Objectives
To determine the distribution of the age of diagnosis of recurrent respiratory papillomatosis (RRP) and to determine the incidence and prevalence of RRP in both adults and children in the ...Free State province of South Africa in order to provide data from a population in sub‐Saharan African.
Design
Retrospective record review.
Participants
All patients with RRP in the Free State province of South Africa between 2011 and 2015.
Main outcome measures
Distribution of the age of diagnosis of RRP and incidence and prevalence of RRP.
Results
The best fitting mixture distribution for the age of diagnosis of RRP was a two‐component mixture of log‐normal distributions. Within the first component (JoRRP), the age of diagnosis was significantly lower in patients with human papillomavirus (HPV)11 disease (median 3.2 year) than those with HPV6 disease (median 5.6 years) (P = .021), while in the second component (AoRRP), there was no significant difference in the age of diagnosis between HPV11 disease (30.7 year) and HPV6 disease (median 44.0 years) (P = .0696).
The incidence and prevalence of JoRRP were 1.34/100000 population/year and 3.88/100000 population, respectively, while the incidence and prevalence of AoRRP were 0.18/100000 population/year and 0.38/100000 population, respectively.
Conclusion
Recurrent respiratory papillomatosis in the Free State province of South Africa is a disease with a predominantly juvenile onset, with AoRRP having a lower prevalence than in Europe. This is probably reflective of the situation in sub‐Saharan Africa.
Aims
Bioequivalence (BE) trials aim to demonstrate that the 90% confidence interval of the T/R‐ratio of the pharmacokinetic metrics between two formulations (test T and reference R) of a drug is ...fully included in the acceptance interval 0.80, 1.25. Traditionally, the sample size of BE trials is based on a power calculation based on the intrasubject variability coefficient of variation (CV) and the T/R‐ratio of the metrics. Since the exact value of the T/R‐ratio is not known prior to the trial, it is often assumed that the difference between the treatments does not exceed 5%. Hence, uncertainty about the T/R‐ratio is expressed by using a fixed value for the sample size calculation. We propose to characterise the uncertainty about the T/R‐ratio by a (normal) distribution for the log(T/R‐ratio), with an assumed mean of log θ = 0.00 (i.e. θ = 1.00) and a standard deviation σu, which quantifies the uncertainty. Evaluating this distribution leads to the statistical assurance of the BE trial.
Methods
The assurance of a clinical trial can be derived by integrating the power over the distribution of the input parameters, in this case, the assumed distribution of the log(T/R)‐ratio. Because it is an average power, the assurance can be interpreted as a measure of the probability of success that does not depend on a specific assumed value for the log(T/R)‐ratio. The relationship between power and assurance will be analysed by comparing the numerical outcomes.
Results
Using the assurance concept, values of the standard deviation for the distribution of potential log(T/R)‐ratios can be chosen to reflect the magnitude of uncertainty. For most practical cases (i.e. when 0.95 ≤ θ ≤ 1.05), the sample size is not, or only slightly, changed when σ = |log(θ)|.
Conclusion
The advantage of deriving the assurance for BE trials is that uncertainty is directly expressed as a parameter of variability.
Introduction
Discrepancies have been previously reported for one‐stage clotting and chromogenic assays for FVIII activity analysis. Inter‐laboratory variations in instruments, method of clot ...detection, assay set‐up, reference standard calibration, reagent source and reagent composition all contribute to assay variability.
Aim
To characterise multilaboratory assay variability in measuring ADYNOVATE, OBIZUR and ADVATE FVIII activity in human plasma and survey multinational FVIII activity assay preferences.
Methods
As samples from patients treated with either of the FVIII products are not available in the quantities required for a systematic collaborative study, haemophilia A plasma was spiked in vitro with either ADYNOVATE (PEGylated rFVIII), OBIZUR Porcine Sequence Antihaemophilic Factor (Recombinant) or ADVATE at high (0.80 IU or U mL−1), medium (0.20 IU or U mL−1) and low (0.05 IU or U mL−1) FVIII concentrations, based on labelled potencies. Clinical laboratories used their routine FVIII activity assay to determine FVIII activity of each product. Thirty‐five data sets using one‐stage clotting assay and 11 sets using chromogenic assay were obtained.
Results
A vast majority of laboratories (98%) prefer and rely on the one‐stage clotting assay. Mean recoveries across all concentrations were 113%, 120% and 127% for ADYNOVATE, OBIZUR and ADVATE respectively. Assay variation was comparable between ADVATE, ADYNOVATE and OBIZUR with inter‐laboratory percent coefficients of variation (%CV) ranging from 11 to 22%. Mean chromogenic assay results were 116%, 51% and 113% for ADYNOVATE, OBIZUR and ADVATE respectively. Inter‐laboratory CV's were similar for ADYNOVATE, OBIZUR and ADVATE.
