Successive Occasions Research Articles

Calibration approach-based estimator of population total under successive sampling design

The present article deals with the estimation of the finite population total on two occasions using a calibration approach. The estimators from different approaches on two successive occasions using calibration technique are obtained. Some of the properties of proposed estimators are also provided, including optimum composite weights and their sensitivity interval. An empirical study has been carried out using real data for numerical illustration to show the efficiency of the proposed calibrated estimator. In addition, a simulation study is also performed where proposed estimators are found to be more efficient than the other existing traditional estimators for different choices of tuning weights and composite weights under various sample proportions.

Head-to-head comparison of 68Ga-PSMA-11 PET with 99mTc-MDP bone scan for detection of bone disease in patients with prostate cancer with biochemical progression during ADT: A single center prospective study.

e17072 Background: 68Ga-PSMA-11 PET/CT (PSMA-PET) was approved by the U.S. Food and Drug Administration in patients with prostate cancer (PCa) at primary staging or biochemical recurrence. A head-to-head comparison between PSMA-PET and conventional imaging (99mTc-MDP bone scan [BS] and CT) in men with advanced prostate cancer was not performed. We aimed to compare the detection rate of bone disease for PSMA-PET vs BS in men with PCa and with biochemical progression during androgen deprivation therapy (ADT). Methods: This was a prospective single-center, open-label, single-arm, head-to-head comparison, prospective phase 2 study (NCT04928820). A sample size of 102 men was required to achieve an 80.3% power to detect a difference of 12% positivity rate of bone disease in favor of PSMA-PET vs BS (35% vs 23%). Men with i) biopsy-proved PCa, ii) who had rising PSA levels on 2 successive occasions ≥1 week apart, iii) were receiving treatment with hormonal therapy, iii) and had an absolute PSA value ≥1 ng/ml were eligible. Men who were enrolled received PSMA-PET and bone scan within 30 days. The primary endpoint was detection rate of bone disease for PSMA-PET vs BS. Secondary endpoint was the number of bone lesions detected by PSMA-PET vs BS. Number of lesions was categorized into: 0 vs 1 vs 2 vs 3 vs 4 vs 5 vs > 5. A p value < 0.05 was considered statistically significant. Results: 22 men were enrolled between July 8, 2021 and June 9, 2022. The median patients age was 71 years (range: 56-94). The median time between scans was 12 days (range: 1-29). The median PSA value was 9.5 ng/ml (range: 1.2 – 1717). 11/22 (11%) patients had hormone-sensitive PCa, while 11/22 (50%) had castration-resistant PCa prior to receiving the scans. The positivity rate for bone disease was equal for PSMA-PET and BS in all cases: 7/22 (32%) patients had negative scans on both imaging modalities and 15 (68%) had ≥1 bone lesion detected on both imaging modalities (p = 1.00). In 15/22 (68%) men, both imaging modalities showed equal number of bone lesions: 0 lesions in 7/22 (32%) men and > 5 lesions in 8/22 (36%) men. In 3/22 (14%) men BS showed higher number of lesions, while in 4/22 (18%) men PSMA-PET showed higher number of lesions. No statistical difference was noticed between PSMA-PET and BS in number of bone lesions detected (p > 0.05). The trial was terminated early since these preliminary results gave already a 95% confidence interval of 81-100% for equivalent positivity rate of bone disease between PSMA-PET and BS. Conclusions: In this prospective study of patients with prostate cancer with rising PSA levels under hormonal therapy, 68Ga-PSMA-11 PET and 99mTc-MDP bone scan had similar detection rate for bone disease. Further studies investigating similar comparison between PSMA-PET and BS in clinically-relevant selected patient population are warranted. Clinical trial information: NCT04928820 .

