATISTICAL ANALYSIS OF FIVE-YEAR AVERAGE INFANT MORTALITY RATES Due to the small number of infant deaths in Delaware, slight year-to-year changes in the number of deaths can lead to substantial fluctuations in annual rates. In many cases, this problem makes interpretation of annual rates extremely difficult, if not impossible. Since there is far less random fluctuation in five-year average (FYA) rates, they are much better for assessing the health status of infants in Delaware.2 When rolling FYA rates (e.g., rates for 1980-1984, 1981-1985, and 1982-1986) are used, the patterns of changes in infant mortality over a number of years can be determined. A description of the methods used to calculate the running FYA rates and the statistical methodology used to compare infant mortality rates are described below. FIVE-YEAR AVERAGE INFANT MORTALITY RATES: Running FYA infant, neonatal, and postneonatal mortality rates (see Definitions) were calculated by race for the U.S., Delaware, and Delaware's three counties. The rates (i.e., infant, neonatal, or postneonatal) were computed by dividing the total number of deaths over each five-year period by the total number of live births over the same five-year period and multiplying the result by 1,000. STATISTICAL TESTS: Confidence intervals for rates based on fewer than 100 deaths: Confidence intervals for rates based 100 or more deaths: Comparison of two infant mortality rates - When the number of events for one or both of the rates was less than 100, comparisons between rates were based on the confidence intervals for each. If they overlapped, the difference was not significant. When the number of events for both rates was 100 or more, the following z-test was used to define a significant test statistic: If |z| > 1.96 then the difference between the rates was statistically significant at the 0.05-level. APPENDIX C CREATION OF A LIVE BIRTH COHORT FILE APPENDIX D Comparable category codes for selected causes of infant death. Category codes according to Cause of death ICD-101 ICD-92 Certain intestinal infectious diseases A00-A08 001-008 Septicemia A40-A41 038 All other infectious and parasitic diseases A09-A39,A42-B99 009-033,034.1-037,039-134,136-139,771.3 Endocrine, nutritional and metabolic diseases E00-E88 240-278 Diseases of the nervous system G00-G98 320-359 Diseases of the circulatory system I00-I99 390- 434,436-459 Influenza and pneumonia J10-J18 480-487 All other diseases of the respiratory system J00-J09,J19-J98 034.0,460-479,488-519 Diseases of the digestive system K00-K92 520-579 Renal failure and other disorders of kidney N17-N19,N25,N27 584-589 Other and unspecified diseases of genitourinary system N00-N15,N20-N23,N26, 580-583,590-629 N28-N98 Newborn affected by maternal complication of pregnancy P01 761 Newborn affected by complications of placenta, P02 762 cord, and membranes Disorders related to short gestation and low birth weight, P07 765 not elsewhere classified Slow fetal growth and fetal malnutrition P05 764 Birth trauma P10-P15 767 Intrauterine hypoxia and birth asphyxia P20-P21 768 Respiratory distress of newborn P22 769 Other respiratory conditions originating in perinatal period P23-P28 770 Infections specific to the perinatal period P35-P39 771.0-771.2,771.4-771.8 All other conditions originating in the perinatal period P00,P03-P04,P08- P09,P16-P19 760-763,772-779 ,P29-P34,P40-P96 Congenital malformations, deformations, and Q00-Q99 740-759 chromosomal abnormalities Sudden infant death syndrome R95 798.0 Other symptoms, signs, and abnormal clinical and lab R00-R53,R55-R94,R96-R99 780-796,798.1-799 findings not elsewhere classified Accidents V01-X59 800-869,880-929 Homicide X85-Y09 960-968 APPENDIX E Comparable category codes for selected causes of death. Category codes according to Cause of death ICD-101 ICD-92 Diseases of the heart I00-I09, I11, I13, I20-I51 390-398, 402, 404, 410-429 Malignant neoplasms C00-C97 140-208 Cerebrovascular diseases I60-I69 430-434, 436- 438 Chronic lower respiratory diseases J40-J47 490-494, 496 Diabetes mellitus E10-E14 250 Influenza and pneumonia J10-J18 480-487 Alzheimer's disease G30 331.0 Nephritis, nephrotic