Tag: nevin manimala

Stat Methods Med Res. 2023 May 17:9622802231173491. doi: 10.1177/09622802231173491. Online ahead of print.

ABSTRACT

The goal of causal mediation analysis, often described within the potential outcomes framework, is to decompose the effect of an exposure on an outcome of interest along different causal pathways. Using the assumption of sequential ignorability to attain non-parametric identification, Imai et al. (2010) proposed a flexible approach to measuring mediation effects, focusing on parametric and semiparametric normal/Bernoulli models for the outcome and mediator. Less attention has been paid to the case where the outcome and/or mediator model are mixed-scale, ordinal, or otherwise fall outside the normal/Bernoulli setting. We develop a simple, but flexible, parametric modeling framework to accommodate the common situation where the responses are mixed continuous and binary, and, apply it to a zero-one inflated beta model for the outcome and mediator. Applying our proposed methods to the publicly-available JOBS II dataset, we (i) argue for the need for non-normal models, (ii) show how to estimate both average and quantile mediation effects for boundary-censored data, and (iii) show how to conduct a meaningful sensitivity analysis by introducing unidentified, scientifically meaningful, sensitivity parameters.

PMID:37194551 | DOI:10.1177/09622802231173491

Bull Entomol Res. 2023 May 17:1-12. doi: 10.1017/S0007485323000159. Online ahead of print.

ABSTRACT

Between 1990 and 1999, at Rekomitjie Research Station, Zambezi Valley, Zimbabwe, 29,360 female G. pallidipes were dissected to determine their ovarian category and trypanosome infection status. Overall prevalences were 3.45 and 2.66% for T. vivax and T. congolense, respectively, declining during each year as temperatures increased from July – December. Fits to age-prevalence data using Susceptible-Exposed-Infective (SEI) and SI compartmental models were statistically better than those obtained using a published catalytic model, which made the unrealistic assumption that no female tsetse survived more than seven ovulations. The improved models require knowledge of fly mortality, estimated separately from ovarian category distributions. Infection rates were not significantly higher for T. vivax than for T. congolense. For T. congolense in field-sampled female G. pallidipes, we found no statistical support for a model where the force of infection was higher at the first feed than subsequently. The long survival of adult female tsetse, combined with feeding at intervals ≤3 days, ensures that post-teneral feeds, rather than the first feed, play the dominant role in the epidemiology of T. congolense infections in G. pallidipes. This is supported by estimates that only about 3% of wild hosts at Rekomitjie were harbouring sufficient T. congolense to ensure that tsetse feeding off them take an infected meal, so that the probability of ingesting an infected meal is low at every meal.

PMID:37194504 | DOI:10.1017/S0007485323000159

Stat Med. 2023 May 30;42(12):1909-1930. doi: 10.1002/sim.9704. Epub 2023 Mar 7.

ABSTRACT

In this article, we propose a two-level copula joint model to analyze clinical data with multiple disparate continuous longitudinal outcomes and multiple event-times in the presence of competing risks. At the first level, we use a copula to model the dependence between competing latent event-times, in the process constructing the submodel for the observed event-time, and employ the Gaussian copula to construct the submodel for the longitudinal outcomes that accounts for their conditional dependence; these submodels are glued together at the second level via the Gaussian copula to construct a joint model that incorporates conditional dependence between the observed event-time and the longitudinal outcomes. To have the flexibility to accommodate skewed data and examine possibly different covariate effects on quantiles of a non-Gaussian outcome, we propose linear quantile mixed models for the continuous longitudinal data. We adopt a Bayesian framework for model estimation and inference via Markov Chain Monte Carlo sampling. We examine the performance of the copula joint model through a simulation study and show that our proposed method outperforms the conventional approach assuming conditional independence with smaller biases and better coverage probabilities of the Bayesian credible intervals. Finally, we carry out an analysis of clinical data on renal transplantation for illustration.

PMID:37194500 | DOI:10.1002/sim.9704

Psychol Med. 2023 May 17:1-12. doi: 10.1017/S0033291723001010. Online ahead of print.

