Tag: statistics

Work. 2024 May 21. doi: 10.3233/WOR-230528. Online ahead of print.

ABSTRACT

BACKGROUND: Using a computer may lead to pain in wrists, neck, and back. In addition, adopting various body postures like sitting cross-legged, semi-fowler’s position, and putting the laptop on the leg may lead to the development of persistent and irreversible discomfort.

OBJECTIVE: The purpose of this research is to design and build an adjustable ergonomic laptop desk based on the anthropometric characteristics of students in the age range of 20 to 30 years and to evaluate its efficiency using RULA and NERPA methods.

METHODS: This cross-sectional study conducted on 108 students, in which an adjustable and portable ergonomic desk designed and built based on 10 anthropometric dimensions of students and the length and width of 10 different laptop models. Two assessment methods, RULA and NERPA, were used. Wilcoxon statistic test and SPSS version 26 software used for data analysis.

RESULTS: The dimensions of the desk were calculated in three positions, and the desk was made with the ability to adjust height, width and tilt, each with two degrees of freedom. The statistical analysis comparing score of RULA and NERPA in two situations without using a desk and using an ergonomic laptop desk had a significant difference (P-value < 0.001). Comparison of RULA and NERPA scores showed that NERPA evaluated the low ergonomic risk level better than RULA method.

CONCLUSIONS: Due to the ability to adjust the designed desk, the changes in RULA and NERPA score in all three modes, it indicates the effectiveness of the table in improving the body posture of users when using a laptop.

PMID:38788108 | DOI:10.3233/WOR-230528

Technol Health Care. 2024 Apr 27. doi: 10.3233/THC-231757. Online ahead of print.

ABSTRACT

BACKGROUND: Dental education is considered as a complex, challenging and often stressful educational procedure. Acquisition of psychomotor skills by undergraduate students is an important step in many health professions to become a successful professional. During under graduation, class II cavity preparation exercise is of utmost important in dentistry.

OBJECTIVE: To compare class II cavities prepared by students after hands-on live demonstration and pre-recorded video demonstration using well-organised evaluation rubrics.

METHOD: Preclinical dental students (n= 50) were divided into two groups. The students in group I (n= 25) attended a hands-on live demonstration performed by one faculty while students in group II (n= 25) watched a 15-minute pre-recorded procedural video on the projector. Both groups were appealed to prepare class II cavity for amalgam involving disto-occlusal surface of mandibular second molar articulated on jaw model (TRU LON study model, Jayna industries, Ghaziabad U.P., India). Following completion of the preparations, all teeth were collected, and labelled grades of prepared cavities were given according to prespecified rubrics. The data of scores were presented as means and standard deviation. Statistical analysis of data was executed using SPSS software. A paired t-test was used to compare scores between groups.

RESULTS: The study shows that the video-supported demonstration of a cavity preparation was better than the live hands-on demonstration. A higher mean response for the procedural video group was found compared to the live demonstration group (p= 0.000133).

CONCLUSION: Pre-recorded video-supported demonstration along with guidance by a tutor may be a viable alternative to hands-on live demonstration in cavity preparation procedures during undergraduate dental training. Moreover, rubric methods can be implemented in the teaching of various preclinical exercises for conservative dentistry and endodontics.

PMID:38788102 | DOI:10.3233/THC-231757

Cardiovasc J Afr. 2024 Apr 5;34:1-9. doi: 10.5830/CVJA-2024-005. Online ahead of print.

ABSTRACT

Cardiovascular risk is a health concern in people living with HIV/AIDS (PLWH). This longitudinal study (baseline vs 36 months) aimed to investigate the relationship between body composition and markers of cardiovascular risk in a South African study population [HIV free, n = 22 vs HIV positive on antiretroviral therapy (HIV+ART), n = 73)]. Health questionnaires, anthropometric measurements, biochemical analyses and flow-mediated dilation were performed. Linear mixed-model statistical analyses were applied. The HIV+ART vs the HIV-free groups were independently associated with body mass index (BMI) [-4.92 (-7.99 to -1.84), p = 0.002] and waist circumference [-10.5 (-17.2 to -3.77), p = 0.003]. ART duration was associated with BMI [2.60 (0.57-4.62), p = 0.013], waist circumference [3.83 (0.03-7.63), p = 0.048] and high-density lipoprotein cholesterol [20.18 (2.37-41.09), p = 0.025]. The data showed that intricate relationships existed in this study population between HIV, ART, body composition and cardiometabolic variables. There is a need for more research investigating cardiovascular risk in PLWH, particularly in the context of changes in body composition measures.