E064 A rare hereditary haemochromatosis type three (3) related arthritis

Abstract Background/Aims Arthritis is a common manifestation in hereditary haemochromatosis (HHC). Haemochromatosis arthropathy frequently involves small joint of hands especially the metacarpo-phalangeal joints (MCPJs) and hence is one of the differentials when assessing for rheumatoid arthritis, psoriatic arthritis along with osteoarthritis but requires a high index of suspicion. We report a case of Haemochromatosis arthropathy where the arthropathy was due to type 3 hereditary haemochromatosis (HHC) which is a much rarer form and requires specialist genetic testing. Methods A 38-year-old lady was referred with abnormal iron profile and ten-month history of small joint arthralgia mainly affecting the index and middle finger in right hand with occasional swelling. She had a normal body mass index with minimal alcohol intake. Clinical examination showed low grade synovitis in index finger metacarpo-phalangeal joint (MCPJ). Blood investigations for Rheumatoid arthritis and connective tissue diseases were negative with normal CRP & ESR, Ferritin was slightly raised at 236 and transferrin saturation was 100% on two successive occasions, LFTs were normal. Xray of hands showed slight narrowing of 2nd MCPJ and US hands showed thickened synovium but no erosions or Doppler activity in 2nd MCPJ. Results Based on these, possible hereditary haemochromatosis (HHC) arthropathy was considered. By that time, she had been seen by the hepatology service where no evidence of iron deposition in other organs was found. Surprisingly her genetic testing for hereditary haemochromatosis (HHC) (Cys282Y/H63D in HFE gene) was negative resulting in most common HFE-related HHC excluded. Iron studies were repeated which were still raised, hence after discussion with hepatologist and biochemist the plan was made to investigate for rarer form of hereditary haemochromatosis (HHC), genetic tests showed that she had TFR2 variant mutation which would be consistent with type 3 hereditary haemochromatosis (HHC), which is inherited in autosomal recessive pattern. Venesections were started with ferritin levels improving to less than 50 with plans to monitor arthralgia to see if there is any improvement over time. Conclusion Metacarpo-phalangeal joints (MCPJs) involvement is common in various arthropathies. This case highlights the importance of considering other, much rarer forms of hereditary haemochromatosis (HHC) as treatment will help in preventing iron deposition in other organs like liver, heart, pancreas etc. These conditions are very rare and there is need to create awareness of genetic testing as hereditary haemochromatosis (HHC) arthropathy does present not uncommonly to rheumatology services and requires dedicated non-HFE molecular panel. Disclosure H. Umair: None. M. Kazmi: None.

Change in prevalence over time and factors associated with depression among Bangladeshi older adults during the COVID-19 pandemic.

Globally, the COVID-19 pandemic seriously affected both physical and mental health conditions. This study aims to assess changes in the prevalence of depression among older adults during the COVID-19 pandemic in Bangladesh and explore the correlates of depression in pooled data. This study followed a repeated cross-sectional design and was conducted through telephone interviews on two successive occasions during the COVID-19 pandemic (October 2020 and September 2021) among 2077 (1032 in 2020-survey and 1045 in 2021-survey) older Bangladeshi adults aged 60 years and above. Depression was measured using the 15-item Geriatric Depression Scale (GDS-15). The binary logistic regression model was used to identify the factors associated with depression in pooled data. A significant increase in the prevalence of depression was noted in the 2021 survey compared to the 2020 survey (47.2% versus 40.3%; adjusted odds ratio (aOR): 1.40, 95% confidence interval (CI): 1.11-1.75). Depression was significantly higher among participants without a partner (aOR 1.92, 95% CI 1.45-2.53), with a monthly family income of <5000 BDT (aOR: 2.65, 95% CI 1.82-3.86) or 5000-10 000 BDT (aOR: 1.30, 95% CI 1.03-1.65), living alone (aOR 2.24, 95% CI 1.40-3.61), feeling isolated (aOR 3.15, 95% CI 2.49-3.98), with poor memory/concentration (aOR 2.02, 95% CI 1.58-2.57), with non-communicable chronic conditions (aOR 1.34, 95% CI 1.06-1.69), overwhelmed by COVID-19 (aOR 1.54, 95% CI 1.18-2.00), having difficulty earning (aOR 1.49, 95% CI 1.15-1.92) or obtaining food (aOR 1.56, 95% CI 1.17-2.09) during COVID-19 pandemic, communicating less frequently (aOR 1.35, 95% CI 1.07-1.70) and needing extra care (aOR 2.28, 95% CI 1.75-2.96) during the pandemic. Policymakers and public health practitioners should provide immediate mental health support initiatives for this vulnerable population during the COVID-19 pandemic and beyond. Policymakers should also invest in creating safe places to practise mindful eating, exercise, or other refuelling activities as a means of preventing and managing depression.