ABSTRACT

BACKGROUND: Since 2008, the Improving Access to Psychological Therapies (IAPT) programme has offered adults in England evidence-based psychological treatments for common mental disorders (CMDs) such as depression and anxiety disorders. However, inequalities in access have not been explored at the national level.

METHODS: Using a unique individual patient dataset that linked 2011 Census information of English residents to national IAPT data collected between April 2017 and March 2018, we estimated the rate of access by a wide range of socio-demographic characteristics that are not routinely available. A large household survey was used to estimate the prevalence of probable CMDs by these socio-demographic characteristics. We estimated the probability of access to IAPT amongst people with CMDs by comparing the rates of access from IAPT data and the estimates of prevalence of CMDs from the household survey. Both unadjusted and adjusted (for important patient characteristics) access rates were estimated in logistic regression models.

RESULTS: As a proportion of those with a probable CMD, access to IAPT varied markedly by socio-demographic characteristics. Older adults, males, people born outside of the UK, people with religious beliefs, people from Asian ethnic backgrounds, people reporting a disability and those without any academic or professional qualifications were underrepresented in IAPT services nationally, in adjusted models.

CONCLUSIONS: The identification of patients who may be underrepresented in IAPT provides an opportunity for services to target outreach and engagement with these groups. Further understanding of barriers to access should help increase equity in access.

PMID:37194490 | DOI:10.1017/S0033291723001010

Hosp Pediatr. 2023 May 17:e2022007075. doi: 10.1542/hpeds.2022-007075. Online ahead of print.

ABSTRACT

OBJECTIVES: There is a lack of guidance on the management of febrile neutropenia in otherwise healthy children, including the need for hospitalization and antibiotic administration, leading to significant practice variation in management. The aim of this initiative was to decrease the number of unnecessary hospitalizations and empirical antibiotics prescribed by 50% over a 24-month period for well-appearing, previously healthy patients older than 6 months presenting to the emergency department with a first episode of febrile neutropenia.

METHODS: A multidisciplinary team of stakeholders was assembled to develop a multipronged intervention strategy using the Model for Improvement. A guideline for the management of healthy children with febrile neutropenia was created, coupled with education, targeted audit and feedback, and reminders. Statistical control process methods were used to analyze the primary outcome of the percentage of low-risk patients receiving empirical antibiotics and/or hospitalization. Balancing measures included missed serious bacterial infection, emergency department (ED) return visit, and a new hematologic diagnosis.

RESULTS: Over the 44-month study period, the mean percentage of low-risk patients hospitalized and/or who received antibiotics decreased from 73.3% to 12.9%. Importantly, there were no missed serious bacterial infections, no new hematologic diagnoses after ED discharge, and only 2 ED return visits within 72 hours without adverse outcomes.

CONCLUSIONS: A guideline for the standardized management of febrile neutropenia in low-risk patients increases value-based care through reduced hospitalizations and antibiotics. Education, targeted audit and feedback, and reminders supported sustainability of these improvements.

PMID:37194483 | DOI:10.1542/hpeds.2022-007075

J Med Radiat Sci. 2023 May 17. doi: 10.1002/jmrs.687. Online ahead of print.

ABSTRACT

INTRODUCTION: Impalpable breast lesions generally require image-guided localisation for breast-conserving surgery. A standard technique is to place a hook wire (HW) within the lesion. Radioguided occult lesion localisation using iodine seeds (ROLLIS) involves inserting a 4.5 mm iodine-125 seed (seed) into the lesion. We hypothesised that a seed could be more precisely positioned in relation to the lesion than a HW and that this may be associated with a lower re-excision rate.

METHODS: Retrospective review of consecutive participant data from three ROLLIS RCT (ACTRN12613000655741) sites. Participants underwent preoperative lesion localisation (PLL) with seed or HW between September 2013 and December 2017. Lesion and procedural characteristics were recorded. Distances between (1) any part of the seed or thickened segment of the HW (‘TSHW’) and the lesion/clip (‘distance to device’ DTD) and (2) centre of the TSHW/seed and centre of the lesion/clip (device centre to target centre ‘DCTC’) were measured on immediate postinsertion mammograms. Pathological margin involvement and re-excision rates were compared.

