Selection bias on prevalence. Medical search. Frequent questions

The actual incidence and prevalence of müllerian anomalies in the general population are unknown. (medscape.com)
Other factors that affect reporting irregularities in incidence and prevalence rates include nonstandardization of classification systems, nonuniform diagnostic modalities, and different study populations of women. (medscape.com)
Low back pain (LBP) is a common health problem among adults of working age population, and its prevalence or incidence increases with increasing in age. (springer.com)
The purpose of this review was to examine the real-world prevalence or incidence of LBP. (springer.com)
The prevalence and incidence of LBP ranged from 1.4 to 20.0% and 0.024-7.0%, respectively. (springer.com)
The results of this study highlighted there is a substantial difference within studies that estimated the prevalence and incidence of LBP. (springer.com)
The previous published reviews of prevalence and incidence of LBP studies were focused on evaluating peer-reviewed journals conducted via population-based longitudinal and cross-sectional designs. (springer.com)
Since it will take several decades until the effects of HPV vaccines on cervical cancer incidence will be visible, monitoring of HPV prevalence and genotype distribution prior to, and after vaccine introduction is essential to evaluate the short-term impact of HPV vaccination in a population. (biomedcentral.com)
The global incidence and prevalence of MDRTB is unknown. (bmj.com)
Atrial fibrillation is associated with substantial morbidity and mortality and both its incidence and prevalence are high. (revespcardiol.org)
Screening initiatives undertaken in Sweden showed a steep decrease in prevalence of chlamydial infections followed by decreasing incidence of reported PID and ectopic pregnancy. (bmj.com)
Advances in epidemiology of the different subgroups, including data on incidence and/or prevalence, increasing age at presentation and stagnating diagnostic delay are reported. (ersjournals.com)
Despite this high prevalence of PFO in the general population, and the relatively common occurrence of venous gas bubbles in diving and altitude exposures, the incidence of Type II DCS in diving or with altitude is remarkably low. (who.int)
Whilst the availability of incidence and prevalence data in IPF has greatly improved over the years, little information is available for other ILDs [ 10 ]. (springer.com)

Impact that the coronavirus (COVID-19) pandemic has had on data collection, how this has influenced estimates of smoking prevalence and the comparability of these estimates. (ons.gov.uk)
Data from the OPN were not affected by a change in survey mode during the coronavirus pandemic and are the next best alternative source for estimating smoking prevalence as the estimates are consistent with those published previously. (ons.gov.uk)
Estimates of Human Papillomavirus (HPV) prevalence in a population prior to and after HPV vaccine introduction are essential to evaluate the short-term impact of vaccination. (biomedcentral.com)
Nevertheless, study sample selection and attrition over time can bias associations between variables, generating potentially biased estimates for genetic associations. (cdc.gov)
The prevalence estimates were generally higher among female than male HCPs. (bmj.com)
In the present paper we discuss the effects of insufficient or imprecise age data on estimates of undernutrition prevalence. (uc3m.es)
Although prevalence estimates were well established in previous studies, more recent data on sex and age are needed to inform intervention design. (who.int)
Title : State-level Estimates of Childhood Obesity Prevalence in the United States Corrected for Report Bias Personal Author(s) : Long, Michael W.;Ward, Zachary J.;Resch, Stephen C.;Cradock, Angie L.;Wang, Y. Claire;Giles, Catherine M.;Gortmaker, Steven L. (cdc.gov)

The objectives of this article are to demonstrate that the obesity paradox may be explained by collider stratification bias and to estimate the biasing effects of unmeasured common causes of cardiovascular disease (CVD) and mortality on the observed obesity-mortality relationship. (nih.gov)
The survey was not designed to estimate the prevalence of sexual harassment or assault at field sites. (wikipedia.org)
We aimed to collate the literature on acute stroke and frailty to estimate the prevalence of pre-stroke frailty and its associations with outcomes. (gla.ac.uk)
The aim of this study was to estimate the prevalence of atrial fibrillation in Spain. (revespcardiol.org)
To estimate the prevalence of spine postural deviations in Brazilian schoolchildren. (bvsalud.org)
Even performing the meta-analysis separated by subgroups according to the spine region, the heterogeneity level it was up to 90%, it is not possible to perform the meta-analysis to estimate the prevalence of spine postural deviations in Brazilian schoolchildren. (bvsalud.org)