Conclusions
One‐stage clotting assays can and will be used with sufficient accuracy and precision for the measurement of ADYNOVATE, OBIZUR and ADVATE in plasma samples from subjects with haemophilia A. Chromogenic assay underestimates OBIZUR potency, particularly at lower concentrations.
Diuretic antihypertensive therapy is recommended as first choice by many guidelines, often in combination with beta-blockers. However, such recommendations are based on relatively short-term trials, ...whereas treatment for hypertension is often a lifetime process. A meta-analysis of seven studies in 58,010 individuals, showed that the 'new' therapies, namely angiotensin-converting enzyme (ACE) inhibitors, angiotensin II type 1 receptor blockers (ARBs) and calcium channel blockers (CCBs) provoke less new diabetes than the conventional 'old' therapies (diuretics and beta-blockers). ACE inhibitors/ARBs decreased new diabetes by 20% (P < 0.001), whereas CCBs decreased new diabetes by 16% (P < 0.001). The number needed to treat for approximately 4 years by new rather than old conventional therapy to avoid one case of new diabetes is about 60-70. Other factors contributing to increased coronary risk are increased metabolic syndrome, blood lipid changes and hypokalaemia. It is not certain whether it is the new therapy that provides protection against new diabetes or the conventional therapy that precipitates new diabetes. However, when compared with placebo, ACE inhibition by ramipril or by the ARB, candesartan, both decrease the incidence of new diabetes, raising the hypothesis that these agents actually prevent the changes leading to insulin resistance, possibly by lessening the adverse effects of angiotensin II on the endothelium. Conversely, lipid abnormalities with conventional treatment could exert adverse effects on the endothelium. Therefore endothelial changes could help to explain the benefits of 'modern' treatment compared with the defects of conventional therapy.
In randomized, double-blind, placebo-controlled clinical trials the efficacy of immunotherapy for allergic rhinoconjunctivitis is evaluated using the Average Rhinoconjunctivitis Total Symptom Score ...(ARTSS). Effective treatment is associated with lower ARTSS relative to placebo. For ethical reasons patients are provided with registered rescue medication, which may alleviate symptoms and thus reduce symptom scores. This effect biases the mean difference in ARTSS between effective treatment and placebo towards zero. Therefore, when rescue medication is taken by a patient, the ARTSS needs to be adjusted appropriately. We considered five outcome measures: ARTSS, Average Rescue Medication Score (ARMS), and three combined symptom and RMSs. To assess the different outcome measures regarding their power to discriminate between effective treatment and placebo, we calculated their effect size when applied to data from a clinical trial of immunotherapy for allergic rhinoconjunctivitis. Of the five outcome measures considered, the average of the ARTSS and ARMS was associated with the largest effect size, and thus with the highest power to show treatment efficacy. Discriminant and multivariate analyses suggest that this average is approximately optimal among all weighted sums of ARTSS and ARMS. Our findings support recommendations made in a World Allergy Organisation document on methodological aspects of immunotherapy trials. The average of the ARTSS and ARMS should be considered as a primary efficacy variable in clinical trials of immunotherapy for allergic rhinoconjunctivitis.
With drought expected to increase in frequency and severity as a result of climate change, drought and rainfall variability assessments at interannual time scales using long-term rainfall data are ...necessary to develop drought mitigation strategies and planning measures, especially in semi-arid and arid environments where drought impact is expected to be adverse. The objective of this study was to determine the occurrence and severity of droughts and interannual rainfall variability trends in the Ghaap plateau, Northern Cape Province, South Africa. This study was based on long-term rainfall data for three meteorological stations (Postmasburg, Douglas and Groblershoop) from 1918 to 2014, sourced from the South African Weather Services (SAWS). Calculation of the Standardized Precipitation Index (SPI) showed that more droughts occurred since the 1990s; these droughts were all moderately dry with SPI values ranging between −1.03 and −1.46, except for the 1992 drought at Groblershoop which was severe. The longest drought duration on record in the study area was 2 years. Fitting of the long-term rainfall data to a non-parametric spline smoother revealed that the total annual rainfall, number of rainfall days and extreme rainfall events were essentially stable. The total annual rainfall, however, followed a secular pattern of fluctuations over the years.
•More droughts which were moderate, occurred post 1990.•Droughts were moderated and lasted for at most two consecutive years.•Total annual rainfall followed a secular pattern of fluctuations over the years.•Number of rainfall days and extreme rainfall events were essentially stable.
Background: Questions remain as to whether core stability represents a single or more components, how to assess core stability, and if a relationship exists with athletic performance in different ...sport codes.
Objectives: To investigate the relationship between core stability and athletic performance in female university athletes.
Methods: Eighty-three female athletes (hockey, netball, running, soccer and tennis) participated in this quantitative, cross-sectional study. The isometric back extension (IBE), lateral flexion (LF) and abdominal flexion (AF) tests were used to measure core strength and endurance. The core stability grading system using a pressure biofeedback unit was applied to measure core neuromuscular control (NMC). Athletic performance was assessed using the 40 m sprint, T-test, vertical jump (VJ) and the medicine ball chest throw (MBCT). Correlations between the core stability tests and the athletic performance tests were determined, overall and separately by sport. The effect of core stability on athletic performance was analysed using ANCOVA.
