Validity and bias in epidemiological research

2021 ◽  
pp. 161-182
Author(s):  
Sander Greenland ◽  
Tyler J. VanderWeele
Keyword(s):  
Competing Risks ◽  
Retrospective Cohort ◽  
Average Risk ◽  
Statistical Interpretation ◽  
Cross Sectional ◽  
Epidemiological Research ◽  
Classification Schemes ◽  
Retrospective Cohort Studies ◽  
Study Designs ◽  
Prediction Problems

Some of the major concepts of validity and bias in epidemiological research are outlined in this chapter. The contents are organized in four main sections: Validity in statistical interpretation, validity in prediction problems, validity in causal inference, and special validity problems in case–control and retrospective cohort studies. Familiarity with the basics of epidemiological study design and a number of terms of epidemiological theory, among them risk, competing risks, average risk, population at risk, and rate, is assumed. Despite similarities, there is considerable diversity and conflict among the classification schemes and terminologies employed in various textbooks. This diversity reflects that there is no unique way of classifying validity conditions, biases, and errors. It follows that the classification schemes employed here and elsewhere should not be regarded as anything more than convenient frameworks for organizing discussions of validity and bias in epidemiological inference. Several important study designs, including randomized trials, prevalence (cross-sectional) studies, and ecological studies, are not discussed in this chapter. Such studies require consideration of the validity conditions mentioned earlier and also require special considerations of their own. A number of central problems of epidemiological inference are also not covered, including choice of effect measures, problems of induction, and causal modelling.

scholarly journals Nationwide cross-sectional survey of patients with relapsing polychondritis in 2019 demonstrates reduction of airway involvement compared with that in 2009

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Jun Shimizu ◽  
Yoshihisa Yamano ◽  
Kimito Kawahata ◽  
Noboru Suzuki
Keyword(s):  
Retrospective Cohort ◽  
Disease Duration ◽  
Relapsing Polychondritis ◽  
Calcineurin Inhibitors ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Age And Gender ◽  
Frequent Use ◽  
Retrospective Cohort Studies ◽  
And Gender

AbstractWe conducted retrospective cohort studies of patients with relapsing polychondritis (RP) twice in 2009 and 2019, using a physician questionnaire. We compared the patients’ clinical statuses between the years. Age and gender were comparable between the two surveys. Mean disease duration was longer in 2019 survey (8.3 years) than that in 2009 survey (4.8 years, P < 0.001). The mortality rate declined in 2019 survey compared with those in 2009 survey (from 9.2 to 1.6%, P < 0.001). Incidence of airway involvement decreased in 2019 survey compared with that in 2009 survey (from 49 to 37%, P = 0.012). In 2019 survey, we found more frequent use of biological agents and immunosuppressants in patients with airway involvement. When we focused on RP patients with airway involvement, physicians in 2019 chose methotrexate and calcineurin inhibitors preferentially, compared with azathioprine and cyclophosphamide. Of note is that increased use of infliximab was observed in RP patients with airway involvement, but not in those without. Reduction of airway involvement and mortality in patients with RP was observed in 2019 survey. The reduction may associate with the frequent use of biologics including infliximab in RP patients with airway involvement.

Nutritional, Metabolic and Endocrine Disorders in Patients with Bipolar Disorder: A Systematic Review

2009 ◽  
Vol 24 (S1) ◽  
pp. 1-1
Author(s):  
E. Vieta ◽  
J. Mostaza ◽  
J. Bobes ◽  
J. Saiz-Ruiz ◽  
F. Rico-Villademoros ◽  
...  
Keyword(s):  
Bipolar Disorder ◽  
General Population ◽  
Retrospective Cohort ◽  
Reference Lists ◽  
Population Based ◽  
Endocrine Disorders ◽  
Cross Sectional ◽  
Medline Search ◽  
Study Designs ◽  
Manual Review

