Tag: statistics

Anal Chem. 2025 Apr 11. doi: 10.1021/acs.analchem.4c06815. Online ahead of print.

ABSTRACT

The target neutrophil-activating peptide-2, NAP2, is a potential biomarker for early lung cancer diagnosis, whereas there are currently no precise techniques for differentiating NAP2 from its precursors. To overcome this difficulty, we created an electrochemical aptamer-based sensor (E-AB) consisting of the 33-mer aptamer domain, a 2-bp three-junction region, and two conductive signal reporter stems. Whereas E-AB-AT and E-AB-RAN sensors with two (AT)₆ or N₁₂ stems, respectively, were unable to distinguish between platelet basic protein (PBP) (94 aa) and NAP2 (70 aa). However, in contrast, the E-AB-GC sensor with two (GC)₆ stems could selectively detect NAP2 but hardly recorded PBP. Here, we developed an E-AB-GC point-of-care test (POCT) technique to detect NAP2 away from its precursors in 10 μL of human serum and provide concentration data in 5 min. Interestingly, serum NAP2 levels in human samples, as determined by the E-AB-GC sensor, were roughly 30-50% lower than those obtained by ELISA. Results also showed that E-AB-GC analysis of serum NAP2 in patients in stages I through IV revealed statistical significance and an excellent guiding function in the early diagnosis of lung cancer, particularly for patients in stage I cancer (p = 0.0054, area under the curve, 0.95). Importantly, this E-AB-GC POCT platform has shown potential as an on-site quick diagnostic tool, which can also be used to detect other lung cancer markers. Our research on the impacts of stem sequencing on sensing capabilities might assist in the future development of E-AB biomarker sensors.

PMID:40215095 | DOI:10.1021/acs.analchem.4c06815

Musculoskeletal Care. 2025 Jun;23(2):e70099. doi: 10.1002/msc.70099.

ABSTRACT

BACKGROUND: General practitioners (GPs) use of imaging for acute low back pain (LBP) is above guideline recommendations, and the reasons for this remain under-researched. We examined the perspectives, expectations and information needs of Australian GPs requesting lumbar spine diagnostic imaging for patients presenting with acute LBP.

METHODS: We completed semi-structured interviews with 12 GPs practising in Victoria, Australia. Transcripts were thematically analysed, and themes compared according to whether or not GPs reported they regularly requested imaging for LBP.

RESULTS: We identified four themes. (1) Besides responding to ‘red flags’, GPs’ experiences of uncovering unexpected but serious findings on imaging for LBP as well as perceived external pressures motivated their defensive imaging practices. (2) While most were reluctant to request imaging for LBP, once requested, GPs escalated through imaging modalities and focused on the diagnostic benefit of their findings. (3) GPs supported the inclusion of epidemiological data on imaging reports, but (4) largely opposed imaging reports being written in plain language, believing reports to be clinician-to-clinician communications that patients would misunderstand. All GPs were aware of the limited utility of imaging for diagnosing LBP, and themes were similar between GPs who regularly requested imaging and those who did not. Factors other than knowledge of imaging efficacy for LBP seemed to play an important role in imaging requests.

CONCLUSIONS: Our study identified key drivers of imaging use for LBP in primary care. The findings underscore that interventions targeting GPs addressing the overuse of imaging for LBP should transcend knowledge deficit models.

PMID:40215089 | DOI:10.1002/msc.70099

Psychooncology. 2025 Apr;34(4):e70149. doi: 10.1002/pon.70149.

ABSTRACT

PURPOSE: Death preparedness plays a crucial role in improving the quality of death for advanced cancer patients. However, existing tools only assess certain aspects of death preparedness in advanced cancer patients, and there is limited evidence regarding their reliability and validity. To develop and validate a specific and comprehensive measurement tool for death preparedness in advanced cancer patients.

METHODS: The scale was developed using an exploratory mixed-methods approach, which included both qualitative and quantitative stages. Grounded theory and existing literature were used to construct a death preparedness scale for advanced cancer patients. Content validity was assessed using the Delphi method. A convenience sampling approach was employed to recruit 753 advanced cancer patients from the oncology wards of six tertiary grade-A general hospitals in Hubei and Anhui provinces, China, for psychometric testing of the scale. Item selection was based on item analysis, exploratory factor analysis was conducted to extract factors, and confirmatory factor analysis was used to assess structural validity.

