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Journal of Neuromuscular Diseases 2021Careful quantitative analysis of histological preparations of muscle samples is crucial to accurate investigation of myopathies in man and of interpretation of data from... (Review)
Review
Careful quantitative analysis of histological preparations of muscle samples is crucial to accurate investigation of myopathies in man and of interpretation of data from animals subjected to experimental or potentially therapeutic treatments. Protocols for measuring cell numbers are subject to problems arising from biases associated with preparative and analytical techniques. Prominent among these is the effect of polarized structure of skeletal muscle on sampling bias. It is also common in this tissue to collect data as ratios to convenient reference dominators, the fundamental bases of which are ill-defined, or unrecognized or not accurately assessable. Use of such 'floating' denominators raises a barrier to estimation of the absolute values that assume practical importance in medical research, where accurate comparison between different scenarios in different species is essential to the aim of translating preclinical research findings in animal models to clinical utility in Homo sapiens.This review identifies some of the underappreciated problems with current morphometric practice, some of which are exacerbated in skeletal muscle, and evaluates the extent of their intrusiveness into the of building an objective, accurate, picture of the structure of the muscle sample. It also contains recommendations for eliminating or at least minimizing these problems. Principal among these, would be the use of stereological procedures to avoid the substantial counting biases arising from inter-procedure differences in object size and section thickness.Attention is also drawn to the distortions of interpretation arising from use of undefined or inappropriate denominators.
Topics: Animals; Histological Techniques; Humans; Muscle, Skeletal
PubMed: 34511511
DOI: 10.3233/JND-210736 -
Medical Decision Making : An... 2010Denominator neglect is the focus on the number of times a target event has happened (e.g., the number of treated and nontreated patients who die) without considering the...
BACKGROUND AND OBJECTIVE
Denominator neglect is the focus on the number of times a target event has happened (e.g., the number of treated and nontreated patients who die) without considering the overall number of opportunities for it to happen (e.g., the overall number of treated and nontreated patients). In 2 studies, we addressed the effect of denominator neglect in problems involving treatment risk reduction where samples of treated and non-treated patients and the relative risk reduction were of different sizes. We also tested whether using icon arrays helps people take these different sample sizes into account. We especially focused on older adults, who are often more disadvantaged when making decisions about their health.
DESIGN
. Study 1 was conducted on a laboratory sample using a within-subjects design; study 2 was conducted on a nonstudent sample interviewed through the Web using a between-subjects design.
OUTCOME MEASURES
Accuracy of understanding risk reduction.
RESULTS
Participants often paid too much attention to numerators and insufficient attention to denominators when numerical information about treatment risk reduction was provided. Adding icon arrays to the numerical information, however, drew participants' attention to the denominators and helped them make more accurate assessments of treatment risk reduction. Icon arrays were equally helpful to younger and older adults.
CONCLUSIONS
Building on previous research showing that problems with understanding numerical information often do not reside in the mind but in the representation of the problem, the results show that icon arrays are an effective method of eliminating denominator neglect.
Topics: Adult; Aged; Aged, 80 and over; Analysis of Variance; Bias; Communication; Decision Support Techniques; Female; Health Education; Health Literacy; Humans; Male; Mathematics; Middle Aged; Risk; Risk Reduction Behavior; Statistics as Topic; Visual Perception; Young Adult
PubMed: 20484088
DOI: 10.1177/0272989X10369000 -
Pakistan Development Review 1977
Topics: Asia; Asia, Southeastern; Bangladesh; Birth Rate; Demography; Developing Countries; Fertility; Maternal Age; Mortality; Pakistan; Population; Population Dynamics; Population Growth; Research; Statistics as Topic
PubMed: 12260625
DOI: No ID Found -
The Journal of Family Planning and... Jul 2016Presenting risk information to patients is an important part of clinical encounters. Good risk communication improves patient satisfaction with their care and the... (Review)
Review
OBJECTIVES
Presenting risk information to patients is an important part of clinical encounters. Good risk communication improves patient satisfaction with their care and the decisions they make. In sexual and reproductive healthcare (SRH), women frequently need to make decisions based on their perceived risk. Risk perception can be altered by how actual risk is presented to patients.
METHODS
Databases were searched using MeSH terms combined with a keyword search for articles relevant to SRH; the search was limited to English language.
RESULTS
Personalised risk communication where a risk score is provided, increases knowledge and slightly increases uptake of screening tests. Decision aids improve a patient's knowledge of the options, create realistic expectations of their benefits and harms, reduce difficulty with decision-making, and increase participation in the process. The most effective way to present risks uses a range of structured, tailored presentation styles; interactive formats are best. Framing the information improves patient understanding. Most people understand natural frequencies or event rates better than probability formats with varying denominators. Expressing changes in risk as an absolute risk reduction or relative risk reduction with baseline risk formats improves understanding. Descriptive terms such as 'low risk' or 'high risk' should be quantified as a frequency rather than a percentage. Using a consistent denominator to portray risk is recommended. Using the 'number needed to treat' and visual aids puts benefits or risks into perspective. The duration of risk should be presented.