Objective: To determine the prevalence of respiratory symptoms and make an awareness about the harmful effects of ores dust in the Artisanal miner in the city of Lubumbashi, Katanga province, in the Democratic Republic of the Congo (DRC). (scirp.org)
This study consisted of the following 4 objectives: 1) to elucidate the growth patterns of each dural venous sinus from birth to 20 years of age, 2) to compare the mean size of each dural venous sinus among ages, 3) to compare the prevalence of persistent prenatal sinuses among ages, and 4) to determine the prevalence of transverse sinus-dominance patterns among ages. (ajnr.org)

The present study aimed to assess the prevalence and characteristics of child sexual abuse (CSA) in a large-scale sample of Slovak late adolescents. (researchgate.net)
Objectives To assess the consultation prevalence of musculoskeletal (MSK) conditions as presented in different healthcare systems, and to determine the feasibility of comparing prevalence figures between nations. (bmj.com)
This study aimed to accurately assess the cryptorchidism prevalence in the general population of Rotterdam. (eur.nl)
The aim of this study was to assess the prevalence of and the risk factors for E. vermicularis infestation in preschool children in north West Bank. (who.int)

Because the response rates to the glucose tolerance component were under 50 percent, attention to Section B regarding nonresponse bias is strongly urged. (cdc.gov)
Section IV presents an overview of the interview and examination response rates, a summary of nonresponse bias analysis, and application of imputation to adjust for item nonresponse. (cdc.gov)

On the other hand, systematic error or bias reflects a problem of validity of the study and arises because of any error resulting from methods used by the investigator when recruiting individuals for the study, from factors affecting the study participation (selection bias) or from systematic distortions when collecting information about exposures and outcomes (information bias) . (karger.com)
In view of the latest survival data confirming poor outcomes of SSc-associated PH 15 , the need to accurately measure its prevalence and identify the subset of patients at highest risk has become pressing. (jrheum.org)
Collider bias threatens the validity of study results by distorting relationships between exposures and outcomes. (cdc.gov)
Increased implementation of evidence-based community-level and clinic-level interventions, such as universal alcohol screening and brief counseling in primary and prenatal care, could decrease the prevalence of drinking during pregnancy, which might ultimately reduce the prevalence of FASDs and other adverse pregnancy and birth outcomes. (cdc.gov)

Conclusions A rigorous methodological approach allowed feasible comparison of MSK consultation prevalence between England and Sweden. (bmj.com)
In part this has been due to methodological problems including the absence of longitudinal studies to detect trends, the failure to differentiate primary and acquired drug resistance in studies, the selection bias of many surveys, and the absence of high quality culture facilities. (bmj.com)
Finally, the benefits of registries and methodological aspects are discussed, including immortal time bias, registry data quality and recommendations from EU organisations (EUCERD and PARENT). (ersjournals.com)
Two independent reviewers realized the study selection, evaluated the methodological quality and the risk of bias and extracted data. (bvsalud.org)

Methods: The prevalence of respiratory symptoms and sensitization used. (cdc.gov)

Conclusions: Selection bias towards registered children and underestimation of children's age can lead to an underestimation of the prevalence of undernutrition. (uc3m.es)

Considerable selection bias has impeded the collection of accurate epidemiologic data. (medscape.com)
Our data provide a mechanistic basis for the osimertinib-induced selection of EGFR G724S -mutant clones and a rationale to treat these patients with clinically approved second-generation EGFR inhibitors. (nature.com)
Available data are not adequate to conclude whether this represents an increased prevalence of the JAK2 mutation in the population tested. (cdc.gov)
Two review authors independently assessed the eligibility of studies for inclusion, extracted data from included studies and assessed the risk of bias of the included studies. (unboundmedicine.com)
CDC estimated the prevalence of self-reported current drinking (at least one alcohol drink in the past 30 days) and binge drinking (consuming four or more drinks on at least one occasion in the past 30 days) among pregnant women aged 18-44 years, using 2015-2017 data from the Behavioral Risk Factor Surveillance System (BRFSS). (cdc.gov)
Part of the problem, Waugh observes, is that the publication of prevalence data has become highly politicised, with different interest groups making competing claims in order to support extant agendas: "In general, the industry wants to show low prevalence while public health activists - rather morbidly perhaps - appear to crave high prevalence. (igamingbusiness.com)
There are limited data on the prevalence rate of Metabolic Syndrome (MetS) among college students attending any Historically Black College and University (HBCU), which are mostly attended by young African Americans (AA). (biomedcentral.com)