RESULTS: The final scale consists of 4 dimensions and 22 items. These four dimensions are named “Death awareness,” “Emotional response,” “Hospice program,” and “Reflexive care.” They explain 64.010% of the total variance. The confirmatory factor analysis (CFA) model showed that the 4-factor model fit the data well. The overall Cronbach’s alpha coefficient for the scale was 0.991.

CONCLUSION: The death preparedness scale for advanced cancer patients that we developed demonstrates good reliability and validity, and can be used to comprehensively assess the death preparedness level of advanced cancer patients. Additionally, with the subscale scoring system, healthcare professionals can provide targeted interventions in specific areas of death preparedness for patients, thereby improving both the quality of life and quality of death for advanced cancer patients.

PMID:40215084 | DOI:10.1002/pon.70149

Ann Indian Acad Neurol. 2025 Apr 11. doi: 10.4103/aian.aian_773_24. Online ahead of print.

ABSTRACT

BACKGROUND AND OBJECTIVES: Persons with epilepsy (PWE) have poor dental hygiene, contributed by the severity of epilepsy, ignoring oral health, and the medications used. A continuing need exists for a better understanding of the effects of antiseizure medications (ASMs) on oral health. Several studies have shown the effects of older ASMs on oral health, but there is a lack of those exploring oral side effects of newer ASMs.

METHODS: A cross-sectional study was conducted in which 69 PWE on ASMs were compared with 33 controls. A structured questionnaire was used to collect data on demographics, oral hygiene practices, and medication history including use of older and newer ASMs. Dental examination along with plaque, gingival, Decayed, Missing, and Filled Teeth (DMFT), and Decayed, Missing, and Filled teeth Surface (DMFS) indices were assessed. PWE were divided into three groups based on whether they were on older ASMs, newer ASMs, or a combination of both. Data was statistically analyzed.

RESULTS: PWE have poor dental health with significantly higher gingival index, plaque index, calculus, DMFS, and DMFT scores compared to controls (P < 0.001). Concerning ASMs, patients on older ASMs had poor dental health with higher gingival index, gingivitis, and periodontitis compared to those on newer ASMs (P < 0.005). Patients on polytherapy tended to have worse periodontal parameters. Gingival hyperplasia was common in patients taking phenytoin alone compared to those taking folic acid along with phenytoin (P < 0.05).

CONCLUSION: Older ASMs, especially phenytoin, can be associated with significant oral side effects. Newer ASMs are relatively safe, but further research is needed to fully understand their long-term effects.

PMID:40215081 | DOI:10.4103/aian.aian_773_24

JAMA Health Forum. 2025 Apr 4;6(4):e250423. doi: 10.1001/jamahealthforum.2025.0423.

ABSTRACT

IMPORTANCE: Patients may initiate dialysis at their predialysis nephrologists’ primary facilities (ie, where the nephrologist saw the most patients) to preserve continuity of care, even if the facilities are of low quality. Patients from minoritized racial and ethnic groups may be the most negatively impacted.

OBJECTIVE: To examine starts at nephrologists’ primary facilities, downstream outcomes, and racial disparities in dialysis start quality.

DESIGN, SETTING, AND PARTICIPANTS: This cohort study used Medicare administrative data of patients initiating dialysis at freestanding US dialysis facilities from January 1, 2015, to October 31, 2020, with 1 year of follow-up (ending October 31, 2021). Analyses concluded January 26, 2025. Participants were adults with fee-for-service Medicare initiating dialysis.

EXPOSURES: Quality of nephrologists’ primary facilities (using publicly available 5-star ratings) and primary facilities’ proximity to patients.

MAIN OUTCOMES AND MEASURES: The primary outcomes were starting dialysis at the nephrologist’s primary facility (ie, primary facility starts), whether the starting facility was high quality (ie, 4-star or 5-star ratings), mortality and hospitalization rates, and racial and ethnic disparities in high-quality primary facilities and in starting dialysis at high-quality facilities. Analyses used multivariable linear and Poisson regression with hospital service area fixed effects (unique intercepts for each area).