Changes in loneliness prevalence and its associated factors among Bangladeshi older adults during the COVID-19 pandemic.

Worldwide, loneliness is one of the most common psychological phenomena among older adults, adversely affecting their physical and mental health conditions during the COVID-19 pandemic. This study aims to assess changes in the prevalence of loneliness in the two timeframes (first and second waves of COVID-19 in Bangladesh) and identify its correlates in pooled data. This repeated cross-sectional study was conducted on two successive occasions (October 2020 and September 2021), overlapping with the first and second waves of the COVID-19 pandemic in Bangladesh. The survey was conducted remotely through telephone interviews among 2077 (1032 in the 2020-survey and 1045 in the 2021-survey) older Bangladeshi adults aged 60 years and above. Loneliness was measured using the 3-item UCLA Loneliness scale. The binary logistic regression model was used to identify the factors associated with loneliness in pooled data. We found a decline in the loneliness prevalence among the participants in two survey rounds (51.5% in 2021 versus 45.7% in 2020; P = 0.008), corresponding to 33% lower odds in the 2021-survey (AOR 0.67, 95% CI 0.54-0.84). Still, nearly half of the participants were found to be lonely in the latest survey. We also found that, compared to their respective counterparts, the odds of loneliness were significantly higher among the participants without a partner (AOR 1.58, 95% CI 1.20-2.08), with a monthly family income less than 5000 BDT (AOR 2.34, 95% CI 1.58-3.47), who lived alone (AOR 2.17, 95% CI 1.34-3.51), with poor memory or concentration (AOR 1.58, 95% CI 1.23-2.03), and suffering from non-communicable chronic conditions (AOR 1.55, 95% CI 1.23-1.95). Various COVID-19-related characteristics, such as concern about COVID-19 (AOR 1.28, 95% CI 0.94-1.73), overwhelm by COVID-19 (AOR 1.53, 95% CI 1.14-2.06), difficulty earning (AOR 2.00, 95% CI 1.54-2.59), and receiving routine medical care during COVID-19 (AOR 2.08, 95% CI 1.61-2.68), and perception that the participants required additional care during the pandemic (AOR 2.93, 95% CI 2.27-3.79) were also associated with significantly higher odds of loneliness. However, the odds of loneliness were significantly lower among the participants with formal schooling (AOR 0.71, 95% CI 0.57-0.89) and with a family of more than four members (AOR 0.76, 95% CI 0.60-0.96). The current study found a decreased prevalence of loneliness among Bangladeshi older adults during the ongoing pandemic. However, the prevalence is still very high. The findings suggest the need for mental health interventions that may include improving social interactions increasing opportunities for meaningful social connections with family and community members and providing psychosocial support to the vulnerable population including older adults during the pandemic. It also suggests that policymakers and public health practitioners should emphasise providing mental health services at the peripheral level where the majority of older adults reside.

Changes in Prevalence and Determinants of Self-Reported Hypertension among Bangladeshi Older Adults during the COVID-19 Pandemic.