CONCLUSION
Presenting risk information to patients can be optimised using a number of strategies.
PubMed: 27267797
DOI: 10.1136/jfprhc-2012-100301 -
The HIV care cascade in sub-Saharan Africa: systematic review of published criteria and definitions.Journal of the International AIDS... Jul 2021The HIV care cascade examines the attrition of people living with HIV from diagnosis to the use of antiretroviral therapy (ART) and suppression of viral replication. We... (Review)
Review
INTRODUCTION
The HIV care cascade examines the attrition of people living with HIV from diagnosis to the use of antiretroviral therapy (ART) and suppression of viral replication. We reviewed the literature from sub-Saharan Africa to assess the definitions used for the different steps in the HIV care cascade.
METHODS
We searched PubMed, Embase and CINAHL for articles published from January 2004 to December 2020. Longitudinal and cross-sectional studies were included if they reported on at least one step of the UNAIDS 90-90-90 cascade or two steps of an extended 7-step cascade. A step was clearly defined if authors reported definitions for numerator and denominator, including the description of the eligible population and methods of assessment or measurement. The review protocol has been published and registered in Prospero.
RESULTS AND DISCUSSION
Overall, 3364 articles were screened, and 82 studies from 19 countries met the inclusion criteria. Most studies were from Southern (38 studies, 34 from South Africa) and East Africa (29 studies). Fifty-eight studies (71.6%) were longitudinal, with a median follow-up of three years. The medium number of steps covered out of 7 steps was 3 (interquartile range [IQR] 2 to 4); the median year of publication was 2015 (IQR 2013 to 2019). The number of different definitions for the numerators ranged from four definitions (for step "People living with HIV") to 21 (step "Viral suppression"). For the denominators, it ranged from three definitions ("Diagnosed and aware of HIV status") to 14 ("Viral suppression"). Only 12 studies assessed all three of the 90-90-90 steps. Most studies used longitudinal data, but denominator-denominator or denominator-numerator linkages over several steps were rare. Also, cascade data are lacking for many countries. Our review covers the academic literature but did not consider other data, such as government reports on the HIV care cascade. Also, it did not examine disengagement and reengagement in care.
CONCLUSIONS
The proportions of patients retained at each step of the HIV care cascade cannot be compared between studies, countries and time periods, nor meta-analysed, due to the many different definitions used for numerators and denominators. There is a need for standardization of methods and definitions.
Topics: Africa, Eastern; Cross-Sectional Studies; Delivery of Health Care; HIV Infections; Humans; South Africa
PubMed: 34292649
DOI: 10.1002/jia2.25761 -
Canadian Family Physician Medecin de... Jan 1985It is usually impossible to determine the size of a primary care practice for use as a denominator in calculating rates of morbid and other events within a practice....
It is usually impossible to determine the size of a primary care practice for use as a denominator in calculating rates of morbid and other events within a practice. Although this denominator problem has been a major hurdle for primary care researchers, its nature and significance are not broadly appreciated. This article describes the need for a denominator, defines the term 'practice population', outlines the need for the practice population as a valid denominator, and identifies the areas in which the practice population is the denominator of choice.
PubMed: 21279144
DOI: No ID Found -
Sports Medicine (Auckland, N.Z.) Jun 1992The term incidence is interpreted in many different ways in the literature. Running injury epidemiology should include denominator-based incidence rates, in which the... (Review)
Review
The term incidence is interpreted in many different ways in the literature. Running injury epidemiology should include denominator-based incidence rates, in which the number of new injuries observed during 1 year is related to the population of runners at risk. In 10 studies with denominator-based incidences selected from the literature, the annual incidence rates of injured runners vary from 24 to 65%. Comparison of denominator-based incidence rates from different studies requires a discussion of the denominator and of the numerator; i.e. the study population and the definition of running injury. Injury definitions differ from one study to another. Study populations are particular subgroups of the total running population and they differ from one study to another. Subgroups may differ in origin: volunteers, runners from a mailing list or entrants of a road race. Incidence rates are higher among supervised volunteers than among listed runners, and higher among both these groups than among race-entrants. The choice from the universe of the running population and the used injury definition are methodological issues. Incidence is dependently associated with the prevalence of predisposing running injury factors. There is consistent epidemiological support for the role of a few aetiological factors; i.e. higher mileage per week, previous running injury, higher running speed and lesser running experience. Higher mileage per week is probably the strongest predictor. In the selected injury studies, mileage per week differs from one study population to another. Differences in mileage per week do not explain differences in incidence rate between these studies. In conclusion, caution must be taken when comparing annual incidence rates of different studies. Methodological issues are at least as important as aetiological factors. Study populations may refer to different selections of the universe of the running population. The lengths of observation periods and 'running injury' definitions may differ from one study to another.