The prevalence of LBP in high-income countries was estimated at 30.0%, which is higher than low-income countries, 18.0% [ 7 ]. (springer.com)
This study compared the prevalence of depression in older adults living in high-altitude and low-altitude regions, and their association with quality of life (QOL). (frontiersin.org)
The prevalence of depression was 26.9% (95% CI: 23.43-30.37%) in the whole sample of older nursing home residents, with 11.1% (95% CI: 8.01-14.05%) in those living in low-altitude and 59.4% (95% CI: 52.68-66.17%) in those living in high-altitude regions. (frontiersin.org)
Prevalence of any high-risk type was 34.4%, and in 17.4% of all women, more than one genotype was identified. (biomedcentral.com)
We demonstrate a high prevalence of high-risk HPV genotypes in non-vaccinated women living in Germany that can be potentially prevented by vaccination. (biomedcentral.com)
We downgraded evidence due to high risk of selection bias and unclear risk of performance bias in one of two included studies, high heterogeneity and wide CIs crossing the line of no effect for anaemia prevalence and haemoglobin concentration. (unboundmedicine.com)
Waterpipe smoking prevalence was high in southeast London, and users exhibited a different sociodemographic profile to cigarette users. (biomedcentral.com)
2 Samoa has historically reported high rates of chlamydia and gonorrhoea and low rates of HIV and syphilis from cross-sectional antenatal prevalence studies. (who.int)
8 This suggests a persistently high prevalence of STIs, particularly chlamydia, for the past decade. (who.int)

The purpose of this study was to explore the differences between the prevalence and impact factors of adolescent dissociative symptoms (ADSs) by using sex-stratification during the coronavirus disease 2019 (COVID-19) pandemic. (nature.com)
Gender differences in the prevalence and impact factors of dissociative symptoms seem to be significant among adolescents. (nature.com)
Prevalences of work-related asthma symptoms, work-exacerbated asthma and occupational asthma were higher among female healthcare professionals. (bmj.com)

The epidemiology of the depression in older adults has been widely studied, with prevalence ranging between 6.35% ( 6 ) and 60.3% ( 7 ). (frontiersin.org)

This paper describes the prevalence of Chlamydia in 15-29 year old women and men in rural and urban areas, as determined through systematic population based screening organised by the Municipal Public Health Services (MHS), and discusses the implications of this screening strategy for routine implementation. (bmj.com)
Chlamydia prevalence was significantly lower in rural areas (0.6%, 95% CI 0.1 to 1.1) compared with very highly urbanised areas (3.2%, 95% CI 2.4 to 4.0). (bmj.com)
The results of this analysis confirm previously observed trends in Samoa for younger age groups' prevalence of chlamydia and gonorrhoea, and for older age groups' prevalence of hepatitis B and C. But the analysis also unexpectedly found that older age groups (aged 45 and above) are more likely to test positive for syphilis (for years 2014 and 2017). (who.int)

These patterns were also observed for 7-year period consultation prevalences. (bmj.com)
Findings from the WHO study showed that the prevalence of abuse was much lower in industrialized environments than in any other study settings, possibly suggesting that variations of prevalence can be related to cultural and economic differences in the patterns of abuse. (biomedcentral.com)
The prevalence of persistent prenatal sinuses and transverse sinus-dominance patterns was compared across ages. (ajnr.org)
This study therefore aimed to evaluate the prevalence, correlates and patterns of waterpipe users among young people in a diverse ethnic urban area of the UK. (biomedcentral.com)

