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T M Ezzati-Rice

Publications and source records attributed to T M Ezzati-Rice.

12 recordsLinked to original sources
PubMed2001

Comparison of NIS and NHIS/NIPRCS vaccination coverage estimates. National Immunization Survey. National Health Interview Survey/National Immunization Provider Record Check Study.

BACKGROUND: The National Immunization Survey (NIS) and the National Health Interview Survey (NHIS) produce national coverage estimates for children aged 19 months to 35 months. The NIS is a cost-effective, random-digit-dialing telephone survey that produces national and state-level vaccination coverage estimates. The National Immunization Provider Record Check Study (NIPRCS) is conducted in conjunction with the annual NHIS, which is a face-to-face household survey. As the NIS is a telephone survey, potential coverage bias exists as the survey excludes children living in nontelephone households. METHODS: To assess the validity of estimates of vaccine coverage from the NIS, we compared 1995 and 1996 NIS national estimates with results from the NHIS/NIPRCS for the same years. RESULTS: Both the NIS and the NHIS/NIPRCS produce similar results. CONCLUSION: The NHIS/NIPRCS supports the findings of the NIS.

Child, Preschool↗
PubMed2001

Forty years and four surveys: how does our measuring measure up?

OBJECTIVE: This article reviews four surveys methodologies that have been used over the past 40 years to assess immunization rates in young children in the United States. These methods include three national surveys: (1) United States Immunization Survey (1959-1985), which was first a household and then a telephone survey; (2) National Health Interview Survey (1991-present), which interviews people in their homes; and (3) National Immunization Survey (1994-present), a random-digit-dialing telephone survey. In addition, a series of retrospective school record surveys that used standard sampling and assessment methodologies were conducted nationally during 4 school years September 1990-May 1991. METHODS: Federal publications, National Immunization Conference proceedings, and Centers for Disease Control and Prevention (CDC) internal reports regarding national immunization surveys were reviewed. The methodology used in each survey is presented, and selected examples of previously tabulated results are presented. CONCLUSIONS: The assessment of immunization coverage in American preschool children requires ongoing commitment and survey expertise. Over the past 40 years the CDC's efforts to determine vaccination coverage in young children has evolved from the comparatively simple United States Immunization Survey to the current National Immunization Survey that utilizes sophisticated statistical and survey techniques to obtain the most-accurate results yet available.

Child↗
PubMed2001

Compensating for provider nonresponse using response propensities to form adjustment cells: the National Immunization Survey.

OBJECTIVES: The National Immunization Survey (NIS) uses two phases of data collection to obtain vaccination information from a sample of young children: a random-digit-dialing (RDD) survey for identifying households with children 19-35 months of age, followed by a mail survey for obtaining provider-reported vaccination histories about these children. Provider-reported vaccination histories are used to estimate vaccination coverage rates. In 1998, provider-reported vaccination histories were not obtained for 32.9% of children with a completed RDD interview. This report describes the statistical methods adopted in 1998 to reduce the bias in vaccination coverage estimates that could result from "vaccination history nonresponse," that is, differences between children for whom provider data was obtained and those for whom it was not obtained. METHODS: In the methods adopted in 1998, children with completed NIS RDD interviews are grouped into adjustment cells defined by their propensity to have adequate provider data. Sampling weights of children with adequate provider data are divided by the cell-specific weighted response rate to allow these children to represent all children in the cell. RESULTS: Using an "optimal" number of cells, the overall extent of bias reduction was 0.5%, suggesting that provider nonresponse bias was small. Authoritative literature suggests using five cells. No statistically significant differences were observed in vaccination coverage estimates when comparing estimates based on the "optimal" number of cells with five cells. Thus, five adjustment cells are used to reduce provider nonresponse bias in the NIS vaccination coverage estimates. No substantively important differences were observed between estimates based on the methodology used prior to 1998 and the methodology adopted in 1998.

Algorithms↗
PubMed2000

National, state, and urban area vaccination coverage levels among children aged 19-35 months--United States, 1998.

