Unequal Sample Research Articles

Measurements and medication data are indispensable for population blood pressure monitoring

Abstract Background The National Study on Health of Older People in Germany “Gesundheit 65+” included blood pressure (BP) measurements at home by a study nurse and classification of all current medication. Methods Nationally representative examination survey of the population aged 65 years and older residing in Germany using two-stage population registry sampling from 128 sample points, with a standardized examination at home from June 2022 to April 2023. Three standardized blood pressure measurements at two-minute intervals were taken after 5 minutes rest with an oscillometric device (Mobil-O-Graph) using one of five cuffs according to upper arm circumference. The mean of the second and third measurement was used for analysis. Hypertension was defined as mean systolic BP (SBP) at or above 140 mmHg, or mean diastolic BP (DBP) at or above 90 mmHg, or the use of antihypertensives (antihypertensives, diuretics, beta-blockers, calcium-channel blockers, ACEI and ARB) in participants with self-reported hypertension diagnosis. Provisional weights account for unequal sampling and participation probabilities. Results The “Gesundheit 65+” examination part included 1,493 participants of whom 1,475 (98.8%) had successful BP measurements (763 men and 712 women, aged 66 to 101 years). Based on self-reported diagnoses alone, the prevalence of hypertension would be 58.3% [95% CI 53.2-63.3] in men and 59.5% [53.8-64.9] in women. However, overall hypertension prevalence was estimated at 70.4% [65.8-74.7] in men and 72.3% [66.9-77.1] in women based on the study definition which combines self-reported diagnoses, standardized BP measurements and medication. Conclusions The prevalence of hypertension is greatly underestimated in the absence of examination survey data with standardized measurements and recording of medication use. In addition, measurement and medication data are needed for monitoring the hypertension cascade, i.e. awareness, treatment and control of hypertension. Key messages • Hypertension prevalence is underestimated in the absence of health examination surveys with measurements and medication data. • The hypertension cascade, i.e. assessment of awareness, treatment and control of hypertension needs population surveys with measurements and medication assessment.

Statistical inference and data analysis for inverted Kumaraswamy distribution based on maximum ranked set sampling with unequal samples

A very useful modification to ranked set sampling (RSS) that allows a larger set size without significantly increasing ranking errors is the maximum ranked set sampling with unequal samples (MRSSU) approach. This article covers the parameter estimation of the inverted Kumaraswamy distribution using MRSSU and RSS designs. The maximum likelihood and Bayesian estimation techniques are considered. The regarded Bayesian estimation technique is determined in the case of non-informative and informative priors represented by Jeffreys and gamma priors, respectively. Squared error and minimum expected are the two loss functions that are employed. We presented a simulation study to evaluate the performance of the recommended estimations using root mean squared error and relative bias. The Bayes point estimates were computed using the Metropolis–Hastings algorithm. Additional conclusions have been made based on actual geological data regarding the intervals between Kiama Blowhole’s 64 consecutive eruptions. Based on the same number of measured units, the results of simulation and real data analysis showed that MRSSU estimators performed much better than their RSS counterparts.

Readers' Comprehension of New Text Formats. Part I. Empirical Evidence from Russian and Research Methodology Behind It

In this article, we review a range of Russian-language studies investigating readers’ interaction with new text formats. We identify the key problems preventing proper generalization of such research data. These include: (1) the absence of agreed terminology for describing texts of new formats shared by most researchers, and (2) the lack of consistency in theoretical approaches for describing cognitive mechanisms underpinning processing of these types of texts by readers. The following factors further complicate comparison and systematization of the data obtained by different research groups: (1) the lack of explicitly described theoretical bases of the hypotheses formulated by researchers, (2) the lack of consistency in describing the putative connections between such theoretical backgrounds and empirically tested hypotheses, (3) heterogeneity of methodological approaches, (4) insufficient, unequal or unbalanced sample sizes, (5) low reliability of statistical approaches and tools used for data analysis, as well as (6) research artefacts confounding the results.

Pairwise likelihood estimation and limited-information goodness-of-fit test statistics for binary factor analysis models under complex survey sampling.