PMID:38787609 | DOI:10.5830/CVJA-2024-005

JMIR Public Health Surveill. 2024 May 24;10:e39297. doi: 10.2196/39297.

ABSTRACT

BACKGROUND: Innovation in seasonal influenza vaccine development has resulted in a wider range of formulations becoming available. Understanding vaccine coverage across populations including the timing of administration is important when evaluating vaccine benefits and risks.

OBJECTIVE: This study aims to report the representativeness, uptake of influenza vaccines, different formulations of influenza vaccines, and timing of administration within the English Primary Care Sentinel Cohort (PCSC).

METHODS: We used the PCSC of the Oxford-Royal College of General Practitioners Research and Surveillance Centre. We included patients of all ages registered with PCSC member general practices, reporting influenza vaccine coverage between September 1, 2019, and January 29, 2020. We identified influenza vaccination recipients and characterized them by age, clinical risk groups, and vaccine type. We reported the date of influenza vaccination within the PCSC by International Standard Organization (ISO) week. The representativeness of the PCSC population was compared with population data provided by the Office for National Statistics. PCSC influenza vaccine coverage was compared with published UK Health Security Agency’s national data. We used paired t tests to compare populations, reported with 95% CI.

RESULTS: The PCSC comprised 7,010,627 people from 693 general practices. The study population included a greater proportion of people aged 18-49 years (2,982,390/7,010,627, 42.5%; 95% CI 42.5%-42.6%) compared with the Office for National Statistics 2019 midyear population estimates (23,219,730/56,286,961, 41.3%; 95% CI 4.12%-41.3%; P<.001). People who are more deprived were underrepresented and those in the least deprived quintile were overrepresented. Within the study population, 24.7% (1,731,062/7,010,627; 95% CI 24.7%-24.7%) of people of all ages received an influenza vaccine compared with 24.2% (14,468,665/59,764,928; 95% CI 24.2%-24.2%; P<.001) in national data. The highest coverage was in people aged ≥65 years (913,695/1,264,700, 72.3%; 95% CI 72.2%-72.3%). The proportion of people in risk groups who received an influenza vaccine was also higher; for example, 69.8% (284,280/407,228; 95% CI 69.7%-70%) of people with diabetes in the PCSC received an influenza vaccine compared with 61.2% (983,727/1,607,996; 95% CI 61.1%-61.3%; P<.001) in national data. In the PCSC, vaccine type and brand information were available for 71.8% (358,365/498,923; 95% CI 71.7%-72%) of people aged 16-64 years and 81.9% (748,312/913,695; 95% CI 81.8%-82%) of people aged ≥65 years, compared with 23.6% (696,880/2,900,000) and 17.8% (1,385,888/7,700,000), respectively, of the same age groups in national data. Vaccination commenced during ISO week 35, continued until ISO week 3, and peaked during ISO week 41. The in-week peak in vaccination administration was on Saturdays.

CONCLUSIONS: The PCSC’s sociodemographic profile was similar to the national population and captured more data about risk groups, vaccine brands, and batches. This may reflect higher data quality. Its capabilities included reporting precise dates of administration. The PCSC is suitable for undertaking studies of influenza vaccine coverage.

PMID:38787605 | DOI:10.2196/39297

Int J Prosthodont. 2024 Feb 21;37(7):221-226. doi: 10.11607/prd.8928.

ABSTRACT

PURPOSE: To evaluate fracture load values of five types of interim CAD/CAM crowns with and without thermocycling.

MATERIALS AND METHODS: A complete coverage crown was designed on a mandibular first molar with a uniform 1.5-mm axial and occlusal reduction, and the STL file was exported to manufacture 100 crowns using five materials (20 crowns per material): ZCAD Temp Esthetic (SM-ZCAD; Harvest Dental); Telio CAD (SM-TCAD); P pro Crown and Bridge (AM-PPRO); E-Dent 400 C&B MHF (AM-EDENT); and DENTCA Crown & Bridge (AM-DENTCA). Each group was then divided into two subgroups: before and after thermocycling (10 cornws per subgroup). The STL file of the mandibular first molar die was used to manufacture 100 resin dies. Each die was assigned to one interim crown. Interim crowns were then luted to their assigned die using a temporary luting agent. The fracture strength of crowns was then assessed using a universal testing machine at a crosshead speed of 2 mm/minute. Two-way ANOVA followed by Tukey multiple comparations post-hoc tests were used to assess the effect of material choice and thermocycling process on the fracture strength of interim crowns (α = .05).