PROBLEM/CONDITION: High vaccination levels in the population are necessary to decrease disease transmission and prevent disease; therefore, an important component of the U.S. vaccination program is the assessment of vaccination coverage. Current goals are for > or = 90% coverage with recommended vaccines during the first 2 years of life. REPORTING PERIOD: January-December 1998. DESCRIPTION OF SYSTEMS: The National Immunization Survey (NIS) is an ongoing, random-digit-dialed telephone survey that gathers vaccination coverage data for children aged 19-35 months in all 50 states and 28 urban areas. Vaccination coverage rates derived from NIS data are adjusted statistically for households with multiple telephone lines, household nonresponse, the proportion of households without telephones, and vaccination provider nonresponse. The results were also adjusted to match the known total population of children in each survey area. RESULTS: On the basis of NIS data, national coverage was > or = 90% for three doses of poliovirus vaccine (Polio), three doses of Haemophilus influenzae type b vaccine (Hib), and one dose of measles-containing vaccine (MCV). Coverage was the highest ever reported for four doses of any diphtheria and tetanus toxoids and pertussis vaccine (DTP) (i.e., diphtheria and tetanus toxoids and pertussis vaccine, diphtheria and tetanus toxoids [DT], or diphtheria and tetanus toxoids and acellular pertussis vaccine [DTaP]) (83.9%), three doses of hepatitis B vaccine (Hep B, 87.0%), and one dose of varicella vaccine (43.2%). The number of states achieving the > or = 90% goal was 47 for three doses of Hib, 40 for three doses of Polio, 40 for one dose of MCV, nine for three doses of Hep B, and seven for four doses of DTP. Proportionally fewer urban areas achieved the > or = 90% goal: 23 of 28 for three doses of Hib, 13 for three doses of Polio, 16 for one dose of MCV, five for three doses of Hep B, and one for four doses of DTP. No state or urban area has yet achieved the > or = 90% goal for varicella. INTERPRETATION: Findings from the 1998 NIS indicate that national vaccination coverage levels for routinely recommended childhood vaccines are at the highest levels ever reported. However, substantial variation in coverage remains at the state and urban area levels. PUBLIC HEALTH ACTIONS: The public health community and vaccination providers in areas with low coverage should intensify their efforts to implement recommended strategies for increasing vaccination coverage to ensure that children are equally well protected throughout the United States.

Child, Preschool↗
PubMed1995

A population-based serologic survey of immunity to tetanus in the United States.

BACKGROUND: Vaccination rates are frequently considered a surrogate measure of protection. To provide more accurate estimates, serum levels of antibody against tetanus were measured as part of the third National Health and Nutrition Examination Survey (NHANES III), which studied a representative sample of the civilian, noninstitutionalized population of the United States. METHODS: We measured tetanus antitoxin using a solid-phase enzyme immunoassay in serum samples from 10,618 persons six years of age and older who were examined during phase 1 of NHANES III in 1988 to 1991. RESULTS: Overall, 69.7 percent of Americans six years of age and older had protective levels of tetanus antibodies (> 0.15 IU per milliliter). The rate decreased from 87.7 percent among those 6 to 11 years of age to 27.8 percent among those 70 years of age or older. Among children 6 to 16 years of age, 82.2 percent had protective levels of tetanus antibodies, with little variation according to race or ethnicity. More men than women were immune (79.0 percent vs. 62.4 percent). Mexican Americans had a significantly lower rate of immunity (57.9 percent, P < 0.05) than either non-Hispanic whites (72.7 percent) or non-Hispanic blacks (68.1 percent). Those with a history of military service, higher levels of education, or incomes above the poverty level were more likely to have protective antibody levels. Although the prevalence of immunity declined rapidly starting at the age of 40 years, most of the 107 cases of tetanus (with 20 deaths) reported in 1989 and 1990 occurred in persons 60 years of age or older. CONCLUSIONS: Despite the fact that effective vaccines against tetanus have been available since the 1940s, many Americans do not have immunity to tetanus, and the rates are lowest among the elderly. There is an excellent correlation between vaccination rates (96 percent) and immunity (96 percent) among six-year-olds. However, antibody levels decline over time, and one fifth of older children (10 to 16 years of age) do not have protective antibody levels.