This paper discusses estimation and limited-information goodness-of-fit test statistics in factor models for binary data using pairwise likelihood estimation and sampling weights. The paper extends the applicability of pairwise likelihood estimation for factor models with binary data to accommodate complex sampling designs. Additionally, it introduces two key limited-information test statistics: the Pearson chi-squared test and the Wald test. To enhance computational efficiency, the paper introduces modifications to both test statistics. The performance of the estimation and the proposed test statistics under simple random sampling and unequal probability sampling is evaluated using simulated data.

The Bahadur representations of quantile estimators in general unequal probability sampling

In this study, we establish the Bahadur representations of quantile estimators based on the Hájek and the Horvitz–Thompson estimators for the population distribution function in unequal probability sampling designs under general conditions. We also present the asymptotic normality of the above quantile estimators. The simulation studies using real data confirm the validity of the asymptotic normality.

Analysis of dependent complementary competing risks data from a generalized inverted family of lifetime distributions under a maximum ranked set sampling procedure with unequal samples

This paper explores analysis of a dependent complementary competing risks model when the failure causes are distributed by the proposed generalized inverted family of lifetime distributions. Under maximum ranked set sampling with unequal samples (MRSSU), statistical inference of model parameters and reliability indices is discussed under classical frequentist and Bayesian approaches, respectively. Maximum likelihood estimators along with their existence and uniqueness are obtained for model parameters, and associated approximate confidence intervals are constructed in consequence. Bayesian estimation is also performed with respect to general flexible priors, and the Markov Chain Monte Carlo (MCMC) algorithm is proposed for complex posterior computation. The study further examines classical and Bayesian estimations with order restriction of parameters when additional historical information is available in the MRSSU scenario. Finally, the performance of different results is evaluated through numerical simulations and a real data example is presented for demonstrating the application of our methods.

Weighted exponential parameters estimation using maximum ranked set sampling with unequal samples

The two-parameter weighted exponential distribution exhibits various intriguing characteristics and is a powerful tool for analyzing skewed datasets. This study focuses on enhancing the efficiency of parameter estimation for the scale and shape parameters of the weighted exponential distribution. We investigate several estimators utilizing maximum ranked set sampling with unequal samples (MaxRSSU) for the aforementioned parameters. A comparison is made between the estimators obtained through MaxRSSU and those derived from simple random sampling (SRS). Our numerical findings demonstrate that the estimators obtained through MaxRSSU outperform their SRS counterparts significantly in terms of efficiency. Furthermore, we provide a practical illustration by applying our approach to a real dataset.

Frequentist Prediction Sets for Species Abundance using Indirect Information

Abstract Citizen science databases that consist of volunteer-led sampling efforts of species communities are relied on as essential sources of data in ecology. Summarising such data across counties with frequentist-valid prediction sets for each county provides an interpretable comparison across counties of varying size or composition. As citizen science data often feature unequal sampling efforts across a spatial domain, prediction sets constructed with indirect methods that share information across counties may be used to improve precision. In this article, we present a nonparametric framework to obtain precise prediction sets for a multinomial random sample based on indirect information that maintain frequentist coverage guarantees for each county. We detail a simple algorithm to obtain prediction sets for each county using indirect information where the computation time does not depend on the sample size and scales nicely with the number of species considered. The indirect information may be estimated by a proposed empirical Bayes procedure based on information from auxiliary data. Our approach makes inference for under-sampled counties more precise, while maintaining area-specific frequentist validity for each county. Our method is used to provide a useful description of avian species abundance in North Carolina, USA based on citizen science data from the eBird database.

Statistical power and optimal design for randomized controlled trials investigating mediation effects.

Mediation analyses in randomized controlled trials (RCTs) can unpack potential causal pathways between interventions and outcomes and help the iterative improvement of interventions. When designing RCTs investigating these mechanisms, two key considerations are (a) the sample size needed to achieve adequate statistical power and (b) the efficient use of resources. The current study has developed closed-form statistical power formulas for RCTs investigating mediation effects with and without covariates under the Sobel and joint significance tests. The power formulas are functions of sample size, sample allocation between treatment conditions, effect sizes in the treatment-mediator and mediator-outcome paths, and other common parameters (e.g., significance level, one- or two-tailed test). The power formulas allow us to assess how covariates impact the magnitude of mediation effects and statistical power. Accounting for the potential unequal sampling costs between treatment conditions, we have further developed an optimal design framework to identify optimal sample allocations that provide the maximum statistical power under a fixed budget or use the minimum resources to achieve a target power. Illustrations show that the proposed method can identify more efficient and powerful sample allocations than conventional designs with an equal number of individuals in each treatment condition. We have implemented the methods in the R package odr to improve the accessibility of the work. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Intentional learning establishes multiple attentional sets that simultaneously guide attention.