RESULTS: Material choice and the thermocycling process exerted a significant (P < .001) impact on the fracture strength of interim crowns. However, the interaction between these two factors did not yield a statistically significant effect (P = .176).

CONCLUSIONS: Within the limitations of this study, the type of interim materials and thermocycling process have a significant impact on the fracture strength of interim crowns.

PMID:38787587 | DOI:10.11607/prd.8928

Int J Prosthodont. 2024 Feb 21;37(7):195-202.

ABSTRACT

PURPOSE: To evaluate the fracture resistance of permanent resin crowns for primary teeth produced using two different 3D-printing technologies (digital light processing [DLP] and stereolithography [SLA]) and cemented with various luting cements (glass ionomer, resin-modified glass ionomer, and self-adhesive resin cement), whether thermally aged or not.

MATERIALS AND METHODS: A typodont primary mandibular second molar tooth was prepared and scanned, and a restoration design was created with web-based artificial intelligence (AI) dental software. A total of 96 crowns were prepared, and 12 experimental groups were generated according to the cement type, 3Dprinting technology (DLP or SLA), and thermal aging. Fracture resistance values and failure types of the specimens were noted. The results were statistically analyzed with three-way ANOVA and Tukey HSD tests (α = .05).

RESULTS: The results of the three-way ANOVA showed that there was an interaction among the factors (3D-printing technology, cement type, and thermal aging) (P = .003). Thermal aging significantly decreased the fracture resistance values in all experimental groups. DLP-printed crowns showed higher fracture resistance values than SLA-printed crowns. Cement type also affected the fracture resistance, with glass ionomer cement showing the lowest values after aging. Resin-modified glass ionomer and resin cements were more preferable for 3D-printed crowns.

CONCLUSIONS: The type of cement and the 3D-printing technology significantly influenced the fracture resistance of 3D-printed permanent resin crowns for primary teeth, and it was decided that these crowns would be able to withstand masticatory forces in children.

PMID:38787584

Int J Prosthodont. 2024 Feb 21;37(7):187-193. doi: 10.11607/ijp.8905.

ABSTRACT

PURPOSE: To characterize material changes that may occur in virgin cobalt-chromium (Co-Cr) alloy powder when it is blended with alloy powders that have been reused multiple times.

MATERIALS AND METHODS: Initially, 20 kg of virgin Co-Cr powder was loaded into a laser-sintering device. The tensile test specimens were fabricated in the first (Group 1), fourth (Group 2), seventh (Group 3), tenth (Group 4), and thirteenth (Group 5) production cycles (N = 15). Prior to fabricating the specimens, powder alloy samples were collected from the powder bed for analysis. The tensile strength, elastic modulus, and percent elongation were calculated with tensile testing. Scanning electron microscopy and energy dispersive x-ray spectroscopy (SEM/EDS) and laser particle size distribution (LPSD) were used to analyze the alloy powder samples. The fracture surface of one tensile test specimen from each group was examined via SEM/EDS. One-way ANOVA followed by Dunnett T3 test was used for statistical analysis (α = .05).

RESULTS: No difference was observed between groups in terms of tensile strength. A statistically significant difference was observed between Groups 1 and 2 in terms of percent elongation. Groups 2 and 4 were statistically significantly different in terms of both elastic modulus and percent elongation (P ≤ .05). SEM images of the powder alloy showed noticeable differences with increasing numbers of cycles. SEM images and the EDS analysis of the fractured specimens were in accordance with the strength data.

CONCLUSIONS: Reusing Co-Cr alloy powder increased the particle size distribution. However, there was no correlation between increased cycle number and the mechanical properties of the powder.

PMID:38787583 | DOI:10.11607/ijp.8905

Health Phys. 2024 May 24. doi: 10.1097/HP.0000000000001830. Online ahead of print.