The present study aimed to assess the changes in the prevalence and determinants of self-reported hypertension among older adults during the COVID-19 pandemic in Bangladesh. This repeated cross-sectional study was conducted on two successive occasions (October 2020 and September 2021), overlapping the first and second waves of the COVID-19 pandemic in Bangladesh. The survey was conducted through telephone interviews among Bangladeshi older adults aged 60 years and above. The prevalence of hypertension was measured by asking a question about whether a doctor or health professional told the participants that they have hypertension or high blood pressure and/or whether they are currently using medication to control it. We also collected information on the socio-economic characteristics of the participants, their cognitive ability, and their COVID-19-related attributes. A total of 2077 older adults with a mean age of 66.7 ± 6.4 years participated in the study. The samples were randomly selected on two successive occasions from a pre-established registry developed by the ARCED Foundation. Thus, the sample in the 2021-survey (round two; n = 1045) was not the same as that in the 2020-survey (round one; n = 1031) but both were drawn from the same population. The findings revealed that the prevalence of hypertension significantly increased across the two periods (43.7% versus 56.3%; p = 0.006). The odds of hypertension were 1.34 times more likely in round two than in the round one cohort (AOR 1.34, 95% CI 1.06–1.70). We also found that having formal schooling, poorer memory or concentration, and having had received COVID-19 information were all associated with an increased risk of hypertension in both rounds (p < 0.05). The findings of the present study suggest providing immediate support to ensure proper screening, control, and treatment of hypertension among older adults in Bangladesh.

A tale of osteoarthritis among older adults during the COVID-19 pandemic in Bangladesh: A repeated cross-sectional study.

Due to restrictions in social gatherings imposed due to the COVID-19 pandemic, physical and other daily activities were limited among the older adults. The present study aimed to estimate the change in osteoarthritis prevalence among older adults during the COVID-19 pandemic in Bangladesh. This repeated cross-sectional study was conducted through telephone interviews among older adults aged 60 years and above on two successive occasions (October 2020 and September 2021) during the COVID-19 pandemic in Bangladesh. The prevalence of osteoarthritis was measured by asking the participants if they had osteoarthritis or joint pain problems. A total of 2077 participants (1032 in 2020-survey and 1045 in 2021-survey) participated in the study. The prevalence of self-reported joint pains or osteoarthritis significantly increased from 45.3% in 2020 to 54.7% in 2021 (P = 0.006), with an increasing odd in the adjusted analysis (aOR 1.27, 95% CI 1.04-1.54). We also found that osteoarthritis prevalence significantly increased among the participants from the Chattogram and Mymensingh divisions, aged 60-69 years, males, married, rural residents, and living with a family. A significant increase was also documented among those who received formal schooling, had a family income of 5000-10000 BDT, resided with a large family, were unemployed or retired, and lived away from a health facility. Our study reported a significant increased prevalence of osteoarthritis among older adults from 2020 to 2021 during this pandemic in Bangladesh. This study highlights the need for the development and implementation of initiatives for the screening and management of osteoarthritis through a primary health care approach during any public health emergencies.

Axillary management for early invasive breast cancer patients: Who will truly benefit?

BackgroundThe implementation of sentinel lymph node biopsy (SLNB) and further completion axillary lymph node dissection (cALND) after positive sentinel lymph nodes (SLNs) on early invasive breast cancer patients should be cautiously tailored. Identifying predictors for SLN and non-sentinel lymph node (nSLN) metastases can help surgeons make better surgical decisions.MethodsA retrospective case-control study was designed and a total of 560 eligible patients were enrolled consecutively. They were all diagnosed in our center and received appropriate medical care. According to the metastasis of SLN and nSLN, they were divided into metastatic and non-metastatic groups on two successive occasions to investigate the relationship between clinical factors, pathological factors, hematological factors and lymph node metastasis.ResultsIn total, 101 (18.04%) patients developed SLN metastases, including 98 patients with macro-metastases and 3 patients with micro-metastases. Out of 97 patients receiving further cALND, 20 patients (20.62%) developed nSLN metastases. Multivariate analysis revealed that “high expression of Ki-67” and “lymphatic invasion” predicted a higher risk of SLN metastasis; and “increased number of positive SLNs” and “increased systemic inflammation index (SII)” predicted a higher risk of nSLN metastasis.ConclusionSurgery for early invasive breast cancer patients should be more customized and precise. Appropriate axillary management is necessary for patients with the associated predictors.