Bias is any error resulting from methods used by the investigator to recruit individuals for the study, from factors affecting the study participation (selection bias) or from systematic distortions when collecting information about exposures and diseases (information bias) . (karger.com)
using validated methods we have measured the prevalence of symptomatic and asymptomatic coronary heart disease in a sample of 290 men born and still living in East Hertfordshire. (bmj.com)
However, long-term studies on PSCI are scarce and may be influenced by assessment methods and selection bias. (lu.se)
A recent JAMA Guide to Statistics and Methods reviews how collider bias can lead to erroneous inference on causal relationships in clinical and epidemiological studies, potentially leading to incorrect clinical decision making and ineffective public health action. (cdc.gov)
The JAMA Guide to Statistics and Methods considers how collider bias applies to this study. (cdc.gov)

What is Collider Bias? (cdc.gov)
Collider bias occurs when an exposure and an outcome each influence a common third variable and that variable or collider is controlled for by study design or in the analysis (see figure below). (cdc.gov)
Collider bias is different from confounding which occurs when an exposure and an outcome have a shared common cause that is not controlled for. (cdc.gov)
Collider bias is often inadvertently introduced by controlling for a variable that occurs after the exposure. (cdc.gov)
For example, collider bias can be introduced when study participants are systematically different from the population they represent at the beginning of a study or follow up over time. (cdc.gov)
Low response rates or differential loss to follow-up in a study can lead to collider bias because the analysis is limited to a subgroup of the population. (cdc.gov)
Collider bias can make associations appear real when there is not a true causal association in the general population. (cdc.gov)
Collider bias can also dilute or hide underlying true causal associations. (cdc.gov)
If this hypothesis were true, then collider bias may be a concern because the study is restricted to individuals with confirmed COVID-19. (cdc.gov)
The authors of the study addressed the possibility of collider bias from sample selection by showing that ACEI/ARB was not associated with increased susceptibility to COVID-19, indicating that collider bias may not apply in this case. (cdc.gov)
This example illustrates the importance of scoping out study design and analytics and their potential for inducing collider bias and spurious associations. (cdc.gov)
Illustration of Collider Bias. (cdc.gov)
Directed acyclic graph illustrating collider bias between an independent exposure and outcome variable where each influences a third variable, called the "collider. (cdc.gov)

smoking prevalence fell after August and was statistically significantly lower in November (13.5%) and December (12.5%) when compared with August 2020. (ons.gov.uk)
In 223 vaccinated women, prevalence of HPV 16/18 was significantly lower compared to non-vaccinated women (13.9% vs. 22.5%, p = 0.007). (biomedcentral.com)

The metaanalysis of 3818 patients showed a prevalence of precapillary PH of 9% (95% CI 6%-12%) and identified advanced age, longer disease duration, and limited cutaneous disease subset as risk factors for this condition. (jrheum.org)
Between 2010 and 2012 we conducted a population-based cross-sectional study in Germany to determine HPV prevalence, genotype distribution and risk factors for HPV-infection in women aged 20-25 years. (biomedcentral.com)
Prevalence studies of abuse and identification of risk factors provide valuable information for the prevention of violence against women. (biomedcentral.com)
Although its prevalence increases with age and Body Mass Index (BMI), the individual risk factors also vary between races and ethnicities. (biomedcentral.com)

Does selection bias explain the obesity paradox among individuals with cardiovascular disease? (nih.gov)
We use directed acyclic graphs, regression modeling, and sensitivity analyses to explore whether the observed protective effect of obesity among individuals with CVD can be plausibly attributed to selection bias. (nih.gov)

Objectives In anticancer clinical trials, particularly open-label trials, central reviewers are recommended to evaluate progression-free survival (PFS) and objective response rate (ORR) to avoid detection bias of local investigators. (bmj.com)
Therefore, the objective of this study was to evaluate the detection bias in oncological open-label trials by confirming whether local investigators overestimate the PFS and ORR compared with the findings of central reviewers. (bmj.com)

In the non-vaccinated population, HPV prevalence of any type was 38.1%, with HPV 16 (19.5%) being the most prevalent genotype. (biomedcentral.com)

Results Combining primary and secondary care, annual consultation prevalences of any MSK condition (2143 vs 1610/10 000) and low back pain (587 vs 294/10 000) were higher in England than in Sweden, but higher for RA, spondyloarthritis and psoriatic arthritis in Sweden. (bmj.com)

low quality evidence, downgraded due to heterogeneity, bias). (gla.ac.uk)