ABSTRACT

The aim of this study was to investigate the effects of tube current and tube voltage choices on patient dose in adult and pediatric CT protocols by qualitative analysis using Principal Component Analysis (PCA), cluster analysis, and statistical analysis.Dose length product (DLP), Effective mAs (Eff. mAs), and volume-weighted CT dose index (CTDIvol) dose descriptors were obtained from 16 adult and pediatric head phantom CT examinations. Different tube voltage and tube current values were selected in both pediatric head and adult head CT imaging protocols, and PCA and cluster analysis were applied to the data obtained for qualitative analysis of the relationship between CTDIvol, Eff. mAs and Total DLP values. The two principial components (PC) with the highest values among those obtained as a result of the PCA method were used. PC1 was 70.97%, and PC2 was 28.03%. In the cluster analysis, it was observed that the values obtained from pediatric and adult phantom CT scans were classified into two different clusters. The correlation coefficient for adult patients was r = 0.998, and for pediatric patients, the correlation coefficient was r = 0.947. When the obtained clusters were examined, the degree of closeness or distance of the variables could be observed. In the study, as a result of the analysis of CTDIvol, Eff. mAs and Total DLP data based on manufacturer data at different kV and mA values with PCA and cluster analysis, it was shown that pediatric patients could be exposed to more radiation than the adult patients.

PMID:38787573 | DOI:10.1097/HP.0000000000001830

J Vis. 2024 May 1;24(5):12. doi: 10.1167/jov.24.5.12.

ABSTRACT

Materials exhibit an extraordinary range of visual appearances. Characterizing and quantifying appearance is important not only for basic research on perceptual mechanisms but also for computer graphics and a wide range of industrial applications. Although methods exist for capturing and representing the optical properties of materials and how they vary across surfaces (Haindl & Filip, 2013), the representations are typically very high-dimensional, and how these representations relate to subjective perceptual impressions of material appearance remains poorly understood. Here, we used a data-driven approach to characterizing the perceived appearance characteristics of 30 samples of wood veneer using a “visual fingerprint” that describes each sample as a multidimensional feature vector, with each dimension capturing a different aspect of the appearance. Fifty-six crowd-sourced participants viewed triplets of movies depicting different wood samples as the sample rotated. Their task was to report which of the two match samples was subjectively most similar to the test sample. In another online experiment, 45 participants rated 10 wood-related appearance characteristics for each of the samples. The results reveal a consistent embedding of the samples across both experiments and a set of nine perceptual dimensions capturing aspects including the roughness, directionality, and spatial scale of the surface patterns. We also showed that a weighted linear combination of 11 image statistics, inspired by the rating characteristics, predicts perceptual dimensions well.

PMID:38787569 | DOI:10.1167/jov.24.5.12

JAMA Netw Open. 2024 May 1;7(5):e2410994. doi: 10.1001/jamanetworkopen.2024.10994.

ABSTRACT

IMPORTANCE: The health care workforce continues to experience high rates of depression and anxiety. Finding ways to effectively support the mental health and well-being of health care workers is challenging.

OBJECTIVE: To test the effectiveness of remote, pushed digital assessments and engagement to improve depression and anxiety among health care workers compared with usual care.

DESIGN, SETTING, AND PARTICIPANTS: This was a 9-month randomized clinical trial with a 6-month intervention period. Participants were health care workers with self-reported daily access to a smartphone and at least 4 clinical hours per week. Participants were randomized to usual care or the intervention between January 2022 and March 2023. Data analyses were conducted between May and July 2023.

INTERVENTIONS: All participants completed baseline, 6-month, and 9-month mental health, well-being, and burnout assessments. The control group had open access to a web-based mental health platform. Participants in the intervention group received monthly text messaging about mental health, mental health assessments, and linkages to care.

MAIN OUTCOMES AND MEASURES: The primary outcomes were mean change in depression and anxiety scores at 6 months from baseline. Secondary outcomes include mean change in well-being, burnout, and self-reported workplace productivity.

RESULTS: In this study, 1275 participants were randomized (642 [50.4%] to the intervention group and 633 [49.6%] to control group). Participants had a mean (SD) age of 38.6 (10.9) years, 1063 participants (83.4%) were female, 320 (25.1%) self-identified as Black, and 793 (62.2%) self-identified as White. Across the groups, the mean difference in depression score was significantly different at 6 months (-0.96 [95% CI, -1.52 to -0.40]) and at 9 months (-1.14 [95% CI, -1.69 to -0.58]). The mean difference in anxiety score from baseline to 6 months was statistically significantly larger for those in the intervention group vs usual care (-0.71 [95% CI, -1.25 to -0.17]) and held true at 9 months (-1.06 [95% CI, -1.59 to -0.52]).

CONCLUSIONS AND RELEVANCE: In a trial of health care workers, a proactive digital engagement strategy, including pushed text messaging, mobile mental health assessments, and connection to care, improved depression and anxiety over a 6-month period compared with simply making the same resources available for individuals to find and use.

TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05028075.

PMID:38787562 | DOI:10.1001/jamanetworkopen.2024.10994