the descriptive epidemiologic variable age is related to:

Table 3 presents age at HPV vaccine series initiation and proportion of series initiators who completed the series, stratified by adolescent age and sex. However, for descriptive questions designed to inform public-health planning for secondary or tertiary prevention measures, prevalence might be the most relevant measure of occurrence, as it reflects the population of people who might access those services. Rates of stomach cancer also vary among countries. As the overall population becomes more elderly, there would be an increase in Alzheimer's due to age alone. For example, rates are the standard measure of incidence used for notifiable diseases, where health departments count case reports to get the numerator and use midyear census estimates for the denominator. What is Descriptive Epidemiology? | Kent MPH/EPI The graph shows that prior to 1978 there were just occasional cases of toxic shock syndrome in the United States. Many descriptive and causal questions are answered using convenience samples without a clear sampling frame (e.g., people recruited using Web-based surveys, frequent clinic attendees, or people who sought medical care in a particular hospital system) and implicitly assume that the study sample is a random sample (perhaps conditional on covariates with known sampling probabilities) of the target population. Location. Additionally, data rely on HIV viral load and CD4 cell-count laboratory tests as a proxy for clinical visits, and the proxy is imperfect (19, 20); thus, we cannot accurately apply the second inclusion criterion for target population membership: linkage to clinical care. (a) Describe the primary statistical methods used to estimate the measure of disease occurrence being targeted; discuss assumptions of that method in light of data limitations (e.g., assumption of independent censoring for people lost to follow-up). Copyright 2023 Johns Hopkins Bloomberg School of Public Health. For our example question, the target population is everyone living in the United States (place) who was aged18 years, was infected and diagnosed with HIV, and attended 1 clinical visit for HIV care with a clinician who was aware of their infection and could prescribe antiretroviral medication (person) before December 31, 2019, and was alive through December 31, 2019 (time). Reasons for gender differences in mortality may include: The target population might be, for example, the population for which we will be providing public health services. However, the NIS-Teen methods are robust and have been used for nearly two decades, and provide a solid framework for assessing adolescent vaccination in the US. As part of this analysis, we compared the frequency of being up-to-date (UTD) for HPV vaccination based on age at first vaccine dose, and compared vaccine uptake epidemiology across multiple socio-demographic measures. Viral suppression is influenced by access to health care and is only possible if people are receiving antiretroviral therapy (except, in rare cases, for elite controllers) (41). (e.g., influenza), Has it changed over the course of days? Failure to suppress viral load below a lower threshold may also be a more sensitive indicator of subsequent morbidity and mortality (2428), but suppression below a higher threshold is more relevant as an indicator of an individuals transmission potential (29, 30), so our choice of threshold may depend on how our results will be used. Example: Our outcome is viral suppression on December 31, 2019, but there is no single, standard threshold for suppression. Inclusion in an NLM database does not imply endorsement of, or agreement with, First, random digit dialing is used to identify households with children aged 1317years, and in eligible households where parental consent is obtained, the parent is surveyed about their adolescents vaccination history. Med 96:875, 1982]. While the proportion of adolescents initiating HPV vaccination at 910years was relatively low, series up-to-date status among these adolescents was consistently high (ranging from 93% to 100% across age- and sex-groups). Permit evaluation of trends in health and disease. Descriptive epidemiology classifies the occurrence of disease according to the variables of person, place, and time. Prevalent outcomes are often not of interest in causal investigations, as temporality is more challenging to determine and reverse causation is a potential problem. Person (Among Whom?) The study describes the distribution of a set of variables, without regard to causal or other hypotheses. HPV vaccine series initiation at 910years of age is low, but younger adolescents have a slightly higher proportion of initiation at this age group, possibly indicating some increased acceptance of this age for vaccination. Walker TY, Elam-Evans LD, Yankey D, Markowitz LE, Williams CL, Mbaeyi SA, Fredua B, Stokley S. National, regional, state, and selected local area vaccination coverage among adolescents aged 1317 years United States, 2017, National and state vaccination coverage among adolescents aged 13 through 17 yearsUnited States , 2010. Achieving a representative sample may involve considerable work and may be very resource-intensive (12). e. all of the above. While the recommendation for HPV vaccination starts at 9years of age, little is known about the epidemiology of vaccination at ages 910years. Statistics and Probability questions and answers, The descriptive epidemiologic variable AGE is related to: Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. Markowitz LE, Dunne EF, Saraiya M, Chesson HW, Curtis CR, Gee J, Bocchini JA, Unger ER. Table 2.2 Types of Variables. Consider a large outbreak of hepatitis A that occurred in Pennsylvania in 2003. Notably, NIS-Teen reports have consistently reported higher vaccination among racial and ethnic minorities compared to white and non-Hispanic/Latino adolescents, and adolescents living below the poverty line