The quality of the included studies was assessed using a tool that consists of ten items addressing a risk of bias. (springer.com)
All the included studies were assessed to be methodologically sound (low risk of bias). (springer.com)
A review of 56 studies from Walker has also indicated that the point prevalence of LBP was between 12.0 and 33.0% [ 7 ]. (springer.com)
To measure the prevalence of different types of pulmonary hypertension (PH) and to identify patients with systemic sclerosis (SSc) at highest risk in a multicenter European sample, with a metaanalysis of relevant studies. (jrheum.org)
This bias can be magnified in the case of studying phenotypic associations with polygenic risk scores in large scale cohort studies of unrepresentative or highly selected populations, such as the UK biobank , and potentially in the newly launched All of Us Research Program cohort study. (cdc.gov)
Seven studies were at risk of bias, from participant selection or method of frailty assessment. (gla.ac.uk)
Searches were conducted in databases EMBASE, LILACS, PubMed, SCOPUS, SciELO, Science Direct, and Web of Science, as well as manual searches to identify studies that evaluated the prevalence of spine postural deviations in Brazilian schoolchildren. (bvsalud.org)

The 95 % probability intervals and Student's t test were used to evaluate the effect of age bias and error. (uc3m.es)

The internal validity, i.e. the characteristic of a clinical study to produce valid results, can be affected by random and systematic (bias) errors. (karger.com)
However, it is not clear whether the bias has been adequately identified, or to what extent it consistently distorts the results. (bmj.com)

It remains unclear, however, to what extent the prevalence of certain other genotypes will change due to cross-protection or potentially by replacement by other genotypes. (biomedcentral.com)

Differences in prevalence of inflammatory and unspecific pain conditions may be partially explained by known variations in healthcare systems and recording practice. (bmj.com)

Probable first vaccination effects on the HPV prevalence were observed in women who were vaccinated at younger age. (biomedcentral.com)

Published trends and geographical differences in cryptorchidism rates are almost exclusively derived from, hospital-based birth defect registers, which are sensitive to selection bias and incomplete reporting. (eur.nl)
We report the prevalence and gender differences in the components of MetS in a sample population from an HBCU campus. (biomedcentral.com)

The reported prevalence of any lifetime abuse was substantial in our low-risk pregnant population. (biomedcentral.com)

Prevalence rates for MetS criteria varied depending on the definition used. (biomedcentral.com)

LETTERS ing in the Israeli Defense Force con- pertussis toxin were calculated as terized by the same median duration stitute a unique adult population arbitrary ELISA units according to a of cough (14 days), a substantially because of their special living and calibration curve of a serially, double- lower prevalence of pertussis was service conditions. (cdc.gov)
The number of people consulting per 10 000 registered population in primary care, and in primary or secondary care, in the year 2010 (annual consultation prevalence) were determined for doctor-diagnosed osteoarthritis (OA), rheumatoid arthritis (RA), low back pain, and spondyloarthritis including psoriatic arthritis and ankylosing spondylitis (AS). (bmj.com)
Our aim was to investigate the prevalence of self-reported sexual, physical and emotional abuse in a large obstetric population in Norway, and the associations between exposure to adult abuse, socio-demographics and other characteristics. (biomedcentral.com)
The reported prevalence was standardized for the age and sex distribution of the Spanish population. (revespcardiol.org)
This large, population based study found very low prevalence in rural populations, suggesting that nationwide systematic screening is not indicated in the Netherlands and that targeted approaches are a better option. (bmj.com)
There is a higher prevalence of MetS in this study population than any other reports on college students. (biomedcentral.com)

Efforts to expand implementation of community-level interventions and universal alcohol screening and brief counseling might decrease the prevalence of drinking during pregnancy. (cdc.gov)

Bias in selection of the Japanese cohort was considered the most likely explanation. (cdc.gov)
To address possible concerns about selection bias in the main cohort, all of whom underwent ablation, a secondary analysis was conducted with 91 patients with known asymptomatic coronary disease and monomorphic VT storm who were selected from the registry without regard to whether they underwent catheter ablation. (medscape.com)