syndrome, and nephrosis N00-N07, N17-N19, N25-N27 580-589 Septicemia A40-A41 038 Intentional self-harm (suicide) U03, X60-X84,Y87.0 E950-E959 Chronic liver disease and cirrhosis K70, K73-K74 571 Assault (Homicide) U01-U02, X85-Y09, Y87.1 E960-E969 Certain conditions originating in the P00-P96 760-771.2, 771.4-779 perinatal period Congenital malformations Q00-Q99 740-759 Human immunodeficiency virus (HIV) B20-B24 042-044 Accidents (unintentional injuries) V01-X59,Y85-Y86 E800- E869, E880-E929 Essential (primary) hypertension and hypertensive renal disease I10, I12 401, 403 Aortic aneurysm and dissection I71 441 Atherosclerosis I70 440 Other diseases of respiratory system J00-J06,J30-J39,J67,J70-J98 034.0,460-465,470-478,495,508-519 Other diseases of circulatory system I71-I78 441-448 Pneumonitis J69 507 Parkinson's disease G20-G21 332 Alcohol-induced deaths F10,G31.2,G62.1,I42.6,K29.2,K70, 291,303,305.0,357.5,425.5,535.3, R78.0,X45,X65,Y15 571.0–571.3,790.3,E860 Drug-induced deaths F11.0–F11.5,F11.7–F11.9,F12.0–F12.5, 292,304,305.2–305.9,E850–E858, F12.7–F12.9,F13.0–F13.5,F13.7–F13.9, E950.0– E950.5,E962.0,E980.0–E980.5 F14.0–F14.5,F14.7–F14.9,F15.0–F15.5, F15.7–F15.9,F16.0–F16.5,F16.7–F16.9, F17.0,F17.3–F17.5,F17.7–F17.9, F18.0–F18.5,F18.7–F18.9,F19.0–F19.5, F19.7–F19.9,X40–X44,X60–X64,X85,Y10–Y14 APPENDIX F STATE OF DELAWARE CERTIFICATE OF LIVE BIRTH APPENDIX F (cont.) STATE OF DELAWARE CERTIFICATE OF LIVE BIRTH STATISTICAL SECTION APPENDIX G STATE OF DELAWARE CERTIFICATE OF DEATH APPENDIX H STATE OF DELAWARE CERTIFICATE OF FETAL DEATH APPENDIX I STATE OF DELAWARE CERTIFICATE OF MARRIAGE APPENDIX J STATE OF DELAWARE CERTIFICATE OF DIVORCE OR ANNULMENT APPENDIX K STATE OF DELAWARE REPORT OF INDUCED TERMINATION OF PREGNANCY REFERENCES Anderson RN and Rosenberg HM. Age Standardization of Death Rates: Implementation of the Year 2000 Standard. National Vital Statistics Reports. Vol. 47(3). Hyattsville, MD: National Center for Health Statistics, 1998. Anderson RN, Minino AM, Hoyert DL, Rosenberg HM. Comparability of Cause of Death Between ICD-9 and ICD-10: Preliminary estimates. National Vital Statistics Reports. Vol 49(2). Hyattsville, Maryland: National Center for Health Statistics. 2001. Callaghan WM, MacDorman MF, Rasmussen S, Cheng Q, Lackritz E. The Contribution of Preterm Birth to Infant Mortality Rates in the United States. Pediatrics. 2006; 118: 1566-1573. Hamilton BE, Martin JA, Ventura SJ. Births: Preliminary data for 2005. National Vital Statistics Reports. Vol 55. Hyattsville, MD: National Center for Health Statistics. Available from: http://www.cdc.gov/nchs/products/pubs/pubd/hestats/prelimbirths05/prelimbirths05 .htm. International Classification of Diseases and Related Health Problems. Tenth Revision, Volume 1. Geneva, World Health Organization, 1992. London Health Observatory. Calculating Life Expectancy and Infant Mortality Rates – Mapping Health Inequalities Across London – technical supplement. September, 2001. Available at http://www.lho.org.uk/Health_Inequalities/Attachments/PDF_Files/tech_supp.pdf. Munson ML, Sutton PD. Births, marriages, divorces, and deaths: Provisional data for 2005. National Vital Statistics Reports. Vol 54 (20). Hyattsville, MD: National Center for Health Statistics. 2006. National Center for Health Statistics. Instruction Manual, Part 11: Computer Edits for Mortality Data, Including Separate Section for Fetal Deaths, Effective 2005. National Center for Health Statistics, Hyattsville, MD. October 2004. National Center for Health Statistics. Instruction Manual, Part 12: Computer Edits for Natality Data, Effective 1993. National Center for Health Statistics, Hyattsville, MD. March 1995. National Office of Vital Statistics, C.L. Chiang. Standard Error of the Age- Adjusted Death Rate. Vital Statistics-Special Reports. Vol. 47, No. 9. Public Health Service. Washington, D.C., Aug. 1961. Ventura, SJ, Taffel, S, and Mosher, WD Estimates of Pregnancies and Pregnancy Rates for the United States, 1976-1981. Public Health Reports. 100(1): 31-34, 1985. 1See Appendix A for more details. 2See Appendix A for a description of random variation and rationale for use of five-year average rates.