Objective:To evaluate the frequency of nutritional, metabolic and endocrine disorders in patients with bipolar disorder (BD).Methods:A Medline search (up to January 2008) in and manual review of reference lists of relevant primary articles and review articles. All studies in Spanish or English, all study designs, BD diagnosis by any criteria, with a sample size of ≥ 30 patients, and which reported any measure of frequency measure or association.Results:Thirty studies were identified: 18 (60%) cross-sectional and 12 (40%) retrospective cohort; 2 (6.7%) population- based; and 2 (6.7%) random sampling. The frequency of obesity in patients with BD was higher than that of the general population (n=4, 19-53% vs 9-14%), of other medical populations (n=1, 4.6% vs 1.1%) and of patients with schizophrenia (n=1, 11.6% vs 9.9%). The frequency of diabetes in patients with BD was higher than (n=5, 6-26% vs 2-16%) or similar to (n=2, 3.5-4.3% vs 3.4-4.8%) that of the general population; higher than that of other medical samples (n=2, 1.8-4.4% vs 0.6-2.2%) and similar to that in of patients with schizophrenia (n=1, 17.7% vs 17.6%). The frequency of dyslipidaemia was higher than that found in a medical sample (n=1, 0.9% vs 0.3%) and in patients with schizophrenia (n=1, 27% vs 23%). The frequency of hypothyroidism was higher than that of a medical sample (n=1, 10% vs 3%).Conclusion:BD appears to be associated with obesity. It may also be associated with dyslipidaemia and hypothyroidism. Data on the association between BD and diabetes are inconclusive.

scholarly journals Definitions and Prevalence of Multimorbidity in Large Database Studies: A Scoping Review

2021 ◽  
Vol 18 (4) ◽  
pp. 1673
Author(s):  
Ying Pin Chua ◽  
Ying Xie ◽  
Poay Sian Sabrina Lee ◽  
Eng Sing Lee
Keyword(s):  
Scoping Review ◽  
Chronic Conditions ◽  
Meta Analysis ◽  
Epidemiological Studies ◽  
Cross Sectional ◽  
Coding Systems ◽  
Wide Range ◽  
Scoping Reviews ◽  
Retrospective Cohort Studies ◽  
Definition Of

Background: Multimorbidity presents a key challenge to healthcare systems globally. However, heterogeneity in the definition of multimorbidity and design of epidemiological studies results in difficulty in comparing multimorbidity studies. This scoping review aimed to describe multimorbidity prevalence in studies using large datasets and report the differences in multimorbidity definition and study design. Methods: We conducted a systematic search of MEDLINE, EMBASE, and CINAHL databases to identify large epidemiological studies on multimorbidity. We used the Preferred Reporting Items for Systematic Reviews and Meta-analysis Extension for Scoping Reviews (PRISMA-ScR) protocol for reporting the results. Results: Twenty articles were identified. We found two key definitions of multimorbidity: at least two (MM2+) or at least three (MM3+) chronic conditions. The prevalence of multimorbidity MM2+ ranged from 15.3% to 93.1%, and 11.8% to 89.7% in MM3+. The number of chronic conditions used by the articles ranged from 15 to 147, which were organized into 21 body system categories. There were seventeen cross-sectional studies and three retrospective cohort studies, and four diagnosis coding systems were used. Conclusions: We found a wide range in reported prevalence, definition, and conduct of multimorbidity studies. Obtaining consensus in these areas will facilitate better understanding of the magnitude and epidemiology of multimorbidity.

scholarly journals Cross-sectional adherence with the multi-target stool DNA test for colorectal cancer screening in a large, nationally insured cohort

2021 ◽  
Author(s):  
Lesley-Ann Miller-Wilson ◽  
Lila J Finney Rutten ◽  
Jack Van Thomme ◽  
A Burak Ozbay ◽  
Paul J Limburg
Keyword(s):  
Colorectal Cancer ◽  
National Sample ◽  
Adherence Rate ◽  
Average Risk ◽  
Cross Sectional ◽  
Commercial Insurance ◽  
Dna Test ◽  
Crc Screening ◽  
Stool Dna ◽  
Insured Patients

Abstract Purpose Colorectal cancer (CRC) is the second most deadly cancer in the USA. Early detection can improve CRC outcomes, but recent national screening rates (62%) remain below the 80% goal set by the National Colorectal Cancer Roundtable. Multiple options are endorsed for average-risk CRC screening, including the multi-target stool DNA (mt-sDNA) test. We evaluated cross-sectional mt-sDNA test completion in a population of commercially and Medicare-insured patients. Methods Participants included individuals ages 50 years and older with commercial insurance or Medicare, with a valid mt-sDNA test shipped by Exact Sciences Laboratories LLC between January 1, 2018, and December 31, 2018 (n = 1,420,460). In 2020, we analyzed cross-sectional adherence, as the percent of successfully completed tests within 365 days of shipment date. Results Overall cross-sectional adherence was 66.8%. Adherence was 72.1% in participants with Traditional Medicare, 69.1% in participants with Medicare Advantage, and 61.9% in participants with commercial insurance. Adherence increased with age: 60.8% for ages 50–64, 71.3% for ages 65–75, and 74.7% for ages 76 + years. Participants with mt-sDNA tests ordered by gastroenterologists had a higher adherence rate (78.3%) than those with orders by primary care clinicians (67.2%). Geographically, adherence rates were highest among highly rural patients (70.8%) and ordering providers in the Pacific region (71.4%). Conclusions Data from this large, national sample of insured patients demonstrate high cross-sectional adherence with the mt-sDNA test, supporting its role as an accepted, noninvasive option for average-risk CRC screening. Attributes of mt-sDNA screening, including home-based convenience and accompanying navigation support, likely contributed to high completion rates.