RESULTS: Of 143 776 adults (median [IQR] age, 73 [67-79] years; 64 447 female [45%]; 4989 Asian [3%]; 28 515 Black [20%]; 11 296 Hispanic [8%]; 96 639 non-Hispanic White [67%]), 64 186 (45%) had managing nephrologists with high-quality primary facilities. Primary facility starts were lower as the primary facility’s quality increased (0.5 percentage points [pp] lower for every 1-star increase in rating; 95% CI, 0.1-0.8 pp; P = .03). In contrast, primary facility starts were 33.9 pp (95% CI, 33.0-34.9 pp; P < .001) more likely when primary facilities were close to patients than when distant. Each additional quality star in nephrologists’ primary facility was associated with more 4-star or 5-star facility starts (7.4 pp; 95% CI, 6.9-7.9 pp) and 4.5 fewer hospitalizations per 100 person-years (95% CI, 2.8-6.1 hospitalizations per 100 person-years). Compared with White patients, Black patients were 2.8 pp (95% CI, 1.7-3.9 pp) less likely to start at 4-star or 5-star facilities and 2.0 pp (95% CI, 1.0-3.0 pp) less likely to be treated by nephrologists with 4-star or 5-star primary facilities.

CONCLUSIONS AND RELEVANCE: Primary facility starts were common even when they were low quality, and outcomes were worse when nephrologists had low-quality primary facilities. Black patients disproportionately start dialysis at low-quality facilities and are less likely to have nephrologists with high-quality primary facilities. Policies that promote improved access to high-quality dialysis facilities may be necessary to alleviate these disparities.

PMID:40215072 | DOI:10.1001/jamahealthforum.2025.0423

JAMA Health Forum. 2025 Apr 4;6(4):e250433. doi: 10.1001/jamahealthforum.2025.0433.

ABSTRACT

IMPORTANCE: Under certain circumstances, advance practice clinicians (APCs), such as physician assistants and nurse practitioners, can bill Medicare directly or indirectly (ie, incident to the services of a physician). With indirect billing, the submitted claim states the care was provided by the physician, and the reimbursement is higher.

OBJECTIVE: To quantify volume and spending on office-based encounters billed indirectly in the Medicare program.

DESIGN, SETTING, AND PARTICIPANTS: This cohort study used Medicare fee-for-service and Medicare Advantage claims data to identify indirectly billed APC services. To do so, office-based Medicare Part B claims (ie, clinician services) were linked to Part D claims for prescription drug fills. Because the latter contains the prescribing clinician’s unique identifier, this linkage distinguished between directly and indirectly billed services provided by APCs. In this way, the fraction of encounters and component services billed indirectly by APCs and physicians were quantified.

MAIN OUTCOMES AND MEASURES: Share of fee-for-service and Medicare Advantage office encounters provided by APCs and billed indirectly. Share of a physician’s billed claims actually provided by an APC and billed indirectly.

RESULTS: In 2022, of all office encounters provided by an APC, 38.9% were billed indirectly. Conversely, for the median physician in 2022, indirect billing on behalf of APCs represented 11.1% of all billed encounters. Billing for care delivered by APCs was most common among surgical specialists (29.7% of encounters) and least common for primary care physicians (3.9%). If all indirectly billed APC-provided care was billed directly by the APC, Medicare would have saved $270 million in 2022.

CONCLUSIONS AND RELEVANCE: The results of this cohort study suggest that APCs provide a substantial fraction of office-based care received by Medicare beneficiaries. Identifying indirectly billed APC-provided care is integral to understanding who serves Medicare beneficiaries.

PMID:40215071 | DOI:10.1001/jamahealthforum.2025.0433

J Vis. 2025 Apr 1;25(5):9. doi: 10.1167/jov.25.5.9.

ABSTRACT

Fixational eye movements (FEMs) are small, fluctuating eye motions when fixating on a target. Given our visual system is evolved, we may ask why FEMs are beneficial and whether they are optimal. A possible reason for FEMs is overcoming retinal adaptation (fading perception of a fixed image). We present a simple model system allowing theoretical investigation of FEM influence on information about an external stimulus. The model incorporates temporal stimulus modulation, retinal image motion due to the drift component of FEMs, blurring due to optics and receptor size, uniform sampling by the receptor array, adaptation via a bandpass temporal filter, and added noise. We investigate how elements of the model mediate the information transmitted, via: i) mutual information between visual system response and external stimulus, ii) direct estimation of stimulus from the system response, and iii) contrast threshold for signal detection. For all these we find a common quantity that must be maximized. For each spatial frequency this quantity is a summed power transmitted due to stimulus temporal modulation and phase shifts from FEMs, when passed through the temporal filter. We demonstrate that the information transmitted can be increased by adding local persistence to an underlying diffusive process. We also quantify the contribution of FEMs to signal detection for targets of different size and duration; such predictions provide a qualitative account of human psychophysical performance.