RESULTS: A total of 390 lesions (190 ROLLIS and 200 HWL) were analysed. Lesion characteristics and guidance modality used were similar between groups. Ultrasound-guided DTD and DCTC for seed were smaller than for HW (77.1% and 60.6%, respectively, P-value < 0.001). Stereotactic-guided DCTC for seeds was 41.6% smaller than for HW (P-value = 0.001). No statistically significant difference in the re-excision rates was found.

CONCLUSION: Iodine-125 seeds can be more precisely positioned for preoperative lesion localisation than HW, however, no statistically significant difference in re-excision rates was detected.

PMID:37194479 | DOI:10.1002/jmrs.687

Trends Hear. 2023 Jan-Dec;27:23312165231171987. doi: 10.1177/23312165231171987.

ABSTRACT

Subjects utilizing a cochlear implant (CI) in one ear and a hearing aid (HA) on the contralateral ear suffer from mismatches in stimulation timing due to different processing latencies of both devices. This device delay mismatch leads to a temporal mismatch in auditory nerve stimulation. Compensating for this auditory nerve stimulation mismatch by compensating for the device delay mismatch can significantly improve sound source localization accuracy. One CI manufacturer has already implemented the possibility of mismatch compensation in its current fitting software. This study investigated if this fitting parameter can be readily used in clinical settings and determined the effects of familiarization to a compensated device delay mismatch over a period of 3-4 weeks. Sound localization accuracy and speech understanding in noise were measured in eleven bimodal CI/HA users, with and without a compensation of the device delay mismatch. The results showed that sound localization bias improved to 0°, implying that the localization bias towards the CI was eliminated when the device delay mismatch was compensated. The RMS error was improved by 18% with this improvement not reaching statistical significance. The effects were acute and did not further improve after 3 weeks of familiarization. For the speech tests, spatial release from masking did not improve with a compensated mismatch. The results show that this fitting parameter can be readily used by clinicians to improve sound localization ability in bimodal users. Further, our findings suggest that subjects with poor sound localization ability benefit the most from the device delay mismatch compensation.

PMID:37194477 | DOI:10.1177/23312165231171987

BJS Open. 2023 May 5;7(3):zrad024. doi: 10.1093/bjsopen/zrad024.

ABSTRACT

BACKGROUND: Achieving a better prognosis for patients and reducing the risk of complications are primary considerations in surgical decisions for hilar cholangiocarcinoma.

METHODS: A retrospective analysis of the authors’ clinical practice outcomes in the surgical management of patients with hilar cholangiocarcinoma following the planned-hepatectomy surgical treatment programme between 2009 and 2018.

RESULTS: Some 473 patients were included, of whom 127 (26.8 per cent) underwent bile duct tumour resection alone, 44 (9.3 per cent) underwent bile duct tumour resection combined with restrictive hepatectomy, and 302 (63.8 per cent) underwent bile duct tumour resection combined with extensive hepatectomy. R0 resection was achieved in 82.2 per cent and the postoperative complication rate was similar between the different operations. The 5-year survival rates after surgery were 37.0, 37.3, and 28.4 per cent in the bile duct tumour resection alone, restrictive hepatectomy, and extensive hepatectomy groups respectively, with no statistically significant differences. As TNM staging progressed, the 1-5-year cumulative survival rate for the patients in the three groups showed a significant downward trend.

CONCLUSION: In the setting of a high-volume centre, a planned-hepatectomy surgical treatment programme helps to strike a better balance between achieving radical tumour resection for hilar cholangiocarcinoma and reasonable control of the extent of surgical damage.

PMID:37194459 | DOI:10.1093/bjsopen/zrad024

Acta Obstet Gynecol Scand. 2023 May 16. doi: 10.1111/aogs.14585. Online ahead of print.