Adolescent↗
PubMed1995

Issues associated with the design of a national probability sample for human exposure assessment.

Data obtained from national probability sample surveys provide important information on the prevalence of various health conditions and distributions of physical and biochemical characteristics of the U.S. population. The sample design of a survey specifies how sampling from a designated population over a stated period is to be accomplished. A survey's analytical objectives and interests--in particular subpopulations--affect the sample design strategy. Selected subdomains of the population often must be oversampled so that estimates can be made with acceptable precision. This article addresses sample design considerations for a national probability sample for human tissue monitoring and specimen banking. Among the sampling issues addressed are the oversampling of special populations e.g., minority groups and at-risk groups such as low income or elderly persons; geographic coverage; and sample size considerations. The sample design for a major health survey, the Third National Health and Nutrition Examination Survey (NHANES III), is used to illustrate a complex, multistage probability sample design and to highlight some of the sampling issues discussed in this article.

Data Collection↗
PubMed1994

Risk behavior and correlates of risk for HIV infection in the Dallas County Household HIV survey.

OBJECTIVES: The Dallas County study of a proposed national household seroprevalence survey was designed to assess the feasibility of conducting a national survey and to estimate the prevalence of human immunodeficiency virus (HIV) and hepatitis B virus infection for Dallas County. Risk behavior data were collected and correlated with HIV infection. METHODS: Participants in this survey represented a probability sample of the county. A self-administered questionnaire on demographic characteristics and HIV risk behavior was completed and a blood sample was obtained. RESULTS: Of the 1724 adults eligible for the survey, 1446 completed the questionnaire and 1374 provided a blood sample. The prevalence estimates were 0.4% for HIV and 7.3% for hepatitis B virus. A strong relationship was observed between HIV and hepatitis B status and risk behavior. CONCLUSIONS: In this study population, receptive anal intercourse and increasing numbers of male partners had the strongest correlation with the prevalence of HIV and hepatitis B virus infection in men. The high level of risk reporting for individuals positive for HIV or hepatitis B suggests that survey participants who engage in risk behaviors were willing to report those behaviors.

Adult↗
PubMed1994

The seroepidemiology of human immunodeficiency virus in the United States household population: NHANES III, 1988-1991.

To provide an estimate of the seroprevalence of human immunodeficiency virus (HIV) in a representative sample of the U.S. household population, serum samples from participants in the third National Health and Nutrition Examination Survey (NHANES III) were tested for HIV antibody. The testing was performed anonymously on 5,430 individuals 18-59 years old from phase 1 of NHANES III conducted from 1988 to 1991. Twenty-nine individuals were HIV positive. The total weighted prevalence was 0.39%. The population estimate of infected individuals was 547,000, with a 95% confidence interval of 299,000-1,020,000 infected persons. Black participants were four times more likely to be HIV positive than white/other individuals and three times more likely than Mexican Americans. Men were three times more likely to be infected than women. Higher nonresponse to the survey and to phlebotomy was observed in young white men; therefore these data provide a conservative estimate of HIV infection in the general household population. This estimate does not include individuals who do not live in households and who may be at higher risk of infection, such as persons in penal institutions, the homeless, or certain hospitalized patients.

Adult↗
PubMedDate not supplied

National Immunization Survey: the methodology of a vaccination surveillance system.

The National Immunization Survey (NIS) was designed to measure vaccination coverage estimates for the US, the 50 states, and selected urban areas for children ages 19-35 months. The NIS includes a random-digit-dialed telephone survey and a provider record check study. Data are weighted to account for the sample design and to reduce nonresponse and non-coverage biases in order to improve vaccination coverage estimates. Adjustments are made for biases resulting from nonresponse and nontelephone households, and estimation procedures are used to reduce measurement bias. The NIS coverage estimates represent all US children, not just children living in households with telephones. NIS estimates are highly comparable to vaccination estimates derived from the National Health Interview Survey. The NIS allows comparisons between states and urban areas over time and is used to evaluate current and new vaccination strategies.

Data Collection↗
PubMedDate not supplied

Vaccine coverage.

Explore the source record for details and available documents.

Child, Preschool↗