One of the key human cognitive capabilities is to extract regularities from the environment to guide behavior. An attentional set for a target feature can be established through statistical learning of probabilistic target associations; however, whether an array of attentional sets of predictive target features can be established during intentional learning, and how they might guide attention, is not known yet. To address these questions, we had human observers perform a visual search task where we instructed them to try to use color to find their target shape. We structured the task with a fine-grained statistical regularity such that the target shapes appeared in different colors with five unique probabilities (i.e., 33%, 26%, 19%, 12%, and 5%) while we recorded their electroencephalogram. Observers rapidly learned these regularities, evidenced by being faster to report targets that appeared in higher probability colors. These effects were not due to unequal sample sizes or simple feature priming. More importantly, equivalent speeding across a set of high-probability colors suggests that the brain was driving attention to multiple targets simultaneously. Our electrophysiological results showed larger amplitude N2 posterior contralateral component, indexing perceptual attention, and late positive complex (LPC) component, indexing postperceptual processes, for targets paired with high-probability colors. These electrophysiological data suggest that the learned attentional sets change both perceptual selection and how postperceptual decisions are made. In sum, we show that multiple attentional sets can be established during intentional learning that accompanies general task acquisition and that these attentional sets can simultaneously guide attention by enhancing both perceptual attention and postperceptual processes. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Insights into tuberculosis burden in Karachi, Pakistan: A concurrent adult tuberculosis prevalence and child Mycobacterium tuberculosis infection survey.

Pakistan is one of the five highest tuberculosis burden countries globally. We estimated prevalence of adult bacteriologically confirmed pulmonary tuberculosis and annual risk of Mycobacterium tuberculosis (M. tuberculosis) infection in children aged 2-4 years in Karachi, Pakistan. The survey design enabled exploration of tuberculosis burden by whether the population had previously been exposed to widespread tuberculosis active case-finding (ACF) activities or not. We conducted a concurrent adult pulmonary tuberculosis prevalence survey and a child M. tuberculosis infection survey using interferon gamma release assays in four districts (Korangi, South, West and Central). A cluster-based unequal probability random sampling method was employed with the a priori plan to oversample Korangi district which had been the focus of tuberculosis ACF activities since 2011. We defined Korangi district as the 'prior ACF' zone and remaining districts as the 'no prior ACF' zone. Between March 2018 and May 2019, 34,962 adults (78·5% of those eligible) and 1,505 children (59·9%) participated. Overall estimated prevalence of bacteriologically confirmed pulmonary tuberculosis was 387 cases per 100,000 population (95% CI 276-498) with a prevalence of 421 cases [95% CI 276-567] per 100,000 in the 'no prior ACF' and 279 cases [95% CI 155-403] per 100,000 in the 'prior ACF' zone. We estimated the annual risk of M. tuberculosis infection in children to be 1·1% (95% CI 0·7-1·5) in the 'no prior ACF' zone and 0·6% (95% CI 0·3-1·1) in the 'prior ACF' zone. We observed consistent differences in the population distribution of tuberculosis between the 'prior ACF' and 'no prior' ACF zones with a trend towards lower estimates of burden and M. tuberculosis transmission in the 'prior ACF' zone. A plausible explanation is that intensive ACF activities that have been ongoing in Korangi district for the preceding years have noticeably reduced the burden of tuberculosis and transmission.

Prevalence and predictors of HIV testing among young men in Papua New Guinea: A cross-sectional analysis of a nationally representative sample.