A daylength-neutral winged bean (Psophocarpus tetragonolobus) for Southern Australian latitudes

Abstract. Eagleton GE. 2022. A daylength-neutral winged bean (Psophocarpus tetragonolobus) for Southern Australian latitudes. Asian J Agric 6: 68-78. In the summer of 2019, on the central coast of NSW, Australia (at Latitude 34°S), an early-maturing genotype of the tropical legume crop, winged bean (Psophocarpus tetragonolobus (L.) DC.), was detected among a range of late-maturing accessions. The performance of this accession, MY0-01 from Bago in Myanmar, was evaluated in staked plots alongside one other accession from Myanmar and two from the island of New Guinea planted on three successive occasions between October and late November 2020 in a split-plot experiment. Across the three planting dates, the mean number of days from planting to the first open flower for MYO-01 ranged from 68 to 82 + s.e. 3.2 compared with a range of 119 to 167 for the other three accessions. The mean accumulated seed yield of MYO-01 obtained from the October planting equated to 3.1 t ha-1, but by the third planting in late November, the yield was only half as much. Among the four accessions, MYO-01 was second in the amount of lower stem branching and tuber yield, with the smallest pods and hardest seeds. Hard seededness creates difficulties for germination and plant establishment and is a limitation in MYO-01, as are its small pods, which lowers its potential for vegetable production. Investigating genetic control of photoperiod insensitivity in MYO-01 and combining the ability for pod and seed characteristics is relevant to sub-tropical latitudes and for developing stable early maturity cultivars for the tropics.

Inspection of the Production Lot Using Two Successive Occasions Sampling Under Neutrosophy

The efficiency of the measuring tools and operators is a significant part of lot sentencing decisions. These tools have to pass some pre-specified quality levels to avoid problems during the quality assessment scenarios. These measurements have a serious risk to be encountered with any extent of ambiguity, doubt, or indeterminacy due to any of the factors like variation among the operating regimes, warming effects in the hot climatic conditions, the operators’ casual attitude, and so on. These factors as the most significant sources of extraneous variations can deeply affect the efficacy of lot sentencing decisions. Hence, the decision when based on the measurement through the operating tools and these tools have to pass which have fulfilled some adequate standards only then lot sentencing may avoid or save from the rejection of a good lot. The authors have put their focus on dealing with the factors that arise by measuring variability among the measured or determined values despite having the normal population distribution. In this study, the auxiliary information is used to estimate the variable of interest over the two successive occasions under the neutrosophic interval numbers and proved helpful to overcome this issue. The presented approach has discussed that in blurred, doubted, uncertain and undetermined datasets partially or completely, the efficacy of the decision for the whole lot cannot be decided on the single point crisped value. But the range of values around such a single crisp point in the form of neutrosophic theory is proved far better. In this context, the neutrosophic interval number successive sampling-based sampling plan is proposed which is the major contribution to the existing literature. It is explained in terms of operating characteristic function and the plan parameters are determined through the neutrosophic non-linear optimization approach. The comparative analysis is presented with the existing sampling plans and found efficient. Moreover, a real-life industrial dataset is used as an application of the concept.

'We did everything we could': An account of toxic leadership.