Topics: Epidemiology; Humans; Incidence; Risk Factors; Running
PubMed: 1615258
DOI: 10.2165/00007256-199213060-00004 -
Research in Sports Medicine (Print) Jul 2012Accurate documentation of injury incidence is critical for study of injury risk factors and prevention. Comparisons of published incidences of anterior cruciate ligament... (Review)
Review
Accurate documentation of injury incidence is critical for study of injury risk factors and prevention. Comparisons of published incidences of anterior cruciate ligament (ACL) injuries and surgical reconstructions are difficult, however, because of the variations in units. Some studies report absolute time-based denominators (such as annual incidence or incidence per 100,000 person years), whereas others report exposure-based denominators (such as incidence per 1,000 player hours or athlete exposures). We converted exposure-based units into annual incidences to compare various studies. National population studies show annual incidence rates of up to 0.05% per person per year in Australia. Professional athletes in basketball, soccer, and the other football codes report an annual incidence of 0.15%-3.7% in studies with at least a moderate sample size. Annual ACL incidence in amateur sporting groups was generally higher than the entire population but lower than among professional athletes. Converting incidence rates to annual units allowed better comparisons to be made between population rates across different studies.
Topics: Anterior Cruciate Ligament; Anterior Cruciate Ligament Injuries; Anterior Cruciate Ligament Reconstruction; Athletic Injuries; Cohort Studies; Female; Humans; Male; Military Personnel
PubMed: 22742074
DOI: 10.1080/15438627.2012.680633 -
MDM Policy & Practice 2018A 2nd edition of has now been published by a group of medical decision-making experts known collectively as the 2nd Panel. This is a critical review of the...
A 2nd edition of has now been published by a group of medical decision-making experts known collectively as the 2nd Panel. This is a critical review of the recommendations for how to deal with costs in cost-effectiveness analysis, recommendations that are contained in Chapter 8 of that edition, titled "Estimating Costs and Valuations of Non-Health Benefits in Cost-Effectiveness Analysis," authored primarily but not exclusively by Anirban Basu. This review focuses on the correspondence between the costs in the numerator of the incremental cost-effectiveness ratio (ICER) and what is measured in the denominator of the ICER by the quality-adjusted life years (QALYs). Although it raises a number of issues regarding what is actually being measured in the numerator and denominator of the ICER, it primarily challenges the 2nd Panel's recommendation that the costs of non-health consumption in any additional years of life generated by the intervention in question be accounted for in the numerator, even though no measures of the benefits are included in the QALYs in the denominator. This review is adapted from a review of the entire 2 edition that was sent to the 2 Panel steering committee on January 8, 2016.
PubMed: 30288440
DOI: 10.1177/2381468318765162 -
Journal of Global Health Dec 2020Accurate estimation of intervention coverage is a vital component of malaria program monitoring and evaluation, both for process evaluation (how well program targets are... (Review)
Review
BACKGROUND
Accurate estimation of intervention coverage is a vital component of malaria program monitoring and evaluation, both for process evaluation (how well program targets are achieved), and impact evaluation (whether intervention coverage had an impact on malaria burden). There is growing interest in maximizing the utility of program data to generate interim estimates of intervention coverage in the periods between large-scale cross-sectional surveys (the gold standard). As such, this study aimed to identify relevant concepts and themes that may guide future optimization of intervention coverage estimation using routinely collected data, or data collected during and following intervention campaigns, with a particular focus on strategies to define the denominator.
METHODS
We conducted a scoping review of current practices to estimate malaria intervention coverage for insecticide-treated nets (ITNs); indoor residual spray (IRS); intermittent preventive treatment in pregnancy (IPTp); mass drug administration (MDA); and seasonal malaria chemoprevention (SMC) interventions; case management was excluded. Multiple databases were searched for relevant articles published from January 1, 2015 to June 1, 2018. Additionally, we identified and included other guidance relevant to estimating population denominators, with a focus on innovative techniques.
RESULTS
While program data have the potential to provide intervention coverage data, there are still substantial challenges in selecting appropriate denominators. The review identified a lack of consistency in how coverage was defined and reported for each intervention type, with denominator estimation methods not clearly or consistently reported, and denominator estimates rarely triangulated with other data sources to present the feasible range of denominator values and consequently the range of likely coverage estimates.
CONCLUSIONS
Though household survey-based estimates of intervention coverage remain the gold standard, efforts should be made to further standardize practices for generating interim measurements of intervention coverage from program data, and for estimating and reporting population denominators. This includes fully describing any projections or adjustments made to existing census or population data, exploring opportunities to validate available data by comparing with other sources, and explaining how the denominator has been restricted (or not) to reflect exclusion criteria.
Topics: Chemoprevention; Cross-Sectional Studies; Female; Humans; Insecticide-Treated Bednets; Insecticides; Malaria; Mass Drug Administration; Mosquito Control; Pregnancy
PubMed: 33110575
DOI: 10.7189/jogh.10.020413