HIV testing is an important component of HIV prevention and serves as a gateway to other HIV-related services. However, the uptake remains suboptimal among young people, particularly in highly prevalent settings such as Papua New Guinea (PNG). This study aimed to assess the prevalence and determine the predictors of HIV testing uptake among young men aged 15-24 years in PNG. The 2016-2018 PNG Demographic and Health Survey (DHS) data was used. A total of 1,275 young men aged 15-24 years were included in the final analysis. Descriptive, bivariate, and multivariable logistic regression analyses were performed to determine independent predictors of HIV testing. Adjusted odds ratios (AORs) with 95% confidence intervals (CIs) were reported. All analyses were adjusted using survey weights to account for unequal sampling probabilities. The overall prevalence of HIV testing among young men was 17.1% (95% CI: 15-19). Of those who were tested for HIV, about one-third (32.9%) had experienced a sexual debut at age <15 years, and 33.9% inconsistently used condoms during sex. In multivariable analysis, men aged 20-24 years (AOR 1.18, 95% CI: 1.00-2.31), who owned mobile phones (AOR 1.43, 95% CI: 1.00-2.55), who were aware that consistent condom use during sex can reduce HIV risk (AOR 2.18, 95% CI: 1.18-4.04), who had paid for sex (AOR 1.75, 95% CI: 1.01-5.83), and who had two or more sexual partners (AOR 1.37, 95% CI: 1.01-3.14) had increased odds of HIV testing. However, decreased odds of HIV testing were found among men who were never married (AOR 0.51, 95% CI: 0.29-0.88), lived in rural areas (AOR 0.54, 95% CI: 0.32-0.92), and consistently used condoms during sex (AOR 0.59, 95% CI: 0.34-1.01). The findings show that HIV testing is low among young men in PNG. To increase HIV testing uptake among young men, it is crucial to implement comprehensive youth-friendly HIV/STI education and tailored sensitization programs and enable more accessible and affordable HIV testing services. Also, outreach and community-based testing programs for young men in rural and prioritized areas requiring urgent prevention interventions are feasible options in PNG.

General weighted extropy of minimum and maximum ranked set sampling with unequal samples

. In industrial, environmental, and ecological investigations, ranked set sampling is a sample method that enables the experimenter to use the whole range of population values. The ranked set sampling process can be modified in two extremely helpful ways: maximum ranked set sampling with unequal samples and minimum ranked set sampling with unequal samples. They permit an increase in set size without too many ranking errors being introduced. In this article, we are defining general weighted extropy (GWJ) of minimum and maximum ranked set samples when samples are of unequal size (minRSSU and maxRSSU, respectively). Stochastic comparison and monotone properties have been studied under different situations. Additionally, we compare the extropy of these two sampling data with that of ranked set sampling data and simple random sampling data. Bounds of GWJ of minRSSU and maxRSSU have been obtained. Finally, we investigate the weighted discrimination information between simple random sampling, ranked set sampling, and minimum and maximum ranked set sampling with unequal sample sizes. Some results for equality of GWJ of minRSSU and maxRSSU under symmetric assumption are also obtained.

Data-Driven Batch Process Monitoring for Continuous Annealing of Cold-Rolled Strip Steel

The continuous annealing process (CAP) is a crucial process of steel production, which has a significant impact on the uniformity and stability of mechanical properties. A novel batch monitoring process based on kernel dissimilarity (KDISSIM) and Kmeans++ is proposed in this paper, focusing on problems such as unequal sample lengths between batches and nonlinearity between variables. First, KDISSIM is used to describe the dissimilarity between batches. Secondly, Kmeans++ is employed to improve the accuracy of clustering tasks based on historical batches. The largest cluster is considered to be at a relatively stable control level, and these batches are further used as training data. Then, the center batch and boundary batch of the training set are used as the reference batch and monitoring threshold for the monitoring model, respectively. Finally, the effectiveness of the proposed method is verified via the actual CAP data, providing a feasible solution for CAP batch monitoring.

A class of nonparametric tests for the two-sample problem based on order statistics

In this paper, a new class of distribution-free statistics based on order statistics from two independent samples is introduced to test the equality of two continuous distributions. The null distributions are obtained, and the symmetry property of the proposed test statistics is studied. The exact power functions of the new class of tests under the Lehmann alternative family are derived. Extensions of the proposed class of test statistics to situations with unequal sample sizes are discussed. We also study the power performance of the proposed test under the location-shift and scale-shift alternatives using Monte Carlo simulations. We observe that the power performance of the new class of test procedures is comparable to some commonly used nonparametric tests under various scenarios, which indicates that the new class of test procedures can be a good alternative to those classic nonparametric tests for the two-sample problem.