Results: Most correlations were weak (r=0.10–0.39), although a very strong correlation was found between LF (strength) and VJ (r=0.90). When considered separately, moderate correlations (r=0.40–0.69) were found between core strength, endurance and motor control with certain athletic performance tests in all five sport codes. In runners, strong correlations (r=0.70–0.89) occurred between AF (endurance) and VJ, and in tennis players between IBE (strength) and the sprint.
Conclusion: Correlations were found between core stability and athletic performance, although most correlations were negligible or weak. Athletic performance in different sport codes is associated with different components of core stability.
Background Children with attention deficit and hyperactivity disorder (ADHD) can experience visual motor control difficulties. Therefore, early identification of such difficulties is ...important.Objective To determine whether ADHD symptoms are associated with visual motor control difficulties in Grade 1 learners.Method In total, 382 children participated in the study. To determine the presence of ADHD symptoms, the educators completed the Strength and Weaknesses of ADHD symptoms Normal behaviour scale (SWAN) for each learner after six months of observing their class behaviour. Two kinderkineticists applied two tests, namely the Pyfer Sensory Input Systems Screening test and one subtest of the Quick Neurological Screening Test-II (QNST-II). Fisher’s exact test was used to determine if ADHD symptoms were associated with visual functioning difficulties.Results ADHD symptoms were found to be significantly associated with 10 out of 21 visual functioning difficulties. These skills included fixation with both eyes (p=0.0491), fixation with the right eye (p=0.0003), fixation with the left eye (p=0.0042), ocular alignment of the right eye (p=0.0029), visual tracking with both eyes on X shape (p=0.0284), visual tracking with the right eye (p=0.0301), and visual tacking with the left eye on a circle (p=0.0032). Furthermore, ADHD symptoms were significantly associated with the QNST-II tracking test normal range (p=0.0028), moderate discrepancy (p=0.0028) and severe discrepancy (p=0.0075).Conclusion ADHD symptoms are significantly associated with approximately half of the tested visual functioning of Grade 1 learners. Appropriate interventions should be implemented by professionals to assist these learners.
Background: Physical and physiological profile data for elite netball players in South Africa and internationally are limited but are necessary for conditioning programme information. Objective: To ...determine the physical and physiological profiles of U18, U19, U21 and senior level elite netball players at provincial level in the Free State, South Africa. The information provided is by age group and playing position. The fitness of the players for South African and New Zealand netball is also given using the fitness normative data (norms). Methods: This cross-sectional, descriptive study consisted of 77 elite South African netball players. Anthropometric measurements were taken according to international standards. Fitness tests included the Star Execution Balance Test, standing broad jump, double- and single-leg vertical jump, Yo-Yo Intermittent Recovery Level 1(IR1) test, sprints over 5, 10 and 40 m, horizontal pull-ups and press-ups, the prone bridge test and anaerobic Octorepeater tests with 10 m and 20 m repeated shuttle sprints. In keeping with the descriptive nature of the study, descriptive statistics were calculated for numerical data by age group and playing position. Results: Players generally did not meet the accepted fitness standards in the following areas: press-ups (all age groups), horizontal pull-ups (senior and U21), standing broad jump (senior and U21), vertical squat jump (senior and U21), 5 m and 10 m sprints (senior and U21); anaerobic Octorepeater (senior players), and the aerobic Yo-Yo IR1 test (all age groups). Conclusion: Strength and conditioning coaches should develop training programmes to address fitness areas where players do not meet the international standards.
Background: Despite a substantial body of literature on injuries among elite netball players in South Africa, no study reports on the timing and type of injuries and the reason for injuries. ...Objective: To determine the epidemiology of injuries in U18, U19, U21 and senior netball players in the Free State (FS), South Africa, over two consecutive netball seasons (2017/2018). Methods: An injury questionnaire was used to collect data on 96 eligible players. Results: A total of 48 injuries were reported. The profile of injuries revealed that 58% (n=28) of the injuries occurred during matches, 29% (n=14) during practice and 13% (n=6) during preseason training. Acute injuries accounted for 54% (n=26) of the total, while 46% (n=22) were overuse injuries. A third of all the injuries were re-injuries. The centre (C) position had the highest incidence of injuries in players (n=14; 29%). The ankle was the most frequently injured body part (n=18; 36%), followed by the lower leg and Achilles tendon (n=6; 13%) thus largely the ligaments and muscles. The overall incidence rate of injuries during match play was 33.9 injuries per 1 000 hours of match play. Conclusion: Preventative strategies should consist of ankle and lower leg strengthening and neuromuscular balance techniques. The focus should be on correct landing techniques, results of abrupt change of direction movements and short bursts of speed.
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