PMID:40215060 | DOI:10.1167/jov.25.5.9

J Vis. 2025 Apr 1;25(5):35. doi: 10.1167/jov.25.5.35.

ABSTRACT

It has been proposed that colour perception is calibrated to the chromatic statistics of the environment. Here we investigate whether perceived white is calibrated to the chromatic statistics of the local current ‘visual diet’. We compare achromatic settings for participants in Norway living above (Tromsø, N = 165) or below (Oslo, N = 158) the Arctic Circle and across seasons. To capture the local visual diets we used images from colour-calibrated head-mounted cameras worn during daily life. For each image we computed average chromaticity (L/(L+M) and S/(L+M)) and the amount of blue-yellow bias in the distribution of chromaticities. We find that perceived white is warmer (higher L/(L+M) and lower S/(L+M)), and more blue-yellow biased for observers living in Oslo compared to Tromsø. However, visual diets were warmer and more blue-yellow biased in Tromsø compared to Oslo. Perceived white did not vary significantly with season, yet visual diets were warmest in the winter. In order to explore the effects of visual environment in early life, we also investigate how perceived white varies with latitude of birth and season of birth for participants living in Tromsø. Perceived white was lower in S/(L+M) (yellower) for adults born below the Arctic Circle than adults born above, and was higher in L/(L+M) (redder) for adults born in the summer. Combined, the findings suggest a possible link between colour perception and visual diet, and we discuss potential mechanisms.

PMID:40215034 | DOI:10.1167/jov.25.5.35

J Vis. 2025 Apr 1;25(5):38. doi: 10.1167/jov.25.5.38.

ABSTRACT

It has been suggested that objects are more likely to be warmer in colour, redder and more saturated than the background. Here, we investigate the colour statistics of objects, and the brain regions that are responsive to these statistics. First, we analysed the Natural Scenes Dataset (NSD), a 7T dataset in which 8 participants viewed up to 10,000 natural scenes. Our analysis of the chromaticities of the 80 segmented object classes and backgrounds confirmed that object pixels were warmer, redder, more saturated and darker than background pixels. The probability that pixels were from objects rather than backgrounds (the ‘Object Colour Probability’, OCP) was calculated for 240 hue bins. The mean OCP of images correlated with NSD BOLD responses mostly in the ventral visual pathway. Other image statistics (e.g., number of food pixels) better explained the responses of correlated voxels. A second fMRI study, in which colours were shown as a single patch on a grey background, was analysed to study whether ventral visual pathway is responsive to OCP in the absence of other scene statistics. To constrain our analyses to functionally relevant areas, we used independent functional localizers to identify colour- and object-selective areas and combined these with NSD defined OCP responsive areas. The OCP of the colour patches significantly correlated with BOLD in colour-selective but not object-selective visual regions. Implications for the role of colour in object vision are discussed.

PMID:40215031 | DOI:10.1167/jov.25.5.38

J Vis. 2025 Apr 1;25(5):41. doi: 10.1167/jov.25.5.41.

ABSTRACT

Visual discomfort describes an aversive subjective experience characterised by perceptual distortions, blurred vision, diplopia, pain in the eyes, headache and/or nausea. Previous laboratory studies have found that levels of visual discomfort can be predicted from some statistical properties of scenes, including the spectral slope (e.g. Penacchio & Wilkins, 2015) and colour contrast (Juricevic et al. 2010; Penacchio et al. 2021). Lighting flicker (e.g. Yoshimoto et al., 2017) and colour temperature (e.g. Kakitsuba 2015) have also been shown to trigger discomfort. We investigated everyday occurrences of visual discomfort using a visual survey method. Participants (N = 36) captured scenes which they found to be visually uncomfortable within a university library. Participants gave a narrative and discomfort rating for each image. We also surveyed the lighting in the photographed areas, measuring flicker and the spectral power distribution of the illumination. Analysis showed some support for the importance of the image statistical features identified in laboratory studies, although there was no interaction between these features and lighting flicker or colour temperature. Qualitative analysis of participant narratives revealed that experiences of discomfort were attributed to low-level features (e.g. pattern, contrast), but also structural features (e.g. depth, disorganisation). These results provide new insights into the causes of visual discomfort in the everyday environment.

PMID:40215028 | DOI:10.1167/jov.25.5.41