Diversity on the American Academy of Orthopaedic Surgeons National Meeting Podium: Changes Over Two Decades.

There has been an increase in diversity initiatives regarding selecting speakers for the American Academy of Orthopaedic Surgeons (AAOS) annual meeting and courses. The purpose of this study was to determine the percentage of female or underrepresented minority (URM) speakers for instructional course lectures (ICLs) and AAOS courses over the past 2 decades including a surrogate for expertise. For 2002, 2012, and 2022, the academic and demographic information of speakers and the number of publications at the time of their speaking role were obtained and compared by sex and URM status. Owing to the unequal sample sizes between male versus female cohorts and URM versus non-URM cohorts, the Welch t -test was used. The percentage of ICL and AAOS course speakers who were female increased over time (ICL, AAOS courses): 2002 (2.6%, 3.3%), 2012 (3.9%, 6.3%), and 2022 (11.8%, 15.5%) ( P < 0.001, P < 0.001). The percentage of female AAOS fellows in these years was 2.9%, 4.7%, and 7.4%, respectively. For ICLs and AAOS course speakers, female presenters had fewer publications than male counterparts (ICL, AAOS courses): 2002 ( P < 0.001, P = 0.048), 2012 ( P = 0.003, P < 0.001), and 2022 ( P < 0.001, P < 0.001). For ICLs in 2022, URM speakers had a similar number of publications compared with non-URM speakers. In 2022, URMs comprised 6.9% of ICL speakers and 4% of AAOS fellows. For 2022 ICLs, there were no significant differences in academic institution, position, or region when compared by sex or URM status. For AAOS courses, the percentage of URM speakers increased over time: 2002 (1.1%), 2012 (4.5%), and 2022 (8.6%). For AAOS courses, URM presenters had similar publications compared with non-URM presenters in 2002 and 2022 but less in 2012 ( P = 0.027). The percentage of women and URMs presenting ICLs and AAOS courses has increased over the past 2 decades and exceeded the percentage they represent in the AAOS by over 50%. The female cohort has fewer publications, on average, than the male cohort for all years evaluated, indicating no institutional bias against female speakers.

Family Relationship and Attitude towards Children with Disability among Households with Children living with Disability in Southeast Nigeria: Implication to Sustainable Development

Disability has come to stay with humanity and now placing demand on our technological, scientific, spirituality and humanitarian management prowess and capability in adapting and managing it as global community. However, there are different levels and contexts at which people living with disability are highlighted and practically require our cooperation and assistance, which included family setting. In sub-Saharan Africa and other developing nations, families with children living with disability have found it a difficult task to meet the needs of these ones especially the children. This study investigated the relationship challenges faced by children living with disability among their siblings in southeast Nigeria among households with children living with disability. The study applied cross-sectional survey design; one hundred and eighteen (118) adolescent participants that have at least one sibling with any form of physical disability took part in the study, while attitude towards disabled sibling scale developed by the researchers using some adaptations from the Attitude Scale of Parents towards their mentally retarded children (Govender, 2002). A 2 x 3 x 2 Analysis of Variance (Three-way ANOVA) technique from unequal sample size was used to analyze the data. According to the major findings, there is significant interaction of birth order and Parental level of Education (PLoE) on attitude of siblings towards their physically disabled brother/sister, F(1,108)=7.568, p

Inference of Constant-Stress Model of Fréchet Distribution under a Maximum Ranked Set Sampling with Unequal Samples

Inference of Constant-Stress Model of Fréchet Distribution under a Maximum Ranked Set Sampling with Unequal Samples

The safety effect of increased pedestrian protection, autonomous emergency braking for pedestrians and bicyclists on passenger cars, and speed management