The UK government's reckless and incompetent response to Covid-19 has produced an outcome which is amongst the worst in the world, and arguably the worst in terms of deaths per 100,000 population of major countries (especially when one measures mortality from Covid in terms of cause of death on the death certificate, rather than the UK government's own measure-death of a tested individual within 28 days of testing). This article updates my initial analysis in this journal over a year ago, and traces the negligent and shambolic policy-making, and supine official scientific advice, which has led to such a dismal outcome. It does so by examining the policies and approach of the UK government from the begining of the pandemic (in UK terms, January 2020) up to June 2021. All relevant declarations, speeches, decisions, public interviews and policies were noted on a daily basis, examined and critically assessed-along with daily data and information over the whole period on Covid's threat to, and spread across, the UK. On three successive occasions, Boris Johnson and his compliant Ministers acted too late and too weakly to prevent avoidable death and illness. At the time of writing the vaccination programme in the UK has been destabilised by the government-yet again-having failed to secure its borders, this time against the Delta variant (Indian mutation) of the virus. Overall, in terms of border control, quarantine, testing, tracing, isolation and timely and enforced lockdown, the government put short-term, superficial considerations above coherent strategy. It dressed up its incompetence as a superficial libertarianism and defence of the economy, but thereby managed to achieve the worst of all worlds in terms of three egregious failures-appalling health outcomes; (ironically) worse economic damage than countries which took draconian action; and (also ironically) continually recurring restrictions as a result of earlier failure to take strong action to suppress Covid and keep it at bay. Public reaction in England (unlike in Scotland and Wales) to the Johnson government's shenanigans has not been commensurate with that government's level of failure, which sadly reflects a debasement of the political culture in England.

Comparing the acute effects of shiftwork on mothers and fathers.

BackgroundShift work may impact women more negatively than men due to the increased burden of coping with demanding work schedules while also undertaking more of the domestic chores, including childcare.AimsTo examine whether the combination of shift working and caring for children affects the sleep, fatigue and work–family conflict experienced by women more than it affects men.MethodsUsing data from a survey of the Swedish working population, mixed linear regression models examined work schedule (daywork, shift work with nights, shift work without nights), gender and presence of children <13 years at home as predictors of sleep insufficiency, sleep disturbance, fatigue and work–family conflict, over up to three successive measurement occasions. Adjustments were made for age, education, full/part-time working and baseline year.ResultsIn fully adjusted models (N = 8938), shift work was associated with insufficient sleep (P < 0.01), disturbed sleep (P < 0.01), fatigue (P < 0.05) and work–family conflict (P < 0.001). Interactions in the analyses of sleep disturbance (P < 0.001) and work–family interference (P < 0.05) indicated that among participants with no children, females reported more disturbed sleep and more work–family conflict than their male counterparts, irrespective of schedule; while among participants with children, female dayworkers reported more disturbed sleep than their male counterparts, and females working shifts without nights reported more work–family interference.ConclusionsHaving young children did not exacerbate negative effects of shift work, in either men or women. This may reflect high levels of gender equality and childcare provision in Sweden.

First encounter effects in testing of highly automated vehicles during two experimental occasions – The need for recurrent testing

Abstract To explore driver behavior in highly automated vehicles (HAVs), independent researchers are mainly conducting short experiments. This limits the ability to explore drivers’ behavioral changes over time, which is crucial when research has the intention to reveal human behavior beyond the first-time use. The current paper shows the methodological importance of repeated testing in experience and behavior related studies of HAVs. The study combined quantitative and qualitative data to capture effects of repeated interaction between drivers and HAVs. Each driver ( n = 8 n=8 ) participated in the experiment on two different occasions (∼90 minutes) with one-week interval. On both occasions, the drivers traveled approximately 40 km on a rural road at AstaZero proving grounds in Sweden and encountered various traffic situations. The participants could use automated driving (SAE level 4) or choose to drive manually. Examples of data collected include gaze behavior, perceived safety, as well as interviews and questionnaires capturing general impressions, trust and acceptance. The analysis shows that habituation effects were attenuated over time. The drivers went from being exhilarated on the first occasion, to a more neutral behavior on the second occasion. Furthermore, there were smaller variations in drivers’ self-assessed perceived safety on the second occasion, and drivers were faster to engage in non-driving related activities and become relaxed (e. g., they spent more time glancing off road and could focus more on non-driving related activities such as reading). These findings suggest that exposing drivers to HAVs on two (or more) successive occasions may provide more informative and realistic insights into driver behavior and experience as compared to only one occasion. Repeating an experiment on several occasions is of course a balance between the cost and added value, and future research should investigate in more detail which studies need to be repeated on several occasions and to what extent.