The Gambling Commission's pilot gambling prevalence survey released this week reports a "problem gambling" rate among adults of 1.3% on the Problem Gambling Severity Index (PSGI). (igamingbusiness.com)

The prevalence of specific IgG was higher in polyurethane (PU) products, such as foams, paints, lacquers, (2-50.4%) and strongly associated with exposure. (cdc.gov)

Annual primary care prevalence figures for OA (176 vs 196/10 000), RA (25 vs 26/10 000), spondyloarthritis (both 8/10 000) and psoriatic arthritis (5 vs 3/10 000) were similar between England and Sweden. (bmj.com)

The fixed anatomy of the DVS system and the prevalence of certain anatomic variations are relatively well-understood. (ajnr.org)

To determine whether low birth weight and low weight at 1 year are followed by an increased prevalence of coronary heart disease in adult life. (bmj.com)

A meta-analysis revealed that the prevalence of depression was 23.6% among older adults in China ( 8 ). (frontiersin.org)

In a subgroup of these patients we identified an association between selection of EGFR T790M -negative but EGFR G724S -positive subclones and osimertinib resistance. (nature.com)

A lower prevalence is expected when information is collected from self-administered questionnaires compared with personal interviews and a higher prevalence with well qualified interviewers, use of structured screen and with repeated questioning [ 7 , 10 , 11 ]. (biomedcentral.com)
Children differ from adults with respect to H pylori infection in terms of the prevalence of the infection, the complication rate, the near-absence of gastric malignancies, age-specific problems with diagnostic tests and drugs, and a higher rate of antibiotic resistance. (medscape.com)

The prevalence of CSA was analyzed separately for three clusters of CSA and gender. (researchgate.net)
Fisher's exact chi-square tests were used to analyze the prevalence of MetS criteria per gender, the number of MetS criteria per BMI category and the prevalence of MetS criteria. (biomedcentral.com)

Minimizing the risk of bias is critical for proper handling of research analyses and, ultimately, developing reliable interventions. (cdc.gov)

The Gambling Commission and the NHS use surveys to make guesses of prevalence - but some guesses are better informed than others. (igamingbusiness.com)

We sought to address this by calculating the prevalence of waterpipe smoking among secondary school students in southeast London. (biomedcentral.com)
Some evidence exists that E. that a prevalence of more than 20% is common in many vermicularis infestation may be a cause of secondary parts of the world (8) . (who.int)

While survival is improving, the prevalence of life-limiting illness and chronic disease in British children is increasing. (bmj.com)

The overall age-adjusted prevalence of atrial fibrillation was 4.4% (95% confidence interval, 3.8-5.1). (revespcardiol.org)

Prevalence of pregnancy-related abuse also varies. (biomedcentral.com)
In a review article from the United States, prevalence of abuse during pregnancy was reported to range from 0.9% to 20.1% [ 7 ]. (biomedcentral.com)

Based on this, smoking prevalence among those aged 16 years or over fell by 1.3% in 2020, compared with 2019. (ons.gov.uk)

Diseases1

Analytical, Diagnostic and Therapeutic Techniques and Equipment20

Phenomena and Processes3

Disciplines and Occupations1

Anthropology, Education, Sociology and Social Phenomena3

Information Science5

Named Groups1

Health Care29

Geographicals6

Incidence14

Estimates8

Estimate6

Determine the prevalence2

Assess4

Nonresponse bias2

Outcomes4

Methodological4

Respiratory symptoms1

Conclusions1

Data7

High9

Symptoms3

Epidemiology1

Chlamydia3

Patterns4

Methods5

Collider13

Significantly lower2

Risk factors4

Obesity2

Objective2

Prevalent1

Combining1

Heterogeneity1

Studies7

Evaluate1

Results2

Extent1

Healthcare1

Younger1

Differences2

Lifetime1

Rates1

Population6

Decrease1

Cohort2

Among adults1

Exposure1

Sweden1

Variations1

Birth1

Depression1

Subgroup1

Higher2

Gender2

Ultimately1

Surveys1

Secondary2

Survival1

Confidence interval1

Pregnancy2

Years1