This was the first retrospective study to estimate the effect of increased pedestrian protection, autonomous emergency braking, and speed management to reduce serious injuries among pedestrians and bicyclists. More specifically, the aim was to estimate the injury mitigating effects of the following interventions: AEB with pedestrian and bicyclist detection, Euro NCAP pedestrian test score, active bonnet, traffic calming at pedestrian and bicycle crossings, and additionally, the combined effect of the above-mentioned treatments. The main source of data was the Swedish traffic data acquisition system (Strada), where information of road traffic crashes between passenger cars and pedestrians or bicyclists for the period 1 January 2003–31 December 2022 was obtained. Cars with optional fitment of AEB systems were identified, and the license registration number was used to access individual car equipment lists to identify whether the vehicle was equipped with AEB with pedestrian and/or cyclist detection. Information about traffic calming at pedestrian and bicycle crossings was obtained from the Swedish Transport Administration. The injury metric used was risk of permanent medical impairment (RPMI) of at least one percent and ten percent. RPMI captures the risk of long-term medical impairment based on a diagnosed injury location and Abbreviated Injury Severity (AIS) score. The relative difference between the mean values of RPMI (mRPMI1%+ and mRPMI10%+) was calculated and tested using an independent two sample t-test which was conducted for unequal sample sizes and variance. Although many results were found to be statistically non-significant, the following results were found to be significant at least at 90% level. Pedestrian mRPMI10%+ was reduced by 44% in speed zones ≤ 50 km/h comparing the group struck by cars equipped with AEB with pedestrian detection compared to the group struck by cars without the system. For cyclists, the mRPMI10%+ was reduced by 35% in speed zones ≤ 50 km/h. For crashes within ± 20 meters from a pedestrian or bicycle crossing, the AEB system reduced 60% of pedestrians mRPMI10%+ at crossings with good safety standard compared to crossings of poor safety standard. The comparison of cars with poor performance (1–9 points) in the NCAP pedestrian test and cars with a high score (28–36 points) showed that pedestrian mRPMI10%+ was reduced by 48% across all speed limits, and by 64% including only those aged ≤ 64 years. For bicyclists, a significant reduction of cyclist mRPMI10%+ was found comparing low scoring cars to high scoring cars in ≤ 30 km/h speed limit (-73%) and across all speed limits (-36%). Including only those aged ≤ 64 years, the reduction was 49%. For the active bonnet, a significant reduction of mRPMI1%+ by 24% was observed but given that the rate of helmet wearing was higher in the group struck by cars with active bonnet, this difference cannot be attributed to an effect of an active bonnet. The STA safety rating of pedestrian and bicycle crossings showed that overall pedestrian mRPMI1%+ was reduced by 15%, while cyclists mRPMI10%+ was reduced by 32% comparing crossings of high safety level to crossings of poor safety level. The analysis of combined interventions showed that the total reduction of pedestrians and cyclists mRPMI10%+ together was 69%, from 6.4% to 2%. This paper demonstrates that a road environment with adapted infrastructure and speed, combined with passenger car technologies that improve the safety for vulnerable road users, can create significant reductions of serious (long-term) injuries among pedestrians and bicyclists.

Evaluation of 278 New Bluephase Style Light Curing Units Purchased Over Six Years.

This study measured 278 new curing lights (LCUs) to determine if they met the manufacturer's specifications. Over a 6-year period, the light output from 278 Bluephase Style LCUs was measured before the LCUs were given to students (41 in 2017, 44 in 2018, 46 in 2019, 48 in 2020, 50 in 2021, and 49 in 2022). The radiant exitance (mW/cm²) from each year was compared using ANOVA and Tukey- Kramer multiple comparisons test with adjustment for the unequal sample sizes (α=0.05). The results were also compared against the manufacturer's stated radiant exitance of 1200 mW/cm². The 278 LCUs delivered an average (± standard deviation) radiant exitance of 1203 ± 16.7 mW/cm². The lowest radiant exitance was 1149 mW/cm² and the highest was 1257 mW/cm². Although there were statistically significant differences in the LCUs from each year, these values were within the manufacturer's tolerance of values of ± 10%. Approximately 13% of the emitted light was below 420 nm, and 87% was above 420 nm. These new LCUs were all multiple peak LCUs that emitted an average radiant exitance of 1,203 mW/cm² (range 1149 to 1257 mW/cm². Purchasers of the Style LCU can be confident that their new LCU will meet the manufacturer's specifications.