compared to at or above poverty.16,1930 The interaction between race/ethnicity and poverty status has been previously been shown to further amplify those differences.31 In this analysis, we confirm that these patterns are also present for age at HPV vaccine series initiation, with higher HPV vaccine uptake at 910years of age for racial and ethnic minorities, and adolescents living below the poverty line, compared to white, non-Hispanic/Latino, and above poverty adolescents. We might use information from the analytical sample to attempt to quantify disease occurrence in the study sample, but we must rely on assumptions to do so (e.g., assuming data are missing at random and imputing missing data or reweighting study participants with complete data). Source: Atlas of Cancer Mortality for U.S. The https:// ensures that you are connecting to the Table 1 presents a summary of adolescent vaccine uptake, stratified by sex, age, history of an 1112year old well-check, poverty status, race, and ethnicity. For valid inferences, the incidence of the outcome in the sample must be able to stand in for the incidence in the target population. Sources Epidemiology, as defined in this lesson, would include which of the following activities? C. Allows comparisons by age, sex, and race. von Elm E, Altman DG, Egger M, et al. Without applying quantitative approaches to generalize data from the sample to the target population, descriptive results will be biased. Nominal- and ordinal-scale variables are considered qualitative or categorical variables, whereas interval- and ratio-scale variables are considered quantitative or continuous variables. To account for socio-demographic characteristics, we used available covariate data on adolescents sex, age, history of 1112year old well visit, poverty status (recoded to at/above poverty and below poverty), race, and Hispanic ethnicity. Except in special cases (e.g., when the selected estimand is the one scale on which effect measure modification is absent), if absolute measures differ between the sample and the target, most contrasts of the outcome across exposure groups in the sample will also be biased for the same contrasts in the target population (causal results will be biased) (1416). Module 3 Flashcards | Quizlet Offord C. How (not) to do an antibody survey for SARS-CoV-2. When looking at age as a continuous variable, standard epidemiological textbooks such as Rothman and Greenland's and many others recommend registering age as precisely as . Parent and provider perspectives on immunization: are providers overestimating parental concerns? Age is a risk factor for cardiovascular disease, but it is unlikely to cause confounding in this particular study, because the mean age is 52.1-52.3 years in all five quintiles. Approximately 1 in 5 primary care professionals indicated they routinely recommend HPV vaccination starting at 9years of age in 2021.17 As this has not become a routinized practice, there still may be some hesitation on the part of both healthcare providers and parents of adolescents. Little is known about the epidemiology of age at HPV vaccination, and the frequency of vaccination occurring at 910years of age. However, that same survey found that an additional 48% of providers were at least somewhat willing to begin recommending HPV vaccine to parents of 910year old adolescents;18 additional support for provider communication around this topic is needed. While there was some catch-up vaccination through adolescence, only 20% of 1317year old had initiated HPV vaccination at 1317years of age (16% [95% CI 15.0%-17.0%] at 1314years, when two doses are required to complete the series, and 4% [95% CI 3.4%-4.4%] at age 1517years). The estimation challenge for descriptive analyses is that we may not completely observe all of the actual outcomes. Prior studies have used plasma HIV RNA levels of <20, <50, <200, or<400 copies/mL (23). 2003-2023 Chegg Inc. All rights reserved. This lack of birth date data makes combining multiple years of NIS-Teen data together, with a focus on adolescent age, difficult, as small differences in timing of surveys and survey year could lead to misclassification. Many, if not all, of the considerations discussed in this framework apply to estimation of valid causal effects in a population, although they may be frequently overlooked. of variables without regard to causal associations . Basic Principles of Epidemiology - Public Health - Merck Veterinary Manual Learn about the veterinary topic of Basic Principles of Epidemiology. While the effect of this on coverage estimates leads only to minor differences, it is important to point out that our analysis specifically focused on vaccination related to specific timepoints in the HPV vaccine recommendations. Principles of Epidemiology | Lesson 1 - Section 1 - Centers for Disease A well-defined descriptive question aims to quantify and characterize some feature of the health of a population and must clearly state: 1) the target population, characterized by In this paper, we propose a framework for thinking through the design and conduct of descriptive epidemiologic studies. Different measures of occurrence will provide different pictures of what is happening in the world. PDF Descriptive Epidemiology - University of South Florida A well-defined question should be stated with enough specificity and clarity that answering it is at least theoretically possible. A well-defined question specifies the target population a priori. Age at initiation of human papillomavirus vaccination among US adolescents, stratified by key sociodemographic characteristics, national immunization survey-2020. For example, when describing temporal trends for the incidence of HIV diagnoses since the beginning of the epidemic in the 1980s, there will be people who were not born (not at risk for the outcome) in the 1980s who should be counted in the target population in the 2010s.

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