This article discusses statistical measures of variability in relation to measures of central tendency and levels of measurement. Three measures of variability used in healthcare research (the range, the interquartile range, and the standard deviation) are described and compared, including their uses and limitations. The article describes how each of the three measures is calculated, and it provides a step-by-step example of calculating the sums of squares, variance, and standard deviation. Graphs of frequency and percentage distributions are used to show how the interquartile range and the standard deviation represent the variability observed within distributions. The article discusses the properties of the normal curve regarding the distribution of scores around the mean in relation to the standard deviation, and illustrates differences in the shapes of normal curves with the same mean but different standard deviations.
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http://dx.doi.org/10.1080/08854726.2015.1054671 | DOI Listing |
J Vector Borne Dis
October 2024
Department of Pediatrics, IMS and SUM Hospital, Siksha 'O' Anusandhan (deemed to be) University, K8, Kalinga Nagar, Bhubaneswar, Odisha, India.
Background Objectives: Scrub typhus is an acute febrile zoonotic disease caused by the obligate intracellular gram-negative bacteria Orientia tsutsugamushi. Growing data over the last few years on the Indian subcontinent suggest that it is one of the most widespread but under-reported diseases. The study aimed to document the clinical and paraclinical profile and evaluate complications of scrub typhus in severe and nonsevere pediatric age groups.
View Article and Find Full Text PDFJ Ophthalmic Inflamm Infect
January 2025
School of Medicine, National Taiwan University, Taipei, Taiwan.
Purpose: To identify the macular retinal layer thickness changes in polyarteritis nodosa (PAN) patients without pathological findings appearing in color fundus photography (CFP), and to investigate the correlations with disease durations.
Methods: A total of 24 PAN patients who had been for 3 years or more and underwent SD-OCT were recruited from the UK Biobank, with exclusions for diabetes, eye disease, or abnormal CFP findings. Only the right eyes were included, with each PAN patient paired one-to-one with a control matched for age, sex, and ethnicity.
Background: Pediatric ultrasound (US)-guided percutaneous liver biopsy is a commonly performed procedure in children, and may be performed in a variety of clinical settings. However, there is little research on the relative costs associated with different sedation methods and locations.
Objective: This study uses time-driven activity-based costing (TDABC) to identify relevant costs associated with different biopsy sedation techniques and locations to help inform providers and patients as well as guide value-conscious care.
Invest Ophthalmol Vis Sci
January 2025
NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom.
Purpose: To investigate the effect of average intraocular pressure (IOP) on the true rate of glaucoma progression (RoP) in the United Kingdom Glaucoma Treatment Study (UKGTS).
Methods: UKGTS participants were randomized to placebo or Latanoprost drops and monitored for up to two years with visual field tests (VF, 24-2 SITA standard), IOP measurements, and optic nerve imaging. We included eyes with at least three structural or functional assessments (VF with <15% false-positive errors).
Cornea
January 2025
Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA.
Purpose: To report on optical coherence tomography angiography (OCTA) in patients with a type 1 Boston keratoprosthesis (KPro) and determine its feasibility through assessment of imaging artifacts.
Methods: KPro and non-KPro subjects were matched for age, gender, and glaucoma diagnosis. OCTA images of the peripapillary optic nerve were obtained, reviewed by 2 readers masked to the diagnosis for artifacts and usability, and used for microvascular measurements.
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