Assessing the Feasibility of Retrospective Cohort Studies

1987 ◽  
Vol 12 (4) ◽  
pp. 419-430 ◽  
Author(s):  
Kyle Steenland ◽  
Leslie Stayner ◽  
Alice Greife
Keyword(s):  
Cohort Studies ◽  
Retrospective Cohort ◽  
Retrospective Cohort Studies

Predictors of Psychiatric Morbidity in Cancer Patients

1994 ◽  
Vol 165 (5) ◽  
pp. 593-598 ◽  
Author(s):  
Judy Harrison ◽  
Peter Maguire
Keyword(s):  
Risk Factors ◽  
Cancer Patients ◽  
Psychiatric Morbidity ◽  
Significant Proportion ◽  
Cross Sectional Study ◽  
Future Research ◽  
Cross Sectional ◽  
Appropriate Treatment ◽  
Study Designs ◽  
Patients Experience

BackgroundA significant proportion of cancer patients experience psychiatric morbidity in association with diagnosis and treatment. If this morbidity is to be reduced, a better understanding is needed of the factors which influence adjustment to cancer.MethodA review of the literature was carried out to explore those factors associated with poor psychological adjustment to cancer. These are described under four headings: characteristics of the patient; disease and treatment variables; the interaction between patient and illness; and environmental factors.ResultsA number of risk factors for psychiatric morbidity can be identified from each of the four areas. Methodological limitations are highlighted, in particular the preponderance of cross-sectional study designs.ConclusionsIncreased awareness of the risk factors for psychiatric morbidity should lead to earlier detection and more appropriate treatment. Future research should focus on those risk factors which are potentially modifiable.

Management of Oral Anticoagulation Therapy After Gastrointestinal Bleeding: Whether to, When to, and How to Restart an Anticoagulation Therapy

2017 ◽  
Vol 51 (11) ◽  
pp. 1000-1007 ◽  
Author(s):  
Kazuhiko Kido ◽  
Michael J. Scalese
Keyword(s):  
Gastrointestinal Bleeding ◽  
Cohort Studies ◽  
Oral Anticoagulation ◽  
Retrospective Cohort ◽  
Oral Anticoagulants ◽  
Direct Oral Anticoagulants ◽  
Anticoagulation Therapy ◽  
Cochrane Library ◽  
Oral Anticoagulation Therapy ◽  
Retrospective Cohort Studies

Objective: To evaluate current clinical evidence for management of oral anticoagulation therapy after gastrointestinal bleeding (GIB) with an emphasis on whether to, when to, and how to resume an anticoagulation therapy. Data Sources: Relevant articles from MEDLINE, Cochrane Library, and EMBASE databases were identified from 1946 through May 20, 2017, using the keywords: gastrointestinal hemorrhage or gastrointestinal bleeding and antithrombotic therapy or anticoagulation therapy or warfarin or dabigatran or rivaroxaban or apixaban or edoxaban.Study Selection and Data Extraction: All English-language studies assessing management of oral anticoagulation therapy after GIB were evaluated. Data Synthesis: A total of 9 studies were identified. Four retrospective cohort studies showed that resuming anticoagulation therapy was associated with significantly lower rate of thromboembolism (TE) in the general population. Meta-analyses and prospective cohort studies also supported this finding. Two retrospective cohort studies indicated an increase in GIB when anticoagulation reinitiation occurred in less than 7 days without a decrease in TE. Resuming therapy between 7 and 15 days did not demonstrate a significant increase in GIB or TE. A large retrospective study showed that apixaban was associated with the significantly lowest risk of GIB compared with both rivaroxaban and dabigatran. Conclusion: Anticoagulation therapy resumption is recommended, with resumption being considered between 7 and 14 days following GIB regardless of the therapy chosen. Data for warfarin management after GIB should be applied with caution to direct oral anticoagulants (DOACs) because of the quicker onset and experimental nature of reversal agents. Apixaban may be a preferred option when restarting a DOAC therapy.

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