ABSTRACT

INTRODUCTION: We aimed to describe physiological changes in endometrial blood flow (minute arterioles running through the endometrium) from ovulation to the mid-luteal phase using superb microvascular imaging.

MATERIAL AND METHODS: The study involved 17 women (median age, 32.5 years; first to third interquartile range, 29.8-40.0 years) with regular menstrual cycles who were managed in our institute from 2020 to 2021. The uterus was delineated at the sagittal section using transvaginal ultrasonography incorporated with superb microvascular imaging. For each participant, a total of 28 cycles were observed; 17 cycles observed within one day of ovulation and the implantation period, 5-7 days (D5-7) after ovulation in the same cycle, and nine cycles in which only ovulation was observed, and two cycles in which only D5-7 was observed. Therefore, 26 and 19 images at ovulation and D5-7, respectively, were acquired. Endometrial blood flow was evaluated by depth of the vascular signal in the endometrium and categorized as follows: signals only in the basal layer of the endometrium (grade 1), reaching up to half the endometrium (grade 2), and covering the whole endometrium (grade 3). Changes in the grade of endometrial blood flow from ovulation to D5-7 after ovulation, and the relationship between the grade of endometrial blood flow and the endometrial thickness on ovulation and D5-7 after ovulation, were analyzed. Statistical significance was set at p < 0.05.

RESULTS: The endometrial blood flow from ovulation to D5-7 after ovulation during the same menstrual period showed a downgrade in 14 of 17 cycles (82.3%) and no change in the remaining three cycles (17.6%), indicating a decrease in the endometrial blood flow from ovulation to D5-7 after ovulation (p = 0.001). There were differences between the grade of endometrial blood flow and median endometrial thickness on ovulation (grade 1: 5.9 mm, grade 2: 9.1 mm, and grade 3: 11.2 mm); however, no differences in the endometrial thickness were found between the grades on D5-7 after ovulation.

CONCLUSIONS: In the normal menstrual cycle, endometrial blood flow decreased from ovulation to the mid-luteal phase, and the endometrial thickness in the ovulatory phase was related to the endometrial perfusion.

PMID:37194424 | DOI:10.1111/aogs.14585

J Oncol Pharm Pract. 2023 May 16:10781552231174858. doi: 10.1177/10781552231174858. Online ahead of print.

ABSTRACT

This study was designed to describe the landscape of oncology pharmacy practice at patient facing institutional healthcare organizations throughout the United States. Methods: The Hematology/Oncology Pharmacy Association (HOPA) Practice Outcomes and Professional Benchmarking Committee conducted a multi-organization, voluntary survey of HOPA members between March 2021 and January 2022. Four overarching domains were targeted: institutional description, job function, staffing, and training/certification. Data were evaluated using descriptive statistics. Results: A total of 68 responses were analyzed including 59% and 41% who self-identified their organization as academic and community centers, respectively. The median number of infusion chairs and annual infusion visits were 49 (interquartile range (IQR): 32-92) and 23,500 (IQR: 8300-300,000), respectively. Pharmacy departments reported to a business leader, physician leader, and nursing leader 57%, 24%, and 10% of the time, respectively. The median oncology pharmacy full-time equivalents was 16 (IQR: 5-60). At academic centers, 50% (IQR: 26-60) of inpatient and 30% (IQR: 21-38) of ambulatory pharmacist FTEs were dedicated to clinical activities. At community centers, 45% (IQR: 26-65) of inpatient and 50% (IQR: 42-58) of ambulatory pharmacist FTEs were dedicated to clinical activities. As many as 18% and 65% of organizations required or encouraged certification for oncology pharmacists, respectively. The median number of Board-Certified Oncology Pharmacists was 4 (IQR: 2-15). Conclusion: As the number of patients with cancer rises, the oncology workforce must grow to support this expanding population. These results describe the practice landscape of oncology pharmacy at US healthcare institutions to serve as a foundation for future research evaluating metrics and benchmarks.

PMID:37194276 | DOI:10.1177/10781552231174858