Diagnostic imaging in acute interstitial pneumonia in foals: High variability of interpretation of chest radiographs and good conformity between ultrasonographic and post-mortem findings.

Acute interstitial pneumonia (AIP) in foals is a rare but challenging syndrome. Diagnostic imaging is crucial for its diagnosis. While there are some reports on radiographic findings, ultrasound is sparsely described. Variability in the evaluation of radiographs in AIP has been well described in human literature. Part one of this study is a prospective, observational, observer agreement study investigating inter- and intraobserver agreement in the assessment of thoracic radiographs. Part two is a prospective, controlled, descriptive study on thoracic ultrasonography in foals with AIP. Eighteen foals with AIP were examined daily by thoracic ultrasound. Thoracic radiographs were taken on three successive occasions. Blinded radiographs were assessed by three observers based on two semi-quantitative scores (pattern recognition, subjective evaluation). Foals that died underwent postmortem examination (n=9); postmortem findings were compared to ultrasound findings on the day of death. Ultrasonographic findings were consistent with postmortem findings. Comet tail scores in foals with AIP were significantly higher (p<0.0001) than in control foals. Interrater agreement for the assessment of radiographs was none to moderate (κ=0.07-0.65) for pattern recognition and weak to moderate (κ=0.58-0.62) for subjective scoring. Intrarater agreement varied from minimal to strong (κ=0.30-0.80) for pattern recognition but was strong (κ=0.83) for subjective scoring. In conclusion, the diagnostic value of thoracic ultrasound in foals with AIP is high due to good conformity with postmortem findings. The evaluation of thoracic radiographs showed high variability in inter- and intra-agreement.

Study to Alter the Nuisance Effect of Non-Response Using Scrambled Mechanism.

IntroductionIn biometric sample surveys, our objective is to get ready-made information for future planning and policy implementations related to the subject matters of highly sensitive issues. In such situations, we apply randomized response/scrambled response techniques. There are many highly sensitive issues which need to be examined over time as they may have a tendency to change. To get rid of these types of practical cases we need a scrambled response technique on successive occasions.MethodsUsing an additive and multiplicative technique, we proposed new effective scrambled response models to estimate the population mean of quantitative sensitive characteristics. Degree of privacy protection and unified measure approaches are used to examine the efficacy of the proposed models. Efficiency of the proposed models has been checked using MATLAB software. The utility of the proposed models under two occasions of successive sampling has been also explored using exponential-type estimators. Empirical and simulation studies are carried out to justify the proposition of the proposed estimators using MATLAB software.ResultsThe percent relative efficiencies of the proposed models are always greater than 100 with respect to the well-known Bar-Lev et al model. In terms of degree of privacy protection, most of the values are greater than 0.5 and closer to 1. Similarly, the values of the proposed models are smaller with respect to the Bar-Lev et al model in terms of a unified measure approach. When the proposed scrambled response models are used on successive occasions, the percent relative efficiency is always found greater than 100 for all cases over its competitors.DiscussionIn this study, after deeply examining the properties of the proposed models, we found that the proposed models performed better over the well-known existing model. The proposed models may be used in human survey when we deal with highly sensitive issues. The proposed models also performed better when we utilized them in successive sampling. Hence, if sensitive characteristics change with time, the proposed estimators may be the best alternative to deal with these types of situations.Mathematics Subject Classification62D05.

Two successive occasions resubmitted sampling scheme‐based control chart

AbstractIn this paper, a resubmitted sampling‐based successive sampling over two successive occasions control chart is proposed to monitor the underlying characteristic of interest. Auxiliary information of the first occasion is utilized to monitor the relative change in the study variable over the second occasion successively despite high degree of correlation. The structural and operational design is presented along with the comparative performance evaluation. The average run length is used as a performance evaluation measure and proved the argument in favor of the presented concept in comparison with the other auxiliary data control charts. The implementation is explained through two real examples.

Advances in Estimation of Sensitive Issues on Successive Occasions

Surveys related to sensitive issues are accompanied with social desirability response bias which flaw the validity of analysis. This problem became serious when sensitive issues are estimated on successive occasions. The scrambled response technique is an alternative solution as it preserve respondents anonymity. Therefore, the present article endeavours to propose an improved class of estimators for estimating sensitive population mean at current occasion using an innocuous variable in two occasion successive sampling. Detailed properties of the estimators are analysed. Optimum allocation to fresh and matched samples are obtained. Many existing estimators in successive sampling have been modified to work for sensitive population mean estimation under scrambled response technique. The proposed estimators has been compared with recent modified estimators. Theoretical considerations are integrated with empirical and simulation studies to ascertain the efficiency gain derived from the proposed improved class of estimators.

Is Post-Reprocessing Microbiological Surveillance of Duodenoscopes Effective in Reducing the Potential Risk in Transmitting Pathogens?

Background: The use of a contaminated endoscope may lead to infections due to the transmission of potential pathogens from patient to patient. Methods: Post-reprocessing microbiological surveillance of four duodenoscopes was carried out over a three-year period in the Digestive Endoscopy Unit of an Italian hospital. Sampling of duodenoscopes was performed after the devices have been reprocessed. The initial phase of surveillance involved the contemporary evaluation of the four duodenoscopes; afterwards, microbiological surveillance proceeded at monthly intervals. Results: The initial phase of surveillance revealed that three duodenoscopes presented a high level of contamination with “high-concern” micro-organisms, some of which were multi-drug-resistant. The highest values of contamination regarded the species P. aeruginosa (2500 CFU/duodenoscope), K. pneumoniae (2580 CFU/duodenoscope), and A. baumannii (2600 CFU/duodenoscope). Since the cultures were repeatedly positive on three successive occasions, the contaminated devices were sent to the manufacturer for evaluation. Audits were carried out with the personnel responsible for reprocessing, which was aimed to optimize the procedures used, and subsequently, only one case of non-conformity was found. Conclusions: Our study highlighted both the potential risk of transmitting pathogens through the use of duodenoscopes and the importance of implementing a well-structured system of microbiological surveillance and training programs, in order to reduce the risk of spreading retrograde cholangiopancreatography (ERCP)-associated infections.

Improvement estimation on two successive occasions in cluster sampling

In this paper we attempt the problem of estimation of the sum of mean and the change of mean in mail surveys. This problem is conducted for current occasion in the context of cluster sampling over sampling on two successive occasions. The sampling units are clusters and the observations on the first occasion are regarded as ancillary information for the observations on the second or current occasion. The results obtained are demonstrated with the help of an empirical study, which reveals that under certain condition, the cluster sampling on two occasions is more efficient than the simple random sampling on two occasions.

A successive sampling control chart using multiple dependent state sampling over two successive occasions

AbstractIn this paper, successive sampling (SS) mean monitoring control chart is proposed for two successive occasions using multiple dependent state (MDS) sampling and characterized as MDS‐SS control chart. The sample size is selected on the basis of SS for the control statistic in two pairs of the control limits. The average run length is evaluated, and the performance of the proposed concept over the existing SS control chart is presented using a real‐life example. The SS monitoring chart concept is compiled with MDS, and it becomes more sophisticated in detection of warning signs.